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Invasive species can be particularly disruptive when they intersect with organisms of conservation concern. Stabilizing the declining eastern migratory population of monarch butterflies (Danaus plexippus) is projected to require extensive habitat restoration across multiple land use sectors including metropolitan areas. Numerous conservation programs encourage urban citizens to plant gardens with milkweeds, the obligate larval host plants of the monarch. Here, we show that predation by Polistes dominula, an invasive paper wasp that is particularly abundant in urban settings, can turn such sites into ecological traps for monarch larvae. Polistes dominula was the predominant paper wasp seen foraging in central Kentucky pollinator gardens. In 120 observed encounters with monarch larvae on milkweeds in gardens, most second to fourth instars were killed, whereas most fifth instars escaped by thrashing or dropping. The wasps bit and carried off second instars whole, whereas third and fourth instar kills were first gutted, then processed and carried away piecemeal. Predation on sentinel larvae was much higher in urban gardens than in rural settings. The wasps exploited ornamental butterfly “hibernation boxes” in pollinator gardens as nesting habitat. Polistes dominula is an under-recognized predator that may diminish the urban sector’s contributions to monarch habitat restoration.

The gut microbiota is recognized as having major impact in health and disease. Sample storage is an important aspect to obtain reliable results. Mostly recommended is immediate freezing, however, this is not always feasible. Faecal occult blood test (FOBT) papers are an appealing solution in such situations, and most studies find these to be applicable, showing no major changes within 7 days storage at room temperature (RT). As fieldwork often requires RT storage for longer periods, evaluation of this is warranted. We performed 16S rRNA gene sequencing of 19 paired faecal samples immediately frozen or kept five weeks and five months at RT on FOBT papers. Alpha-diversity evaluation revealed no effect of FOBT storage, and evaluation of beta-diversity showed that host explained 65% of community variation, while storage method explained 5%. Evaluation of community dispersion and the Firmicutes/Bacteroidetes ratio revealed a larger effect of storage time for fresh-frozen samples. Single taxa evaluation (order-to-genus level) showed significant alterations of four (of 37) genera after five weeks and five genera after five months. When comparing the two timepoints, alterations were only detectable for fresh-frozen samples. Our findings reveal that long term storage on FOBT papers is an applicable approach for microbiota research.

In this study, polyacrylic acid modified filter paper (FP/PAA) was synthesized by in-situ polymerization of acrylic acid, which was used as a matrix to chelate nano-scale zero valent iron (nZVI). The loading content of nZVI in the filter paper reached 24.8%. The fabricated composite FP/PAA/nZVI was characterized by SEM, FT-IR and TGA respectively. Moreover, it was used for the removal of methyl blue and methylene blue as model anionic and cationic dyes. The effect of initial dye concentration on decolorization efficiency was investigated. The results showed that FP/PAA/nZVI enhanced the removal of dye from the simulated dye wastewater and the decolorization efficiency exceeded 95% for the dye solutions lower than 20 mg/L. More importantly, the filter paper supported nZVI realized the continuous treatment of simulated dye wastewater by a simple filtration process. This study hopes to serve as a basis for the application of nZVI in textile wastewater treatment.

Metal oxides based graphene nanocomposites were used for ammonia vapour sensing. The self-assembly process was adopted to prepare freestanding flexible pure rGO, CeO2-rGO and SnO2-rGO composite papers. The structural studies confirmed the formation of rGO composite papers. The ammonia vapor sensing was demonstrated using an impedance analyzer at different humidity levels as well as concentration. The CeO2-rGO composite paper achieved a sensitivity of 51.70 ± 1.2%, which was higher than that of pure rGO and SnO2-rGO composite paper. Both the surfaces (top and bottom) of the papers are active in efficiently sensing ammonia, which makes the present work unique. The results reveal that metal oxide/rGO papers can be effectively utilized in real time sensor application.

Here, we follow the stable propagation of a roughening crack using simultaneously Digital Image Correlation and Infra-Red imaging. In a quasi-two-dimensional paper sample, the crack tip and ahead of that the fracture process zone follow the slowly, diffusively moving “hot spot” ahead of the tip. This also holds when the crack starts to roughen during propagation. The well-established intermittency of the crack advancement and the roughening of the crack in paper are thus subject to the dissipation and decohesion in the hot spot zone. They are therefore not only a result of the depinning of the crack in a heterogeneous material.

We present a rapid (

Paper degradation on a macroscopic scale is characterised primarily by yellowing, an increase in brittleness, and other destructive changes caused by the hydrolysis of glycoside bonds and oxidation reactions. Until now, lignin has been believed to cause these changes. However, contemporary analysis has not confirmed this assumption and has attributed low paper resistance to ageing with acidification owing to the production in acid environments that involve aluminium sulfate. In view of the common belief this manuscript presents studies on the accelerated ageing of papers with different lignin contents that are produced in neutral environments. To achieve the objective, artificially aged papers under conditions of increased humidity and temperature were investigated using chromatographic (SEC) and spectroscopic (FTIR and UV–Vis spectroscopy) techniques. Mechanical tests were used to determine the decrease in tensile properties of the samples. We observed no effects of the lignin content on the ageing rate of paper produced at neutral pH. This work also reveals the extent to which spectroscopic methods are useful for studying the papers containing lignin.

Microsatellite loci are commonly used markers in population genetic studies. In this study, we present 40 novel and polymorphic microsatellite loci elaborated for the ichneumonid parasitoid Latibulus argiolus (Rossi, 1790). Reaction condition optimisation procedures allowed 14 of these loci to be co-amplified in two PCRs and loaded in two multiplex panels onto a genetic analyser. The assay was tested on 197 individuals of L. argiolus originating from ten natural populations obtained from the host nests of paper wasps. The validated loci were polymorphic with high allele numbers ranging from eight to 27 (average 17.6 alleles per locus). Both observed and expected heterozygosity values were high, ranging between 0.75 and 0.92 for HO (mean 0.83) and from 0.70 to 0.90 for HE (mean 0.85). The optimized assay showed low genotyping error rate and negligible null allele frequency. The designed multiplex panels could be successfully applied in relatedness analyses and genetic variability studies of L. argiolus populations, which would be particularly interesting considering the coevolutionary context of this species with its social host.

