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[Display omitted] By introducing a minute quantity of phytate ammonium into the conventional dilute zinc sulfate electrolyte, a static physical barrier is established by the phytic anion. Simultaneously, a dynamic electrostatic shield layer collaborates, yielding superior electrochemical performance. This addition facilitates an accelerated de-solvation process, effectively suppressing the so-called "tip effect" and mitigating dendrite growth. • Developed facile and effective additives for aqueous zinc-ion batteries. • Utilized both cation and anion for a multi-functional additive. • Physical barrier and dynamic electrostatic-field shield layer enhance performance. • Realized a dual protection mechanism for high performance. Corrosion and the formation of by-products resulting from parasitic side reactions, as well as random dendrite growth, pose significant challenges for aqueous zinc-ion batteries (AZIBs). In this study, phytate ammonium is introduced into the traditional dilute Zinc sulfate electrolyte as a multi-functional additive. Leveraging the inherent zincophilic nature of the phytic anion, a protective layer is formed on the surface of the zinc anode. This layer can effectively manipulate the deposition process, mitigate parasitic reactions, and reduce the accumulation of detrimental by-products. Additionally, the competitive deposition between dissociated ammonium ions and Zn2+ promotes uniform deposition, thereby alleviating dendrite growth. Consequently, the modified electrolyte with a lower volume addition exhibits superior performance. The zinc symmetric battery demonstrates much more reversible plating/stripping, sustaining over 2000 h at 5 mA cm−2 and 1 mA h cm−2. A high average deposition/stripping efficiency of 99.83 % is achieved, indicating the significant boosting effect and practical potential of our strategy for high-performance aqueous zinc-ion batteries. [ABSTRACT FROM AUTHOR]

• Bipolar membrane ED was used for nutrient recovery from AD dewatering sidestream. • Concentrated acid and base streams containing separated nutrients were produced. • Ammonia was recovered using a produced acid solution by membrane stripping. • Phosphate was recovery as struvite or hydroxyapatite by chemical precipitation. • Nutrient recovery was achieved with minimized chemical and energy inputs. Anaerobic digestion (AD) offers an efficient means for treating sludge generated in wastewater treatment plants (WWTPs), but nutrient-rich AD dewatering sidestream contributes as much as 30 % of the overall nutrient loading of WWTPs. Several electrochemical approaches are being developed as a sidestream treatment strategy to prevent return of nutrients to WWTP headworks and recover them for fertilizer production. One such method is to produce acids and bases, essential chemicals necessary to facilitate nutrient recovery, using bipolar membrane electrodialysis (BMED). In this study we show simultaneous separation of nutrients and production of acid/base streams with an additional consideration for increasing the concentration of ammonium and phosphate in the final product stream by systematically altering compartment flow rates and hence the retention time of each stream. Using a three-compartment BMED system with a synthetic sidestream containing 50 mM NH 3 -N and 2 mM PO 4 -P, we achieved up to 80 % ammonia removal (via a cation exchange membrane) and up to 60 % phosphate removal (via an anion exchange membrane) at a productivity of 34.2 L m−2 h−1. Separated ammonia was recovered (>90 %) in a subsequent membrane contactor (MC) that was fed with acid and base streams produced by the BMED unit. A phosphate recovery > 80 % was achieved by chemical precipitation (CP). In a combined BMED-MC-CP process, the concentrated final product contained 333.9 mM NH 3 -N and 3.1 mM PO 4 -P with an energy consumption of 8.9 kWh kg−1 N recovered. These results illustrate that the BMED-based treatment train is a promising strategy for nutrient recovery from AD dewatering sidestream. [ABSTRACT FROM AUTHOR]

The QCD36A 1-1 350 shows excellent photocatalytic activity for H 2 O 2 production under visible light irradiation. [Display omitted] • A quaternary ammonium cyclodextrin polymeric photocatalyst QCD36A 1-1 350 is successfully synthesized. • The quaternary ammonium group in the QCD36A 1-1 350 structure broadened the absorption of visible light. • The introduction of quaternary ammonium groups can facilitate efficient charge transfer, speed up the 2e- ORR process. • A photocatalytic H 2 O 2 yield of 2.51 mmol g−1h−1 was achieved in purified water without an electron donor or aeration. A photocatalytic system can be used to efficiently produce hydrogen peroxide (H 2 O 2) without introducing a sacrificial agent or oxygen (O 2). This system has practical application potential but remains challenging to implement. To increase the H 2 O 2 yield of this system, a quaternary ammonium cyclodextrin polymeric photocatalyst QCD36A 1-1 350 is successfully synthesized using quaternization modification and low-temperature polycondensation. The photocatalyst is used to produce H 2 O 2 from pure water and air by the one-step two electron oxygen reduction reaction. Under irradiation by visible light, QCD36A 1-1 350 produces a higher H 2 O 2 yield (of up to 2.51 mmol g−1h−1) than unquaternized polymers and reported metal-free catalysts under similar conditions. Experimental and theoretical studies clearly show that the introduction of quaternary ammonium groups can effectively broaden the visible light absorption of polymer catalysts, while increasing the hydrophilicity, charge transfer efficiency and surface stability. The practicability of efficient photocatalytic production of H 2 O 2 is realized by increasing the activity and selectivity of the polymer photocatalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • UDB and DB at different pyrolysis temperatures played contrasting roles. • DB800-amended group displayed superior nitrogen removal performance. • DB at lower pyrolysis temperature imposed suppression. • Properties of dissolved organic matter released by DB were tracked at molecular level. Biochar has attracted increasingly attention in the biological wastewater treatment owing to its unique environmental behavior. However, the differential effects of undissolved and dissolved fractions of biochar (hereafter named as UDB and DB, respectively) on the anaerobic ammonium oxidation (anammox) process remain unclear. The study evaluated the nitrogen removal performance of anammox system in response to UDB and DB prepared at different pyrolysis temperatures (300 °C, 550 °C and 800 °C). The DB800-amended group displayed superior nitrogen removal performance with the total nitrogen removal efficiency (TNRE) of 92.8 ± 1.4 %. Compared with CK, TNRE was changed by +5.0 % (UDB300), +0.4 % (UDB550) and −22.3 % (UDB800) for UDB-amended groups, and by −16.0 % (DB300), −9.4 % (DB550), and +9.2 % (DB800) for DB-amended groups, respectively. The differences were closely related to the physicochemical properties of UDB and DB. Particularly, dissolved organic matter released by DB were tracked at molecular level, which revealed that CHO occupied the highest proportion of 70.3 % and lignin-like and carboxylic rich alicyclic molecules were dominant in DB800. This study would facilitate the understanding of the differences between the nitrogen removal performance of UDB and DB-amended anammox, thus providing deeper insights for the comprehensive assessment of the impacts of biochar on the anammox process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Micro-oxygen combined with applied voltage promote total nitrogen removal. • Electrode regulates the spatial distribution of functional microorganisms. • Applied voltage regulates function gene abundance and enzyme activity. • Hydroxylamine oxidation peaks and up-regulation hao gene are demonstrated. Anodic ammonium oxidation catalyzed by microorganisms holds great potential as an effective anaerobic approach for ammonium and total nitrogen removal. However, the application of this approach is constrained by a low rate of ammonium oxidation, limiting the efficiency of total nitrogen removal. To overcome this limitation, a small amount of oxygen was introduced into a single-chamber microbial electrolysis cell to initiate the production of hydroxylamine through ammonium oxidation. Enhanced efficiency of overall nitrogen removal was obtained by the combined regulation of micro-oxygen and microbial electrode catalysis for ammonium oxidation and denitrification. According to the ammonium oxidation amount, the total oxidized nitrogen removal efficiency reached 67.87 ± 0.25 % and total nitrogen removal amount was 202.9 ± 0.5 mg/L, showing a high performance for treating high ammonium-contained wastewater. The oxidation peaks of hydroxylamine were determined at 0.43 V (vs. Ag/AgCl) for revealing the possible process of anodic hydroxylamine oxidation coupling to cathodic denitrification. In addition, microbial community analysis revealed that increasing the applied voltage regulated the abundance of nitrifying and denitrifying functional microbial communities both in the solution and on electrodes, and the key functional genes including hydroxylamine oxidation (hao), nitrate reduction (narG , narH , narI , napA , napB), nitrite reduce (nirK, nirS), and nitric oxide reduce (norB , norC), increased significantly at the applied voltage of 0.9 V, which accompanied by an obvious enhancement of enzyme activity compared to anaerobic and open circuit voltage. This work revealed the enhanced performance and mechanism on synergistic regulation by micro-oxygen and applied voltage for ammonium oxidation and denitrification, and provided new insights and feasible enhancing measures for treating high ammonium-nitrogen wastewater with low C/N ratio. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nature based redox materials can serve as electron acceptors and donors. • Complete nitrogen removal based on redox materials. • Emergence of a new pathway for anerobic ammonium oxidation. • Nature-based sustainable solutions for nitrogen management. Complete nitrogen removal depends on the requirement of oxygen as an electron acceptor and organics as electron donors. In the natural environment, these electron acceptors and donors regulate the nitrogen cycle in association with several nature-based processes, such as iron dependent (feammox), sulphur dependent (sulfammox), and nitrite dependent (annamox). These processes represent the latest discoveries in the nitrification part of the nitrogen cycle and provide the electron acceptors for anaerobic ammonium oxidation. Research findings on these processes suggest that a previously undescribed pathway is available for anaerobic ammonium oxidation, which can regulate the nitrogen cycle in natural environments. It has been shown that some redox active materials can serve simultaneously as electron acceptors and donors in the nitrogen cycle. This review provides comprehensive information of the known oxidative processes in the nitrogen cycle and highlights the emergence of a new pathway for anaerobic NH 4 + oxidation, which is dependent on insoluble redox active materials as electron donors and acceptors. This new pathway is not limited to anaerobic NH 4 + oxidation, but it also includes reductive pathways to nitrogen gas, and thus can lead to complete nitrogen removal from nitrogen environments. Recent developments and knowledge advancement in the nitrogen cycle open a new path for nature-based sustainable solutions for nitrogen management. This new knowledge can provide innovative and novel approaches for conventional NH 4 + removal processes. [ABSTRACT FROM AUTHOR]

