土霉素对SBR系统细菌的抑制效应与机制研究

基于SBR系统,从脱氮过程、化学需氧量(COD)的去除过程、胞外聚合物(EPS)的总量变化过程、比呼吸速率(SOUR)的变化过程及微生物群落的变化等多个角度出发,较系统地研究了不同浓度土霉素对SBR系统的冲击作用.结果表明,由于土霉素(OTC)的作用,系统氨氮去除率从空白对照组的99.0%分别下降至77.2%(OTC 1 mg·L~(-1))、47.4%(OTC 5 mg·L~(-1))及10.0%(OTC 10 mg·L~(-1)).此外,高浓度土霉素(10mg·L~(-1))引起EPS分泌量和异养菌SOUR分别下降至空白组的44.3%和41.2%.由高通量分析可得,由于高浓度土霉素(5 mg·L~(-1)以上)的作用,活性污泥中微生物的多样性显著下降,且微生物的群落结构也发生显著变化.属层面的分析可得,高浓度土霉素(5 mg·L~(-1)以上)反应器中的部分氨氧化菌,如Nitrospira和Nitrosomonas均受到了抑制.     

溶解氧和温度对地下水除铁、锰效果的影响

研究锰砂滤层去除铁、锰过程中温度、溶解氧两个因素对去除效果的影响,为生物法除铁、锰的实际运行提供了参考依据。从经济性和微生物角度考虑,原水DO维持在3mg／L左右即可满足运行要求,采用跌水曝气的方式去除效果优于管道混合器。当铁锰共存时最适宜的处理环境温度为20℃。     

不同喷雾方式下低阻文丘里振弦栅除尘配置优化实验研究

为了对比径向外喷和轴向喷雾下的低阻文丘里振弦栅耦合除尘效果,以除尘效率和系统阻力为参照,选定喉管气速、振弦栅数、纤维丝间隙和喉管液气比进行单因素实验。结果表明2种喷雾方式的除尘效率和系统阻力的变化趋势相同。利用SPSS软件进行4因素3水平正交实验设计,在特定参数条件下,2种喷雾方式的因素影响排序相同,除尘效率为纤维栅数＞纤维丝间隙＞喉管气速＞喷雾量;系统阻力为喉管气速＞纤维栅数＞纤维丝间隙＞喷雾量;径向外喷最佳配置为喉管气速24 m/s、喷雾量2.3 L/min、2块间隙为0.8 mm纤维栅板;轴向喷雾为喉管气速28 m/s、喷雾量2.4 L/min、2块间隙为0.8 mm纤维栅板;在最优配置下的除尘性能为径向外喷＞轴向喷雾。     

某处理厂CASS池改造工艺选择及运行效果

随着污水处理厂排到受纳水体标准的不断提高及区域污染物排放限值的要求,已建的污水处理厂需要提标改造提高排放标准。本文所提工程对现有的CASS池进行改造,通过投加悬浮填料形成CASS+MBBR工艺,其中TN污染物的去除率可提高到8%~15%间,其它污染物也能达到预期的设计标准。     

关于锅炉烟气脱硫除尘技术的探讨

目前国内能源结构仍以煤炭为主,大气污染非常的严重,尤其是酸雨和粉尘危害相对较大。在生态文明建设的时代背景下,我们应当加强锅炉脱硫以及除尘技术创新与改造,对燃煤烟尘以及二氧化硫等污染物的排放进行严格控制。本文先对锅炉烟气脱硫除尘现状进行了分析,并在此基础上就电厂锅炉如何进行烟气脱硫与除尘提出了一些观点与认识,以供参考。     

畜禽环境中抗生素的去除及其风险评估

抗生素作为饲料添加剂广泛应用于畜禽养殖业,造成养殖环境抗生素大量蓄积,尤其是在畜禽粪便中,长期的积累不仅污染养殖场内土壤环境,残留的抗生素还会随畜禽粪便进入周边水体及农田环境,威胁农作物及人体健康。目前,国内相关研究主要集中在抗生素的降解工艺及降解规律方面,而对其去除效率的影响因素及风险评价研究相对较少。笔者综述了国内外抗生素的降解转化及去除方式等的研究进展,并概述了抗生素在畜禽环境中的生态风险评估的研究现状,为抗生素的高效去除、风险预估及畜禽粪便资源化安全利用提供理论基础和技术支撑。     