Throughout the last decade, the expansion of food testing has been gradually moving towards ordinary high throughput screening methods performed on-site. The demand for point-of-care testing, able to distinguish molecular signatures with high accuracy, sensitivity and specificity has been significantly increasing. This new requirement relies on the on-site detection and monitorization of molecular signatures suitable for the surveillance of food production and processing. The widespread use of antibiotics has contributed to disease control of livestock but has also created problems for the dairy industry and consumers. Its therapeutic and subtherapeutic use has increased the risk of contamination in milk in enough concentrations to cause economic losses to the dairy industry and have a health impact in highly sensitive individuals. This study focuses on the development of a simple Surface-Enhanced Raman Spectroscopy (SERS) method for fast high throughput screening of tetracycline (TET) in milk. For this, we integrate a paper-based low-cost, fully recyclable and highly stable SERS platform, with a minimal sample preparation protocol. A two-microliter sample of milk solutions spiked with TET (from 0.01 to 1000 ppm) is dried on a silver nanoparticle coated cardboard substrate and measured via a Raman spectrophotometer. The SERS substrate showed to be extremely stable with a shelf life of several months. A global spectrum principal component analysis approach was used to test all the detected vibrational modes and their correlation with TET concentration. Peak intensity ratios (455 cm−1/1280 cm−1 and 874 cm−1/1397 cm−1) were found to be correlated with TET concentrations in milk, achieving a sensitivity as low as 0.1 ppm. Results indicate that this SERS method combined with portable Raman spectrometer is a potential tool that can be used on-site for the monitoring of TET residues and other antibiotics.

Paper has been pursued as an interesting substrate material for sensors in applications such as microfluidics, bio-sensing of analytes and printed microelectronics. It offers advantages of being inexpensive, lightweight, environmentally friendly and easy to use. However, currently available paper-based mechanical sensors suffer from inadequate range and accuracy. Here, using the principle of supercapacitive sensing, we fabricate force sensors from paper with ultra-high sensitivity and unprecedented configurability. The high sensitivity comes from the sensitive dependence of a supercapacitor’s response on the contact area between a deformable electrolyte and a pair of electrodes. As a key component, we develop highly deformable electrolytes by coating ionic gel on paper substrates which can be cut and shaped into complex three-dimensional geometries. Paper dissolves in the ionic gel after determining the shape of the electrolytes, leaving behind transparent electrolytes with micro-structured fissures responsible for their high deformability. Exploiting this simple paper-based fabrication process, we construct diverse sensors of different configurations that can measure not just force but also its normal and shear components. The new sensors have range and sensitivity several orders of magnitude higher than traditional MEMS capacitive sensors, in spite of their being easily fabricated from paper with no cleanroom facilities.

We report fabrication of new generation nanoflowers (NFs) using gallic acid (GA) and copper (II) ions (Cu2+) acted as an organic and inorganic component, respectively with effective peroxidase mimic activities in solution and on filter membrane. Unlike the typical protein NFs synthesis mechanism, gallic acid NFs (GA-NFs) was formed via coordination reaction between carboxyl groups of GA and Cu2+. The different morphologies of the GA-NFs were acquired based upon whether the carboxyl groups in gallic acid are active or not. The peroxidase mimic activity of the GA-NFs relied on the Fenton reaction in the presence of hydrogen peroxide (H2O2) was tested towards m-cresol as a function of concentration of the GA-NFs, m-cresol, H2O2 and reaction time. Under the optimized conditions, the oxidative coupling of m-cresol with 4-aminoantipyrine (4-AAP) was catalyzed by the GA-NFs dispersed in solution and adsorbed on filter paper to form an antipyrine dye and it was visually and spectrophotometrically recorded. The m-cresol with range of 0.05–0.5 mM was detected in 10 min and 15 min by using the GA-NFs in solution and on filter paper, respectively. We demonstrated that the NFs can be produced from non-protein molecules and GA-NFs can be used as a promising nanocatalyst for a variety of applications.

The study demonstrates a sustainable process for production of bio-crude oil via hydrothermal liquefaction of microbial biomass generated through co-cultivation of microalgae and bacteria coupled with wastewater remediation. Biomass concentration and wastewater treatment efficiency of a tertiary consortium (two microalgae and two bacteria) was evaluated on four different wastewater samples. Total biomass concentration, total nitrogen and COD removal efficiency was found to be 3.17 g L−1, 99.95% and 95.16% respectively when consortium was grown using paper industry wastewater in a photobioreactor under batch mode. Biomass concentration was enhanced to 4.1 g L−1 through intermittent feeding of nitrogen source and phosphate. GC-MS and FTIR analysis of bio-crude oil indicates abundance of the hydrocarbon fraction and in turn, better oil quality. Maximum distillate fraction of 30.62% lies within the boiling point range of 200–300 °C depicting suitability of the bio-crude oil for conversion into diesel oil, jet fuel and fuel for stoves.

Carbon dots (CDs) have been studied for years as one of the most promising fluorescent nanomaterials. However, CDs with red or solid-state fluorescence are rarely reported. Herein, through a one-pot solvothermal treatment, hydrophobic CDs (H-CDs) with blue dispersed emission and red aggregation-induced emission are obtained. When water is introduced, the hydrophobic interaction leads to aggregation of the H-CDs. The formation of H-CD clusters induces the turning off of the blue emission, as the carbonized cores suffer from π-π stacking interactions, and the turning on of the red fluorescence, due to restriction of the surfaces’ intramolecular rotation around disulfide bonds, which conforms to the aggregation-induced-emission phenomenon. This on-off fluorescence of the H-CDs is reversible when the H-CD powder is completely dissolved. Moreover, the H-CD solution dispersed in filter paper is nearly colorless. Finally, we develop a reversible two switch-mode luminescence ink for advanced anti-counterfeiting and dual-encryption., Carbon dots that display long-wavelength and multicolor emission are desirable for biological and anti-counterfeiting applications. Here, the authors design hydrophobic carbon dots with reversible two-mode fluorescence, which exhibit blue emission when dissolved in solution, and red solid-state fluorescence when aggregated.

The aim of this study was to test the use of IP-10 detection in dried plasma from contact studies individuals (contacts of smear positive patients), by comparing it with IP-10 and IFN-γ detection in direct plasma, to establish IP-10 detection in DPS as a useful assay for LTBI diagnosis. Whole blood samples were collected from 80 subjects: 12 with active tuberculosis (TB), and 68 from contact studies. The amount of IFN-γ produced by sensitized T cells was determined in direct plasma by QuantiFERON Gold In-Tube test. IP-10 levels were determined in direct and dried plasma by an in-house ELISA. For dried plasma IP-10 determination, two 25 µl plasma drops were dried in Whatman903 filter paper and sent by mail to the laboratory. Regarding TB patients, 100.0%, 91.7% and 75.0% were positive for IFN-γ detection and IP-10 detection in direct and dried plasma, respectively. In contacts, 69.1%, 60.3% and 48.5% had positive results after IFN-γ and IP-10 in direct and dried plasma, respectively. The agreement among in vitro tests was substantial and IP-10 levels in direct and dried plasma were strongly correlated (r = 0.897). In conclusion, IP-10 detection in dried plasma is a simple and safe method that would help improve LTBI management.