• Biological nitrogen removal is a carbon source of wastewater treatment. • Nitrogen neutrality determines carbon neutrality of wastewater treatment. • Ammonium recovery is necessary for carbon–neutral wastewater treatment. • Nature inspired green approaches for ammonium recovery are highly desirable. • AnMBR coupled with microalgae can address the water-energy-resources nexus. With rapidly evolving global climate change, municipal wastewater treatment has been identified as a nonneglected carbon source contributing to about 1–2% of total carbon emissions worldwide. Given such a situation, the development of carbon–neutral municipal wastewater treatment process has become highly desirable and pressing. However, almost all wastewater ammonium is biologically converted to nitrogen gas in the present biological treatment processes of municipal wastewater, making ammonium recovery impossible. It is shown in this article that the current biological nitrogen removal (BNR) processes indeed are a significant carbon source, implying that nitrogen neutrality largely determines carbon neutrality of wastewater treatment. To tackle this challenge, ammonium recovery instead of BNR should be incorporated into future municipal wastewater treatment processes. Although several advanced bio/electrochemical approaches have recently been developed for ammonium recovery from municipal wastewater, their engineering and economic feasibility have not yet been determined. Instead, the nature-inspired green approach for recovery of wastewater ammonium should deserve more attention and effort. It is shown that an integrated anaerobic fixed-film membrane bioreactor-microalgae bacterial granular sludge process coupled with heat exchange can create a significant carbon sink, likely leading to carbon-negative municipal wastewater treatment. Consequently, it is reasonable to consider that the way forward is to explore a green-to-green engineering approach through harnessing the synergies among wastewater treatment, energy-heat-nutrients recovery, and carbon dioxide capture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multiple mediators function as electron shuttles to promote anammox process; • The EET capability of anammox bacteria can be facilitated by external mediators; • The concurrent presence of mediators triggered the activation of essential enzymes; • The application perspective should focus on the EET-enhanced anammox optimization. The anaerobic ammonium oxidation (anammox) process, transforming ammonia into nitrogen gas in oxygen-free environments using nitrite as an electron acceptor, is increasingly recognized for its potential in treating ammonium-rich wastewater. A major challenge for widespread application of this technology is the limited presence of nitrite in most wastewaters. The intrinsic electroactivity of anammox bacteria implies that the introduction of exogenous additives through the extracellular electron transfer (EET) process could effectively stimulate ammonia oxidation even in the absence of nitrite. This comprehensive review consolidates various approaches to enhance EET-dependent anammox, including the utilization of carbonaceous materials, metal ions, and humic substances. Molecular mechanisms involved in enhancing nitrogen removal performance based on extracellular electron transfer capacity are expounded. The co-occurrence of electron acceptors and exogenous electron shuttles is proposed to increase the activity of c-type cytochromes (c -Cyts) and N-acyl-homoserine lactones (AHLs) in extracellular polymeric substances (EPS), as well as enzymes such as hydrazine synthase (HZS) and hydrazine dehydrogenase (HDH), leading to stable a nitrogen removal performance. This review presents novel insights into the engineering of the EET-enhanced anammox process, providing a theoretical framework for its advancement and optimization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxalate ions form a protective layer on zinc anode, inhibiting side reactions. • Oxalate ions alter solvation of zinc ions, replacing water molecules. • Oxalate ions promote Zn (0 0 2) crystal plane growth, optimizing deposition. • Ammonium ions shield zinc protrusions, suppressing tip effect. • Ammonium oxalate enhances cycle life in Zn-Zn cells and Zn-MnO 2 batteries. The natural reactivity of Zn metal in aqueous environments leads to surface deterioration and uncontrolled dendrite growth, posing challenges in the advancement of Zn-ion batteries. In this research, we introduce an environmentally friendly and cost-effective electrolyte additive, ammonium oxalate (AO), to significantly extend the cycle life of Zn-ion batteries with minimal usage. Oxalate ions within AO actively participate in the solvation of hydrated Zn ions and attach to the Zn anode surface prior to H 2 O molecules, creating a robust solid-electrolyte interface (SEI) layer. This SEI layer serves a dual purpose: it inhibits further reactions with H 2 O and restricts the two-dimensional movement of Zn ions, promoting the preferential growth of the (0 0 2) crystal plane. Consequently, Zn||Zn cells exhibit an impressive lifespan surpassing 1800 h (at 1 mA cm−2, 1 mAh cm−2), and Zn||Cu cells experience a tenfold increase in cycling life. Moreover, Zn||MnO 2 full cells, incorporating this low-cost and highly efficient inorganic additive, maintain an outstanding 80.84 % capacity retention after 1200 cycles at 1 A g−1. This breakthrough with AO offers a promising avenue for the practical implementation of Zn-ion batteries, emphasizing their cost-effectiveness and environmental sustainability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electro-oxidation of N-heterocycles produces N 2 , N H 3 / N H 4 + , N O 3 - , C O and C O 2. • N H 3 / N H 4 + and an apparent N 2 yield correlate linearly with carbon removal. • Both apparent N 2 and N O 3 - form directly from organic intermediates rather than N H 3 / N H 4 +. • Higher concentrations of parent compounds promote a higher apparent N 2 selectivity. • N O 3 - dominates when oxidation of carbon is mass transfer-limited or at basic pH. We report for the first time the carbon and nitrogen product distribution during the electrochemical oxidation (EO) of pyrazine and related N-heterocyclic compounds (NHCs) present in the hard-to-treat wastewater from a biofuel production process. The experimental study was carried out using a boron-doped diamond anode. Identified and quantified intermediate products included oxamic acid, formamide, oxalic acid, and formic acid. Analysis of the C and N yields as a function of the extent of carbon removal reveals the influence of the current- and mass transfer-control operating regimes on product distribution. Carbon monoxide, which was detected among the gaseous products, suggests a possible decarbonylation pathway in the current-controlled regime. An apparent nitrogen gas and ammonium yields correlated linearly with the carbon removal, while nitrate yields significantly increased in the mass transfer-controlled regime. Nitrate and apparent nitrogen gas appear to form directly from organic nitrogen intermediates, rather than from the ammonium that also forms in the process. The research gives new insights into the NHCs degradation pathways, product distribution, and final water composition as a function of operating regime in the EO of recalcitrant wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flower-like hierarchical (NH 4) x WO 3 nanocrystal composed of tunnel nanobelts was constructed. • Tungsten bronze (NH 4) x WO 3 powder and film displayed remarkable reversible photochromism. • Proton-coupled electron insertion/de-insertion and ions exchange during color-switching were investigated. • Chromogenic (NH 4) y WO 3 :nH-based energy-saving windows realized excellent thermal radiation regulation. Understanding photochromism is crucial for developing new ways to modulate the optical responses of materials. Here, we prepared ammonium tungsten bronze (NH 4) x WO 3 , representing a significant advance in photochromism over the rarely chromogenic tungsten bronze. The high color difference, 12.89 and 30.49 for 10 s and 90 s exposure, respectively (AM 1.5G), was due to the large surface area created by the distinctive flower-like hierarchical structure, which exposed more photoactive sites, as well as to the highly efficient adsorption of the proton-coupled electron as a color center on the surface to trapped electrons. The elucidation of NH 4 + protonation under the light field and/or chemical interactions with neighboring protonated species was revealed by the ion exchange sites in hexagonal, trigonal, and square sites, suggesting an essential surface structure-breaking behaviors of hydrogen bonds between NH 4 + and tunneled WO 3 frameworks. In particular, the created energy-saving window, based on hydrogen ammonium tungsten bronze (NH 4) y WO 3 :nH/polyvinyl alcohol/polyvinylpyrrolidone coating, enabled a reduction of indoor air temperature by 6.3 °C in hot weather and reduced temperature difference between various indoor areas. The modification of the chemical environment of WO 3 and the identification of the photochromism mechanism hold promise for the development of energy-saving windows using chromogenic nanomaterials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The deficient inorganic N, P, and C sources induced decline in S0AD efficiency. • Specific thresholds for inorganic N, P, and C to robust S0AD were established. • Substantial reduction in SOBs occurred under deficient inorganic nutrients. • External supplying mitigated nutrient constraints in a pilot-scale S0PB bioreactor. Elemental sulfur packed-bed (S0PB) bioreactors are increasingly employed to treat secondary effluents from wastewater treatment plants. Limited availability of inorganic nutrients, such as ammonium, phosphate, and inorganic carbon, significantly determines the growth of autotrophic microorganisms and the denitrification efficiency. This study investigated the constraining thresholds of inorganic nutrients on the elemental sulfur autotrophic denitrification process. In the absence of ammonium, phosphate, and bicarbonate, the denitrification rate decreased. Specifically, the ammonium assimilation process could be replaced by nitrate assimilation pathways, resulting in a 29.5 % decline in denitrification efficiency when the ammonium-N feed was reduced from 2.0 to 0 mg-N/L. However, the absence of phosphate-P and bicarbonate-C led to substantial drops in denitrification efficiency by 66.7 % and 77.5 %, respectively. This was primarily attributed to diminished biomass yield, as evidenced by reductions of 77.8–82.6 % in ATP and 35.7–44.3 % in protein content, along with a 12.4 %–14.7 % decrease in the relative abundances of dominant sulfur-oxidizing bacteria. Correlation analyses established specific thresholds for desired nitrate removal amounts: 0.131 for ammonium-N, 0.053 for phosphate-P, and 0.597 for bicarbonate-C. These thresholds provided valuable guidance for adjusting real-life wastewater through external supplementation when employing a pilot-scale S0PB bioreactor, leading to a significant enhancement of denitrification efficiency. This study emphasizes the significance of considering the concentrations of inorganic nutrients in wastewater when implementing S0PB bioreactors, which is a context that frequently neglects potential negative consequences. [ABSTRACT FROM AUTHOR]

