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The effect of particle morphology on denitrification performance in element sulfur-based denitrification (ESDeN) packed-bed process is a gap. In this study, three different types of commercial sulfur particles were selected to build the ESDeN reactors. The results showed the reactors filled with rougher sulfur particles took shorter time to reach stable denitrification performance in the start-up stage. The reactors filled with cap-shape sulfur particles received the maximum nitrate removal rate of 849.49 ± 79.29 g N m

Constructed wetlands (CWs) integrated with sulfur autotrophic denitrification to stimulate high-rate nitrogen removal from carbon-limited wastewater holds particular application prospect due to no excessive carbon source addition, high efficiency, and good stability. In this study, we conducted elemental sulfur-based constructed wetland (SCW) and traditional constructed wetland (CW) under different C/N (2, 1, and 0.5) to explore the feasibility and mechanisms for nitrogen removal from low C/N wastewater. Compared with CW, SCW was demonstrated more robust in nitrogen removal in the case of low C/N influent. When the influent C/N control was at 0.5, SCW observed total nitrogen (TN) and nitrate removal efficiency of 69.36 ± 3.96% and 81.71 ± 3.96%, with the corresponding removal rate of 1.18 ± 0.66 and 1.70 ± 0.92 g-N·m

Electrostimulated hydrolysis acidification (eHA) has been used as an efficient biological pre-treatment of refractory industrial wastewater. However, the effects of electrostimulation on the function and assembly of planktonic anaerobic sludge microbial communities are poorly understood. Using 16S rRNA gene and metagenomic sequencing, we investigated planktonic sludge microbial community structure, composition, function, assembly, and microbial interactions in response to electrostimulation. Compared with a conventional hydrolysis acidification (HA) reactor, the planktonic sludge microbial communities selected by electrostimulation promoted biotransformation of the azo dye Alizarin Yellow R. The taxonomic and functional structure and composition were significantly shifted upon electrostimulation with azo dyes degraders (e.g. Acinetobacter and Dechloromonas) and electroactive bacteria (e.g. Pseudomonas) being enriched. More microbial interactions between fermenters and decolorizing and electroactive bacteria, as well as fewer interactions between different fermenters evolved in the eHA microbial communities. Moreover, the decolorizing bacteria were linked to the higher abundance of genes encoding for azo- and nitro-reductases and redox mediator (e.g. ubiquinone) biosynthesis involved in the transformation of azo dye. Microbial community assembly was more driven by deterministic processes upon electrostimulation. This study offers new insights into the effects of electrostimulation on planktonic sludge microbial community function and assembly, and provides a promising strategy for the manipulation of anaerobic sludge microbiomes in HA engineering systems.

Constructed wetlands (CWs) integrated with the bioelectrochemical system (BES-CW) to stimulate bio-refractory compounds removal holds particular promise, owing to its inherent greater scale and well-recognized environmentally benign wastewater advanced purification technology. However, the knowledge regarding the feasibility and removal mechanisms, particularly the potential negative effects of biorefractory compounds on nitrogen removal performance for the CWs is far insufficient. This study performed a critical assessment by using BES-CW (ECW) and conventional CW (CW) to investigate the effects of p-Chloronitrobenzene (pCNB) on nitrogen transformations in CWs. The results showed that low concentration (1 mg·L

Pyridine contamination poses a significant threat to human and environmental health. Due to the presence of nitrogen atom in the pyridine ring, the pi bond electrons are attracted toward it and make difficult for pyridine treatment with biological and chemical methods. In this study, coupling Fenton treatment with different biological process was designed to enhance pyridine biotransformation and further mineralization. After Fenton oxidation process optimized, pretreated pyridine was evaluated under three biological (anaerobic, aerobic and microaerobic) operating conditions. Under optimum Fenton oxidation, pyridine (30–75%) and TOC (5–25%) removal efficiencies were poor. Biological process alone also showed insignificant removal efficiency, particularly anaerobic (pyridine = 8.2%; TOC = 5.3%) culturing condition. However, combining Fenton pretreatment with biological process increased pyridine (93–99%) and TOC (87–93%) removals, suggesting that hydroxyl radical generated during Fenton oxidation enhanced pyridine hydroxylation and further mineralization in the biological (aerobic > microaerobic > anaerobic) process. Intermediates were analyzed with UPLC-MS and showed presence of maleic acid, pyruvic acid, glutaric dialdehyde, succinic semialdehyde and 4-formylamino-butyric acid. High-throughput sequencing analysis also indicated that Proteobacteria (35–43%) followed by Chloroflexi (10.6–24.3%) and Acidobacteria (8.0–29%) were the dominant phyla detected in the three biological treatment conditions. Co-existence of dominant genera under aerobic/microaerobic (Nitrospira > Dokdonella > Caldilinea) and anaerobic (Nitrospira > Caldilinea > Longilinea) systems most probably play significant role in biotransformation of pyridine and its intermediate products. Overall, integrating Fenton pretreatment with different biological process is a promising technology for pyridine treatment, especially the combined system enhanced anaerobic (>10 times) microbial pyridine biotransformation activity.