In situ formation of bimetallic FeNi nanoparticles on sand through green technology: Application for tetracycline removal

• In situ preparation of FeNi nanoparticles on the sand via green synthesis approach. • Removal of tetracycline using GS-FeNi in batch and column study. • Both reductive degradation and sorption played crucial role the process. • Reusability of GS-FeNi showed about 77.39±4.3% removal on 4th cycle. • TC by-products after interaction showed less toxic as compared with TC. In this study, FeNi nanoparticles were green synthesized using Punica granatum (pomegranate) peel extract, and these nanoparticles were also formed in situ over quartz sand (GS-FeNi) for removal of tetracycline (TC). Under the optimized operating conditions, (GS-FeNi concentration: 1.5% w/v; concentration of TC: 20 mg/L; interaction period: 180 min), 99±0.2% TC removal was achieved in the batch reactor. The removal capacity was 181±1 mg/g. A detailed characterization of the sorbent and the solution before and after the interaction revealed that the removal mechanism(s) involved both the sorption and degradation of TC. The reusability of reactant was assessed for four cycles of operation, and 77±4% of TC removal was obtained in the cycle. To judge the environmental sustainability of the process, residual toxicity assay of the interacted TC solution was performed with indicator bacteria (Bacillus and Pseudomonas) and algae (Chlorella sp.), which confirmed a substantial decrease in the toxicity. The continuous column studies were undertaken in the packed bed reactors using GS-FeNi. Employing the optimized conditions, quite high removal efficiency (978±5 mg/g) was obtained in the columns. The application of GS-FeNi for antibiotic removal was further evaluated in lake water, tap water, and ground water spiked with TC, and the removal capacity achieved was found to be 781±5, 712±5, and 687±3 mg/g, respectively. This work can pave the way for treatment of antibiotics and other pollutants in the reactors using novel green composites prepared from fruit wastes.     

Kinetics and thermodynamic studies of Methyl Orange removal by polyvinylidene fluoride-PEDOT mats

We report the preparation of poly(3,4-ethylene dioxythiophene) (PEDOT)-modified polyvinylidene fluoride electrospun fibers and their use as a novel adsorbent material for the removal of the anionic dye Methyl Orange (MO) from aqueous media. This novel adsorbent material can be used to selectively remove MO on a wide pH range (3.0–10.0), with a maximum capacity of 143.8 mg/g at pH 3.0. When used in a recirculating filtration system, the maximum absorption capacity was reached in a shorter time (20 min) than that observed for batch mode experiments (360 min). Based on the analyses of the kinetics and adsorption isotherm data, one can conclude that the predominant mechanism of interaction between the membrane and the dissolved dye molecules is electrostatic. Besides, considering the estimated values for the Gibbs energy, and entropy and enthalpy changes, it was established that the adsorption process is spontaneous and occurs in an endothermic manner. The good mechanical and environmental stability of these membranes allowed their use in at least 20 consecutive adsorption/desorption cycles, without significant loss of their characteristics. We suggest that the physical-chemical characteristics of PEDOT make these hybrid mats a promising adsorbent material for use in water remediation protocols and effluent treatment systems.     

改良型Carrousel氧化沟工艺生物脱氮除磷效果研究

为了提高改良型Carrousel氧化沟工艺污水处理厂的脱氮除磷效果,结合某污水处理厂3年的运行实践,讨论了该工艺的处理效果,生物脱氮除磷原理及影响出水效果的因素.分析表明将DO控制在0.3～0.7 mg/L范围内,能够使出水中的TN浓度低于20 mg/L;在氧化沟中发生的同步硝化反硝化反应(SND)对总氮的去除的贡献占总系统脱氮的66%;该系统剩余污泥的含磷率为3.0%,生物细胞中平均含磷量可达细胞干重的4.2%;总磷去除率与污泥龄具有很好的线性关系,加大污泥排放量可以提高除磷效果.     

好氧颗粒污泥在生物强化除磷中的应用

结合近年来好氧颗粒污泥的最新研究成果,分析了好氧颗粒污泥的物理、化学、生物学、结构特征,并从生物除磷、反硝化除磷和沉淀作用三方面对好氧颗粒污泥除磷现象进行探讨。旨在为好氧颗粒污泥在生物强化除磷中的实际应用提供理论知识。