[Display omitted] • V(V) reduction and denitrification, coupled with S0 oxidation, were observed. • 96.7 ± 2.2 % and 99.0 ± 1.1 % of V(V) reduction and NH 4 +-N oxidation were accomplished. • V(V) was reduced by MAGs containing genes (narG , napA) or MHCs (OmcB , MtrA). • NH 4 +-N was oxidized to NO 3 –-N/ NO 2 –-N, and then reduced to N 2 or assimilated. • NH 4 +-N oxidation was primarily facilitated by nitrifiers (e.g., Anaeromyxobacter sp.). The extensive use of ammonium (NH 4 +) as a precipitant in non-ferrous metallurgy, such as vanadium production, leads to the co-occurrence of toxic heavy metals and NH 4 +-N in the resultant wastewater. Finding an efficient and cost-effective method for simultaneously removing vanadate [V(V)] and NH 4 +-N in a single step has remained unexplored. This study presents a novel approach by establishing the synchronous bio-elimination of V(V) and NH 4 +-N in a sulfur (S0)-based autotrophic system. Remarkably, 96.7 ± 2.2 % of V(V) and 99.4 ± 0.8 % of NH 4 +-N were successfully removed within 24 hrs. V(V) was transformed into V(IV) precipitates, while S0 was oxidized into sulfate, achieving complete nitrogen removal. Fifty-six genomes were retrieved and constructed from metagenomic binning, unveiling symbiotic interactions involved in sulfur, nitrogen, and vanadium transformation. With the annotation of functional genes (e.g., nar , nir , nap , nor , nos , sox , sor , dsr) and multi-heme c-type cytochromes, it was identified that V(V) reduction and denitrification, coupled with S0 oxidation, were mediated by species such as Sulfuricurvum sp., Achromobacter sp., and Thiomonas sp.. Meanwhile, NH 4 + oxidation was accomplished by Anaeromyxobacter sp.. Furthermore, autotrophs harnessed inorganic carbon through the Calvin-Benson-Bassham and Wood-Ljungdahl pathways to synthesize organic intermediates, which were subsequently consumed by heterotrophic organisms (e.g., Pseudomonas sp.) to facilitate V(V) reduction and denitrification. The quantification of transcripts associated with genes responsible for V and N metabolism provided additional evidence of these metabolic pathways' existence. This study offers a sustainable and environmentally friendly strategy for mitigating the adverse environmental impacts of vanadium production wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • The dual network strategy fabricated a 3D printing gel ink with shear-thinning rheology. • Printed hydrogel exhibits remarkable mechanical properties, transparency, biocompatibility, and adhesion. • This hydrogel accurately monitors body movement and electrocardiogram (ECG) signals. 3D printing of high-strength hydrogel remains a great challenge owing to trade-off between strength and printability. Herein, a zwitterionic strategy was proposed through electrostatic reversible interaction to improve the rheology of shear-thinning based on an agarose-based network. Therefore, this mechanism of dual network (DN) ultimately imparts the hydrogel with remarkable strength (with a tensile strength of 0.79 MPa and a compressive strength of 14.18 MPa) and ductility (with a toughness of 766%), while simultaneously possessing multiple functionalities, such as high transparency, excellent biocompatibility, and adhesion. Furthermore, the developed agarose/poly([2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium -co-N- hydroxyethylacrylamide) (A/D-H) DN hydrogel exhibited impressive strain sensitivity with a strain gauge factor GF of 4.33 even under large deformations. Various forms of flexible sensors based on this printed gel were successfully utilized in human motion sensing and remote heartbeat monitoring, thereby opening up new perspectives for the further expansion of injectable materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • NH 4 + inhibits the degradation of TBBPS in the heat/PDS system. • The reaction between NH 4 + and SO 4 •- generates the nitrating agent NO 2 •. • Coupling of NO 2 • and TBBPS radical intermediates generates nitrated products. • In situ formed free bromine can be scavenged by NH 4 + to form NH 2 Br. • NH 2 Br reacts with certain TBBPS intermediates yielding DBAN. Sulfate radical (SO 4 •-)-based advanced oxidation processes (SR-AOPs) show great potential in the elimination of organic pollutants in wastewater treatment and groundwater remediation. Tetrabromobisphenol S (TBBPS) as an emerging contaminant can be effectively degraded in SR-AOPs. However, the present study found that SO 4 •- also reacted with ammonium (NH 4 +), a ubiquitous inorganic nitrogen species in aquatic environments, thus markedly affected the rates and pathways of TBBPS degradation in SR-AOPs. TBBPS underwent β-scission and debromination upon SO 4 •- attack, leading to various transformation products. The released bromide (Br-) underwent further oxidation by SO 4 •- to form free bromine which reacted with certain TBBPS intermediates, generating disinfection byproducts (DBPs). When NH 4 + was present in such system, the abatement of TBBPS was apparently suppressed. Meanwhile, NH 4 + was oxidized by SO 4 •- to nitrogen dioxide radical (NO 2 •) which coupled with certain radical intermediates of TBBPS oxidation, yielding nitrophenolic products including 2,6-dibromo-4-nitrophenol (DBNP) and mono-nitro substituted TBBPS. When 10 μM TBBPS was treated by heat activated peroxydisulfate with 1 mM NH 4 +, the molar yield of DBNP reached 22% in 2 h. More importantly, NH 4 + scavenged the in situ formed free bromine to form monobromamine (NH 2 Br), decreasing regulated DBPs formation but leading to highly toxic dibromoacetonitrile (DBAN). This study broadens the understanding of interactions between the transformation of halogens and NH 4 + during SO 4 •- oxidation. It also reveals the potential environmental risks when SR-AOPs are employed for the organohalogen pollutants degradation in realistic environments where NH 4 + is present. [ABSTRACT FROM AUTHOR]

[Display omitted] • FA inhibition on microalgal growth and ammonium removal could be mitigated by COD. • Autotrophic consortium removed ammonium by algal assimilation and ammonia oxidation. • Microalgal and bacterial assimilation were main removal pathways in mixotrophic consortium. • Algal-bacterial consortia showed great N 2 O emission reduction compared to PN cultures. • FA enhanced reducing N 2 O emission by limiting oxygen and stimulating bacterial assimilation. The coupling of microalgae and partial nitritation (PN) cultures was a promising technology to treat ammonium-rich sidestream wastewater. However, limited information is available on nitrogen transformation pathways, N 2 O production mechanisms and their association with free ammonia (FA) in this symbiotic system. Enhanced ammonium removal (up to 100%) by the consortium was achieved mainly through algal assimilation (3.2–21.9%) and ammonia oxidation (33.2–72.7%) under autotrophic conditions, while bacterial assimilation (11.6–45.4%) had an important contribution under mixotrophic conditions as it was the least inhibited by FA. Higher FA concentration at the range of 6.53–45.70 mg/L would lead to an increase of N 2 O accumulation from 0.56 to 1.09 mg N/L, but a decrease of N 2 O emission factor from 0.6 to 0.3% in the mixotrophic consortium. At each FA level (6.53–58.76 mg/L), mixotrophic algal-bacterial consortium contributed to significant reductions of N 2 O accumulation by 60.5–83.8% and of N 2 O emission factors by 60.5–92.7% compared to the single PN cultures, with optimal mitigation scenario achieved at FA level of 45.70 mg/L. Herein, heterotrophic denitrification was deemed as the major sink for N 2 O production, while microalgal assimilation played an important role in limiting N 2 O emission factors as it restrained the nitrogen distribution to nitritation and denitritation. This might imply the potential of the consortium of microalgae and PN cultures in achieving higher ammonium removal while reducing greenhouse gas emission during sidestream wastewater treatment. [ABSTRACT FROM AUTHOR]

• TAN recovery via BES as a low-energy intensive alternative to conventional systems. • The TAN recovery rate highly depends on the current density produced. • Challenges for scale-up: nature/quantity of carbon source and NH 4 + concentration. • Describing fundamentals of BES TAN recovery: stripping, absorption or precipitation. Due to the anticipated rise in demand for ammonia, the search for viable methods for its recovery has intensified in recent years, as traditional ammonia production is a high energy intensive process. Bioelectrochemical systems (BESs) offer an alternative solution for ammonia recovery since they have shown lower energy demand (in terms of kJ g−1N recovered) at lab-scale than other methodologies. In BESs, the bioelectrochemically generated current drives the transport of NH 4 + from the wastewater to a concentration chamber through a cation exchange membrane before its subsequent recovery. This paper describes the fundamentals and opportunities for bioelectrochemical ammonia recovery (either by stripping, absorption, or precipitation) in different BES devices such as microbial fuel cells, microbial electrolysis cells, microbial desalination cells and bioelectroconcentration cells and compares the performance of all the reported experimental works so far. Moreover, the most critical challenges (low current density, nature and quantity of the carbon source, inlet ammonium concentration, use of membranes, energy yield and recovery efficiency) have been detailed and discussed in view of better understanding the current bottlenecks for its scale-up and, thus, for its prompt industrial adoption. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A biofilm-CANON system was kept robust by adjusting aeration time and frequency. • NO 2 − accumulation at the end of each non-aeration stage should be <6 mg N/L. • DO microelectrode measurements provided a basis for regulating aeration. • Decrease in temperature and NH 4 + concentration stimulated DO diffusion into biofilm. • NOB were successfully controlled (<0.25%) during the entire operational period. Abstract Dissolved oxygen (DO) is an important parameter for regulation of "completely autotrophic nitrogen removal over nitrite" (CANON) systems, but effective strategies for regulating DO and the mechanisms of its effects remain unclear. Here, DO microelectrode and nitrite accumulation monitoring were to develop an intermittent aeration regime for a biofilm-CANON system with decreasing influent ammonia and temperature. With high ammonium concentration (185 ± 31 mg N/L in the bioreactor) at 35 °C (Phase I) and 20–23 °C (Phase II), three repeats of 40/80 min aeration/non-aeration per reaction cycle enabled the biofilm-CANON to achieve optimal total nitrogen removal rates (TNRR) of 0.35 ± 0.03 and 0.29 ± 0.04 kg N/m3/d, respectively. The nitrite accumulation threshold at the end of each non-aeration period was 6 mg N/L. When the ammonium concentration was decreased to 35.6 ± 4.5 mg N/L (in the bioreactor) at 20–23 °C (Phase III), five repeats of 8/32 min aeration/non-aeration per reaction cycle ensured a stable TNRR of 0.18 ± 0.02 kg N/m3/d. Micro-profile measurements showed that the penetration of DO into the biofilms increased with decreasing temperature and ammonia, to 400, 600 and 1300 μm in Phases I, II and III, respectively, at 0.6 mg O 2 /L, confirming the need to reduce aeration time when temperature and influent ammonia decreased. High-throughput sequencing showed that nitrite oxidizing bacteria were <0.25% of total bacteria during the whole operation. Nitrosomonas -affiliated ammonium oxidizing bacteria (inhabiting both flocs and biofilms) and anammox bacteria Candidatus Kuenenia (mainly inhabiting the biofilms) were consistently the dominant functional bacteria. DO microelectrode provided comprehensive insights into the effects of decreasing temperature and influent ammonia on DO penetration and was valuable in the development of more sophisticated aeration regulation of biofilm-CANON systems. [ABSTRACT FROM AUTHOR]