Bioelectrochemical systems (BESs) have been known as a promising technology for accelerating aromatic contaminants degradation and energy recovery. However, most existing studies concentrate on aromatics metabolized through a benzoyl-CoA pathway while those metabolized through other pathways are limited. In this work, resorcinol, a typical aromatic contaminant as well as a key central intermediate (other than benzoyl-CoA) involved in aromatics anaerobic biodegradation, was studied in BESs. Unlike the general impression of the relatively poor organic-to-current performance in the aromatics driven BESs, high efficiencies for resorcinol-fed BESs were observed with a current density and coulombic efficiency of up to 0.26 ± 0.05 mA cm−2 and 74.3 ± 10.7%, respectively. The higher performance likely correlates to the readily fermentable property of resorcinol. Analysis of microbial communities in the biofilm suggests a syntrophic interaction between resorcinol-degrading bacteria (RDB) and anode-respiring bacteria (ARB) was involved in current generation. Additional tests involving the removal of accumulated acetate through fast resorcinol feeding indicates that a mechanism based on direct utilization of resorcinol for current generation may also exist. This study extends the knowledge for the fate of aromatics in BESs and indicates that aromatics entering into the resorcinol metabolic pathway can be treated efficiently with good energy recovery efficiency in BESs.

Wastewater treatment plants (WWTPs) are designed to eliminate pollutants and alleviate environmental pollution resulting from human activities. However, the construction and operation of WWTPs consume resources, emit greenhouse gases (GHGs) and produce residual sludge, thus require further optimization. WWTPs are complex to control and optimize because of high non-linearity and variation. This study used a novel technique, multi-agent deep reinforcement learning (MADRL), to simultaneously optimize dissolved oxygen (DO) and chemical dosage in a WWTP. The reward function was specially designed from life cycle perspective to achieve sustainable optimization. Five scenarios were considered: baseline, three different effluent quality and cost-oriented scenarios. The result shows that optimization based on LCA has lower environmental impacts compared to baseline scenario, as cost, energy consumption and greenhouse gas emissions reduce to 0.890 CNY/m3-ww, 0.530 kWh/m3-ww, 2.491 kg CO2-eq/m3-ww respectively. The cost-oriented control strategy exhibits comparable overall performance to the LCA-driven strategy since it sacrifices environmental benefits but has lower cost as 0.873 CNY/m3-ww. It is worth mentioning that the retrofitting of WWTPs based on resources should be implemented with the consideration of impact transfer. Specifically, LCA-SW scenario decreases 10 kg PO4-eq in eutrophication potential compared to the baseline within 10 days, while significantly increases other indicators. The major contributors of each indicator are identified for future study and improvement. Last, the authors discussed that novel dynamic control strategies required advanced sensors or a large amount of data, so the selection of control strategies should also consider economic and ecological conditions. In a nutshell, there are still limitations of this work and future studies are required.

Pyridine and its derivatives are widely consumed and detected in the environment persistently, which can cause potential adverse impacts on environment and human health. Considering the fact that pyridine could absorb UV light at 254 nm to generate excited one, which could react with reductive radicals, promoting its structural changes, we proposed that one typical efficient advanced reduction process (ARP) which combines UV irradiation with sulfite could be used to eliminate pyridine quickly. Sulfite/UV process showed a higher pyridine removal rate with a pseudo-first-order reaction rate constant of 0.1439 min−1, which was 3 times of that in UV irradiation and 1.3 times in UV/H2O2 process. This was primarily due to reductive radicals (eaq–, H• and SO3•–) produced by UV irradiation. The removal rate of pyridine was highest in slightly alkaline environment. And the presence of oxygen, as well as certain concentration of humid acid just showed slight inhibition, indicating the possibility of application in practical environment. A positive impact was observed with increasing sulfite dosage, but it was gradually inhabited when the dosage was over 5 mM. The present study may provide an alternative efficient technology for the degradation of pyridine ring-containing substances.

