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Graphical abstract Highlights • Effluent TN as low as 4.0 mg N/L was achieved via PD-Anammox process. • Anammox was stable and accounted for 78.2% on nitrogen removal. • Low nitrous oxide (N2O) was produced in PD-Anammox process. • Oxygen consumption, COD demand and sludge production would be largely reduced. • PD-Anammox process can be easily retrofitted from existing plants. Abstract High nitrate (NO 3 −-N) concentration in the effluent of wastewater treatment plants (WWTPs), cannot meet the increasing stringent discharge limits. Hence, the tertiary treatment is necessary to lower the total nitrogen concentration. In this study, an innovative partial denitrification (PD)-Anammox process was applied to remove the nitrate nitrogen (20–40 mg N/L) from secondary effluent. The nitrate wastewater were firstly fed to PD sequencing batch reactor (SBR, 10 L) to produce nitrite along with the low carbon/nitrogen ratio (C/N) municipal sewage (NH 4 + of 57.8 mg N/L, COD of 175.8 mg/L), then the effluent from SBR was pumped to the anaerobic sludge blanket (UASB, 3.2 L) performing anammox for further nitrogen removal. The integrated process was operated for 224 days with the secondary effluent to municipal sewage volume ratio of 2.9–6. The results suggested that an excellent nitrate removal efficiency of 97.9% was achieved, and the mean removal efficiency of NH 4 +-N and COD from municipal sewage were 95.2% and 81.6%, respectively, leading to the total nitrogen and COD concentration in the final effluent as low as 4.0 mg N/L and 30.1 mg/L, respectively. Anammox was the main nitrogen removal pathway with a mean proportion of 78.2%, and Candidatus_Brocadia was identified as the dominating genus. Furthermore, it was found that a minor nitrous oxide (N 2 O) was produced in the integrated process. The PD-Anammox process was verified to be economically and environmentally feasible for retrofitting of existing plants. [ABSTRACT FROM AUTHOR]

As a new class of multifunctional material, high-temperature annealing enabled iridium oxide nanofibers (IrO 2 NFs) were synthesized and then employed as the sensing element to fabricate a novel dual glucose and pH sensor in this study. The as-prepared IrO 2 NFs were systematically characterized using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy, while the electrochemical and electrocatalytic performance of the IrO 2 NFs based dual sensor toward pH and glucose sensing were evaluated using open circuit potential, cyclic voltammetry and amperometric techniques, respectively. The IrO 2 NFs not only possess good and reversible pH sensitivity as expected, but also demonstrate the electrocatalytic activity toward glucose which was presumably attributed to the crystallinity enabled by high-temperature annealing effect during the preparation of IrO 2 NFs. This unique dual functionality enables us to develop a sensor which can be applied for both non-enzymatic glucose and solid-state pH sensing. The experiment results show that the IrO 2 NFs based dual sensor exhibits a Nernst constant close to a theoretical value with excellent reversibility in pH titration, while it also possesses a sensitivity of 22.22 μA mM -1  cm −2 , a limit of detection of 2.9 μM (S/N = 3), and good selectivity against various interferents in non-enzymatic glucose detection. Its good accuracy for detecting glucose in human serum sample was also demonstrated by comparing to commercial glucose meter. All these features indicate that the high-temperature annealed IrO 2 NF is a promising multifunctional sensing material in the development of an integrated solid-state pH sensor and non-enzymatic glucose sensor. [ABSTRACT FROM AUTHOR]

A novel post-endogenous denitrification and phosphorus removal (post-EDPR) system was developed by enriching denitrifying glycogen accumulating organisms (DGAOs) and phosphorus accumulating organisms (PAOs) to treat low carbon/nitrogen (C/N) wastewater (C/N = 4.4). The unique feature of the post-EDPR system was the continuous alternating anaerobic/oxic/anoxic zone (3.1 h/3.9 h/7 h) with suspended biofilm carriers in oxic zone. The 132-day test results showed that extended anaerobic and anoxic stage strengthened the intracellular carbon storage and endogenous denitrification. Low dissolved oxygen (DO) concentration (1–2 mg/L) in oxic zone promoted the simultaneous nitrification and denitrification (SND) and saved aeration energy, nitrifiers were enriched with the biofilm carriers and nitrification performance was strengthened, so oxic hydraulic retention time (HRT) could be shortened to avoid excessive polyhydroxyalkanoate (PHA) consumption which would be used for the latter anoxic denitrification. In a steady state, the system achieved advanced nitrogen and phosphorus removal (TIN (total inorganic nitrogen) ≤3 mg/L, PO 4 3−  − P ≤ 0.2 mg/L) with a high removal efficiency of 92.15% and 92.67%, respectively, and PHA played a major role for P-uptake and endogenous denitrification. Microbial community analysis demonstrated that PAOs and GAOs were enriched and performed aerobic P-uptake and anoxic endogenous denitrification, respectively. [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]

Anaerobic hydrogen production (AHP) is a biochemical process capable of producing hydrogen and fatty acids from organic substrates in acidogenic phase. Currently, almost all of anaerobic systems use centrally stirred mixing where the flow is essentially rotated uniformly in the radial direction. Given the high energy requirement of mixing and the urgent needs for enhancing the contact between microbial particles and substrates, a new type of mixing strategy should be developed. This study focused on the enhancement of biogas production and organic removal efficiency in AHP systems through a novel chaotic mixing regime. The stirring impeller was operated eccentrically with the stirring center eccentrically located 2 and 4 cm off the center, respectively and at different heights (5, 10.5 and 16 cm). The eccentrically stirred mixing was expected to enhance the mixing efficiency and accelerate the contact between biomass and organic substrates in the AHP system. A numerical finite element model was developed to simulate the flow patterns and the biomass distribution, through which the Lyapunov exponent λ values were calculated in order to assess the strength of eccentrically stirred mixing at different mixing eccentricities. The model simulations showed that at the height of 10.5 and 16 cm, the Lyapunov exponent λ increased as the mixing eccentricity increased. This corresponded well with the experimental results, which showed that the organic removal efficiency and biogas production increased with the mixing eccentricity. Compared with centrally stirred mixing, eccentrically stirred mixing enhanced the interaction of flow and biomass particles and ultimately enhanced the biogas production and organic removal in AHP systems. [ABSTRACT FROM AUTHOR]

In situ direct soil moisture monitoring suffers from crucial problems including bulky sensor size, disturbance of soil texture, low accuracy and costly sensors. This study aimed at tackling this challenge by developing a novel flat thin mm-sized soil moisture sensor (MSMS) using gold compact discs etching. MSMSs were examined in six soil samples (sand/silt/clay mixtures), with soil moisture in each varying from zero to saturated. The capacitance and resistance readings of MSMSs were real-time recorded, and compared with soil moisture derived from conventional measurement. Both capacitance and resistance were found to correlate linearly with soil moisture, and the regression slopes were linearly correlated with soil porosity. This unique relationship facilitates accurate calculation of soil moisture based on MSMS readings for any given soil texture, which eliminates the need for tedious calibration of MSMSs in field applications. Four-week stability tests of MSMS showed the resistance readings did not drift throughout the test period, and the sensor surface observation indicated anti-scratching capability, demonstrating high stability for long-term continuous in situ monitoring of soil moisture. [ABSTRACT FROM AUTHOR]