Highlights • MgO-D was used for the simultaneous recovery of algae, NH 4 +-N and phosphate. • The simultaneous recovery of them can be realized in a wide pH range. • Struvite precipitation was the main way to recover NH 4 +-N and phosphate. • Charge neutralization of MgO-D and sweeping of struvite contributed to harvesting microalgae. Abstract In this study, MgO modified diatomite (MgO-D) was used for recovery of microalgae (Chlorella pyrenoidosa FACHB-9), NH 4 +-N and phosphate from wastewater. The effects of adsorbent dosage, solution pH, contact time, and coexisting substances were investigated. The results showed that MgO-D exhibited excellent recovery efficiency for microalgae, NH 4 +-N and phosphate in a wide pH range of 3.0–9.0. With initial pH = 8.0, MgO-D = 0.5 g/L and reaction time = 2 h, the recovery efficiencies of microalgae, NH 4 +-N and phosphate were 182.04 mg/g, 63.3 mg/g, 121.07 mg/g, respectively. Coexisting organic matters inhibited the recovery of microalgae, NH 4 +-N and phosphate in the order of alginate > humic acid > acetic acid. When in proper concentration range, NH 4 +-N and phosphate were preferentially recovered by MgO-D through struvite precipitation, and then the charge neutralization of hydroxylated Mg(OH) 2 and sweeping of struvite precipitation played an important role in harvesting of microalgal cells. This study shows new guidelines and useful methods for the simultaneous recovery of microalgae, NH 4 +-N and phosphate from wastewater. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Maximum voltage of 0.477 V and power density of 8.07 W m−3 was produced. • Humic substances were removed by 48.27%. • 90.59% of ammonium was removed with majority concentrated in the cathode. • Phosphorus was stored in bacteria cells in the form of poly-P. • Electrogens was dominant community with FL as feed. Abstract This study reports an integrated sludge treatment and resource recovery system that consisted of a sludge pre-treatment reactor and a microbial fuel cell (MFC) aiming for simultaneous energy and nutrients recovery. Nearly one year performance of the system in terms of power generation, nutrients removal efficiency, key dissolved organic matters (DOMs) transformation and microbial community change were investigated and reported. Volatile fatty acids (VFAs) and other soluble organic matters was produced from fermentation of waste activated sludge under thermophilic alkaline condition. Fermented liquor (FL) was used as feed for MFC, which produced maximum voltage of 0.477 V and power density of 8.07 W m−3. Humic-like substances (HSs) were removed by 48.27% within a 5 days cycle. The analysis on DOMs transformation revealed both high and low molecular weight protein and polysaccharides, and HSs were converted and contributed to power generation. Some unknown compounds in FL could enhance the power generation by 5.5 times more compared to pure VFA as feed. 90.59% of ammonium was removed with majority concentrated in the cathode. Phosphorus was removed and stored in the biomass in the form of polyphosphate (poly-P). Microbial community analysis indicated that Exoelectrogenic was the dominant community while Aquamicrobium , Nitrosomonas , Achromobacter and Rhodocyclaceae were also enriched in the anode. This work demonstrates that the integrated system can successfully remove and recover nutrients and generate power simultaneously with long-term stable performance. [ABSTRACT FROM AUTHOR]

Highlights • A tubular PMFC and PBRs were coupled to treat ADE-FW in continuous and batch modes. • Higher algal biomass and nutrient removal rate were obtained in continuous mode. • Nitrogen removal rate in PMFC reached 6.0 mg/(L·d) due to ammonium migration effect. • Anode potentials increased linearly as COD decreased when COD < 3000 mg/L. • Total energy produced in either continuous or batch modes was both 1.8 kWh/m3. Abstract Anaerobically digested effluent from food waste (ADE-FW) needs purification treatment due to its high content of ammonium and organic matter. Here, a system that couples a photosynthetic microbial fuel cell (PMFC) with photobioreactors (PBRs) was developed to recover energy from the ADE-FW. First, the ADE-FW was treated in the PMFC for pollutant removal and power generation. The highest power density obtained from the PMFC was about 3.5 W/m3. Power generation was primarily affected by DO and substrate concentrations, which respectively determined the cathode and anode potentials. About 93% of the ammonium in the anolyte was removed in the continuous mode, owing to the ammonium migration effect. Algal biomass in the PMFC increased from 0.1 mg/L to 0.7 mg/L in the continuous mode, which was 27% higher than that in the batch operating mode (0.55 mg/L). Then the effluents from the cathodic chamber were polished in the PBRs. The nitrogen removal rates in the PBRs under continuous and batch operation were 3.0 mg/(L·d) and 1.8 mg/(L·d), respectively. In terms of energy production, more algal lipid energy was obtained in the continuous mode, but less electricity was obtained in this mode. Consequently, the total energy produced in the coupled systems in the continuous and batch modes were consistently about 1.8 kWh/m3. The high pollutant removal rate and energy recovery efficiency of the coupled system indicated that it would be a practical technology for the industrial-scale applications. [ABSTRACT FROM AUTHOR]

Highlights • Microalgae growth was inhibited at NH 4 +-N concentrations above 100 mg/L. • Microalgae growth in digestate was suppressed by high NH 4 +-N and competing microbes. • Nitrification based pre-treatment was effective in alleviating NH 4 +-N toxicity. • Excellent nitrogen and phosphorus recovery from nitrified digestate by microalgae. • Integrated nitrification and algae cultivation possible using membrane bioreactors. Abstract High ammonium concentration is considered a major challenge in cultivating autotrophic microalgae in anaerobic digestate. In this research, the feasibility of applying nitrification as pretreatment to alleviate ammonium toxicity on microalgae was investigated. Batch experiments conducted in synthetic medium showed that microalgae growth was inhibited at NH 4 +-N > 100 mg/L, but NO 3 −-N was benign at concentrations as high as 350 mg/L. Microalgae growth in 2–50% digestate (v/v) was also affected adversely by invading heterotrophic microorganisms. Digestate pre-treatment using activated sludge mitigated these challenges by converting NH 4 +-N to NO 3 −-N, and reducing organics content in the digestate. Microalgae exhibited excellent growth and nutrients removal in nitrified digestate (5–30% mixed with municipal wastewater) in batch mode. For example, COD, NH 4 +-N, NO 3 −-N and PO 4 3−-P removal in 10% digestate using two-stage bacterial-microalgal process were 87%, 100%, 30% and 77%, respectively. In continuous mode, using a microalgae-based membrane photobioreactor (MPBR) operating downstream to membrane bioreactor (MBR), 91% COD, 97% NH 4 +-N and >99% PO 4 3−-P could be continuously removed from 10% digestate. Although NH 4 +-N removal in the process was mainly through nitrification, total nitrogen removal was >75% at steady state. The effects of lower NH 4 +-N toxicity in the MPBR was also manifested in terms of high microalgae biomass accumulation of about 5 g/L. These results indicate that nitrification can be a promising pretreatment for anaerobic digestate for use in microalgae cultivation. [ABSTRACT FROM AUTHOR]

This study examined the pre-oxidation of ammonium using a nanofiltration (NF) hollow fiber membrane module to provide an alternative to conventional partial nitrification preceding Anammox. A permeability study showed that NF membranes were suitable for use in the pre-oxidation of ammonium due to high ammonium fluxes across the membrane (low rejection of ammonium), while most COD (in the form of glucose) was retained inside the bulk phase (high rejection of glucose-COD). In pre-oxidation, ammonium oxidizing bacteria (AOB) grown in the shell-side of the membrane module could oxidize the ammonium diffusing from the tube side mainly to nitrite, which then diffused back into the tube side, resulting in a mixture of ammonium and nitrite in the exit stream in an approximately equimolar ratio. This would meet the requirement for the Anammox process as suggested by previous reports. The application of a membrane process for the pre-oxidation of ammonium was found to be promising at a laboratory-scale, and practically viable at a scale similar to a full-scale reactor (Whitlingham STC, Norwich, UK) based on an estimate of the number of HF modules needed. However, a proper optimization study of the process is strongly recommended so that its feasibility could be further examined at a larger scale linking both nitritification and Anammox together. [ABSTRACT FROM AUTHOR]