This paper focused on the feasibility and performance of an up-flow anaerobic bio-electrochemical system (UBES) for treating sulfamethoxazole (SMX) antibiotic wastewater at different COD loading rates (LRs) from 2.02 ± 0.13 to 6.09 ± 0.14 kgCOD/(m3·d). Open-circuit UBES had a lower average COD removal rate of 62.4 ± 4.7% in Run2, and the accumulation of volatile fatty acid (VFA) was occurred. However, closed-circuit UBES can alleviate the accumulation of VFA (which was decreased from 720.4 to 102.4 mg/L), the highest average COD, SMX removal rates were 85.7 ± 3.2% and 73.7 ± 2.0%, respectively. The closed-circuit UBES can withstand more than 3 times LR than open-circuit UBES, which proved that the ability of microorganisms to resist toxic substance stress was strengthened. And the mathematical models for pollutants removal rate were established and well interpreted the results, which also can guide the operation of UBES.

Some refractory organic matters or soluble microbial products remained in the effluents of refractory organic wastewater after biological secondary treatment and need an advanced treatment before final disposal. Graphene oxide (GO) was known to have potential to be the next generation membrane material. The functional organics/inorganic salts separation GO membrane preparation and application in wastewater advanced treatment could reduce energy or chemicals consumption and avoid organics/inorganic salts mixed concentrate waste problems after nanofiltration or reverse osmosis. In this study, we developed a novelty GO membrane aiming at advanced purification of organic matters in the secondary effluents of refractory organic wastewater and avoiding the organics/inorganic salts mixed concentrate waste problem. The influence of preparation conditions including pore size of support membrane, the number of GO layers and the applied pressure was investigated. It was found that for organics/inorganic salts mixture separation membrane preparation, the rejection and flux would achieve balance for the support membrane at a pore size of ~0.1μm and the number of GO layers of has an optimization value (~10 layers). A higher assemble pressure (~10bar) contributed to the acquisition of a higher rejection efficiency and lower roughness membrane. This as prepared GO membrane was applied to practical secondary effluent of a chemical synthesis pharmaceuticals wastewater. A good organic matter rejection efficiency (76%) and limited salt separation (

In this study, the removal efficiency of nitrogen, specific nitrification rate (SNR), specific denitrification rate (SDNR) and compliance rate of the novel tapered variable diameter biological fluidized bed (TVDBFB) and anoxic/oxic (AO) process were compared at different temperatures. The results showed that the optimal TN, NH4+-N, and TKN removal efficiencies of the TVDBFB were 76%, 89% and 88%, respectively, and those of AO were 65%, 67% and 69%, respectively. The SNR and SDNR of the TVDBFB were significantly higher than those of AO. The TVDBFB had a smaller footprint than AO. The alkalinity/NH4+-N, BOD5/TN and temperature play important roles in the compliance rate. Increasing the carrier packing rate has emerged as a new strategy for enhancing the compliance rate. Mathematical models were developed and determined to be well-fitted with the experimental values, which can be employed to predict the SNR and SDNR of the TVDBFB.

The biological treatment of antibiotic-containing wastewater is a mainstream process, but the antibacterial activity from the persistence of antibiotics would inhibit the biological activity and function of wastewater treatment plants and lead to the risk of transmission of antibiotic resistant bacteria and genes. In this study, UV photolysis was selected as an appropriate pretreatment technology for antibiotic-containing wastewater. It could decompose many kinds of antibiotics and was not inhibited by the coexisting organics in wastewater. The antibacterial activities of five kinds of antibiotics, which were eliminated with UV irradiation, exhibited a significantly positive correlation with their parent compound concentrations. The photodecomposition of the main functional groups in antibiotics contributed to the elimination of antibacterial activity. Defluorination was the main pathway to eliminate the antibacterial activity of antibiotics containing a fluorine substituent (e.g., florfenicol and ofloxacin), while the photoinduced opening of the β-lactam ring was the most efficient route to eliminate the antibacterial activity of β-lactam antibiotics (e.g. cefalexin, amoxicillin and ampicillin). These results demonstrated that UV photolysis could be adopted as an efficient and promising pretreatment strategy for the source control of antibiotic antibacterial activity by the decomposition of antibiotic functional groups before the biological treatment unit.