The present research is focused on the application of glass beads (GBs) in fixed biofilm reactor (FBR) for the treatment of simulated methylene blue (MB) wastewater for 9 weeks under aerobic conditions. The COD of MB wastewater showed a reduction of 86.48% from 2000 to 270.4 mg/L, and BOD was declined up to 97.7% from 1095.5 to 25.03 mg/L. A drastic increase in the pH was observed until the 3rd week (8.5 to 8.28), and later, marginal changes between 8.30 ± 0.02 were noticed. A dramatic fluctuation was observed in ammonia concentration which increased (74.25 mg/L) up till the 2nd week, and from the 3rd week it started declining. In the 9th week, the ammonia concentration dropped to 16.5 mg/L. The color intensity increased significantly up till the 2nd week (259,237.46 Pt/Co) of the experiment and started decreasing slowly thereafter. The SEM–EDX analysis has shown the maximum quantity of carbon content in the GBs without biofilm, and then in the GB samples of 1st, and 9th-week old aerobic biofilms. Furthermore, Raman spectroscopy results revealed that the 9th-week GBs has a fine and strong MB peak and matched with that of the MB stock solution. Overall, the results have shown that the GBs filter media were suitable for the development of active biofilm communities for the treatment of dye wastewater. Thus, GBs-FBR system can be used for wastewater treatment to solve the current problem of industrial pollution in many countries and to protect the aquatic environment from dye pollution caused by the textile industry.

Wastewater treatment coupled with electricity recovery in microbial fuel cell (MFC) prefer mixed anaerobic sludge as inoculum in anodic chamber than pure stain of electroactive bacteria (EAB), due to robustness and syntrophic association. Genetic modification is difficult to adopt for mixed sludge microbes for enhancing power production of MFC. Hence, we demonstrated use of eco-friendly plant secondary metabolites (PSM) with sub-lethal concentrations to enhance the rate of extracellular electron transfer between EAB and anode and validated it in both bench-scale as well as pilot-scale MFCs. The PSMs contain tannin, saponin and essential oils, which are having electron shuttling properties and their addition to microbes can cause alteration in cell morphology, electroactive behaviour and shifting in microbial population dynamics depending upon concentrations and types of PSM used. Improvement of 2.1-times and 3.8-times in power densities was observed in two different MFCs inoculated with Eucalyptus-extract pre-treated mixed anaerobic sludge and pure culture of Pseudomonas aeruginosa, respectively, as compared to respective control MFCs operated without adding Eucalyptus-extract to inoculum. When Eucalyptus-extract-dose was spiked to anodic chamber (125 l) of pilot-scale MFC, treating septage, the current production was dramatically improved. Thus, PSM-dosing to inoculum holds exciting promise for increasing electricity production of field-scale MFCs.

The effects of rice husk flour (RHF), rice husk biochar (RHB), and rice husk-sludge cake biochar (RH-SCB, expresses sludge cake biochar deriving from a sludge that has been previously conditioned with rice husk) used as physical conditioners on sludge dewaterability were compared. The effects of characteristics of physical conditioners on sludge compressibility and zeta potential were analyzed. The optimal rice husk-based powder was RH-SCB, which presented the highest net sludge solid yield (YN, expresses the dry mass flow by filtration) at 20.39 kg/(m2 h) for 70% dry sludge (DS). Characterization analysis indicates that the hardness and surface Fe content of powders which could influence the compressibility coefficient of sludge cake and sludge zeta potential were the major factors influencing sludge dewaterability. The comparison of feasibility and economic analysis showed that adding RH-SCB improves the quality of the sludge filtrate and reduces the pollution potential of conditioned sludge (the ratio of secondary and primary (RSP) of Cu, Zn, Cd reduces from 43.05, 144.00, 7.25 to 7.89, 14.63, 4.27, respectively), and the costs of using RH-SCB were the lowest (at 88.4% lower than that of the raw sludge). Therefore, it is feasible to use RH-SCB to improve sludge dewaterability.

The use pesticide is one of the indispensable means to combat mosquito borne diseases. However, the repeated use of synthetic pesticides has induced resistance in the vector pest along with undesirable impact on the environment. The biodegradability, non-persistent and user’s safety are the root cause to prefer plant-derived pesticides to synthetic ones. The botanical based pesticides tend to degrade rapidly under the influence of several environmental factors. For the feasible application as pesticides, the plant products are formulated either as liquid or as purely solid. Despite well-established formulation technology in pesticide delivery, their handling trouble is being ignored. There is difficulty in liquid formulation of pesticide products, as they are prone to splashing and spillage, resulting in contamination, wastage and direct exposure to skin; whereas a solid formulation tends to produce dust. In the present work, cedarwood (Cedrus deodara) essential oil embedded pectin nanocapsules were produced. The nanocapsules were characterized according to their morphology, size, encapsulation efficiency and thermal stability. Furthermore, the nanocapsules were impregnated onto mini cotton tea bags to be employed as RTU (ready to use) formulation for treating the breeding sites of mosquitoes. The larvicidal activity of the bags treated with pectin-cedar wood nanocapsules was assessed against malaria vector, Anopheles culicifacies and 98% mortality was recorded till 4 weeks, this suggests its potential and hassle free applications in controlling mosquito vector.

The production of electricity and heat in Poland is the reason why the commercial power industry is the largest emitter of CO2. At the same time, significant amounts of solid by-products of combustion, which can be used to bind CO2 by mineral carbonation, are generated during the production processes. The article presents the results of research on mineral sequestration of CO2 (suspension-CO2) using fluidized bed combustion (FBC) fly ashes from hard coal combustion. The analyzed fluidized bed combustion (FBC) fly ashes were characterized by a significant free CaO content (1.7–6.8%) and a high CO2 binding potential ranging from 9.7 to 15.7%. In the case of fluidized bed combustion (FBC) fly ashes suspensions, the basic product of the carbonation process is calcium carbonate, which is clearly indicated by the results of the phase composition determination of solidified suspensions of fluidized bed combustion (FBC) fly ashes. The degree of carbonation, i.e. the degree of CO2 binding, calculated on the basis of the calcium carbonate content, in the analyzed suspensions was up to 1.1%. Mineral carbonation also reduces the leachability of pollutants such as: Zn, Cu, Pb, Ni, As, Hg, Cd, Cr, Cl, and SO42-. The pH is also reduced from about 12 to about 9. Aqueous suspensions of fluidized bed combustion (FBC) fly ashes with introduced CO2 can potentially be used in underground mining. These activities are in line with the concepts of Carbon Capture and Utilization and the idea of circular economy.

