Search

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.

Nitrate is one of the most common pollutants in the water environment. A key factor for the effective control and removal of nitrate is the ability to accurately determine the nitrate concentration in groundwater and the secondary effluent of wastewater treatment plants. Here, a bioelectrochemical method for real-time detection of the nitrate was developed. In this work, a kinetic model was developed to describe the correlation between the nitrate concentration and the current. Standard addition experiments showed the relative error between indicator predictions and ion chromatographic values ranged from 3.14% to 9.74%. The monitoring results of secondary effluent showed that the system could give a good response at different nitrate concentrations. The average error of not >10.85% between the indicator predictions and ion chromatographic values was demonstrated. This study offers a new method for the development of sustainable bioelectrochemical system (BES)-based technology for the real-time detection of nitrate in groundwater and the secondary effluent.

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.

The expanding population and rapid urbanisation, in particular in the Global South, are leading to global challenges on resource supply stress and rising waste generation. A transformation to resource-circular systems and sustainable recovery of carbon-containing and nutrient-rich waste offers a way to tackle such challenges. Eco-industrial parks have the potential to capture symbioses across individual waste producers, leading to more effective waste-recovery schemes. With whole-system design, economically attractive approaches can be achieved, reducing the nvironmental impacts while increasing the recovery of high-value resources. In this paper, an optimisation framework is developed to enable such design, allowing for wide ranging treatment options to be considered capturing both technological and fnancial detail. As well as technology selection, the framework also accounts for spatial aspects, with the design of suitable transport networks playing a key role. A range of scenarios are investigated using the network, highlighting the multi-faceted nature of the problem. The need to incorporate the impact of resource recovery at the design stage is shown to be of particular importance., Comment: 31 pages, 13 figures

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.

The Nernst-Monod model is used to describe bio-anode performance with respect to the effect of the electron donor and anode potential. However, electron competition is not considered in the model, limiting its application in wastewater treatment systems. In this work, nitrate was employed to describe the influence of a competitive electron acceptor on bio-anode performance. A new dynamic model of microbial anode respiration and nitrate respiration was developed for the removal of nitrogen oxides. The competitive relationship between microbial anode respiration and nitrate respiration was investigated based on electron transfer as described by the kinetics of Nernst-Monod electron transfer and nitrate reduction. The experimental results showed that nitrate had a significant influence on microbial anode respiration. The model parameters were estimated with the experimental results obtained in a continuous-flow bioelectrochemical system (BES) fed with acetate. The simulated results revealed that nitrate respiration could indirectly affect the microbial anode respiration by altering the available substrate concentration. In addition, bacterial community analysis indicated that there were two dominant functional microorganisms coexisting in the anode chamber. The first microorganism was represented by Geobacter, which has extracellular electron-transfer abilities. The second was denitrifying bacteria, which can use the carbon sources in the anodic chamber and electrons from the electrode for nitrate reduction. This is the first time that mathematical modelling of nitrate reduction has been applied to BESs.

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 (

A 180 L anaerobic membrane bioreactor (AnMBR) was operated for 253 days to treat real pharmaceutical wastewater, which mainly composed of β-lactams antibiotics (BLAs) including amoxicillin, ceftriaxone, cefoperazone and ampicillin. The operation was divided into three stages with hydraulic retention time (HRT) of 48 h, 36 h and 24 h, respectively, the corresponding average organic loading rates (OLRs) and antibiotics loading rates (ALRs) increased from 2.37 ± 0.28 to 4.46 ± 0.87 kg-COD·m−3·d−1, and from 19.06 ± 0.67 to 37.91 ± 3.57 g-BLAs·m−3·d−1, respectively. The highest removal efficiencies of amoxicillin, ceftriaxone, cefoperazone and ampicillin were 73.2 ± 4.3%, 47.7 ± 2.2%, 79.4 ± 4.1% and 34.6 ± 3.3%, respectively. The obtained total COD removal efficiency was as high as 94.0% and accompanied with VFA accumulation (249 ± 25 to 375 ± 61 mg·L−1) as well as biogas generation (0.195 ± 0.017 to 0.291 ± 0.032 L·gCODremoval−1), >66% of which was methane (0.135 ± 0.011 to 0.196 ± 0.021 L·gCODremoval−1). Moreover, basing on the back propagation neural network (BPNN) theory, the mathematical models were developed and well calibrated for simulating the AnMBR performance in the biodegradation of COD and antibiotics.

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.

Low-flush toilets have received increasing attention in relation to the water crisis in water-scarce regions because the vacuum flushing system (VFS) can reduce the amount of water required for flushing by approximately 80%. However, low-flush toilet wastewater exhibits the characteristics of high pollutant concentrations and cannot be directly discharged into urban pipe networks; therefore, decentralized wastewater treatment is necessary. Traditional control process (mainly consisting of hydrolysis acidification tank (HAT), anaerobic-anoxic–oxic (AAO) tank, coagulation sedimentation filtration tank and UV disinfection) was unsatisfactory for treating this type of wastewater. Therefore, a newly designed integrated biological-electrocatalytic (AAIE) process (mainly consisting of anaerobic baffled reactor (ABR), alternating internal circulation activated sludge process (AICS), and electrocatalytic oxidation (EC)) was introduced. ABR achieved large amounts of organic matter removal, the organic biodegradation kinetics revealed that the maximum specific degradation rate of the ABR was 0.050 to 0.082 d−1; AICS further removed COD and nitrogen, the denitrification rate and growth rate of nitrifying bacteria in the AICS were in the range of 0.079–0.121 kg/(kg·d) and 0.32–1.54 d−1, respectively. The temperature and organic loading rate were identified as two key parameters for ABR and AICS to remove pollutants, therefore, EC was the guarantee to make the effluent quality met the directly discharge standard of China (GB 18918-2002), especially in winter. The results showed that the AAIE process presented COD, colority, ammonia and total nitrogen removal rates of 98.5 ± 0.7%, 98.8 ± 0.6%, 97.0 ± 0.4% and 93.4 ± 2.6%, respectively, which were considerably higher than those of the control process. Furthermore, the economic analysis indicated that the AAIE process was feasible and may help to pave the way for wide application of biological-electrocatalytic processes for highly concentrated toilet wastewater treatment.