Biochar was utilized to intensify constructed wetland (CW) for further organic and nitrogen removal from secondary wastewater. Four sets of non-aerated biochar amended vertical flow CW (VFCW) were developed to investigate the synergistic effects of biochar and microbes on pollutant removal. Results showed that the average COD and nitrogen removal efficiencies of VFCW1 (with 1% w/w biochar with microbe and plants) achieved 89.1 ± 5.6% and 90.2 ± 3.1% respectively, and their corresponding removal rates of 10.2 ± 0.8 mg-COD/(m3.d) and 3.57 ± 0.3 mg-TN/(m3.d) which were 35 and 52.3% higher than control. The biochar’s dissolved organic carbon release in VFCWs indicated that water and acidic media portray the optimum conditions for nitrogen removal. The 16S RNA gene sequencing analysis indicated that in the biochar-amended VFCWs, bacterial phylum Proteobacteria (24.13–51.95%) followed by Chloroflexi (5.64–25.01%), Planctomycetes (8.48–14.43%), Acidobacteria (2.29–11.65%) were abundantly enhanced. Conclusively, incorporating biochar in non-aerated VFCWs is an efficient technique for enhancing nitrogen removal from secondary effluent.

Bioelectrochemical systems (BESs) have been studied extensively during the past decades owing primarily to their versatility and potential in addressing the water-energy-resource nexus. In stark contrast to the significant advancements that have been made in developing innovative processes for pollution control and bioresource/bioenergy recovery, minimal progress has been achieved in demonstrating the feasibility of BESs in scaled-up applications. This lack of scaled-up demonstration could be ascribed to the absence of suitable electrode modules (EMs) engineered for large-scale application. In this study, we report a scalable composite-engineered EM (total volume of 1 m3), fabricated using graphite-coated stainless steel and carbon felt, that allows integrating BESs into mainstream wastewater treatment technologies. The cost-effectiveness and easy scalability of this EM provides a viable and clear path to facilitate the transition between the success of the lab studies and applications of BESs to solve multiple pressing environmental issues at full-scale.

In this study, a lab-scale multiple draft tubes airlift loop membrane bioreactor (Mt-ALMBR) was used for treating acidic 7-amino cephalosporanic acid (7-ACA) wastewater under different pHs (3.54–6.20) and hydraulic retention time (HRT) (48 h, 36 h, 24 h and 16 h). During about 200 days operation, under HRT of 48 h and pH condition about 6.0, the optimum average COD and BOD5 removal rates were reach to 84.4 ± 2.1% and 94.9 ± 0.8%, and the highest 7-ACA removal rate also observed as 77.6%. Biodegradation, membrane rejection, hydrolysis and sludge adsorption were the four main pathways of 7-ACA removal. With the increase of pH, biodegradation, membrane rejection and hydrolysis had significant positive impacts on 7-ACA removal, while adsorption had a negative impact. Moreover, mathematical models for 7-ACA removal rate and pH were calculated to guide the operation of Mt-ALMBR. Biodegradation was the main pathway to remove 7-ACA when pH was >4.17.

Unconventional water reclamation, recycling, and reuse have been identified as the major approaches for addressing water scarcity in China. The aim of this study was to evaluate the technical and economic feasibility of water reclamation plants (WRP) based on an anaerobic-anoxic-oxic membrane bioreactor (A2O-MBR) system for unconventional water resource (domestic wastewater and rainwater) treatment and reuse in green building residential community. During a year operation and evaluation process, average chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total nitrogen (TN) and total phosphorus (TP) removal efficiencies averaged 83.7 ± 3.2%, 91.6 ± 2.6%, 69.0 ± 6.5% and 74.5 ± 5.5%, respectively. The effluent quality of wastewater treated by the A2O-MBR system complied with the water quality standards for reuse for green building residential community or for direct discharge. Typical seasonal fluctuations of temperature, COD loading rate, BOD5/COD and COD/TN were the key factors affecting pollutants removal efficiencies, and the membrane fouling rate was accelerated at low temperatures. The total cost of capital and operation was 0.406 $/m3, a cost-benefit analysis incorporating both capital and operating expenditures showed that more than 60% of the reclaimed water is reused in the green building, and the full-scale WRP exhibits a positive net present value. These results demonstrated that A2O-MBR is an efficient and profitable technology for nontraditional water resource recycling in green building residential communities in terms of technical and economic feasibility.