The biofilm system is beneficial for Anammox process designed to treat landfill leachate. In this study, the composition of extracellular polymeric substances (EPS) and the microbial community in an Anammox biofilm system were analyzed to determine the functions driving the biofilm’s ability to treat landfill leachate. The results demonstrated that increasing influent carbon oxygen demand (COD) could stimulate EPS production. EPS helped enrich Anammox bacteria and supplied them with nutrients and enzymes, facilitating effective nitrogen removal (approximately 95%). The variation in Anammox bacteria was similar to the variation in EPS composition. In the tested Anammox Sequencing Biofilm Batch Reactor (SBBR) system, Candidatus Kuenenia was dominant among known Anammox genus, because of its high substrate affinity and because it adapts better to landfill leachate. The relative abundance of Candidatus Kuenenia in the biofilm rose from 3.26% to 12.38%, illustrating the protection and enrichment offered by the biofilm in carrying out Anammox. [ABSTRACT FROM AUTHOR]

An anaerobic-aerobic-anoxic sequencing batch reactor (AOA-SBR) using sludge fermentation products as carbon source was developed to enhance nitrogen and phosphorus removal in municipal wastewater with low C/N ratio (<4) and reduce sludge production. The AOA-SBR achieved simultaneous partial nitrification and denitrification (SND), aerobic phosphorus uptake and anoxic denitrification through the real-time control and the addition of sludge fermentation products. The average removal efficiencies of total nitrogen (TN), phosphorus (PO 4 3− -P) and chemical oxygen demand (COD) after 145-day operation were 88.8%, 99.3% and 81.2%, respectively. Nitrite accumulation ratio (NAR) reached 99.1% and sludge reduction rate reached 44.1–52.1%. Specifically, 34.4% of the TN removal was carried out by SND and 57.5% by denitrification. Illumina MiSeq sequencing indicated that ammonium-oxidizing bacteria ( Nitrosomonas ) were enriched and nitrite-oxidizing bacteria ( Nitrospira ) did not exist in AOA-SBR. The system demonstrated potential to solve the dual problem of insufficient carbon source and sludge reduction. [ABSTRACT FROM AUTHOR]

This study tested the feasibility of plug-flow integrated fixed-film activated sludge (IFAS) reactor in applying sewage partial nitritation/anammox (PN/A) process. The IFAS reactor was fed with real pre-treated sewage (C/N ratio = 1.3) and operated for 200 days. High nitrogen removal efficiency of 82% was achieved with nitrogen removal rates of 0.097 ± 0.019 kg N/(m 3 ·d). Therefore, plug-flow IFAS reactor could be an alternative to applying sewage PN/A process. Besides, it was found that the stability of sewage PN/A process was significantly affected by residual ammonium. Nitrate accumulated in effluent and PN/A performance deteriorated when residual ammonium was below 1 mg/L. On the contrary, long-term stable PN/A operation was achieved when residual ammonium was over 3 mg/L. [ABSTRACT FROM AUTHOR]

Simultaneous removal of nitrogen in municipal wastewater, metal in industrial wastewater and saline in seawater was achieved in an integrated microbial desalination cell-microbial electrolysis cell (MDC-MEC) system. Batch tests showed that more than 95.1% of nitrogen was oxidized by nitrification in the cathode of MDC and reduced by heterotrophic denitrification in the anode of MDC within 48 h, leading to the total nitrogen removal rate of 4.07 mg L −1 h −1 . Combining of nitrogen removal and desalination in MDC effectively solved the problem of pH fluctuation in anode and cathode, and led to 63.7% of desalination. Power generation of MDC (293.7 mW m −2 ) was 2.9 times higher than the one without salt solution. The electric power of MDC was harvested by a capacitor circuit to supply metal reduction in a MEC, and 99.5% of lead (II) was removed within 48 h. A kinetic MDC model was developed to elucidate the correlation of voltage output and desalination efficiency. Ratio of wastewater and sea water was calculated for MDC optimal operation. Energy balance of nutrient removal, metal removal and desalination in the MDC-MEC system was positive (0.0267 kW h m −3 ), demonstrating the promise of utilizing low power output of MDCs. [ABSTRACT FROM AUTHOR]

Flat enzyme-based lactate biofuel cell (ELBC) integrated with power management system (PMS) was developed as a potential power supply for wearable sensors. Kinetic models of power output and chemical reagent concentration (lactate oxidase LOx and lactate) were developed to determine the limiting factor of the ELBC performance. Given the lactate concentration (0–40 mM) in human sweat, the optimum LOx amount coated on the anode ranged from 6U to 54U based on the experimental maximum power output. In the ELBC-PMS entity simulation test, power discharge/recharge frequency was calculated for self-sustained sensing and data transmission, indicating that the ELBC could support wearable sensors (power requirement: 1–1350 mW; signal transfer frequency: 1–1320 times/h). The electrochemical activity of LOx coated anode was validated using the cyclic voltammetry (CV). The coefficient of variance and regression statistical analysis revealed the high stability and long lifespan (2 weeks) of ELBC without the need of lactate refill. [ABSTRACT FROM AUTHOR]

• Integration of fragility of energy distribution system for system performance evaluations. • Integration of safety matrics of power generation for system performance evaluations. • Component failure of energy distribution system can cause critical failures of the system. • The electricity demand change can affect the power system's performance. Climate change and population growth require the development and operations of critical power infrastructure systems to meet the energy demand. Performance assessment of the power infrastructure usually focuses primarily on the thermodynamic analysis calculating the energy output and system efficiency. However, the energy output from the thermodynamic analysis under normal operation could not fully represent the infrastructure behavior due to the neglect of the component reliability in the energy generation system. There is a lack of consideration of the energy delivery system and its fragility with respect to external meteorological parameters (e.g., wind). In this study, the fragility of the energy-delivery system concerning wind speed is modeled and integrated to assess critical power infrastructure performance. The reliability consideration of the energy generation system is included based on the state space diagram and the frequency-balance method. The fragility of the energy-delivery system is used to derive a system reliability index for the system which is the probability that end-users will receive the energy. Besides, sensitivity analysis is conducted to investigate the influence of the important decision variables on the system performance. The study employs a small-scale power infrastructure system at the University of Connecticut as an example to demonstrate the feasibility of the performance assessment framework. The system is composed of a cogeneration plant and energy distribution systems. The results from the case study prove that the decision variables have considerable nonlinear impacts on the system performance. With the integration of fragility, the proposed approach could estimate the energy received by consumers from the generation site. [ABSTRACT FROM AUTHOR]