To enhance biodegradation in Permeable Reactive Barriers, Diphenyldichlorosilane (DPDSCI) coated ammonium zeolite was selected as a reactive material for development as it undergoes reversible hydrocarbon adsorption and may release nutrients in a controlled manner. To investigate its hydrocarbon adsorption and nutrient release behaviour under varying conditions, batch tests were conducted by immersing the material into different concentrations of toluene and potassium chloride solutions. Results showed that the ammonium release ability was not significantly influenced by a change in toluene concentration, while the toluene adsorption performance was affected by fluctuations in potassium concentration. The overall ammonium release capacity of the modified zeolite was 0.8 mmol/g, and the toluene adsorption capacity was 9.355 µmol/g without KCl in solution. The Langmuir isotherm fitted the adsorption isotherms well, indicating that the adsorption mechanism of DPDSCI coated ammonium zeolite is the same as that of DPDSCI coated natural zeolite: a monolayer and homogenous surface adsorption process. Regeneration tests showed that this material may be used, cleaned and reused at least three times without a significant reduction in performance. [ABSTRACT FROM AUTHOR]

Excessive levels of ammonium, phosphate, and heavy metals in surface water are serious environmental concerns that could potentially cause eutrophication and health issues. In this study, a novel iron/zirconium-pillared clinoptilolite (nano Fe/Zr-PC)was developed by intercalating Fe 3+ /Zr 4+ polyhydroxy-cations into clinoptilolite for the simultaneous removal of ammonium, phosphate, and cadmium (Cd (II)). The obtained material was characterized using a transmission electron microscope (TEM), BET analysis, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR), which indicated that nanoscale Fe or Zr particles were successfully formed on the surface and pore structures of clinoptilolite. Batch experiments were conducted to investigate the effects of varied operation parameters on the adsorption behavior. The results show that nano Fe/Zr-PC achieved high removal efficiencies for ammonium, phosphate, and Cd (II) over a wide pH range (4–8), indicating higher adaptability towards varying environmental conditions. In addition, kinetic analysis suggested that the adsorption process was best represented by the pseudo-second-order kinetic model, suggesting the rate-limiting step for removing ammonium, phosphate, and Cd (II) on nano Fe/Zr-PC may be the chemical adsorption stage. The underlying mechanism was also assessed using X-ray photoelectron spectroscopy (XPS) analysis. Ammonium, phosphate, and Cd (II) were captured via a cation exchange reaction, electrostatic attraction and ligand exchange, and surface precipitation, respectively. Overall, the analysis and the characterization results revealed that nano Fe/Zr-PC is a highly efficient adsorbent for the simultaneous removal of ammonium, phosphate, and Cd (II) with an excellent adaptability to varying and undesirable environmental conditions. [ABSTRACT FROM AUTHOR]

• Acidithiobacillus thiooxidans produce SO 4 2− in the ammonium-rich manure digestate. • NH 4 + biorecovery from the digestate by A. thiooxidans is feasible. • The biorecovered product contained 91% ammonium sulfate. Livestock production has an undesirable impact on the environment as livestock waste generates considerable volumes of manure digestate rich in ammonia nitrogen. The purpose of this study was to develop a treatment technology for biorecovery of ammonium (NH 4 +) from manure digestate to facilitate its use as fertilizer in the form of ammonium sulfate (AS). Our method offers an energy saving, environmentally friendly, and easily controlled way to address the environmental consequences of livestock. Here, the feasibility of NH 4 + biorecovery from the manure digestate by Acidithiobacillus thiooxidans (PTCC 1717) is shown. To conduct biorecovery, the bacterium was first adapted to high NH 4 + concentration by progressive acclimatization to improve its tolerance. Sulfate (SO 4 2−) accumulation of 57 mM at NH 4 +-rich manure digestate after 15 days of incubation exhibited good oxidizing ability of the acclimated A. thiooxidans. At last, the manure digestate rich in NH 4 + and biogenic SO 4 2− were dried at 60 °C and 6.02 g AS L−1 digestate was obtained. XRD and FTIR measurements confirmed the presence of AS in the biorecovered product. [ABSTRACT FROM AUTHOR]

[Display omitted] • Water was decomposed into H+ and OH– during ultrasonic activation. • H+ and OH– from water were combined with biochar, improving surface functional groups. • Different effects of ultrasound on adsorption process of biochar and Mg-biochar. • Ultrasound improved the Q m of NBC and NMBC by 1.30 and 1.31 times, respectively. Ammonium is one of the most important nutrients in agricultural wastewater, and its excessive existence will pose a threat to ecosystem and even human life. The cavitation effect generated by ultrasonic waves with huge energy can break the carbon bonds of biochar and thus increase the abundance of functional groups. In order to adsorb ammonium effectively in water, we used ultrasound to improve biochar or magnesium-loaded biochar performance in removing wastewater pollutant. Batch experiments with material characterization and adsorption models were conducted to assess adsorption characteristics. The nano-biochar (NBC) was obtained after the ultrasonic modification, with porosity, cation exchange capacity (CEC), zero point of charge (pH pzc), and functional groups (–OH, C–O, C–O–H, C–H) effectively being improved, indicating OH– and H+ were separated from water and bound to biochar to form functional groups during ultrasonic cavitation. The nano-Mg-biochar (NMBC) also increased the functional group of metal oxides. The ammonium adsorption of NBC and NMBC was dominated by intraparticle diffusion. The observed ammonium adsorption capacity of NBC and NMBC was best described by the Langmuir isotherm, implying the adsorption derived from the energetically homogeneous surface. Moreover, the maximum adsorption capacities for NH 4 + on NBC, and NMBC were 13.589, and 23.777 mg·g−1, respectively. Ultrasound improved the maximum ammonium adsorption capacity of raw biochar and Mg-biochar through electron attraction and ion exchange, respectively. Notably, ultrasonic modification causes a more uniform distribution of chemical crystals in the biochar and broken carbon bond to combine with more functional groups, which would be a significant way to reorganize functional groups directionally and optimize the adsorption performance of materials. [ABSTRACT FROM AUTHOR]

Hydrazine is an important intermediate for anaerobic ammonium oxidation (anammox), in which ammonium and nitrite are converted to nitrogen gas. Hydrazine addition is known to improve the nitrogen removal capacity in anammox-based processes. However, the underlying mechanism remains unknown. This study investigated the effects of hydrazine addition on conversion performance for normal anammox substrates (ammonium, nitrite and nitrate) using batch experiments with various combinations of nitrogenous as substrates for the anammox bacteria in the presence or absence of hydrazine. Hydrazine addition improved specific anammox activity (SAA) by 42%, of which 5% was attributed to increased ammonium removal by strengthening anammox, 25% to acceleration of nitrite degradation by the bioreaction where exogenous hydrazine was reacted with nitrite to generate azide, and 12% to reducing nitrate production rate through selective inhibition of nitrite-nitrate oxidoreductase (NXR) activity by generating azide. A model in which hydrazine addition enhances the nitrogen removal capacity in an anammox system was established, which can provide theoretical guidance for engineering applications of anammox with trace hydrazine addition. [ABSTRACT FROM AUTHOR]

Current algal-bacterial consortia require hydraulic retention times (HRTs) of up to 2–10 days for wastewater treatment. The application of a photo membrane bioreactor (PMBR) culturing an algal-bacterial consortium should significantly reduce the HRTs, which has not been attempted before. A low light intensity, 200 μmol/(m 2 ·s), was applied in a PMBR. The results showed that ammonium was almost completely removed and the removal efficiency of chemical oxygen demand was 90% when the HRT was as low as 24 h and mechanical aeration was not applied. Ammonium-oxidizing bacteria and algae approximately equally shared the ammonium in the reactor. Phosphate reduction was approximately 3 mg PO 4 3− -P/L.h. A light intensity of up to 600 μmol/(m 2 ·s) did not inhibit algal activity. The complete removal of ammonium resulted in a decline in the chlorophyll a concentration. Nevertheless, the reactor performance remained stable. Heterotrophic bacteria, autotrophs, algae and phosphate-accumulating organisms coexisted and functioned in the reactor. Furthermore, a sustainable flux of 15 L/m 2 .h enabled operating the filter of the PMBR at a transmembrane pressure as low as 4 kPa. Considering the stable pollutant removal performance and significant reduction in HRT, this PMBR has the potential to be applied in wastewater treatment. [ABSTRACT FROM AUTHOR]

The partial nitrification-anammox (PNA) process under intermittent aeration is feasible to treat low-strength ammonium wastewater, but the effect of chemical oxygen demand (COD) on mainstream anammox processes is not fully understood. In this study, PNA process was established for sewage treatment (average ammonium = 59.3 mg-N/L) in a sequencing batch reactor (SBR) with intermittent aeration mode. Influent organic carbon to nitrogen (C/N) ratios were gradually increased (1.1, 1.5, 2.0 and 2.5). With increasing C/N ratios, the total nitrogen (TN) removal efficiency increased steadily from 30.8% to 77.3%. When the C/N ratio increased from 1.1 to 2.0, the improvement of nitrogen removal was attributed to the increase of anammox bacteria, which exponentially increased at the C/N ratios from 1.1 to 1.5. Additionally, nitrate reduction using internal carbon was likely to combine with anammox reaction under intermittent aeration operation, which might further improve the nitrogen removal. Lastly, settleability and particle size of activated sludge were also improved with the elevated C/N ratios, which favored the enrichment of anammox bacteria and facilitated the combination of partial denitrification and anammox. When the C/N ratio was 2.5, TN removal efficiency still increased while the abundance and activity of anammox bacteria remained stable, indicating that influent organic carbon promoted denitrifying bacteria and inhibited anammox bacterial growth rate. Overall, this study demonstrates that influent COD has comprehensive effects on PNA systems and that the influent C/N ratios are suggested to adjust within optimal range to achieve long-term stability. [ABSTRACT FROM AUTHOR]

