矿化垃圾床反应器厌氧甲烷氧化协同生物脱氮的研究

垃圾卫生填埋过程中逸散的甲烷与渗滤液处理过程中反硝化段不够彻底产生的硝酸盐对周围环境具有严重的威胁,反硝化厌氧甲烷氧化技术可实现甲烷与硝酸盐的同步去除,极具应用前景.本研究通过模拟垃圾填埋过程,以矿化垃圾作为垃圾填埋的覆土层与反硝化厌氧甲烷氧化微生物的接种源,建立了矿化垃圾床系统.结果表明,反应系统在140d的运行期间...     

十溴联苯醚在单次暴露的孕和非孕SD大鼠血液内的吸收分布

五溴联苯醚、八溴联苯醚被禁以后,十溴联苯醚（BDE-209〉97%）是现在唯一仍在全球范围内广泛使用的多溴联苯醚阻燃剂。BDE-209在环境介质和生物体,甚至人体的血液、母乳中普遍存在,而且BDE-209的环境含量呈上升趋势。在实验室条件下,BDE-209可以通过生物代谢,或光降解、热降解转换形成毒性更强的低溴代PBDEs、羟基甲氧基PBDEs、致癌物多溴二苯并二噁英/呋喃（PBDD/DFs）。所以BDE-209的环境行为及生物效应成为环境污染物领域研究的热点之一。目前,关于BDE-209对妊娠期生物体的暴露研究还是很少。研究了十溴联苯醚在单次暴露的孕和非孕SD大鼠血液内的吸收代谢。结果表明,BDE-209可以被孕和非孕SD大鼠吸收,孕和非孕SD大鼠血液中吸收的BDE-209都可以快速的排出。BDE209在孕和非孕SD大鼠体内存在脱溴代谢,主要的脱溴代谢物是3种nona-BDE（sBDE-206,-207,-208）和五种octa-BDEs（BDE-196,-197/204,-198/203）,其中3种nona-BDEs是主要的代谢物,而BDE-207是nona-BDEs中含量最大的单体。BDE-209及其脱溴代谢物nona-BDEs的清除速率,在SD孕鼠的体内快于SD非孕鼠,而且在暴露实验的后期还存在统计意义的显著差异性。     

Ni foam/Cu电极电催化还原硝酸盐氮

采用恒流电沉积法制备了泡沫镍/铜（Ni foam/Cu）电极.以Ni foam/Cu电极为阴极、Ti/RuO₂-Ir₂O₃电极为阳极构建电解体系,对水中硝酸盐氮进行电催化还原处理.并研究了电解质对总氮和氨氮去除率的影响和电极的稳定性.在一定范围内,增大电解质NaCl的浓度可以提高总氮和氨氮去除率.当NaCl浓度为0.5 g·L^-1时,在电解电流密度为8 mA·cm^-2的条件下对100 mg·L^-1 NO₃^--N溶液进行6次重复电解实验,2.5 h后硝酸盐氮去除率均可以达到94.5%以上.当NaCl浓度为1.25 g·L^-1时,在电解电流密度为8 mA·cm^-2的条件下对100 mg·L^-1 NO₃^--N溶液电解2.5 h,出水中氨氮浓度只有2.90 mg·L^-1,总氮去除率达到79....     

聚酰胺微塑料对大肠杆菌和脱氮副球菌的毒性

微塑料对环境微生物的毒性尚不清楚.本研究通过生长曲线测试、活性氧(ROS)生成、无机氮转化效率和塑料添加剂检测,探究了聚酰胺(PA)微塑料对典型环境微生物—大肠杆菌和脱氮副球菌生长的影响.PA微塑料对大肠杆菌的毒性与其浓度呈正相关,高浓度PA(100mg·L-1)微塑料对大肠杆菌和脱氮副球菌的生长均产生了显著抑制,胞内...     

主流条件下氮负荷对部分亚硝化活性污泥系统中NOB抑制及微生物群落结构的影响

部分亚硝化(PN)是厌氧氨氧化(ANAMMOX)获取亚硝酸盐(NO^-₂-N)作为基质的重要途径。然而,市政污水氨氮(NH⁺₄-N)浓度较低且波动频繁,导致难以实现稳定的PN。对此,通过缩短水力停留时间(HRT)的方式启动2个反应器,对比不同氮负荷(NLR)下,PN系统中氮素转化规律及微生物群落结构的变化。结果表明：在低氧环境下,R1的NLR从0.15 kg/(m³·d)提高至0.5 kg/(m³·d),氨氮转化率(ACR)从45%升高至65%,亚氮积累率(NAR)从0升高至95%,表明可以实现PN的快速启动,但是稳定运行60 d后PN出现失稳。然而,在高NLR[0.8～1.2 kg/(m³·d)]条件下,ACR和NAR最高分别可达到68%和85%,且能稳定运行,表明高NLR启动运行更易获得稳定有效的NOB抑制。微生物群落结构进一步表明,随着NLR的提高,R2中NOB的相对丰度远低于R1中NOB的相对丰度;同时,R2中NOB的优势菌逐渐...     