The photocatalytic degradation of a local South Africa oil refinery wastewater was conducted under UV radiation using an aqueous catalyst of titanium dioxide (TiO2), Degussa P25 (80% anatase, 20% rutile) in suspension. The experiment was carried out in a batch aerated photocatalytic reactor based on a central composite design (CCD) and analyzed using response surface methodology (RSM). The effects of three operational variables viz. TiO2 dosage (2–8 g/L), runtime (30–90 minutes), and airflow rate (0.768–1.48 L/min) were examined for the removal of phenol and soap oil and grease (SOG). The data derived from the CCD, and the successive analysis of variance (ANOVA) showed the TiO2 dosage to be the most influential factor, while the other factors were also significant (P 2 dosage and runtime as the main interaction factors on the removal efficiency. To maximize the pollutant removal, the optimum conditions were found at runtime of 90 minutes, TiO2 dosage of 8 g/L, and an aeration flow rate of 1.225 L/min. Under the conditions stated, the percentage removal of phenol (300 ± 7) and SOG (4000 ± 23) were 76% and 88% respectively. At 95% confidence level, the predicted models developed results were in reasonable agreement with that of the experimental data, which confirms the adaptability of the models. The first-order kinetic constants were estimated as 0.136 min−1 and 0.083 min−1 for SOG and phenol respectively.

The production cost of controlled-release fertilizers is an important factoring limiting their applications. To reduce the coating cost of diammonium phosphate (DAP) and improve its nutrition release characteristics, the fertilizer cores were modified by water polishing with three dosages at 1, 2, and 3%. The effects of modification were evaluated in terms of particle hardness, size distribution, angle of repose and specific surface area. Castor oil-based polyurethane was used as coating material for fertilizer performance evaluation. A pot experiment was conducted to verify the fertilizer efficiency of coated diammonium phosphate (CDAP) with maize. The results showed that polishing with 2% water reduced the angle of repose by 2.48–10.57% and specific surface area by 5.70–48.76%, making it more suitable for coating. The nutrient release period of CDAP was significantly prolonged by 5.36 times. Soil available phosphorous, enzyme activities, maize grain yield, and phosphorous use efficiency were all improved through the blending application of coated and normal phosphate fertilizer. This study demonstrated that water-based surface modification is a low-cost and effective method for improvement and promotion of controlled release P fertilizers.

The world does not have too much time to ensure that the fast-growing population has enough land, food, water and energy. The rising food demand has brought a positive surge in fertilizers’ demand and agriculture-based economy. The world is using 170 million tons of fertilizer every year for food, fuel, fiber, and feed. The nitrogenous fertilizers are being used to meet 48% of the total food demand of the world. High fertilizer inputs augment the reactive nitrogen levels in soil, air, and water. The unassimilated reactive nitrogen changes into a pollutant and harms the natural resources. The use of controlled-release fertilizers for slowing down the nutrients’ leaching has recently been practiced by farmers. However, to date, monitoring of the complete discharge time and discharge rate of controlled released fertilizers is not completely understood by the researchers. In this work, corn starch was thermally processed into a week gel-like coating material by reacting with urea and borate. The granular urea was coated with native and processed starch in a fluidized bed reactor having bottom-up fluid delivery system. The processed starch exhibited better thermal and mechanical stability as compared to the native starch. Unlike the pure starch, the storage modulus of the processed starch dominated the loss modulus. The release time of urea, coated with processed starch, remained remarkably larger than the uncoated urea.

Spray paint exhaust gas contains recalcitrant volatile organic compounds (VOCs), such as benzene, toluene and xylene (BTX). Treating BTX with a biofilter often achieves unsatisfactory results because the biofilter lacks efficient microbial community. In this work, three strains for BTX degradation were isolated and identified as Pseudomonas putida, Bacillus cereus and Bacillus subtilis by using 16S rRNA sequencing technology. A consortium of highly efficient microbial community was then constructed on a stable biofilm to treat BTX in a biofilter. A relatively suitable ratio of P. putida, B. cereus and B. subtilis was obtained. An efficiency of over 90% was achieved in the biofilter with VOC concentration of 1000 mg/m3 through inoculation with the microbial community after only 10 days of operation. Thus, fast start-up of the biofilter was realised. Analysis of intermediate products by gas chromatography–mass spectrometry indicated that BTX was degraded into short-chain aldehydes or acids via ring opening reactions.

The use of additives in the enzymatic saccharification of lignocellulosic biomass can have positive effects, decreasing the unproductive adsorption of cellulases on lignin and reducing the loss of enzyme activity. Soybean protein stands out as a potential lignin-blocking additive, but the economic impact of its use has not previously been investigated. Here, a systematic evaluation was performed of the process conditions, together with a techno-economic analysis, for the use of soybean protein in the saccharification of hydrothermally pretreated sugarcane bagasse in the context of an integrated 1G-2G ethanol biorefinery. Statistical experimental design methodology was firstly applied as a tool to select the process variable solids loading at 15% (w/w) and soybean protein concentration at 12% (w/w), followed by determination of enzyme dosage at 10 FPU/g and hydrolysis time of 24 h. The saccharification of sugarcane bagasse under these conditions enabled an increase of 26% in the amount of glucose released, compared to the control without additive. The retro-techno-economic analysis (RTEA) technique showed that to make the biorefinery economically feasible, some performance targets should be reached experimentally such as increasing biomass conversion to ideally 80% and reducing enzyme loading to 5.6 FPU/g in the presence of low-cost soybean protein.

Root nodules are agricultural-important symbiotic plant-microbe composites in which microorganisms receive energy from plants and reduce dinitrogen (N2) into fertilizers. Mimicking root nodules using artificial devices can enable renewable energy-driven fertilizer production. This task is challenging due to the necessity of a microscopic dioxygen (O2) concentration gradient, which reconciles anaerobic N2 fixation with O2-rich atmosphere. Here we report our designed electricity-powered biological|inorganic hybrid system that possesses the function of root nodules. We construct silicon-based microwire array electrodes and replicate the O2 gradient of root nodules in the array. The wire array compatibly accommodates N2-fixing symbiotic bacteria, which receive energy and reducing equivalents from inorganic catalysts on microwires, and fix N2 in the air into biomass and free ammonia. A N2 reduction rate up to 6.5 mg N2 per gram dry biomass per hour is observed in the device, about two orders of magnitude higher than the natural counterparts., Root nodules are of key importance in nitrogen fixation. Here, the authors report on an electrically powered artificial root nodule for nitrogen fixation made from silicon-based microwires which can accommodate nitrogen fixing symbiotic bacteria for fixing nitrogen into biomass and free ammonia.