In this study, a novel integrated anaerobic ammonium oxidization with partial denitrification process (termed as ANAMMOX-PD) was developed for advanced nitrogen removal from high-strength wastewater, which excess NO 3 − -N produced by ANAMMOX was fed into PD reactor for NO 2 − -N production and then refluxing to ANAMMOX reactor for further removal. Results showed that total nitrogen (TN) removal efficiency as high as 97.8% was achieved and effluent TN-N was below 20 mg/L at influent TN-N of 820 mg/L. Furthermore, the feasibility of simultaneously treating domestic wastewater was demonstrated in ANAMMOX-PD process, and NH 4 + -N removal efficiency of 96.7% was obtained. The nitrogen removal was mainly carried out through ANAMMOX pathway, and high-throughput sequencing revealed that Candidatus_Brocadia was the major ANAMMOX species. The presented process could effectively solve the problem of excess nitrate residual in ANAMMOX effluent, which hold a great potential in application of currently ANAMMOX treating high-strength wastewater (e.g. sludge digestion supernatant). [ABSTRACT FROM AUTHOR]

A paper-based multi-anode microbial fuel cell (PMMFC) integrated with power management system (PMS) was developed as a disposable self-support real-time “shock” biosensor for wastewater. PMMFCs were examined at three types of shocks (chromium, hypochlorite and acetate) in a batch-mode chamber, and exhibited various responses to shock types and concentrations. The power output of PMMFC sensor was four times as the carbon cloth (CC)-based MFCs, indicating the advantage of paper-based anode for bacterial adhesion. The power output was more sensitive than the voltage output under shocks, and thus preventing the false signals. The simulation of power harvest using PMS indicated that PMMFC could accomplish more frequent data transmission than single-anode MFCs (PSMFC) and CC anode MFCs (CCMMFC), making the self-support wastewater monitor and data transmission possible. Compared with traditional MFC sensors, PMMFCs integrated with PMS exhibit the distinct advantages of tight paper-packed structure, short acclimation period, high power output, and high sensitivity to a wide range of shocks, posing a great potential as “disposable self-support shock sensor” for real time in situ monitoring of wastewater quality. [ABSTRACT FROM AUTHOR]

In order to treat domestic wastewater with high ammonia but low carbon source (low C/N ratio), a novel two sludge pre-A 2 NSBR system (anaerobic/anoxic/aerobic nitrification) was firstly developed by exchanging the sequence of aerobic nitrification and anoxic phase of the conventional A 2 NSBR process (anaerobic/aerobic nitrification/anoxic). The system was operated for 186 days to treat real domestic wastewater with low carbon/nitrogen (C/N = 4.03). Anoxic duration was adjusted and post-aeration phase was added to enhance nitrogen and phosphorus removal. Results indicate that adding post-aeration phase is indispensable to achieve enhanced phosphorus removal, the pre-A 2 NSBR system achieved a high denitrifying phosphorus removal efficiency of 96.86% with efficient utilization of limited carbon source. Specifically, the ammonia effluent was 0.46 mg/L, which solved the bottleneck problem of high ammonia residues in conventional A 2 NSBR process. The fluorescence in situ hybridization (FISH) results showed that PAOs was enriched and GAOs was inhibited in the A 2 SBR, nitrifiers also became dominant in the N-SBR. Moreover, the profiles variation of real-time online indicator such as pH, ORP and DO were demonstrated closely related with the nutrient removal performance, and based on this, it is possible or expected to establish the real time control strategy in the future. [ABSTRACT FROM AUTHOR]

A single-stage partial nitrification-anammox (PN/A) reactor treating low-strength swage was operated for 288 days to investigate the recovery of nitrogen removal from nitrate accumulation. The reactor was quickly started up by inoculating anammox sludge. However, nitrite oxidizing bacteria (NOB) abundance gradually increased on day 25, leading to high effluent nitrate concentration. Two strategies were executed to control the effluent nitrate. In strategy I, dissolved oxygen (DO) concentration was kept low (0.17 ± 0.08 mg/L), but nitrate production increased from 4.71 to 38.18 mg-N/L. In strategy II, intermittent aeration operation mode (aeration 7 min/anoxic 21 min) was adopted, which significantly lowered the nitrate concentration to 1.3 mg-N/L, indicating the NOB was inhibited. The high nitrogen removal rate of 73 mg-N/(L·d) was achieved. The evolution of bacterial activity and abundance verified the changes of the nitrogen removal performance and proved the intermittent aeration strategy could successfully solve the problem of nitrate build-up in the PN/A process. [ABSTRACT FROM AUTHOR]

Although efficient removal of carbon (C), nitrogen (N) and phosphorous (P) from wastewater with low C/N ratio was achieved in anaerobic/aerobic simultaneous nitrification-endogenous denitrification and phosphorus removal (SNEDPR) systems, the removal pathways and metabolic transformations in this complex system are unclear. This work targeted at developing the stoichiometric models for denitrifying glycogen organisms (DGAOs) via nitrite and nitrate (DGAO Ni and DGAO Na ), and demonstrating a novel methodology to quantify diverse functional microorganisms (e.g. ammonia and nitrite oxidizing bacteria, aerobic phosphorus accumulating organisms (APAOs), denitrifying PAOs (DPAOs) and aerobic GAOs (AGAOs)) for the removal of C, N and P. The results showed that the anaerobic intracellular carbon storage (COD intra ) was mainly accomplished by GAOs, and PAOs were only responsible for about 40% of COD intra through a stable P release. At the aerobic stage, 84.9% of P was removed by APAOs with 15.1% left by DPAOs, while 64.6% of N was removed by DGAOs (45.8% by DGAO Ni and 18.8% by DGAO Na ) with 18.1% by DPAOs and 17.3% by bacterial growth. High proportion of N removal via nitrite (partial nitrification-endogenous denitrification) (71%) saved 7.3% aeration and 38% intracellular carbon demand. However, AGAOs still activated well at the aerobic intercellular carbon consumption, which limited the further improvement of N removal efficiency. By elucidating the nutrient removal pathways among diverse functional microorganisms, the methodology developed in this study could accelerate the nutrient removal in the SNEDPR process. [ABSTRACT FROM AUTHOR]

The effect of four alkali reagents (NaOH, KOH, Ca(OH) 2 , mixed alkali) on waste activated sludge (WAS) hydrolytic acidification and microbial community was studied in semi-continuous fermentation systems at low temperature (15 °C) over long term operational time (65 day). The results showed that protein and polysaccharide of NaOH (124.26, 11.92) was similar to that of KOH (109.53, 11.30), both were higher than Ca(OH) 2 (70.66, 3.74) and mixed alkali (90.66, 8.71). The short chain fatty acids (SCFAs) of NaOH (231.62) was higher than KOH (220.62 mg chemical oxygen demand (COD)/g VSS). Although Ca(OH) 2 system had strong acidification capacity, the shortage of SCFAs occurred due to the low activity of hydrolase. Illumina MiSeq sequencing revealed that Tissierella and Erysipelothrix were enriched in the NaOH and Ca(OH) 2 systems, where Peptostreptococcaceae incertae_sedis was enriched in the NaOH and KOH systems, less Anaerolinea was involved in Ca(OH) 2 condition. [ABSTRACT FROM AUTHOR]