It is controversial to introduce oxygen into anode chamber as oxygen would decrease the CE (Coulombic efficiency) while it could also enhance the degradation of aromatics in microbial fuel cell (MFCs). Therefore, it is important to balance the pros and cons of oxygen in aromatics driven MFCs. A RMO (micro-oxygen bioanode MFC) was designed to determine the effect of oxygen on electricity output and phenol degradation. The RMO showed 6-fold higher phenol removal efficiency, 4-fold higher current generation than the RAN (anaerobic bioanode MFC) at a cost of 26.9% decline in CE. The Zoogloea and Geobacter, which account for phenol degradation and current generation, respectively, were dominated in the RMO bioanode biofilm. The biomass also showed great difference between RMO and RAN (114.3 ± 14.1 vs. 2.2 ± 0.5 nmol/g). Therefore, different microbial community, higher biomass as well as the different degradation pathway were suggested as reasons for the better performance in RMO.

The electrodes spacing would exert a pronounced effect on bio-electrochemical systems (BESs) performance, especially for the scaling-up of reactors and practical applications. In this study, we traced the effect of electrode spacing on wastewater treatment performances from the aspects of hydrodynamics and electrochemical characteristics. Three series of folded stainless steel mesh (f-SSM) electrodes with electrode spacing of 2, 4 and 8mm were designed for azo dye (acid orange 7 (AO7)) wastewater treatment. Results showed that BES with electrode spacing of 2mm (RS2) obtained the highest efficiencies of AO7 decolorization (90.9±0.4%) and COD removal (36.8±3.8%) at HRT of 8h, which was 30.7% and 15.2% higher than that in BES with electrode spacing of 8mm (RS8), respectively. Moreover, the relationship between pollutants removal, internal resistance and hydrodynamics of BESs with different electrode spacing supported the hydrodynamics was significantly influence the pollutants removal performance.

The application of bio-electrochemical system (BESs) is strongly depended on the development of the engineering applicable electrode. Here we described an economical and readily processable electrode module with three-dimensional structure, the corrugated stainless-steel mesh electrode module (c-SMEM). This novel developed electrode module was demonstrated to provide a good hydrodynamic characteristic and significantly enhanced the decolorization performance of the BES when serving for treating azo dye (acid orange 7, AO7) containing wastewater. Compared to the conventional planar electrodes module (p-SMEM), c-SMEM was found to prolong the mean residence time (MRTθ) of AO7 and change the flow pattern closer to the plug flow. As a result, the maximum enhancement of the volumetric decolorization rate (vDR) can reach to 255%, even when the c-SMEM and p-SMEM have the same electrode surface area. In addition, a techno-economic analysis model was established to elucidated the effects of the decolorization performance and the material cost on the initial capital cost, which revealed the BES with c-SMEM could be economically comparable to or even better than the traditional bio-decolorization technologies. These results suggest c-SMEM holds great potential for engineering application, which may help paving the way of applying BES at large-scale.

Mathematical statistical method (MSM) is a very important wastewater treatment plant data processing analysis tool. In this study, MSM had been used to evaluate the efficiency, stability and reliability of the low-strengthen complex wastewater treatment system. Results showed that while LSCWWTs upgrading in the future, each influent parameter could be set as the follows: COD = 738 mg/L, BOD = 300 mg/L, SS = 454 mg/L, TN = 64.3 mg/L, NH3-N = 65.2 mg/L and TP = 7.65 mg/L. For effluent of LSCWWTs, the stabilities of COD, BOD, SS and TN were all A, TP was B, and NH3-N was D. For effluent COD, TN and NH3-N reached the first class discharge standard of A, the reliability probabilities were 83.89%, 80.23% and 99.43%, respectively. And the reliability probabilities of effluent WQPs reached the first class discharge standard of B were all more than 98%.