Indigo has been widely used as a dye in the industrial dyeing due to its good color fastness in dyeing cellulose fibers. However, excess reducing agent, “insurance powder (Na2S2O4)”, was always used in the actual production of the factory, sparking serious pollution (water pollution and air pollution). Herein, we developed a practical and environment-friendly indirect electrochemical reduction of indigo, and applied this method for cloth dyeing. The electrochemical device was designed in the combination of source of electro-catalytic reduction and dyeing. The iron-triethanolamine-calcium gluconate (Fe-TEOA-Ca) complex played a role of key intermediate, and ultrasonic wave was found to speed up the indirect electro-catalytic process. The electrochemical performance of intermedia was improved by calcium ion addition. Washed with oxalic acid solution, the dyed fabric could achieve the level of color fastness in industry standard. Generally speaking, our method leads to a green route for indigo reduction using electrochemistry, which may change the crafting process of indigo dyeing in industry.

In this study, actual swage waste activated sludge in batch reactors was employed to assess the synergistic effect of free nitrous acid and Fenton pre-treatments on enhancing methane production in the anaerobic digestion process. In addition to methane enhancement, the mechanisms driving the enhancement were also investigated via measuring enzymes activity and solubilisation of organic matter. This study revealed that the combined pre-treatments solubilised organic matter significantly more than the bioreactors pre-treated with individual FNA and Fenton. For understanding the influence of pre-treatments on solubilisation of organic matter, soluble protein, soluble polysaccharide and soluble chemical oxygen demand (SCOD) were measured before and after the treatments and it was shown that they respectively increased by 973%, 33% and 353% after the treatments. Protease and cellulase activity, as the key constituents of the microbial community in activated sludge, decreased considerably after the combined pre-treatments 42% and 32% respectively, which resulted in considerable methane enhancement. The results corroborate the synergy of the combined FNA and Fenton pre-treatment in degrading the organic and microbial constituents in waste activated sludge, paving the way for the big-scale implementation of these technologies.

The soda ash industry is a part of the chemical industry, which is responsible for the production of sodium carbonate, calcium chloride, absorbent masses, evaporated wet salt, food salt, pickling salt or salt tablets. During manufacturing of those products, strongly alkaline wastewater is generated. It could be characterised by a high electrolytic conductivity and concentration of ions: chlorides, sulfates, phosphates, calcium, sodium, magnesium, potassium and ammonium. The aim of the research was to test the effectiveness of removing sodium, potassium, calcium, magnesium and ammonium from wastewater after production of soda ash by three sorbents: Halosorb, Compakt and Damsorb K. The process was carried out using dynamic method with different flow of wastewater through the column with sorbent. It allowed to reduce concentrations of all cations tested. Moreover, it was found that sorbent type did not significantly affect the removal of any of the ions, but the deposit load had significant impact on the removal of all ions tested.

Microbial biophotovoltaic cells exploit the ability of cyanobacteria and microalgae to convert light energy into electrical current using water as the source of electrons. Such bioelectrochemical systems have a clear advantage over more conventional microbial fuel cells which require the input of organic carbon for microbial growth. However, innovative approaches are needed to address scale-up issues associated with the fabrication of the inorganic (electrodes) and biological (microbe) parts of the biophotovoltaic device. Here we demonstrate the feasibility of using a simple commercial inkjet printer to fabricate a thin-film paper-based biophotovoltaic cell consisting of a layer of cyanobacterial cells on top of a carbon nanotube conducting surface. We show that these printed cyanobacteria are capable of generating a sustained electrical current both in the dark (as a ‘solar bio-battery’) and in response to light (as a ‘bio-solar-panel’) with potential applications in low-power devices., Cyanobacteria can be exploited to convert light energy into electrical current, however utilising them efficiently for power generation is a challenge. Here, the authors use a simple commercial inkjet printer to fabricate a thin-film paper-based biophotovoltaic cell capable of driving low-power devices.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The aim of this work was to enhance the biodiesel quality and hydrocarbon content of green microalga B. braunii strain KMITL 2 cultivated outdoor under several salinity conditions in a batch production. The enhancement would be such that the microalgal biodiesel qualities met or exceeded the current standard so that it would be a good raw material for biodiesel production. The microalga production was in 300 L open oval ponds, among various salinity levels tested (0–20 ppt), 5 ppt was the best for hydrocarbon production, yielding 54.2 ± 0.9% hydrocarbon content and 5.1 ± 0.4 g L−1 biomass. As the microalga production was scaled up by cultivation in 3,675 L open raceway pond under the 5 ppt condition, the microalga yielded a bit higher hydrocarbon content (58.8 ± 2.9%) but much lower biomass (2.5 ± 0.5 g L−1). The production in both oval and raceway ponds yielded a nearly identical biodiesel property (61.06–67.42 cetane number) which exceeded the value specified in international standards. Therefore, it was concluded that B. braunii strain KMITL 2 can be batch cultivated in an open pond at optimum salinity to yield sufficient hydrocarbon and biomass for biodiesel production.

The fluctuation of domestic wastewater characteristic inhibits the current conventional microbial-based treatment. The bioremediation fungi has received attention and reported to be an effective alternative to treat industrial wastewater. Similar efficient performance is envisaged for domestic wastewater whereby assessed performance of fungi for varying carbon-to-nitrogen ratios in domestic wastewater is crucial. Thus, the performance of pre-grown wild-Serbian Ganoderma lucidum mycelial pellets (GLMPs) was evaluated on four different synthetic domestic wastewaters under different conditions of initial pH (pH 4, 5, and 7) and chemical oxygen demand (COD) to nitrogen (COD/N) ratio of 3.6:1, 7.1:1, 14.2:1, and 17.8:1 (C3.6N1, C7.1N1, C14.2N1, and C17.8N1). The COD/N ratios with a constant concentration of ammonia–nitrogen (NH3–N) were chosen on the basis of the urban domestic wastewater characteristics sampled at the inlet basin of a sewage treatment plant (STP). The parameters of pH, COD, and NH3–N were measured periodically during the experiment. The wild-Serbian GLMPs efficiently removed the pollutants from the synthetic sewage. The COD/N ratio of C17.8N1 wastewater had the best COD and NH3–N removal, as compared to the lower COD/N ratio, and the shortest treatment time was obtained in an acidic environment at pH 4. The highest percentage for COD and NH3–N removal achieved was 96.0% and 93.2%, respectively. The results proved that the mycelium of GLMP has high potential in treating domestic wastewater, particularly at high organic content as a naturally sustainable bioremediation system.