Novel flat membrane-based microbial fuel cell (MMFC) sensors were developed by compacting two filter membranes coated with carbon ink. High micro-porosity and hydrophilicity of membranes offered the distinct advantages of short acclimation period (couple hours), simple compact configuration with microliter size, and high sensitivity and stability. MMFC sensors were examined at two toxic shocks (chromium and nickel) in a batch-mode test chamber, and rapidly responded to shock types and concentrations. The variation of voltage output was correlated with open circuit potential (OCP). Filter membranes facilitated bacterial attachment and shortened acclimation. The MMFC sensors showed good reusability and recovered several days after toxic shocks. The robustness of MMFC sensors was validated through 1-month tests. The stability of sensor signals was examined with coefficient of variance (CV) statistical analysis. The flat microliter MMFC has a great potential as “on-line sticker sensor” for real time in situ monitoring of wastewater quality. [ABSTRACT FROM AUTHOR]

Long-term effect of pH (4, 10, and uncontrolled) on short-chain fatty acid (SCFA) accumulation, microbial community and sludge reduction were investigated in waste activated sludge (WAS) fermentors for over 90 days. The average SCFAs accumulation was 1721.4 (at pH 10), 114.2 (at pH 4), and 58.1 (at uncontrolled pH) mg chemical oxygen demand (COD)/L. About 31.65 mg COD/L was produced at pH 10, accounting for 20% of the influent COD. Illumina MiSeq sequencing revealed that Alcaligenes (hydrolic bacteria) and Erysipelothrix (acidogenic bacteria) were enriched at pH 10, while less acidogenic bacteria existed at pH 4 than pH 10, and no acidogenic bacteria were detected at the uncontrolled pH. The ratios of archaea to bacteria were 1:41, 1:16, and 1:9 at the pH of 10, 4, and uncontrolled. This study elucidated the effects of pH on WAS fermentation, and established the correlation of microbial structure with SCFAs accumulations and sludge reduction. [ABSTRACT FROM AUTHOR]

In Microbial Fuel Cells (MFCs), the recovery of water can be achieved with the help of both active (electro-osmosis), and passive (osmosis) transport pathways of electrolyte through the semi-permeable selective separator. The electrical current-dependent transport, results in cations and electro-osmotically dragged water molecules reaching the cathode. The present study reports on the production of catholyte on the surface of the cathode, which was achieved as a direct result of electricity generation using MFCs fed with wastewater, and employing Pt-free carbon based cathode electrodes. The highest pH levels (>13) of produced liquid were achieved by the MFCs with the activated carbon cathodes producing the highest power (309 μW). Caustic catholyte formation is presented in the context of beneficial cathode flooding and transport mechanisms, in an attempt to understand the effects of active and passive diffusion. Active transport was dominant under closed circuit conditions and showed a linear correlation with power performance, whereas osmotic (passive) transport was governing the passive flux of liquid in open circuit conditions. Caustic catholyte was mineralised to a mixture of carbonate and bicarbonate salts (trona) thus demonstrating an active carbon capture mechanism as a result of the MFC energy-generating performance. Carbon capture would be valuable for establishing a carbon negative economy and environmental sustainability of the wastewater treatment process. [ABSTRACT FROM AUTHOR]

In this study, we investigated the molecular mechanism underlying melanoma proliferation, with the aim to discover effective interventions which may markedly improve clinical prognosis. The results showed that gambogenic acid (GNA) could inhibit the proliferation of melanoma cells in vivo (C57BL/6 mice) and in vitro. Long non-coding RNA sequencing was used to identify the most significant long non-coding RNA, i.e., nuclear enriched abundant transcript 1 (NEAT1). NEAT1 was is up-regulated in melanoma, which was found to closely relate to cell proliferation. Melanoma cell lines either over-expressing NEAT1 or with NEAT1 knockdown was established through cloning experiments. A model of transplanted tumors was established to verify the inhibitory effect of GNA on the proliferation of melanoma cells in vitro and in vivo by downregulating NEAT1. Downregulation of NEAT1-induced ferroptosis and autophagy was demonstrated by detecting the effects of NEAT1 overexpressed and downregulated melanoma cell lines and melanoma transplantation model mice. Mechanistically, downregulation of NEAT1 can weaken the direct binding of Slc7a11, indirectly leading to inhibiting GPX-4 activity and subsequent ferroptosis, while, mediating the AMPK/mTOR signal axis-induced autophagy. The levels of Furthermore, NEAT1 decrease under the treatment of Gambogenic acid (GNA), a promising natural anticancer compound, while NEAT1 overexpression suppresses GNA inhibition on cell vitality and eliminates GNA-induced melanoma cell ferroptosis and autophagy. [Display omitted] • lncRNA NEAT1 significantly promotes the proliferation of melanoma cells in vitro and in vivo , and such an effect is abrogated by knockdown of NEAT1. • Downregulation of NEAT1 inhibits the proliferation of melanoma cells by inducing ferroptosis and autophagy. • NEAT1 is involved in the GNA-induced ferroptosis and autophagy through both the SLC7A11 / GPX-4 and AMPK / mTOR signaling pathways. [ABSTRACT FROM AUTHOR]

A self-sustained hybrid bioelectrochemical system consisting of microbial fuel cell (MFC) and microbial electrolysis cell (MEC) was developed to reduce multiple metals simultaneously by utilizing different reaction potentials. Three heavy metals representing spontaneous reaction (chromium, Cr) and unspontaneous reaction (lead, Pb and nickel, Ni) were selected in this batch-mode study. The maximum power density of the MFC achieved 189.4 mW m −2 , and the energy recovery relative to the energy storage circuit (ESC) was ∼450%. At the initial concentration of 100 mg L −1 , the average reduction rate of Cr(VI) was 30.0 mg L −1 d −1 , Pb(II) 32.7 mg L −1 d −1 , and Ni(II) 8.9 mg L −1 d −1 . An electrochemical model was developed to predict the change of metal concentration over time. The power output of the MFC was sufficient to meet the requirement of the ESC and MEC, and the “self-sustained metal reduction” was achieved in this hybrid system. [ABSTRACT FROM AUTHOR]

A new type distributed benthic microbial fuel cell (MFC) (DBMFC) consisting of 18 MFC arrays was developed to enhance the robustness and stability of the power source for subsea sensor networks. A power management system (PMS) was integrated into the DBMFC system to boost the power output for two temperature sensors. The PMS was specifically designed with 18 charge pumps capable of simultaneously harvesting energy from 6 MFC units (18 anodes total) in the DBMFC system. The pilot scale DBMFC (total sediment volume: 1 m 3 ) with continuous ocean water supply showed that the power outputs of individual MFC units were affected by the organic carbon and nitrogen contents in the sediment pore water. The MFC units with higher power output resulted in faster charging/discharging rate of the PMS supercapacitor. Manual disconnection of anodes from the PMS was conducted to simulate the anode malfunction caused by bioturbation. Fewer functional anodes (e.g. 12 out of 18 anodes were disconnected) slowed the charging/discharging rate of the PMS supercapacitor but still supported the PMS to regularly power two sensors. This scale-up DBMFC/PMS/sensor study demonstrated that multiple MFC units with multiple PMS substantially enhanced the stability and robustness of power supply to subsea sensors. [ABSTRACT FROM AUTHOR]