An iron–manganese co-oxide filter film (MeO x ) coated on filter sand has been shown be a good catalyst for the oxidation of ammonium in the treatment of groundwater. However, its catalytic activity decreases gradually when it is used to remove ammonium from surface water. In this study, phosphate was added to sustain the ammonium removal activity of MeO x in a pilot-scale filter system for surface water treatment. The results showed that the ammonium removal efficiency of the MeO x filter without phosphate dosing decreased gradually, and just 27.69% removal efficiency was obtained at 6.1 °C. After dosing with 30 μg/L phosphate, the ammonium removal efficiency remained high after continuous operation for 176 days and reached 85.74%, even at 6.1 °C. It was found that both the biological nitrification activity and the chemical catalytic activity of MeO x were markedly enhanced after phosphate dosing (compared with that without phosphate dosing). Through inactivation by ozone, the biological nitrification and chemical catalytic activity were distinguished. It was found that chemical catalytic activity accounted for around 67.59% of the total ammonium removal. Aluminum was found to accumulate on the surface of MeO x and combine competitively with its active sites. This may be the primary reason for the decrease in the catalytic activity of MeO x . With phosphate dosing, the accumulation of aluminum decreased by 60.53% and the chemical combination of aluminum and MeO x was suppressed, thus sustaining the catalytic activity of MeO x . [ABSTRACT FROM AUTHOR]

High concentration of ammonium (NH 4 + ) often occurs in groundwater. In this study, the behavior of NH 4 + catalytic oxidation by a manganese oxide (MnO x ) filter was investigated systematically and the formation and evolution of the MnO x films were characterized extensively. It was found that the MnO x based filter could be successfully started up within 6 days with the NH 4 + removal efficiency increasing from 1 to 96%. After start-up, the removal efficiency of NH 4 + could keep almost constant under different operating conditions, implying the MnO x filter has a good stability towards NH 4 + removal. Both X-ray diffraction (XRD) and Raman results suggested that MnO x was related to hexagonal birnessite which has low crystallinity and small crystallite sizes. The X-ray photoelectron spectroscopy (XPS) spectra of the Mn2p taken on the surface of MnO x revealed Mn(II), Mn(III) and Mn(IV) species existed in MnO x materials and their atomic concentrations were 20.2%, 57.8% and 22%, respectively. More importantly, the catalysis of films towards NH 4 + oxidation was expected to be closely related to its feature structure. Specifically, the ability of manganese to cycle between +2, +3 and +4 oxidation states during catalysis was considered to play important roles in the NH 4 + conversion on MnO x surface. Based on the above discussion, three major steps involve in NH 4 + catalytic oxidation by MnO x were proposed, which are NH 4 + adsorption, catalytic oxidation, and desorption of reaction products. [ABSTRACT FROM AUTHOR]

• Nutrient recovery from synthetic urine was limited for conventional Donnan dialysis. • A novel Donnan dialysis system was constructed with tubular ion-exchange membranes. • This reactor enabled simultaneous recovery of phosphate, ammonium, and potassium. • Struvite was successfully precipitated in the nutrient-enriched draw solution. • The tubular membrane reactor can be effectively scaled up for real applications. To address interconnected issues related to deteriorated water quality and unsustainable fertilizer production, Donnan dialysis was employed for nutrient recovery from model waste solutions and synthetic urine. Conventional Donnan dialysis reactors with flat-sheet, ion-exchange membranes and 500-mL solutions were deployed to determine the impact of the synthetic urine matrix on nutrient recovery relative to model wastes that only contained sodium phosphate (NaH 2 PO 4) or ammonium chloride (NH 4 Cl). Compared to the model wastes, the competing ions in the synthetic urine caused orthophosphate (P(V)) and ammonium (NH 4 +) removal to decrease from 90.4 % to 55.2 % and from 87.8 % to 84.8 %, respectively. To improve reactor design for future scale up, an innovative Donnan dialysis system was established by placing tubular anion- and cation-exchange membranes into a 30-L waste solution and continuously recirculating 5 L of an NaCl-based draw solution through the inside of the membranes. P(V), NH 4 +, and other nutrients were simultaneously recovered, and the concentrations in the draw solution exceeded those in the initial synthetic urine in accordance with Donnan equilibrium for unequal solution volumes. Over 75 % P(V) and 74 % NH 4 + were removed from the synthetic urine. MgCl 2 and NaOH were added to the nutrient-enriched draw solution to precipitate solids and reset the electrochemical potential gradient, enabling enhanced nutrient recovery. Chemical equilibrium modeling and solids characterization confirmed that the recovered precipitates were ∼73–90 % struvite. The proof-of-concept tubular reactor represents a promising strategy for scaling up Donnan dialysis systems for selective nutrient recovery from urine and other wastes. [ABSTRACT FROM AUTHOR]

Portable smartphone platform offers a new strategy for on-site and visual quantitative detection of ammonium nitrogen in soil and wastewater samples. [Display omitted] • OPA/K 2 SO 3 /R-QDs and OPA/K 2 SO 3 based sensor have been respectively used for determination of low and high concentration range of NH 4 + via two response modes. • The color responses toward the NH 4 + concentrations have been systematically studied. • The proposed strategy can realize visual quantitative detection of NH 4 + in real samples. • Portable smartphone platform brings great convenience for on-site detection of NH 4 +. Ammonium (NH 4 +) is crucial for plant growth as well as various industrial processes, the accurate and field measurement of the NH 4 + level is of great significance for agricultural precision fertilization and water quality monitoring, but excessive amounts of ammonium can lead to eutrophication of aqueous environments. Herein, the ability of the proposed probe solution and test paper to colorimetric change towards high-concentration NH 4 + and ratiometric fluorescence response to low-concentration NH 4 + has been developed for visual detection of ammonium in real samples. Specifically, high concentration of NH 4 + (0.5–7 mM) could interact with the o-phthalaldehyde (OPA) in presence of K 2 SO 3 , resulting in the colorimetric transition from colorless to wine-red with increasing the NH 4 + concentration. Subsequently, the addition of the red-emitting CdTe QDs (R-QDs) constructed the OPA/K 2 SO 3 /R-QDs ratiometric fluorescent probes for low-concentration NH 4 + (less than 1 mM) sensing with a limit of detection (LOD) down to 18 nM, accompanied by a distinct fluorescence color shift from red to blue under UV light. Furthermore, the visualization detection integrated with smartphone was converted to data information (RGB value) through a Color Recognizer APP and successfully used for visual quantitative identification of NH 4 +. Actually, the proposed probe solution and test paper have been applied to the determination of NH 4 + in soil extracts and wastewater samples. Compared with the standard methods, this established strategy can supply stable and reliable detection results, and allow fast sensing at room temperature, exhibiting great application potential for visual on-site detection of NH 4 + at different concentration ranges in environmental samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel composite (FeO x -MgO) was synthetized and used to selectively oxidize NH 4 +. • The base sites on FeO x -MgO composite are crucial for the conversion of NH 4 + to NH 3. • NH 3 can be easily oxidized to ammonia hydride by PS mainly activated by hv. • Fe(IV) formed in FeO x -MgO/PS/ hv system enhanced the selectivity of NH 4 + oxidation. The selective oxidation of ammonium nitrogen (NH 4 +-N) to dinitrogen (N 2) by advanced oxidation processes (AOPs) is of paramount significance, but it is still a great challenge. In this study, a novel composite (FeO x -MgO) was synthesized to activate persulfate (PS) for selective oxidation of ammonium (NH 4 +) to N 2 under simulated solar-light irradiation (hv). The results demonstrated that the conversion of NH 4 + to ammonia (NH 3) on the basic sites of FeO x -MgO was a key step for the selective oxidation of NH 4 +. Fe(IV) species formed in FeO x -MgO/PS/ hv system could enhance both the efficiency and N 2 selectivity of the NH 4 +-N oxidation through the oxidation of ammonia hydride to N 2. The 100 % NH 4 +-N removal and over 95.5 % N 2 selectivity could be achieved after 30 min when initial pH was in range of 2–10, and the initial NH 4 +-N concentration was 30 mg N/L. This study could provide a promising technology for the selective oxidation of NH 4 +-N to N 2 in water and wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combining Bio-Electrochemical and Electrochemical System for NH 3 recovery. • Utilizing one shared cathode for the Bio-Electrochemical and Electrochemical System. • The combined system showed high NH 3 removal 99.8 % at a low energy input 9.2 MJ/kg N. • NH 3 effluent concentration complied with European Urban Water Framework Directive. • Bio-anode instabilities can be compensate by the electrochemical system. Bio-electrochemical systems (BESs) can recover ammonium at low specific energy inputs and can produce hydrogen gas. A reason hampering development of large-scale applications for ammonium recovery is the general instability of the bio-generated current and the thereby variable TAN (ammonia and ammonium) effluent concentrations. Electrochemical systems for ammonium recovery, such as the hydrogen recycling electrochemical system (HRES), can fine-tune the applied current, but require higher specific energy inputs than BES, and may require an additional external hydrogen supply in case of HRES. This research presents for the first time an integrated BES and HRES system for ammonium recovery to combine the advantages of both types of systems to achieve high TAN removal efficiency at low specific energy input. The HRES was able to partially compensate for BES instability, which resulted in an overall high TAN removal efficiency (89–95 %) at an increased energy demand of 5.2–10.2 MJ/kg N. When the BES was performing stably and efficiently, the HRES removed almost all of remaining TAN at up to 99.8 % overall TAN removal efficiency, requiring 9.2 MJ/kg N. The combined system can remove TAN down to much lower effluent concentrations at little to no additional energy input. These results indicate that combining BES and HRES in one system can result in TAN recovery that is more efficient than in each system separately, which could facilitate new application possibilities for (bio-)electrochemical ammonium recovery. [ABSTRACT FROM AUTHOR]