Responses of chlorophyll fluorescence and nitrogen level of Leymus chinensis seedling to changes of soil moisture and temperature

Controlled experiment of Leymus chinensis seedlings grown in the environmental growth chambers at 3 soil moisture levels and 3 temperature levels was conducted in order to improve the understanding how leaf photosynthetic parameters will respond to climatic change. The results indicated that soil drought and high temperature decreased the photochemical efficiency of photosystem ( Fw/Fm ), the overall photochemical quantum yield of PSIl(yield), the coefficient of photochemical fluorescence quenching(qp), but increased the coefficient of non-photochemical fluorescence quenching( q, ). Severe soil drought would decrease Fv/Fm and yield by 3.12% and 37.04% under 26% condition, respectively, and 6.60% and 73.33% under 32% condition, respectively,suggesting that higher temperature may enhance the negative effects of soil drought. All the soil drought treatments resulted in the decline in leaf nitrogen content. There was no significant effect of temperature on leaf nitrogen level,but higher temperature significantly reduced the root nitrogen content and the ratio of root nitrogen to leaf nitrogen,indicating the different strategies of adaptation to soil drought and temperature. It was also implied that higher temperature would enhance the effect of soil drought on leaf photosynthetic capacity, decrease the adaptability of Leymus chinensis to drought.     

Using a zeolite medium biofilter to remove organic pollutant and ammonia simultaneously

IntroductionWatershortageproblemisquiteseriousinmanycitiesofChina .Thereuseofmunicipalwastewaterisoneofthekeymethodstoreleasethisproblem .Makeupwaterforrecirculatingcoolingsystemisthelargestwaterusageinmanyfactories .Thewaterqualitystandardsforreclaimedwa…     

Effect of nitrogen and phosphorus on the water quality in the Three Gorges Reservoir Area during and after its construction

A survey concerning the concentration of the nutrients in the Three Gorges Reservoir Area was carried out. This paper presents the parameters(NO3^- -N, NO2^- -N, KjeldahI-N, non-ionic ammonia, P-PO4 and TP)determined at 16 sampling sites from 1997 to 1999. The dominant soluble nitrogen form was NO3^- -N followed by KjeldahI-N, NO2^- -N and non-ionic ammonia. Mean values of NO3^- -N, NO2^- -N, Kjeldahl-N and non-ionic ammonia ranged from 0.50 to 2.37 mg/L, 0.022 to 0.084 mg/L, 0.33 to 0.99 mg/L and 0.007 to 0.092 mg/L respectively.Mean values of P-PO4 at most sampling sites were higher than 0.1 mg/L for subject to eutrophication. The major factors influencing the concentrations of N and P might be agricultural runoff, municipal and industrial effluents. In addition, 6 kinds of soil were sampled at the area where would inundated after the dam completed. Two approaches were adopted to simulate the N and P release from the inundated soils. The results showed that the soils would release nitrogen and phosphorus to the overlying water when the soils were inundated. The characteristics of soil affected the equilibrium concentrations of N and P between the soil and the overlying water.     

新型复合材料处理氮磷废水的性能研究

采用阳离子表面活性剂十六烷基三甲基溴化铵（Hexadecyl Trimethyl Ammonium Bromide，HDTMA）和稀土溶液氯化镧（LaCl₃）对人造沸石进行改性，以增强其对水中氨氮和总磷的同步去除效果.结果表明，HDTMA和LaCl₃可有效负载于人造沸石表面，且在pH为7的条件下，改性沸石对氨氮和总磷的去除率分别由改性前的75%和1%提高到95.67%和91.96%.影响因素的实验表明，改性沸石对不同浓度废水的氨氮和总磷去除率均达到90%以上；氮、磷的去除率随改性沸石投加量的增加而上升；准二级动力学模型适合描述改性沸石对氨氮吸附的动力学过程，准一级动力学模型适合描述改性沸石对总磷吸附的动力学过程；吸附等温线说明改性沸石对水中氨氮的吸附属于离子交换，对水中磷酸盐的吸附包含离子交换和化学吸附两种过程.此外，通过再生性能、负载强度和离子竞争的试验证明改性沸石能应用于实际生化尾水的氮、磷去除.     

城市污水生物脱氮除磷常规工艺分析

阐述了污水生物脱氮除磷的机理，系统介绍了国内目前常用的污水生物脱氮除磷工艺，对其进行了系统全面的比较分析。并探讨了当今国内的一些脱氮除磷主要研究方向。