A novel simultaneous nitrification denitrification and phosphorous removal-sequencing batch reactor (SNDPR-SBR) enriched with PAOs (phosphorus accumulating organisms), DPAOs (denitrifying PAOs), and GAOs (glycogen accumulating organisms) at the ratio of 2:1:1 was developed to achieve the simultaneous nutrient and carbon removal treating domestic wastewater with low carbon/nitrogen ratio (≤3.5). The SNDPR system was operated for 120 days at extended anaerobic stage (3 h) and short aerobic stage at low oxygen concentration (2.5 h) with short sludge retention time (SRT) of 10.9 d and hydraulic retention time (HRT) of 14.6 h. The results showed that at the stable operating stage, the average effluent chemical oxygen demand (COD) and PO 4 3 − – P concentrations were 47.2 and 0.2 mg L −1 , respectively, the total nitrogen (TN) removal efficiency was 77.7%, and the SND efficiency reached 49.3%. Extended anaerobic stage strengthened the intracellular carbon (mainly poly-β-hydroxybutyrate, PHB) storage, efficiently utilized the organic substances in wastewater, and provided sufficient carbon sources for denitrification and phosphorus uptake without external carbon addition. Short aerobic stage at low oxygen concentration (dissolved oxygen (DO): 1 ± 0.3 mg L −1 ) achieved a concurrence of nitrification, endogenous denitrification, denitrifying and aerobic phosphorus uptake, and saved about 65% energy consumption for aeration. Microbial community analysis demonstrated that P removal was mainly performed by aerobic PAOs while N removal was mainly carried out by denitrifying GAOs (DGAOs), even though DPAOs were also participated in both N and P removal. [ABSTRACT FROM AUTHOR]

Using internal carbon source contained in waste activated sludge (WAS) is beneficial for nitrogen removal from wastewater with low carbon/nitrogen ratio, but it is usually limited by sludge disintegration. This study presented a novel strategy based on free nitrous acid (FNA) pretreatment to intensify the release of organic matters from WAS for enhanced denitrification. During FNA pretreatment, soluble chemical oxygen demand (SCOD) production kept increasing when FNA increased from 0 to 2.04 mg HNO 2 -N/L. Compared with untreated WAS, the internal carbon source production increased by 50% in a simultaneous fermentation and denitrification reactor fed with WAS pretreated by FNA for 24 h at 2.04 mg HNO 2 -N/L. This also increased denitrification efficiency by 76% and sludge reduction by 87.5%. More importantly, greenhouse gas nitrous oxide production in denitrification was alleviated since more electrons could be provided by FNA pretreated WAS. [ABSTRACT FROM AUTHOR]

A novel hybrid binuclear-cobalt-phthalocyanine (Bi-CoPc) is developed as the cathode catalyst to replace the costly platinum (Pt) in single chamber microbial fuel cells (SCMFCs). Bi-CoPc/C is integrated with metal oxides (NiO and CoO) to form macrocyclic complex for enhanced oxygen reduction rate (ORR). The characteristics of hybrid catalysts (Bi-CoPc/C–CoO and Bi-CoPc/C–NiO) are compared with Co-contained catalysts (CoPc/C and Bi-CoPc/C) and metal oxide catalysts (NiO and CoO). The increase in O and N functional groups indicates the benefits of NiO and CoO to the cathode catalysts. The cyclic voltammetry (CV) shows the reduction peak for Bi-CoPc/C–NiO and Bi-CoPc/C–CoO at −0.12 V and −0.22 V, respectively. The power densities (368 mW m −2 and 400 mW m −2 ) of SCMFCs with Bi-CoPc/C–CoO and Bi-CoPc-NiO/C are the highest among the cathodes tested, and close to that of Pt (450 mW m −2 ). This study demonstrates that hybrid Bi-CoPc/C with metal oxides has a great potential as a cost-effective catalyst in MFCs. [ABSTRACT FROM AUTHOR]

Underwater benthic microbial fuel cell (BMFC) systems were studied as a long-term sustainable power source for low-energy aquatic instruments (e.g. sensors). Different electrode materials and a power management system (PMS) arrangement were investigated in the lab-scale BMFCs over 12 weeks. An activated carbon (AC) cathode without catalyst layer (CL) was examined as a low-cost cathode material, and the results showed that AC cathode with a diameter of 5 cm and 20% weight polytetrafluoroethylene (PTFE) was the most effective. Granular Activated Carbon (GAC) column was used as a cost-effective anode for biofilm growth. The efficiency and durability of GAC was compared with other anodes with high surface area (e.g. carbon fiber brush (CB) and activated carbon nanofibers (ACNF)). Although, CB and ACNF outperformed GAC, and could be used as the model anodes in underwater BMFCs, high mechanic strength and durability of GAC are advantageous for long-term operations in benthic applications. Evaluation of a caged BMFC system equipped with multiple pairs of AC cathode and GAC anode showed the peak power and current densities of 0.56 W/m 2 and 0.25 A/m 2 respectively. A PMS was developed and coupled with batch mode BMFC system, to boost the output voltage to 3.3 V necessary for the working load. [ABSTRACT FROM AUTHOR]

Cost-effective activated carbon (AC) material was investigated for the development of gas-diffusion cathode employed in membraneless single chamber microbial fuel cells (SCMFCs) treating different feeding solutions. The electrocatalytic activity of AC cathodes was monitored in synthetic wastewater containing phosphate buffer saline solution and sodium acetate (PBS and NaOAc) and compared with several types of wastewaters (e.g. fresh urine (FU), hydrolysed urine (HU), wastewater and sodium acetate (WW + NaOAc) and raw wastewater (WW)). Solution conductivity and pH significantly affected the cathode and the SCMFCs performance. Synthetic wastewater (PBS) outperformed real wastewater in terms of cathode current and SCMFC power output. The results showed that the SCMFCs fed with urine generated 3 times higher power densities than those with raw WW and 25% higher than those with WW + NaOAc, most likely due to the high amount of electrons generated from organic substances. Chemical analysis showed that nutrient concentrations remained the same in the SCMFCs fed with PBS, but decreased 40% in those fed with urine. High power generation associated with phosphorus removal underlines the possibility of using urine as a feedstock for MFCs in real wastewater treatment processes. [ABSTRACT FROM AUTHOR]

Two different anode materials, carbon veil (CV) and carbon cloth (CC), were modified with a micro-porous layer (MPL) in microbial fuel cells (MFCs). When the biofilm on the anodes matured, the maximum power output from the MPL modified carbon veil (CV20-MPL) and carbon cloth (CC-MPL) was 304.3 μW (60.7 mW/m 2 ) and 253.9 μW (50.6 mW/m 2 ), respectively. These were 2.2 and 1.8 times higher than the power output produced from the unmodified CV and CC, respectively. The 7-month operational tests indicated that the long-term stability of the MFCs was enhanced with the modified MPL anodes, which increased the anode surface roughness and provided higher surface area. Higher bacterial population was observed in the MFCs with the MPL anodes, which confirms the power generation results. This is the first time that the MPL has been used as an efficient anode material in MFCs. [ABSTRACT FROM AUTHOR]