High volumes of formation water comprising of complex mixture of hydrocarbons is generated during crude oil exploration. Owing to ecotoxicological concerns, the discharge of the formation water without remediation of hydrocarbonaceous pollutants is not permitted. Keeping this into mind, we carried out phycoremediation of hydrocarbons in formation water so that it can be safely discharged or re-used. For this, a native algal species was isolated from formation water followed by its morphological and 18S ribosomal RNA based identification confirming the algal isolate to be Chlorella vulgaris BS1 (NCBI GenBank Accession No. MH732950). The algal isolate exhibited high biomass productivity of 1.76 gm L−1 d−1 (specific growth rate: 0.21 d−1, initial inoculum: 1500 mg L−1) along with remediation of 98.63% petroleum hydrocarbons present in formation water within 14 days of incubation indicating an efficient hydrocarbon remediation process. Concomitantly, the hydrocarbon remediation process resulted in reduction of 75% Chemical Oxygen Demand (COD) load and complete removal of sulfate from formation water making it suitable for safe disposal or reuse as oil well injection water respectively. The present process overcomes the bottlenecks of external growth nutrient addition or dilution associated with conventional biological treatment resulting in a practically applicable and cost-effective technology for remediation of oil field formation water.

Biomass-based fly ash and wastewater are undesired products of the pulping industry. Recently, the use of biomass-based fly ash as an adsorbent (i.e., a valued material) for constituents of wastewater effluents was reported. In this work, the settling performance and properties of activated sludge were studied in the presence of fly ash. Upon mixing, fly ash increased the zeta potential of the sludge from −31 mV to −28 mV, which was due to the release of cationic ions from fly ash in the sludge suspension. The sludge settling and its flocculation affinity were improved through the complexation of flocs and released cation ions from fly ash. The relationships between the protein/polysaccharide (PN/PS) ratio and the content of extracellular polymeric substances (EPS) as well as the ratio and the properties of the sludge flocs were determined. A correlation between the total loosely bound-EPS (LB-EPS) content and the effluent suspended solids (ESS) (Pearson’s coefficient, rp = 0.83) was observed. The performance of sludge flocculation and settling were much more closely correlated with LB-EPS than with tightly bound EPS (TB-EPS). Scanning electron microscopy (SEM) analysis of sludge flocs before and after EPS extraction showed that the sludge flocs contained a large number of microorganisms, mainly Bacillus and Cocci. The amount of LB-EPS had an adverse influence on bioflocculation, effluent clarification and sludge settling affinity. The sludge properties had a moderate relationship with the PN/PS ratio of LB-EPS. Also, no correlation could be established between the ratio and the TB-EPS content.

Low permeability oil reservoirs are a widespread petroleum reservoir type all over the world. Therefore, methods to recover these reservoirs efficiently are of importance to guarantee energy supply. Here we report our novel stimulation of indigenous microbes by optimizing the water cut in low permeability reservoirs for green and enhanced oil recovery. We aimed to investigate the characteristics of indigenous bacterial communities with changes in water cut in reservoirs by high-throughput sequencing technology, and reveal the mechanism and characteristics of the crude oil biotreatment under different crude oil-water ratio conditions and the optimum activation time of indigenous functional microbial groups in reservoirs. The indigenous microbial metabolism products were characterized by gas chromatography mass spectrometry. Results showed that Acinetobacter (47.1%) and Pseudomones (19.8%) were the main functional genus of crude oil degradation at the optimal activation time, and can reduce the viscosity of crude oil from 8.33 to 5.75 mPa·s. The dominant bacteria genus for oil recovery after activation of the production fluids was similar to those in the reservoirs with water cut of 60–80%. Furthermore seven mechanism pathways of enhancing oil recovery by the synergistic of functional microbial groups and their metabolites under different water cut conditions in low permeability reservoirs have been established.

Industrial scale-up of microalgal cultures is often a protracted step prone to culture collapse and the occurrence of unwanted contaminants. To solve this problem, a two-stage scale-up process was developed – heterotrophically Chlorella vulgaris cells grown in fermenters (1st stage) were used to directly inoculate an outdoor industrial autotrophic microalgal production unit (2nd stage). A preliminary pilot-scale trial revealed that C. vulgaris cells grown heterotrophically adapted readily to outdoor autotrophic growth conditions (1-m3 photobioreactors) without any measurable difference as compared to conventional autotrophic inocula. Biomass concentration of 174.5 g L−1, the highest value ever reported for this microalga, was achieved in a 5-L fermenter during scale-up using the heterotrophic route. Inocula grown in 0.2- and 5-m3 industrial fermenters with mean productivity of 27.54 ± 5.07 and 31.86 ± 2.87 g L−1 d−1, respectively, were later used to seed several outdoor 100-m3 tubular photobioreactors. Overall, all photobioreactor cultures seeded from the heterotrophic route reached standard protein and chlorophyll contents of 52.18 ± 1.30% of DW and 23.98 ± 1.57 mg g−1 DW, respectively. In addition to providing reproducible, high-quality inocula, this two-stage approach led to a 5-fold and 12-fold decrease in scale-up time and occupancy area used for industrial scale-up, respectively.

Sludge bulking is a major problem that restricts the development of the activated sludge process. The microbial community responsible for sludge bulking varies depending on water quality and operational conditions. This study analysed the microbial community of bulking sludge in oxidation ditch with ultra-low sludge loading and long sludge retention time using high-throughput sequencing. The study found that the relative abundance of bacterial genus Saprospiraceae_norank was the highest in bulking sludge, reaching 13.39–28.83%, followed by Comamonadaceae_unclassified, Ardenticatenia_norank and Tetrasphaera, with the relative abundance of 4.59–11.08%, 0.52–16.60% and 0.17–8.92% respectively. In contrast, the relative abundance of bacteria that easily caused sludge bulking including Microthrix (0.54–2.47%), Trichococcus (0.32–1.71%), Gordonia (0.14–1.28%), and Thiothrix (0.01–0.06%) were relatively low. Saprospiraceae_norank was predominant and induced sludge bulking in oxidation ditch. The relative abundance of fungal genus Trichosporon was the highest in bulking sludge, reaching 16.95–24.98%, while other fungal genera were Saccharomycetales_unclassified (5.59–14.55%), Ascomycota_norank (1.45–13.51%), Galactomyces (5.23–11.23%), and Debaryomyces (7.69–9.42%), whereas Trichosporon was the dominant fungal genus in bulking sludge. This study reported that excessive Saprospiraceae_norank can induce sludge bulking for the first time, which provides important knowledge to control sludge bulking.

