Poor biodegradability and insufficient carbon source are discovered from influent.Influent indices presented positively normal distribution or skewed distribution.Average energy consumption of WWTPs in Taihu Basin was as high as 0.458 kWh/m3.Energy consumption increases with the increase in influent volume and COD reduction.The total energy consumption decreases with the NH3-N reduction. The water quality and energy consumption of wastewater treatment plants (WWTPs) in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods. The influent ammonia nitrogen (NH3-N) and total nitrogen (TN) of WWTPs in Taihu Basin showed normal distribution, whereas chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended solid (SS), and total phosphorus (TP) showed positively skewed distribution. The influent BOD5/COD was 0.4%–0.6%, only 39.2% SS/BOD5 exceeded the standard by 36.3%, the average BOD5/TN was 3.82, and the probability of influent BOD5/TP>20 was 82.8%. The average energy consumption of WWTPs in Taihu Basin in 2017 was 0.458 kWh/m3. The specific energy consumption of WWTPs with a daily treatment capacity of more than 5 × 104 m3 in Taihu Basin was stable at 0.33 kWh/m3. A power function relationship was observed between the reduction in COD and NH3-N and the specific energy consumption of pollutant reduction, and the higher the pollutant reduction is, the lower the specific energy consumption of pollutant reduction presents. In addition, a linear relationship existed between the energy consumption of WWTPs and the specific energy consumption of influent volume and pollutant reduction. Therefore, upgrading and operation with less energy consumption of WWTPs is imperative and the suggestions for Taihu WWTPs based on stringent discharge standard are proposed in detail. 相似文献
Four NF membranes were compared regarding arsenate rejection and their properties.Rejection of arsenate had no relationship with membrane pore size.A more negative surface charge was favorable for arsenate rejection at neutral pH.A severe membrane fouling could lead to a great reduction of arsenic rejection. Nanofiltration (NF) has a great potential in removing arsenate from contaminated water. The performance including arsenate rejection, water permeability and resistance to fouling could however differ substantially among NF membranes. This study was conducted to investigate the influence of membrane pore size and surface properties on these aspects of membrane performance. Four fully-aromatic NF membranes with different physicochemical properties were adopted for this study. The results showed that surface charge, hydrophobicity, roughness and pore size could affect water permeability and/or arsenate rejection considerably. A more negative surface charge was desirable to enhance arsenate rejection rates. NF90 and a non-commercialized membrane (M#1) demonstrated the best performance in terms of arsenate rejection and water permeability. The M#1 membrane showed less membrane fouling than NF90 when used for filtration of real arsenic-containing groundwater. This was mainly due to its distinct chemical composition and surface properties. A severe membrane fouling could lead to a substantial reduction of arsenic rejection. The M#1 membrane showed the best performance, which indicated that membrane modification could indeed enhance the overall membrane performance for water treatment. 相似文献
Reclaimed water threatens the ecological safety of the Chaobai River.SMX, TMP, and SDZ were the first three abundant antibiotics in the research area.SRGs and intI1 were widespread with high abundance after reclaimed water recharge.The SRGs values followed the sequence: Summer>autumn>spring>winter.Strong correlations were detected between SRGs and environmental factors. Reclaimed water represents an important source of antibiotics and antibiotic resistance genes, threatening the ecological safety of receiving environments, while alleviating water resource shortages. This study investigated the dissemination of sulfonamide (SAs), sulfonamide resistance genes (SRGs), and class one integrons (intI1) in the surface water of the recharging area of the Chaobai River. The three antibiotics sulfamethoxazole, trimethoprim, and sulfadiazine had the highest abundance. The highest absolute abundances were 2.91×106, 6.94×106, and 2.18×104 copies/mL for sul1, sul2, and intI1 at the recharge point, respectively. SRGs and intI1 were widespread and had high abundance not only at the recharging point, but also in remote areas up to 8 km away. Seasonal variations of SRGs abundance followed the order of summer>autumn>spring>winter. Significant correlations were found between SRGs and intI1 (R2 = 0.887 and 0.786, p<0.01), indicating the potential risk of SRGs dissemination. Strong correlations between the abundance of SRGs and environmental factors were also found, suggesting that appropriate environmental conditions favor the spread of SRGs. The obtained results indicate that recharging with reclaimed water causes dissemination and enrichment of SAs and SRGs in the receiving river. Further research is required for the risk assessment and scientific management of reclaimed water. 相似文献
• Copper fractal growth was observed during WPCBs recycling by slurry electrolysis.• Dendrites fractal growth could be controlled by additive during electrodeposition.• Additive was proved to be an effective way to refine the copper crystal.• These findings contribute to enrich the study of slurry electrolysis. Superfine copper particles could be directly prepared from waste printed circuit boards by slurry electrolysis. Meanwhile, copper fractal growth could be observed. To better understand this phenomenon, the factors that affect copper dendrites in a point-cathode system were discussed in detail. These results showed that the fractal degree of copper dendrites increased as the increase of applied voltage and the decrease of copper sulfate and gelatin concentrations. Sodium lauryl sulfate and hydrochloric acid concentrations could not significantly impact the fractal degree of copper dendrites, while gelatin concentration could. The minimum copper fractal dimension was 1.069 when gelatin and copper sulfate concentration was 120 mg/L and 0.1 mol/L, respectively with an applied voltage of 11 V. Moreover, the results diffusion-limited aggregation model demonstrated that particle translational speed, particle numbers and binding probability significantly affected copper dendrite patterns. The scanning electron microscopy results indicated that the three additives greatly affected the refinement of the copper crystal. These findings contribute to enrich the theoretical study on metals recovery from e-waste by slurry electrolysis. 相似文献
•CeOx/GF-EP process had the better degradation efficiency than GF-EP process.•CeOx/GF-EP process had the flexible application in the pH range from 5.0 to 9.0.•CeOx could enhance surface hydrophilicity and reduce the charge-transfer resistance.•The interfacial electron transfer process was revealed. E-peroxone (EP) was one of the most attractive AOPs for removing refractory organic compounds from water, but the high energy consumption for in situ generating H2O2 and its low reaction efficiency for activating O3 under acidic conditions made the obstacles for its practical application. In this study, cerium oxide was loaded on the surface of graphite felt (GF) by the hydrothermal method to construct the efficient electrode (CeOx/GF) for mineralizing carbamazepine (CBZ) via EP process. CeOx/GF was an efficient cathode, which led to 69.4% TOC removal in CeOx/GF-EP process with current intensity of 10 mA in 60 min. Moreover, CeOx/GF had the flexible application in the pH range from 5.0 to 9.0, TOC removal had no obvious decline with decrease of pH. Comparative characterizations showed that CeOx could enhance surface hydrophilicity and reduce the charge-transfer resistance of GF. About 5.4 mg/L H2O2 generated in CeOx/GF-EP process, which was 2.1 times as that in GF-EP process. The greater ozone utility was also found in CeOx/GF-EP process. More O3 was activated into hydroxyl radicals, which accounted for the mineralization of CBZ. An interfacial electron transfer process was revealed, which involved the function of oxygen vacancies and Ce3+/Ce4+ redox cycle. CeOx/GF had the good recycling property in fifth times’ use. 相似文献
Environmental Geochemistry and Health - A total of 475 representative cultivated land and 435 crop samples from 11 provinces of China were collected, and lead and cadmium in 6 polluted areas by... 相似文献