Simultaneous sludge fermentation and nitrite removal (SFNR) was investigated as a novel sludge/wastewater treatment process with high nitrogen concentrations. The results showed that introducing nitrite improved the primary sludge (PS) fermentation system by improving the chemical oxygen demand (COD) yields and the volatile suspend solid (VSS) reduction. At a nitrite dosage of 0.2 g g SS −1 , the COD production was 1.02 g g VSS −1 and the VSS reduction was 63.4% within 7-day fermentation, while the COD production was only 0.17 g g VSS −1 and the VSS reduction was only 4.9% in the blank test. Nitrite contained in wastewater was removed through denitrification process in the SFNR system. The solubility of carbohydrate and protein was substantially enhanced, and their contents reached the peak once nitrite was consumed. In addition, the nutrient release and methane generation were inhibited in the SFNR system, which alleviated the environmental pollution. Unlike traditional fermentation systems, neither alkaline condition nor high free nitrite acid (FNA) concentration affected the PS fermentation in the SFNR system. Molecular weight distribution (MWD) and Live/Dead cell analysis indicated that the sludge disruption by nitrite and the consumption of soluble organic substances in sludge might play important roles in SFNR. [ABSTRACT FROM AUTHOR]

Highlights: [•] Carbon cloth was modified electrochemically using three solutions. [•] Surface modification enhanced bacterial adhesion and reduced ohmic resistance. [•] Modification with HNO3/H2SO4 showed the highest current/power generation. [•] PCA analysis showed positive effects of modification on MFC start up. [Copyright &y& Elsevier]

Highlights: [•] Activated carbon (AC) was used as cathode catalyst in membraneless SCMFCs. [•] AC fabrication protocol was improved at various pressure and temperature treatment. [•] Temperature treatment changed the AC surface characteristics. [•] Applied pressure decreased the AC charge transfer resistance. [•] Best performance of AC was achieved at the treatment of 1400psi and 150–200°C. [ABSTRACT FROM AUTHOR]

Abstract: This study focused on the development of novel cathode material based on the pyrolysis of [meso-tetrakis(2-thienyl)porphyrinato]Co(II) (CoTTP) for use in single chamber microbial fuel cells (SCMFCs) to treat wastewater containing methanol. The cathodes produced at two loadings (0.5 and 1.0 mg cm−2) were examined in batch mode SCMFCs treating methanol of different concentrations (ranging from 0.005 to 0.04 M) over a 900 h operational period. Methanol was completely removed in SCMFCs, and the cycle duration was prolonged at high methanol concentrations, indicating methanol was used as fuel in SCMFCs. Methanol had more poisoning effects to the traditional platinum (Pt) cathodes than to the CoTTP cathodes. Specifically, power generations from SCMFCs with Pt cathodes gradually decreased over time, while the ones with CoTTP cathodes remained stable, even at the highest methanol concentration (0.04 M). Cathode linear sweep voltammetry (LSVs) indicated that the electrocatalytic activity of the Pt cathode was suppressed by methanol. Higher CoTTP loadings had similar open circuit potential (OCP) but higher electrocatalytic activity than lower loadings. This study demonstrated that methanol can be co-digested with wastewater and converted to power in MFCs, and a novel cathode CoTTP catalyst exhibits higher tolerance towards methanol compared with traditional Pt catalyst. [Copyright &y& Elsevier]

Highlights: [•] A novel three-stage SBR process was firstly developed to treat landfill leachate. [•] The real landfill leachate without diluted by tap-water was used in this study. [•] The ratio of : in the Anammox influent was not needed to be adjusted. [•] The modified continuous filling mode minimized the nitrite inhibition effects. [•] Quantitative PCR analysis of Anammox showed Anammox gene ratio was less than 5%. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two representative alkali-tolerant bacterial strains were isolated from ES. [•] Acetic and propionic acids were the dominant acid species. [•] The inoculated ES had the most heterogamous bacterial community structure. [•] The inoculated ES produced high VFAs concentration. [•] The inoculated strains survived the competition against indigenous bacteria in ES. [ABSTRACT FROM AUTHOR]

Highlights: [•] The optimal pH for bio-production of VFAs from ES was 10.0. [•] Acetic and propionic acids were the dominant acid species. [•] Bacterial community structure of ES was characterized by PCR-DGGE. [•] Bacterial community structures varied at different pHs of ES. [ABSTRACT FROM AUTHOR]

Abstract: The suitability of carbon nanofibers (CNF) based cathodes as alternative to the platinum (Pt)-based cathode in single chamber microbial fuel cells (SCMFCs) were extensively studied over 3-month operational period. MFCs were fed with two solutions: synthetic wastewater (phosphate buffer (PBS) plus sodium acetate) and real wastewater (mixed liquor suspendedsolid (MLSS) solution). CNFs were chemically activated using HNO3 and then hot pressed on a carbon cloth support to increase surface area. The cathode polarization showed a better behavior of the clean Pt-based cathode in abiotic conditions. The activation of the nanofibers (ACNFs) gave an advantage to the cathode performances compared to the raw CNFs. The SCMFCs fed with PBS showed four times higher power generation compared to MLSS solution. All the cathodes showed a decrease in performances over time, and the advantage of the Pt over CNF/ACNF disappeared. CNF/ACNF cathodes showed more stability in performances in long time operations. Biofilm formation, salt precipitations on the cathode, and the presence of hydrogen sulfide decreased the activity of Pt cathodes. A degradation and Pt detachment were noticed on Pt cathodes over time. In contrast, CNF/ACNF cathodes exhibited less deterioration throughout the operational period, which demonstrated a great potential as cost-effective cathodes for long-term operation. [Copyright &y& Elsevier]

Current membrane deposition approaches (e.g., drop-casting, spin-coating) for solid-state ion selective membrane (S-ISM) sensors suffer from problems including sensor material waste, uncontrollable membrane thickness (100–200 μm), loose contact between sensing membrane and electrode surface, long response time (e.g., >20 s) and poor reading stability (e.g., >3 mV/h). This study addressed these challenges by depositing ISM through electrospray printing technology and enabling accurate and continuous monitoring in water and wastewater. Specifically, the final droplet size and the splash diameter of the electrosprayed droplets deposited a particularly tunable, high resolution and ultra-thin (thickness: ∼1 μm) membrane on the electrode surface, which immensely shortened the sensor response time (9.2 s), strengthened the adhesion between the ISM and the electrode surface, mitigated the formation of water layer in the S-ISM sensor entity, and ultimately enhanced the sensor reading stability (reading drifting <0.66 mV/h). Additionally, the ion diffusion model developed in this study confirmed that fast ion diffusion in the electrosprayed S-ISM polymer matrix effectively shortened the response time of sensors. Electrosprayed S-ISM sensors without anti-fouling protection exhibited high stability and accuracy with an error of less than 2.9 mg/L after continuously monitoring wastewater for 10 days, revealing a great potential for further enhancement. [Display omitted] • Ultra-thin S-ISM sensors were fabricated using electrospray printing technology. • Electrosprayed S-ISM sensors possess high accuracy, sensitivity and stability. • The ion diffusion model confirms the shortened response time of electrosprayed sensors. • Electrosprayed S-ISM mitigates the water layer formation. • Electrosprayed sensors sustained accuracy after 10-day continuously monitoring in wastewater. [ABSTRACT FROM AUTHOR]