Polycyclic aromatic hydrocarbons (PAHs) are regarded as priority pollutants owing to their toxic, mutagenic and carcinogenic characteristics. Perylene is a kind of 5-ring PAH with biological toxicity, and classified as a class III carcinogen by the World Health Organization (WHO). Nowadays, some of its derivatives are often used as industrial pigments. Hence, urgent attention is highly needed to develop new and improved techniques for PAHs and their derivatives removal from the environment. In this study, Fenton oxidation process was hybridized with the biological (anaerobic and aerobic) treatments for the removal of perylene pigment from wastewater. The experiments were carried out by setting Fenton treatment system before and between the biological treatments. The biological results showed that COD removal efficiency reached 60% during 24 h HRT with an effluent COD concentration of 1567.78 mg/L. After the HRT increased to 48 h, the COD removal efficiency was slightly increased (67.9%). However, after combining Fenton treatment with biological treatment (Anaerobic-Fenton-Aerobic), the results revealed over 85% COD removal efficiency and the effluent concentration less than 600 mg/L which was selected as the better treatment configuration for the biological and chemical combined system. The microbial community analysis of activated sludge was carried out with high-throughput Illumina sequencing platform and results showed that Pseudomonas, Citrobacter and Methylocapsa were found to be the dominant genera detected in aerobic and anaerobic reactors. These dominant bacteria depicted that the community composition of the reactors for treating perylene pigments wastewater were similar to that of the soil contaminated by PAHs and the activated sludge from treating PAHs wastewater. Economic analysis results revealed that the reagent cost was relatively cheap, amounting to 10.64 yuan per kilogram COD. This study vividly demonstrated that combining Fenton treatment with biological treatment was efficient and cost-effective.

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.

In this study, the performance and removal mechanisms of a novel lab-scale multiple draft tubes airlift loop membrane bioreactor (Mt-ALMBR) for treating high-strength ampicillin pharmaceutical wastewater under different temperatures (7 °C, 16 °C, 24 °C, 36 °C, 48 °C) were investigated. During 150 days operation, the optimal average chemical oxygen demand (COD) and ampicillin removal rates were 98.2 ± 0.2% (36 °C) and 63.2 ± 5.6% (7 °C), respectively. The main mechanisms of pollutants removal were membrane removal (7 ~ 16 °C) and bioreactor removal (16 ~ 48 °C). Adsorption and membrane rejection were main pathways at low temperature, as temperature increased, hydrolysis and biodegradation gradually occupied a dominant position. Meanwhile, the optimum temperature ranges for activated sludge microorganisms were 16 °C ~ 36 °C, the corresponding β-lactamase at 36 °C was the highest activity value among all the set temperature values. Experimental results showed that temperature had a significant impact on the removal rate, the optimum temperature range was proposed to be at 24 ~ 36 °C. The half-life ( t 1 2 ) of ampicillin drastically decreased from 330.0 d to 2.1 d when the temperature was increased from 7 °C to 48 °C. And the maximum adsorption capacity K f at the adsorption temperatures of 7, 16, 24, 36 and 48 °C was 0.1284, 0.2169, 0.0645, 0.1502 and 0.1524 mg/g, respectively. The values of Δ G ° were all negative, proving that the adsorption process of the ampicillin belonged to a spontaneous physical adsorption. In addition, autoregressive integrated moving average (ARIMA) and mathematical fitting models were developed and well simulated the performance of Mt-ALMBR to treat the ampicillin wastewater. These results suggest that Mt-ALMBR holds great potential for application in ampicillin pharmaceutical wastewater treatment.

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.

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.

This study investigate the influence of different 7-ACA concentration of pharmaceutical wastewater on microbial activity of activated sludge, the studies show that under the different influent 7-ACA concentrations, the corresponding 7-ACA concentrations of the highest value of urease and SOD activities are 0 mg/L, DHO and nitrate reductase are 50 mg/L, inverting enzyme is 40mg/L, PPO is100 mg/L. the study also show that with the increase of intermediate concentration of pharmaceutical wastewater, microbes product β-lactamase enzyme under the stimulates of 7-ACA and the activity of β-lactamase enzyme increased and then decreased. The activity of β-lactamase enzyme observed of the highest 1212.9U and the best removal effect on 7-ACA when the concentration of 7-ACA is 30mg/L. The optimal pH, temperature and DO of the microorganism product the β-lactamase enzyme were 8, 35 ° C, and 2.5 to 3.5mg/ L.

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.

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.