There is a certain amount of intermediate and other ingredient in pharmaceutical wastewater .These pharmaceutical will have a big effect on microorganism in sewage treatment plant. So this article discussed the study one impact of microbial community structure by the different intermediate concentration of Pharmaceutical waste water .The study shows that Microbial community structure are diversity in the pharmaceutical wastewater treatment plant.With the change of the environment some microbes are reduced or even disappear and some microbes are gradually produce. The microbes which have a big effect by different environment have adapt to 7-ACA, won the resistance and become a part of microbial community in stationary phase.

A MLMBR and a conventional IMBR with DO control system were investigated for simultaneously removing organic carbon and nitrogen in the low-strengthen complex wastewater. Four stages of the laboratory scale system with SRT of 30 day and HRTs of 20, 16, 12, and 8 h, respectively, were conducted. During the 4 months experimental period, COD removal efficiencies averaged at 92.2% and 85.3%, SS removal efficiencies averaged at 93.8% and 85.2%, and NH 4 + –N removal efficiencies averaged at 84.1% and 65.3%, respectively, for MLMBR and IMBR. What’s more, the sludge characteristics were explored explicitly, results demonstrate that MLMBR not only perform better in substrates removal, also can alleviate the membrane fouling due to better sludge characteristics. In addition, mathematical statistical models, built on the linear regression techniques were developed for explore the inner relationship between HRTs and the performance of the MLMBR.

In order to investigate the influence of mixed liquor inorganic suspended solids (MLISS) on membrane flux at different ratio of sludge retention time (SRT) to hydraulic retention time (HRT) in a submerged membrane bioreactor (SMBR), a pilot scale test was conducted for 452 days using traditional Chinese medicine (TCM) wastewater as influent. SRT/HRT was controlled at 150, 480 and 750, respectively. The experimental results showed that the average values of MLISS were 1271.9, 1664.5 and 6898.8 mg/L at different SRT/HRT, respectively; MLISS were accumulated from 265.5 g/h to 4912.93 g/h, which indicated that SMBR could not steadily operate for a long period without sludge withdrawal. Sludge oxygen utilized rate (SOUR) decreased from 5.115 to 1.292 mgO 2 /(gVSS h) and volume oxygen utilized rate (VOUR) increased from 10.84 to 18.13 mgO 2 /(L h). Model of membrane flux and MLISS were developed under different temperature and operational pressure by regressions, which were then satisfactorily employed to predict the trend of membrane flux during the experiment.

A full-scale novel combined anaerobic/micro-aerobic and two-stage aerobic biological process is used for the treatment of an actual chemical synthesis-based pharmaceutical wastewater containing amoxicillin. The anaerobic system is an up-flow anaerobic sludge blanket (UASB), the micro-aerobic system is a novel micro-aerobic hydrolysis acidification reactor (NHAR) and the two-stage aerobic process comprised cyclic activated sludge system (CASS) and biological contact oxidation tank (BCOT). The influent wastewater was high in COD, NH 3 -N varying daily 4016–13,093 mg-COD L −1 and 156.4–650.2 mg-NH 3 -N L −1 , amoxicillin varying weekly between 69.1 and 105.4 mg-amoxicillin L −1 , respectively; Almost all the COD, NH 3 -N, amoxicillin were removed by the biological combined system, with removal percentages 97%, 93.4% and 97.2%, respectively, leaving around 104 mg-COD L −1 , 9.4 mg-NH 3 -N L −1 and 2.6 ± 0.8 mg-amoxicillin L −1 in the final clarifier effluent. The performance evaluation of the wastewater treatment plant (WWTP) by mathematical statistic methods shown that at most of time effluent can meet the higher treatment discharge standard. In addition, the fate of amoxicillin in the full-scale WWTP and the amoxicillin removal rate of each different removal routes in UASB, NHAR, CASS, BCOT and final clarifier processes are investigated in this paper. The results show that biodegradation, adsorption and hydrolysis are the major mechanisms for amoxicillin removal.