A novel and robust distributed benthic microbial fuel cell (DBMFC) was developed to address the energy supply issues for oceanographic sensor network applications, especially under scouring and bioturbation by aquatic life. Multi-anode/cathode configuration was employed in the DBMFC system for enhanced robustness and stability in the harsh ocean environment. The results showed that the DBMFC system achieved peak power and current densities of 190 mW/m 2 and 125 mA/m 2 respectively. Stability characterization tests indicated the DBMFC with multiple anodes achieved higher power generation over the systems with single anode. A computational model that integrated physical, electrochemical and biological factors of MFCs was developed to validate the overall performance of the DBMFC system. The model simulation well corresponded with the experimental results, and confirmed the hypothesis that using a multi anode/cathode MFC configuration results in reliable and robust power generation. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated a novel treatment process for human urine in membraneless single-chamber microbial fuel cells (SCMFCs). The performances of SCMFCs with Pt-based or Pt-free cathode were tested for over 1000 hours of operation. The pH of the anodic solution increased from 5.4–6.4 to 9.0 due to the urea hydrolysis, which consequently decreased the anodic performance even though the cathode was not affected, indicating that the MFCs were anode-limited. The solution conductivity increased up to 3 times the initial value. The initial current generated by the Pt-free cathodes SCMFCs was 0.13–0.15 mA, and stabilized at 0.1 mA. The Pt-based cathode SCMFC decreased from 0.18–0.23 mA to 0.13 mA. This study showed that high pH caused by urea hydrolysis lowered the anodic reactions and the SCMFCs overall performance. The Pt-free cathode performance was comparable to that of Pt-based cathodes, thus offering a cost effective alternative for future developments. [Copyright &y& Elsevier]

Abstract: The conversion of glycerol in biodiesel waste streams to valuable products (e.g. hydrogen and 1,3-propanediol (1,3-PD)) was studied through batch-mode anaerobic fermentation with organic soil as inoculum. The production of hydrogen in headspace and 1,3-PD in liquid phase was examined at different hydrogen retention times (HyRTs), which were controlled by gas-collection intervals (GCIs) and initial gas-collection time points (IGCTs). Two purification stages of biodiesel glycerol (P2 and P3) were tested at three concentrations (3, 5 and 7 g/L). Longer HyRT (longer GCI and longer IGCT) led to lower hydrogen yield but higher 1,3-PD yield. The P3 glycerol at the concentration of 7 g/L had the highest 1,3-PD yield (0.65 mol/mol glycerolconsumed) at the GCI/IGCT of 20 h/65 h and the highest hydrogen yield (0.75 mol/mol glycerolconsumed) at the GCI/IGCT of 2.5 h/20 h), respectively. A mixed-order kinetic model was developed to simulate the effects of GCI/IGCT on the production of hydrogen and 1,3-PD. The results showed that the production of hydrogen and 1,3-PD can be optimized by adjusting HyRT in anaerobic fermentation of glycerol. [Copyright &y& Elsevier]

Abstract: Carbon-based materials are the most commonly used electrode material for anodes in microbial fuel cell (MFC), but are often limited by their surface areas available for biofilm growth and subsequent electron transfer process. This study investigated the use of activated carbon nanofibers (ACNF) as the anode material to enhance bacterial biofilm growth, and improve MFC performance. Qualitative and quantitative biofilm adhesion analysis indicated that ACNF exhibited better performance over the other commonly used carbon anodes (granular activated carbon (GAC), carbon cloth (CC)). Batch-scale MFC tests showed that MFCs with ACNF and GAC as anodes achieved power densities of 3.50 ± 0.46 W/m3 and 3.09 ± 0.33 W/m3 respectively, while MFCs with CC had a lower power density of 1.10 ± 0.21 W/m3 In addition, the MFCs with ACNF achieved higher contaminant removal efficiency (85 ± 4%) than those of GAC (75 ± 5%) and CC (70 ± 2%). This study demonstrated the distinct advantages of ACNF in terms of biofilm growth and electron transport. ACNF has a potential for higher power generation of MFCs to treat wastewaters. [Copyright &y& Elsevier]

Abstract: A novel cost-effective cathode catalyst, manganese dioxide (MnO2) featured with a cryptomelane-type octahedral molecular sieve (OMS-2) structure, was examined in continuous flow microbial fuel cells (MFCs). Power generation and organic substrate removal efficiency of two metal ions doped OMS-2 cathodes (cobalt (Co)-OMS-2 and copper (Cu)-OMS-2) were compared with platinum (Pt) cathodes under different hydraulic retention times (HRTs) and chemical oxygen demands (CODs). The 600-h continuous flow tests showed that Cu-OMS-2 MFCs and Co-OMS-2 MFCs achieved the stable power generation of 200±8mV and 190±5mV, and were 50–60mV higher than that of Pt MFCs. The COD removal efficiencies of Cu-OMS-2 MFCs and Co-OMS-2 MFCs were 83–87%, which were 15–19% higher than that of Pt MFCs. The power generation and COD removal efficiency increased with longer HRTs. The Cu-OMS-2 exhibited the highest power density (201mW/m2) at the COD of 1000mg/L. However, Co-OMS-2 cathodes had the better performance than Cu-OMs-2 at high COD concentrations of 2000–4000mg/L, with the power density of 897mW/m2 and COD removal efficiency of 46%. The continuous flow MFC tests demonstrated that the fast reaction rate of OMS-2 cathodes enhanced power generation and COD removal efficiency, and had a great potential to be applied in real-world wastewater treatment processes. [Copyright &y& Elsevier]