Whisky, as a high value product, is often adulterated, with adverse economic effects for both producers and consumers as well as potential public health impacts. Here we report the use of DAPCI-MS to analyse and chemically profile both genuine and counterfeit whisky samples employing a novel ‘direct from the bottle’ methodology with zero sample pre-treatment, zero solvent requirement and almost no sample usage. 25 samples have been analysed from a collection of blended Scotch whisky (n = 15) and known counterfeit whisky products (n = 10). Principal component analysis has been applied to dimensionally reduce the data and discriminate between sample groups. Additional chemometric modelling, a partial least squares regression, has correctly classified samples with 92% success rate. DAPCI-MS shows promise for simple, fast and accurate counterfeit detection with potential for generic aroma profiling and process quality monitoring applications.

Cellulose nanofiber (CNF) with high crystallinity has great mechanical stiffness and strength. However, its length is too short to be used for fibers of environmentally friendly structural composites. This paper presents a fabrication process of cellulose long fiber from CNF suspension by spinning, stretching and drying. Isolation of CNF from the hardwood pulp is done by using (2, 2, 6, 6-tetramethylpiperidine-1-yl) oxidanyl (TEMPO) oxidation. The effect of spinning speed and stretching ratio on mechanical properties of the fabricated fibers are investigated. The modulus of the fabricated fibers increases with the spinning speed as well as the stretching ratio because of the orientation of CNFs. The fabricated long fiber exhibits the maximum tensile modulus of 23.9 GPa with the maximum tensile strength of 383.3 MPa. Moreover, the fabricated long fiber exhibits high strain at break, which indicates high toughness. The results indicate that strong and tough cellulose long fiber can be produced by using ionic crosslinking, controlling spinning speed, stretching and drying.

Ag-LaFeO3 molecularly imprinted polymers (ALMIPs) were fabricated, which provided special recognition sites to methanol. Then ALMIPs fiber 1, fiber 2 and fiber 3 were prepared using filter paper, silk and carbon fibers template, respectively. Based on the observation of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Nitrogen adsorption surface area analyzer (BET), the structure, morphology and surface area of the fibers were characterized. The ALMIPs fibers (fiber 1, fiber 2 and fiber 3) show excellent selectivity and good response to methanol. The responses to 5 ppm methanol and the optimal operating temperature of ALMIPs fibers are 23.5 and 175 °C (fiber 1), 19.67 and 125 °C (fiber 2), 17.59 and 125 °C (fiber 3), and a lower response (≤10, 3, 2) to other test gases including formaldehyde, acetone, ethanol, ammonia, gasoline and benzene was measured, respectively.

In this paper, α-Fe2O3 nanoparticles (NPs)-reduced graphene oxide (RGO), α-FeOOH nanorods (NRs)-RGO and porous α-Fe2O3 NRs-RGO could be selectively synthesized by hydrothermal method. The investigations indicated that the obtained α-Fe2O3 NPs, α-FeOOH NRs and porous α-Fe2O3 NRs were either attached on the surface of RGO sheets or coated uniformly by the RGO sheets. And the as-prepared nanohybrids exhibited excellent microwave absorption performance, which was proved to be ascribed to the quarter-wavelength matching model. The optimum reflection loss (RL) values for α-Fe2O3 NPs-RGO, α-FeOOH NRs-RGO and porous α-Fe2O3 NRs-RGO were ca. −32.3, −37.4 and −71.4 dB, respectively. Moreover, compared to the obtained α-Fe2O3 NPs-RGO and α-FeOOH NRs-RGO, the as-prepared porous α-Fe2O3 NRs-RGO nanohybrids exhibited enhanced microwave absorption properties because of their special structure and synergetic effect. The possible enhanced microwave absorption mechanisms were discussed in details. Our results confirmed that the geometrical morphology had a great influence on their microwave absorption properties, which provided a promising approach to exploit high performance microwave absorbing materials.

The objective of this paper is to elucidate the variables that govern coffee extraction from single serve coffee capsules. The study was conducted on 43 Nespresso and Nespresso-compatible capsules of the same geometry, from all of which the coffee was extracted on the same machine. This allowed the link between a range of coffee and capsule (input) parameters with coffee brew (output) variables to be studied. It was demonstrated that the most efficient way to increase total dissolved solids in the brew is to use more coffee for extraction, and/or to grind the coffee more finely. However, grinding too finely can lead to excessive flow restriction. The most significant new insight from this study is the importance of the proportion of fines (particles smaller than 100 µm) regarding the capsule extraction dynamics. Capsules with a higher share of fines, for similar median particle size of the ground coffee, led to longer extraction times. General rules applicable for capsule coffee product development were established, although fine-tuning of parameters for successful capsule coffee extraction remains specific to production line and type of coffee.

To conserve freshwater resources, domestic and industrial wastewater is recycled. Algal systems have emerged as an efficient, low-cost option for treatment (phycoremediation) of nutrient-rich wastewater and environmental protection. However, industrial wastewater may contain growth inhibitory compounds precluding algal use in phycoremediation. Therefore, extremophyte strains, which thrive in hostile environments, are sought-after. Here, we isolated such an alga - a strain of Synechocystis sp. we found to be capable of switching from commensal exploitation of the nitrogen-fixing Trichormus variabilis, for survival in nitrogen-deficient environments, to free-living growth in nitrate abundance. In nitrogen depletion, the cells are tethered to polysaccharide capsules of T. variabilis using nanotubular structures, presumably for nitrate acquisition. The composite culture failed to establish in industrial/domestic waste effluent. However, gradual exposure to increasing wastewater strength over time untethered Synechocystis cells and killed off T. variabilis. This switched the culture to a stress-acclimated monoculture of Synechocystis sp., which rapidly grew and flourished in wastewater, with ammonium and phosphate removal efficiencies of 99.4% and 97.5%, respectively. Therefore, this strain of Synechocystis sp. shows great promise for use in phycoremediation, with potential to rapidly generate biomass that can find use as a green feedstock for valuable bio-products in industrial applications.