The results of the use of an expert system (ES) to control a novel multi-stage loop membrane bioreactor (MLMBR) for the simultaneous removal of organic substances and nutrients are reported. The study was conducted at a bench-scale plant for the purpose of meeting new discharge standards (GB21904-2008) for the treatment of chemical synthesis-based pharmaceutical wastewater (1200-9600 mg/L COD, 500-2500 mg/L BOD5, 50-200 mg/L NH4+-N and 105-400 mg/L TN in the influent water) by developing a distributed control system. The system allows various expert operational approaches to be deployed with the goal of minimizing organic substances and nitrogen levels in the outlet while using the minimum amount of energy. The proposed distributed control system, which is supervised by a Knowledge-Based Expert System (KBES) constructed with G2 (a tool for expert system development) and a back propagation BP artificial neural network, permits the on-line implementation of every operating strategy of the experimental system. A support vector machine (SVM) is applied to achieve pattern recognition. A set of experiments involving variable sludge retention time (SRT), hydraulic retention time (HRT) and dissolved oxygen (DO) was carried out. Using the proposed system, the amounts of COD, TN and NH4+-N in the effluent decreased by 55%, 62% and 38%, respectively, compared to the usual operating conditions. These improvements were achieved with little energy cost because the performance of the treatment plant was optimized using operating rules implemented in real time.

In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3%±2.5%, 86.2%±3.8% and 93.5%±1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1%±4.7%, 75.4%±5.0% and 82.1%±2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2%±3.7% and 28.30±1.48 mA, respectively. They were significantly increased to 62.1%±2.0% and 34.55±0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.

The general objective for this paper is to reveal the dynamic relationships between the rapid economic development, water pollution and the subsequent waste-load allocation in different economic sectors through a case-study in Shenzhen City, South China. Two-objective analysis model was employed based on the input-output table for Shenzhen with the full consideration of various constraints in local area. The improved Tchebycheff procedure was used for obtaining the solutions. The predictions were made on economic development and pollutants from wastewater in different sectors and different planning years. The present study allows for the consideration of the economic structural adjustment. It is found that the current situation of economic structure is generally good and is subject to further adjustment in Shenzhen, although it has undergone the rapid development in the past 18 years. When the maximum Gross Domestic Production and the minimum Chemical Oxygen Demand are chosen as the two objectives subject to other constraints, the harmonized results indicated a scheme that claims substantial reduction of polluting effluences in Shenzhen while closely keeping the economic growth rate as planned.

The aim of this study was to implement central-composite design (CCD) and response surface methodology (RSM) to optimize the operational parameters for hybrid anaerobic baffled microbial reactor (HABMR) remedying mixed printing and dyeing wastewater (MPDW). The individual and interactive effects of three variables, hydraulic retention time (HRT), pH, sludge loading rate (SLR) on the COD and color removal rates were evaluated. In the area of HRT: 12.5–13.9 h, pH: 9.0–9.5 and SLR: 0.27–0.33 kgCOD/(kgMLVSS d), COD and color removal rates of HABMR exceeded 40% and 60%, simultaneously. The check experiment revealed that the amount of COD and color in the effluent could be decreased by 9.97% and 10.12% compared to the usual operating conditions, respectively. The results verified that the RSM was useful for optimizing the operational parameters of HABMR in treating MPDW.

A full-scale test was conducted with an up-flow anaerobic sludge blanket (UASB) pre-treating pharmaceutical wastewater containing 6-aminopenicillanic acid (6-APA) and amoxicillin. The aim of the study is to investigate the performance of UASB in the condition of a high chemical oxygen demand (COD) loading rate from 12.57 to 21.02 kg m−3 d−1 and a wide pH from 5.57 to 8.26, in order to provide a reference for treating the similar chemical synthetic pharmaceutical wastewater containing 6-APA and amoxicillin. The results demonstrated that the UASB average percentage reduction in COD, 6-APA and amoxicillin were 52.2%, 26.3% and 21.6%, respectively. In addition, three models, built on the back propagation neural network (BPNN) theory and linear regression techniques were developed for the simulation of the UASB system performance in the biodegradation of pharmaceutical wastewater containing 6-APA and amoxicillin. The average error of COD, 6-APA and amoxicillin were −0.63%, 2.19% and 5.40%, respectively. The results indicated that these models built on the BPNN theory were well-fitted to the detected data, and were able to simulate and predict the removal of COD, 6-APA and amoxicillin by UASB.

This article has been retracted: please see Elsevier Policy on ArticleWithdrawal (http://www.elsevier.com/locate/withdrawal policy). This article has been retracted at the request of the Editorin-Chief. This article has been retracted because it has been using a previous published paper as template without making reference to this previous work. The original work can be consulted at, http://dx.doi.org/10.1016/S0043-1354(01)00402-X.