[Display omitted] • Real-time high-resolution sensor data for visualizing transients in water systems. • Non-ideal heterogeneous mixing models are developed for near real-time prediction. • Deterministic global optimization validates non-ideal heterogeneous mixing models. • Non-ideal heterogeneous mixing models predicts system behavior under transient shocks. • Online intermittent calibration enables model-predictive control in water systems. Non-ideal heterogeneous mixing models are developed and incorporated within advanced closed-loop control strategies utilizing high-resolution sensing to maximize the resiliency and minimize the energy consumption of water treatment processes with intelligent model-based decision-making approaches. The proposed non-ideal heterogeneous mixing models capture continuity (heat and mass conservation), yet are extremely simple with few parameters, so they lend themselves to fast online prediction (with extrapolation capabilities) and regular recalibration. Further, they are more accurate than computational fluid dynamics (CFD) (60% less error) and symbolic regression data-driven models (73% less error). Real-time high-resolution sensor data are collected for observing spatiotemporal responses of state variables (conductivity, pH, and temperature) to transient influent shocks. Deterministic global dynamic optimization is used for training and recalibration of the non-ideal heterogeneous mixing models to guarantee the best-possible fits to the sensor data. The models are then deployed within standard model-predictive control and two economic model-predictive control strategies to demonstrate model-based decision-making for disturbance rejection and optimal operation of aeration in a continuous flow nitrification system utilizing high-resolution sensor data from several spatial positions. The new technology platform, consisting of high-resolution sensors, non-ideal heterogeneous mixing modeling, deterministic global dynamic optimization, and model-predictive control, offers superior performance over current approaches in water and wastewater treatment processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Power-sensor entity is capable for in situ energy harvest and supply to power water sensors. • Data transmission of power-sensor entity is uninterrupted under toxic shock. • Novel triggered power management system acts as a switch for power discharge. • Power-Sensor assembly possesses dual-screening capability of capturing shocks. • Power-Sensor assembly can save 42% of energy for wastewater facilities. Uninterrupted energy harvest is critical for self-sustained wastewater monitoring in order to achieve efficient and resilient operation of decentralized onsite wastewater treatment facilities. To address this long-standing challenge, an integrated power entity consisting of a miniature microbial fuel cell (volume: 1.5 mL) and a triggered power management system was developed in this study to power the potentiometric millimeter-sized solid-state water sensors for real-time in situ monitoring and uninterrupted transmission of sensor readings (indicating ammonium concentration) under both ammonium shock and toxic shock in wastewater. Specifically, a data trigger including two capacitors, an operation amplifier and a low-power comparator is equipped in the power management system as a switch for turning on power discharge for data transmission once the ammonium shock is captured by the potentiometric sensors, enabling a sufficient recharge duration to store the power needed for high frequency data transmission (16.23 times/min) required under shocks. Furthermore, this power-sensor entity possesses a unique dual-screening capability of capturing the ammonium and toxic shocks, providing an early warning for swift decision making, reducing ~17% of ammonium discharge and saving ~42% of energy consumption in decentralized onsite wastewater treatment facilities. [ABSTRACT FROM AUTHOR]

A sensitive multiplexed colorimetric analysis platform for the detection of SARS-CoV-2 and human enteric pathogens in wastewater. [Display omitted] • Multiplexed colorimetric detection was developed for detection of SARS-CoV-2 and human enteric pathogens in wastewater. • 3D printed microfluidic chip was designed and fabricated to detect multiple pathogens. • A real-time colorimetric LAMP assay was conducted by smartphone on the microfluidic chip. • Using a portable detection platform, SARS-CoV-2 and human enteric pathogens in wastewater can be monitored in the field. Severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic has become a global public health emergency. The detection of SARS-CoV-2 and human enteric pathogens in wastewater can provide an early warning of disease outbreak. Herein, a sensitive, multiplexed, colorimetric detection (termed "SMCD") method was established for pathogen detection in wastewater samples. The SMCD method integrated on-chip nucleic acid extraction, two-stage isothermal amplification, and colorimetric detection on a 3D printed microfluidic chip. The colorimetric signal during nucleic acid amplification was recorded in real-time and analyzed by a programmed smartphone without the need for complicated equipment. By combining two-stage isothermal amplification assay into the integrated microfluidic platform, we detected SARS-CoV-2 and human enteric pathogens with sensitivities of 100 genome equivalent (GE)/mL and 500 colony-forming units (CFU)/mL, respectively, in wastewater within one hour. Additionally, we realized smart, connected, on-site detection with a reporting framework embedded in a portable detection platform, which exhibited potential for rapid spatiotemporal epidemiologic data collection regarding the environmental dynamics, transmission, and persistence of infectious diseases. [ABSTRACT FROM AUTHOR]

• The possible degradation pathways of SMX by the bio-electro-Fenton process were proposed. • It was worth noting that the absolute abundance of sul 1 was the highest in effluent. • Different SMX concentrations altered the bacterial community composition of anode biofilm. • At the phylum level, Proteobacteria had the highest relative abundance. • When the SMX concentration of 25 mg/L, the power density reached 283.32 ± 16.35 mW/m2. Sulfamethoxazole (SMX) is a general antibiotic that is frequently identified in wastewater and surface water. In this study, the degradation and metabolic pathway of SMX by bio-electro-Fenton systems equipped with a CNT/r-FeOOH cathode were investigated. When initial SMX = 25 mg/L, the removal efficiency of SMX reached 94.66% by the bio-electro-Fenton system. The concentrations of sul 1, sul 2, sul 3, sul A , intI 1 and 16S rRNA genes were examined in effluents. Four out of the six ARGs analysed were detected. Among all quantified sul genes, sul 1 and sul A were the most abundant. High-throughput sequencing revealed that the microbial communities and relative abundance at the phylum and genus levels were affected by different SMX concentrations. In addition, the intermediates were detected and the possible SMX degradation pathway by the bio-electro-Fenton process in the present system was proposed. Furthermore, the highest power density obtained was 283.32 ± 16.35 mW/m2 (SMX = 25 mg/L). This study provides an efficient and cost effective method for degrading antibiotics. [ABSTRACT FROM AUTHOR]

A micro-biosensor based on the screen printed electrode (SPE) modified with carboxylated multi-walled carbon nanotube/rhodamine B/gold nanoparticles (MWCNTs-COOH/RhB/AuNPs) was developed to evaluate the single and combined toxicity of BPA and its analogues on Ctenopharyngodon idella kidney (CIK) cells. • A screen-printed electrode was modified with MWCNTs-COOH/RhB/AuNPs hybrid. • Only 20 μL of sample was required for the electrochemical detection. • The biosensor exhibited excellent electrocatalytic activity and high sensitivity. • BPAF and BPB showed higher toxicity to CIK cells than BPA. • Synergistic and additive effects were observed between BPA and its analogues. Bisphenol analogues have been developed as alternatives to bisphenol A (BPA), a common chemical with potential adverse effects on human health. It is imperative to perform a fast and sensitive evaluation for the toxicity of these bisphenol analogues. This study introduces a label-free electrochemical biosensor based on a screen-printed electrode modified with the carboxylated multi-walled carbon nanotube/rhodamine B/gold nanoparticle. Ctenopharyngodon idella kidney (CIK) cells were used as the biological recognition agent to detect changes in electrochemical signals and indicate the cell viability. Only 20 μL of sample was required for detection, which was much lower than that of other conventional electrochemical methods (≥ 1 mL). This biosensor was examined for the cytotoxicity of BPA, bisphenol AF (BPAF), bisphenol B (BPB), bisphenol F (BPF), and bisphenol S (BPS) to CIK cells. The half inhibition concentration (IC 50) values after 48 h of exposure indicated that the rank order of cytotoxicities was BPAF > BPB > BPA > BPF > BPS. The morphological changes in CIK cells after treatment with various bisphenols were investigated, and the combined toxicities of the binary bisphenol mixtures were determined. Potentially synergistic and additive effects were observed. These findings provide new insights into the cytotoxicity of bisphenol analogues. [ABSTRACT FROM AUTHOR]