This study investigates the influence of inoculated and uninoculated aeration pretreatment on nutrients and phytotoxicity of anaerobic digestion (AD) effluent. Swine manure AD effluent was inoculated with activated and anaerobic sludge, respectively. Our results show that aeration with the addition of activated sludge could reduce the phytotoxicity of AD effluent. Compared to the control treatment without any sludge addition, the addition of activated sludge resulted in a more significant reduction in the AD effluent salinity, NH4+ content, and organic matter (indicated by the chemical oxygen demand) when AD effluent was aerated for less than 8 hours. As a result, a much higher seed germination index (GI) was observed for the treatment with activated sludge addition, particularly when aerated for 4–5 hours, contributing the gas/water ratio of 20:1–30:1. On the other hand, no significant differences in the nutrient contents and GI value were observed for the control treatment and that with the addition of anaerobic sludge. Results from this study shed light on optimizing the management of AD effluent for agricultural application.

Nitrous oxide (N2O) is formed during wastewater nitrogen removal processes. It is a strong greenhouse gas, however, if properly captured it can also be used as a renewable energy source. In this study, a nosZ-deficient strain of Pseudomonas aeruginosa was constructed. During growth under denitrifying conditions, the nosZ-deficient strain was more highly transcribing other genes from the denitrification pathway (narG, nirS, and norB) than the wild-type strain. This strain could also convert 85% of NO2−-N to N2O when it was grown with acetate compared to 2−-N concentrations (700 mg/L) was inoculated with this strain, the N2O conversion efficiencies were >73% and N2O comprised 73~81% of the biogas being generated. The energy yield from wastewater in bioaugmented reactors also reached levels as high as 1260 kJ/m3. These results are significant and show that bioaugmentation of reactors during denitrification treatment processes with nosZ-deficient strains of Pseudomonas or other core denitrifying bacteria might be an effective way to enhance N2O recovery.

To understand the seasonal variation of the activated sludge (AS) bacterial community and identify core microbes in different wastewater processing systems, seasonal AS samples were taken from every biological treatment unit within 4 full-scale wastewater treatment plants. These plants adopted A2/O, A/O and oxidation ditch processes and were active in the treatment of different types and sources of wastewater, some domestic and others industrial. The bacterial community composition was analyzed using high-throughput sequencing technology. The correlations among microbial community structure, dominant microbes and process performance were investigated. Seasonal variation had a stronger impact on the AS bacterial community than any variation within different wastewater treatment system. Facing seasonal variation, the bacterial community within the oxidation ditch process remained more stable those in either the A2/O or A/O processes. The core genera in domestic wastewater treatment systems were Nitrospira, Caldilineaceae, Pseudomonas and Lactococcus. The core genera in the textile dyeing and fine chemical industrial wastewater treatment systems were Nitrospira, Thauera and Thiobacillus.

Freshwater metazoan biodiversity assessment using environmental DNA (eDNA) captured on filters offers new opportunities for water quality management. Filtering of water in the field is a logistical advantage compared to transport of water to the nearest lab, and thus, appropriate filter preservation becomes crucial for maximum DNA recovery. Here, the effect of four different filter preservation strategies, two filter types, and pre-filtration were evaluated by measuring metazoan diversity and community composition, using eDNA collected from a river and a lake ecosystem. The filters were preserved cold on ice, in ethanol, in lysis buffer and dry in silica gel. Our results show that filters preserved either dry or in lysis buffer give the most consistent community composition. In addition, mixed cellulose ester filters yield more consistent community composition than polyethersulfone filters, while the effect of pre-filtration remained ambiguous. Our study facilitates development of guidelines for aquatic community-level eDNA biomonitoring, and we advocate filtering in the field, using mixed cellulose ester filters and preserving the filters either dry or in lysis buffer. © The Author(s) 2018. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

This study developed a high-strength molded fiber material (HMFM) using pulp fibers, which could be a good substitute for plastic and solid wood materials. The surface composition, microstructure and thermal properties of HMFM were investigated by XPS, SEM and DSC, respectively. The SEM observations showed that the obvious adhesive substances and agglomeration appeared among fibers, and the inter-fiber contact area and binding tightness increased after the light-delignification. The XPS examination showed that the oxygen-rich composition on the outer surface of HMFM were reduced, and the outer surface coverage of lignin increased from 70.05% to 90.15% after the light-delignification. The DSC observation showed that the thermal stability of HMFM decreased, the temperature for the maximum rate of mass loss decreased from 370 °C to 345.6 °C, and the enthalpy value required for decomposition was reduced from 110.8 J/g to 68.0 J/g after the light-delignification. The mechanical and hydrophobic properties of HMFM were obviously improved after the light-delignification. When the content of lignin decreased from 24.9% to 11.45%, the density of HMFM increased by 6.0%, the tensile strength increased by 22.0%, the bending strength increased by 23.9%, and the water contact angle increased from 64.3°–72.7° to 80.8°–84.3°.

To better understand the relationship between the environmental variables and microbial communities of activated sludge, we took winter samples from different biological treatment units (anaerobic, oxic, etc) from the WWTP’s of a number of Chinese cities. Differences in influent organic components and activated sludge microbial communities were identified by gas chromatography-mass spectrometry and high-throughput sequencing technology, respectively. Liquid nitrogen grinding pretreatment of samples was found to aid in the obtaining of a more bio-diversified sample. Influent type and dissolved oxygen concentration influenced the activated sludge microbial community structure. Nitrospira, Caldilineaceae and Anaerolineaceae were highly related to domestic wastewater treatment systems, whereas Thauera was the most abundant putative refractory aromatic hydrocarbon decomposer found in industrial wastewater treatment systems. Within the influent composition, we speculate that Thauera, Macellibacteroides and Desulfomicrobium are the key functional genera of the anaerobic environment of the textile dyeing industry wastewater treatment systems, whilst Thauera and Thiobacillus are key functional microbes in fine chemical wastewater treatment systems.

Competition of volatile fatty acids between anoxic denitrification and anaerobic phosphorus release is prominent. Therefore, low concentration wastewater has restricted effects on nitrogen and phosphorus removal. The purpose of this study is to treat dormitory sewage with a biochemical oxygen demand (BOD) ranging from 50 to 150 mg/L using dewatered alum sludge-based sequencing batch constructed wetland system. Vegetation in the wetland system was chosen to be Phragmites australis. Three parallel cases were carried out to assess impacts due to different hydraulic retention time (HRT) and artificial aeration. The results showed that this system is effective in removing total nitrogen (TN), ammonia nitrogen (NH3-N) and total phosphorus (TP) under different HRT. However, nitrous oxide (N2O) emission poses to be the greatest challenge in the high HRT cases. Artificial aeration could reduce N2O emission but is associated with high operational cost. Results indicate that dewatered alum sludge-based sequencing batch constructed wetland system is a promising bio-measure in the treatment of low concentration wastewater.