[Display omitted] • PN achieved within 28 days and maintained about 80 days with paracetamol dose. • Achieving PN by paracetamol was independent of floc, granular sludge or biofilm. • After combining with low DO, PN could recover within 10 days and last for 150 days. • Nitrospira (Oligotype 1) and nxrB inhibition were the reasons of PN by paracetamol. • The inhibition of Nitrotoga by paracetamol and low DO broke the bottleneck of PN. Achieving stable partial nitrification (PN) are the basic guarantee of anaerobic ammonia oxidation (anammox) process. However, there is no recognized feasible method for rapidly achieving stable PN in municipal wastewater, and further research is necessary. In this study, paracetamol was proved as an effective nitrite oxidation inhibitor through long-term experiment lasting 392 days in three systems (floc sludge, granular sludge, biofilm). PN of low-strength ammonium wastewater was rapidly achieved within 28 days and maintained for about 80 days after paracetamol dose, whereas PN recovered again within 10 days and sustained over 150 days under paracetamol dose combined with low dissolved oxygen strategy. The inhibition effect of paracetamol on NOB was almost not affected by biomass growth modes. QPCR and high-throughput sequencing showed that Nitrospira (Oligotype 1) was inhibited by paracetamol, and PICURSt2 analysis indicated its key enzyme NXR was significantly downregulated after paracetamol treatment, which were the key reasons of PN start-up in three systems. The emergence and adaptation of Nitrotoga was the main reason for the instability of PN. This study proved that paracetamol could be used as a novel nitrite oxidation inhibitor, and provided a possibility to achieve the mainstream PN and anammox for treating wastewater with low-strength ammonium. [ABSTRACT FROM AUTHOR]

[Display omitted] • Upgrading nitrogen removal performances in wastewater treatment plants by BES. • Enhancing the polishing action of secondary treatments to avoid tertiary treatments. • Nitrate and ammonium removal without nitrous oxide accumulation. • Disinfection of wastewater via electrochemical anodic oxidation. Economic options to retrofit wastewater treatment plants (WWTPs) without tertiary treatments need to be explored. In this regard, bioelectrochemical systems (BES) can be hybridized with existing technologies, upgrading the removal performance of original techniques while avoiding replacement costs. Yet, few demonstrations of merged systems have been given. For the first time, in this work it was built a lab-scale model of a BES merged with a secondary settler, namely e-settler, to enhance the polishing performance of already existing WWTPs. In particular, to concomitantly increase nitrogen removal and perform wastewater (WW) disinfection, avoiding further tertiary treatments. In the e-settlers, nitrogen removal was increased through bioelectrochemical stimulation. Concomitant ammonium and nitrate removal without nitrite accumulation and a negligible amount of nitrous oxide emissions were observed. Ti-MMO as anode material showed a high disinfectant action. In conclusion, it was demonstrated how a simple bioelectrochemical set-up can upgrade existing WWTPs. The following step requires the study at a larger scale, identifying optimal operational and structural parameters for the in-situ application. The main limitations of the e-settlers were discussed, linking them to possible solutions that need to be deepened in a lab-scale model of conventional secondary treatments (activated sludge followed by secondary settler). [ABSTRACT FROM AUTHOR]

This is a sketch showing the main contents of this work. In this work, a novel fire-resistant cotton fabric by combining SWCNHs and ammonium polyphosphate was proposed. The effects of different concentrations of SWCNHs on the flame retardancy of fabric were investigated, and the mechanism of flame retardancy for SWCNHs was also discussed in detail. [Display omitted] • Single-walled carbon nanohorns (SWCNHs) was first reported for flame retardancy. • High flame retardant performance was achieved by SWCNHs with low mass loading. • The incorporation of SWCNHs can greatly reduce the damage length of cotton fabrics. • The synergistic flame retardant mechanism of SWCNHs was described in detail. The development of environmentally friendly flame retardants that can achieve high efficiency for textiles at low addition levels is of great significance to human life and environmental protection. Halogen flame retardants have long dominated in flame retardant applications. However, there are increasing calls to ban its use because of the threat they pose to human health and the environment. Herein, this work investigated the potential of a novel carbonaceous nanomaterials-single-walled carbon nanohorns (SWCNHs) coating material for flame retardancy of cotton fabrics. The unique combination of SWCNHs and ammonium polyphosphate (APP) in a single halogen-free nanocoating has a synergistic effect, which endows cotton fabric with prominent fire resistance. When the addition amount of SWCNHs was 0.15 %, the limit oxygen index (LOI) could reach 27.5 ± 0.83 %, and the damage length decreased from 30 ± 0.01 % cm to 6.5 ± 0.06 % cm. SEM results showed that Cotton-APP/SWCNHs (0.15) still displayed well-preserved woven structure after the vertical flammability test. Additionally, the pHRR and THR of Cotton-APP/SWCNHs (0.15) were markedly decreased by 92.22 % and 58.44 %, respectively in the cone calorimeter test. Meanwhile, the flame retardant mechanism analysis confirmed that the incorporation of SWCNHs into the APP coatings promoted the formation of dense and stable graphitized carbon layer on the surface of the cotton fabric, and effectively prevented the generation of combustible volatiles, thus enhancing the flame retardant performance of cotton fabrics. This work provides a new insight into developing carbon nanomaterials for flame retardant polymeric materials and extending the application of SWCNHs. [ABSTRACT FROM AUTHOR]

A new bio-sorbent based on the shaddock peel was prepared for perchlorate capture. The shaddock peel was introduced with quaternary-ammonium groups and Fe 3 O 4 nanoparticles, forming the Fe 3 O 4 laden quaternary-ammonium shaddock peel (Fe 3 O 4 -QA-SP). Bio-regeneration of perchlorate laden Fe 3 O 4 -QA-SP considering the oxygen, coexisting anions, bio-fouling and indirect bio-regeneration was conducted. Results indicated that the bio-reduction rate increased as the increase in the amounts of perchlorate laden on Fe 3 O 4 -QA-SP and the optimal reduction rates (0.0226–0.0865 mg p /mg ss /d) were obtained at pH 7.0. Bio-reduction of laden perchlorate in the presence of Cl − (indirect bio-regeneration) help to keep a relatively high capture capacity (86.5%) of Fe 3 O 4 -QA-SP for perchlorate even after 7 cycles of indirect bio-regeneration. In contrast, only 58.3% of capture capacity was left after 3rd of direct bio-regeneration. Bio-fouling was also observed on surface of Fe 3 O 4 -QA-SP after sterilization process. [ABSTRACT FROM AUTHOR]

This study investigates, for the first time ever, the performance of iron(II) as homogeneous catalyst during the catalytic wet oxidation of thiocyanate. The results revealed the suitability of iron salts as cheap, non-toxic catalysts for the homogeneous wet oxidation of thiocyanate in acidic medium, greatly enhancing the oxidation rate and achieving efficiencies above 95% (75 min, 3.58 mM of catalyst). Ammonium, sulphate and bicarbonate were identified as the main reaction products. Other toxic intermediates such as cyanide, cyanate, nitrates or nitrites were not detected at any reaction time. According to the results obtained, a complete reaction pathway, based on the formation of two iron (III)-thiocyanate complexes, was proposed for the degradation of thiocyanate. Finally, a kinetic model, including the effect of the main operating conditions (temperature, pressure and initial concentrations of iron and thiocyanate), was successfully fitted to the experimental data. [ABSTRACT FROM AUTHOR]

Under starvation conditions, bacteria could consume intracellular macromolecules, which deteriorates the performance of the bioreactor. However, the fundamental endogenous metabolism of anaerobic ammonium oxidation (anammox) bacteria is poorly understood. Here, we describe the endogenous metabolism of anammox bacteria biomass under short-term anaerobic and anoxic starvation stress (4.5 d and 40 h, respectively) by protein, mRNA and biochemical analyses. The live/dead staining results showed negligible cell death rates. The activity decay rates (decrease in specific activity of active bacteria) were 0.128 d −1 and 0.629 d −1 under anaerobic and anoxic starvation conditions, respectively. The degradation rates of extracellular polymeric substances (EPS) and hydrazine dehydrogenase protein (HDH) were approximately 4- and 5-fold higher under anoxic starvation than under anaerobic starvation tests, suggesting the electron-donor roles for EPS and HDH in denitrification. The greater consumption of intracellular macromolecules during anoxic starvation corresponded with the greater decrease in anammox activities under this condition. Under both starvation conditions, the mRNA decay rates of nirS , hzsA , and hdh mRNA (representing metabolic stability) of anammox bacteria decreased from their normal levels. Such control of specific mRNAs is important for economizing protein synthesis and aids the cells’ recovery after starvation stress. These identified endogenous characteristics of anammox bacteria provide new insights into starvation stress responses at the transcriptional and translational levels, and will assist the optimization of anammox processes in bioreactors, which frequently experience starvation conditions. [ABSTRACT FROM AUTHOR]

Co-occurrence of organic matter (OM) and nitrogen in industrial and domestic wastewaters is a major obstacle in field scale application of anammox process- a novel technology for biological nitrogen removal. This study explored a new symbiosis amongst different consortium i.e., denitrifiers, anammox and anaerobes, which together minimized the inhibition caused due to OM through its concurrent utilization via other metabolic pathways. This symbiosis was achieved by seeding anaerobic granular sludge in existing anammox hybrid reactors at different seed ratios, i.e., 0.2, 0.4, 0.6 and 0.8. COD/TN and seed ratio played a vital role in controlling the overall dynamics of the three different pathways, i.e., denitrification, anammox and anaerobic degradation. The seed ratio of 0.6 was found ideal for synergistic removal of both OM (95.4%) and nitrogen (97.4%). At higher COD/TN ratio, anaerobes were more prevalent and outcompeted anammox bacteria which showed predominance at lower COD/TN ratio. The process performance data were analysed using multi-linear regression (MLR) and non-linear regression models. Biasness of the models were analysed using t -test which dictated MLR model was unbiased and statistically more precise than non-linear regression model. A new mathematical model coceptualised on the mass balance of substrate predicted N 2 and biogas with least error of precision. [ABSTRACT FROM AUTHOR]

Previous studies have shown that ammonium and manganese could be removed from water by biofilm in a trickling filter. However, it always takes several months to start up a biofilm filter. In this study, by oxidizing manganese and ferrous ion from raw water using potassium permanganate continuously, an iron-manganese co-oxide filter film (MeO x ) was formed quickly on the surface of virgin quartz sand in a pilot-scale filter, and the start-up period was less than 30 days. Interestingly, 90% ammonium and manganese could be removed by the filter film even after the bacteria were inactivated completely in both the filter film and raw water (by aerating ozone and injecting hydrogen peroxide), suggesting that microorganisms may play a negligible role in our system. Additionally, the filter film exhibited high oxidation activity when the temperature was down to 6.6 °C. The filter film was characterized by scanning electron microscopy, X-ray fluorescence spectroscopy and X-ray photoelectron spectroscopy methods. Finally, a chemical catalytic oxidation mechanism for ammonium removal was proposed by the analysis of the oxidation process. Ammonium was oxidized to nitrate through the process of catalytic oxidation, generating hydrogen ions. MeO x plays as a catalyst, and the intermediates O can potentially serve as both oxidant and reductant in one-electron-transfer reactions with NH 4 + and O 2 . [ABSTRACT FROM AUTHOR]

An integrated partial nitrification, sludge fermentation and denitrification process in a sequencing batch reactor (PNSFD-SBR), was developed to enhance nitrogen removal from domestic wastewater with low C/N (i.e. SCOD/TN) between 2 to 3 and to reutilize/reduce external waste activated sludge (WAS). Average ammonium removal efficiency of 95.9%, total nitrogen removal efficiency of 93.5%, and external WAS reduction rate of 21.6% was achieved during long-term experiment at 30 ± 1 °C. Real-time pH-DO (dissolved oxygen) monitor and control played an important role in the PNSFD achievement. A batch test indicated that micro-aeration (less than 1 mg/L) sustained partial nitrification, which further facilitated subsequent sludge fermentation and denitrification processes. Moreover, Illumina MiSeq analysis demonstrated the predominant bacteria were Rhodocyclaceae , Anaerolineaceae and Saprospiraceae on family level and they were key to partial nitrification, denitrification and sludge fermentation, by which the feasibility of PNSFD process to achieve simultaneous nitrogen removal and external WAS reutilization/reduction was verified. [ABSTRACT FROM AUTHOR]

In this work, the rejection of two ions associated with fertilizer pollution of ground water ( NH 4 + and NO 3 - ) by a polyamide nanofiltration (NF270) membrane was studied. Sodium chloride was selected as the dominant salt and the effect of its concentration on the NH 4 + and NO 3 - rejections was evaluated. Filtration experiments were carried out in a cross-flow setup with a rectangular spacer-filled feed channel. The solution-diffusion-electro-migration-film model (SDEFM), previously developed to model the pressure-driven trans-membrane transfer of electrolyte mixtures consisting of a single dominant salt and (any number of) trace ions, was used to obtain membrane ion permeance from the experimental data. In this way, the membrane permeances with respect to single ions (Na + , Cl − , NH 4 + , NO 3 - ) were obtained for various concentrations of both dominant (0.05–0.3 M NaCl) and trace salts (0.001–0.003 M NH 4 Cl/NaNO 3 ). It was observed that when the dominant salt concentration increased, the rejections of dominant salt and trace ions decreased, whereas the membrane permeances to ions increased. This information can be useful for developing design tools for nanofiltration of mixed electrolyte solutions in water-treatment applications. [ABSTRACT FROM AUTHOR]

The anaerobic ammonium oxidation (anammox) consists on the biological conversion of ammonium (NH 4 + ) into dinitrogen gas under absence of oxygen. Nitrite (NO 2 − ) is a substrate of the anammox reaction, but also an inhibitor at high concentrations. This study investigates the effect of nitrite on the microbial community during the batch enrichment of anammox sludge. Six inoculums collected from different environments were enriched after a conditioning pretreatment and under controlled conditions during 4 months. Concerning the mineral medium used, two different nitrite supply strategies were applied; i.e., (i) initially low concentration at 25 mg NO 2 − –N/L and progressive increase to 150 mg NO 2 − –N/L, and (ii) constant high concentration at 150 mg NO 2 − –N/L. All tested inoculums developed anammox activity but only when the enrichment was started at low nitrite concentration. In such case, the specific ammonium conversion rates finally obtained ranged from 21 ± 1 to 118 ± 1 mg NH 4 + –N/g VS/d (VS, volatile solids). Abundance of the functional gene encoding for the enzyme hydrazine oxidoreductase ( hzo ) was assessed using the real-time quantitative polymerase chain reaction (q-PCR) showing positive correlation with the anammox activity finally reported. In addition, high-throughput DNA sequencing helped to elucidate the underlying microbial community dynamics. The raw inoculum source, the conditioning pretreatment, and the cultivation conditions applied were jointly determinants of the final microbial community structure of the enrichments despite a clear convergence at the end of the experimental period. On the other hand, the cultivation conditions alone determined the selection of anammox species belonging to the genus Candidatus Brocadia . [ABSTRACT FROM AUTHOR]

In this paper, we developed a simple and robust synthesis route to fabricate multilayer structured cuprammonium fabric/polypyrrole/copper (CF/PPy/Cu) composite, which could be potentially used as electromagnetic interference (EMI) shield due to its characteristics of both EM wave-absorption and EM wave-reflection. PPy layer was directly deposited onto the bare CF substrate via an in-situ polymerization approach, and the interaction mechanism between PPy and CF substrate was investigated by FT-IR and FT-Raman measurements. The results indicated that the interaction between PPy ( N H) and CF (>C OH) substrate was by hydrogen bonding. Afterwards, Cu film was constructed on the as-made PPy coated CF (CF/PPy) by an electroless copper plating method. The elemental analysis of the samples in each step was conducted by using XPS measurement. XRD analysis showed that the top Cu film had a characteristic face-centered cubic (FCC) crystalline structure. SEM images illustrated that the thickness of the PPy film was about 1.52 μm with 11.4% deviation, which was enough to generate the inter-fiber connection. Moreover, the probable growth mechanism of top-Cu films was proposed according to their surface morphologies. The shielding effectiveness (SE) values of copper plated CF (CF/Cu) and CF/PPy/Cu were recorded and compared by using a Spectrum analyzer (30–1000 MHz). The resultant CF/PPy/Cu composite had a higher EMI SE (30.3–50.4 dB) with sheet resistance of 85.8 mΩ/sq. The results of ultrasonic washing, TGA and tensile measurements revealed that the proposed conductive fabric exhibited an excellent serviceability, which was adequately reliable for practical application. [ABSTRACT FROM AUTHOR]

The combined anammox (anaerobic ammonium oxidation) and autotrophic desulfurization–denitrification (AADD) process represents a promising innovative technology for biological nitrogen and sulfur removal. In this study, an up-flow anaerobic sludge blanket reactor, which was started with anammox and methanogenic granules, was operated for 245 days to evaluate the co-treatment of wastewater containing nitrogen and sulfur. The reactor demonstrated good performance in terms of nitrogen and sulfide removal and exhibited excellent behavior for removal of NH 4 + -N, NO 2 − -N and S 2− -S exceeding 252, 333 and 330 mg L −1 , respectively. The highest nitrogen removal rate and sulfide removal rate attained were 4.00 kgN m −3 d −1 and 2.39 kgS m −3 d −1 , respectively, which were also the highest reported values for a coupling-system. The influent NH 4 + -N:S 2− -S and NO 2 − -N:S 2− -S ratios set at 1.74 and 2.20–2.27 are suitable for maintaining system stability. The specific activities of anammox and autotrophic desulfurization–denitrification (SAA and SADD), extracellular polymeric substance (EPS), heme c (an important cofactor of some anammox bacterial enzymes) and the diversity of anammox and autotrophic desulfurization–denitrification (ADD) bacteria were investigated during the operation. The SAA and SADD are regarded as key factors for high efficiency. The granules contained many EPS (128.4–204.5 mg g −1 VSS) and minor heme c content (1.17 μmol g −1 VSS). The dominant bacteria belonged to members of Brocadiaceae and Hydrogenophilaceae , a majority of which were anammox bacteria and ADD bacteria, respectively. These observations suggest a new removal process for ammonia, nitrite and sulfide utilizing an uncommon mechanism involving simultaneous anammox and ADD. [ABSTRACT FROM AUTHOR]

A chemical-less process using vacuum-UV (VUV) as radiation source was used for direct oxidation of ammonium to N 2 from the contaminated water. The effect of water pH, aeration, initial ammonium concentration, reaction time, and water anions on ammonium oxidation was evaluated in batch experiments. The oxidation of ammonium improved with the increase in water pH and the highest oxidation level obtained at the pH 8. Although the aeration partly improved ammonium oxidation efficiency, it inhibited the selective oxidation of ammonium to N 2 . The complete oxidation of ammonium at concentrations of 25, 50, 75 and 100 mg NH 4 + /L was obtained at the reaction times of 5, 6, 7.5 and 10 h, respectively, following pseudo first-order kinetic model. In addition, the selectivity to nitrate and N 2 formation obtained in the range of 7.7–14.8% and 85.2–92.3%, respectively. In continuous flow experiments, the complete oxidation of 50 mg/L ammonium observed at HRT of 8 h with N 2 selectivity above 99%. Sulfate had the lowest and carbonate had the highest scavenging effect among the selected anions on radicals species generated in the VUV photoreactor. Accordingly, the VUV photoreactor is an efficient and promising chemical-less advanced process for selective oxidation of ammonium to N 2 . [ABSTRACT FROM AUTHOR]