三峡库区中低产土壤重金属含量及其与小麦吸收的关系

三峡库区中低产土壤的Hg,As,Cr,Pb,Cu五个重金属含量（除渝北区外），均在国家土壤环境质量标准内，属自然背景值一级标准。Cd和Zn高于全国土壤中的平均含量和背景值含量，属二级标准。土壤的重金属含量与土壤母质类型，pH值，阳离子交换量，有机质，无定形铁和物理性粘粒有关，同时存在一定的地域分布。重庆近郊的土壤所有重金属含量相对较高。土壤重金属的可给态或有效性含量极低，锌和铜不是过量，而是不足。小麦籽粒中As,Cr,Pb,Zn,Cu含量低于国家食品对重金属限量标准和小麦籽粒背景值标准，Hg,Cd含量高于国家规定标准。籽粒中的Cu,Zn含量是小麦茎叶中的2.0-2.2倍，而茎叶中的Hg,Pb,As,Cr,Cd含量明显高于籽粒。     

滆湖水华初期浮游植物群落特征及与水环境因子相关性分析

为探究滆湖水华初期浮游植物群落特征及与水环境因子的相关性,于2018年5—7月在全湖布设22个点,调查研究滆湖水华初期浮游植物群落时空分布特征,并对引起水华主导环境因子进行分析.结果表明：①共获得7门119属,优势属为绿藻门的小球藻与球团藻、蓝藻门的鞘丝藻与微囊藻,其中湖心区域浮游植物丰度与多样性小,均匀性低,属于中偏重污染区域;湖北区以北属于中污染区域,蓝藻堆积严重;西部沿岸及南端区域属于中偏轻污染区域.②冗余分析得出,湖心藻类与水温（T）有强相关性,与叶绿素a（Chl-a）、溶解性总磷（DTP）、pH、溶解氧（DO）呈一定正相关性;湖北区以北藻类与底泥有机质（OM）、水体悬浮物（SS）、Chl-a及DTP呈强相关性,与T呈一定相关性.T与多项环境因子相关,均值从26.1℃上升到32.4℃;OM与有机磷（OP）呈高度相关性（p<0.05,r=0.892）.水华发生的主导环境因子为T、DTP与pH,底泥OM及OP有一定影响.     

有机废物厌氧发酵生物合成己酸研究进展

厌氧发酵处理有机废物并合成高价值羧酸盐的技术日趋成熟。尤其是己酸作为产物之一,因其附加值高,易于分离,用途广泛,越来越受到关注。微生物合成己酸需要电子供体及受体。详细介绍了乙醇、乙酸分别作为电子供体、受体合成己酸的机理——逆β氧化反应,总结合成己酸底物以及影响合成的因素（温度、pH值、水力停留时间、竞争路径、氢气分压、底物比例、氮源等）。目前采用科氏梭菌以乙醇为电子供体来合成己酸的技术较成熟,探索了利用乳酸为电子供体合成己酸的代谢机理,并指出开发乳酸转化合成己酸的技术可成为未来发展方向。     

基于“BIM+GIS”技术的建筑垃圾精准管控信息管理平台研究初探

近年来,我国建筑垃圾产量不断增加,全国600多座大中城市中有70%被垃圾所包围,其中建筑垃圾贡献率达到40%,而相比于部分发达国家,我国尚缺少针对于建筑垃圾的全过程实时监测与智能管控手段。将"BIM+GIS"技术引入建筑垃圾监管领域,并基于此技术建立建筑垃圾实时监测与智能管控信息管理平台,可实现对建筑垃圾的精准管控。     

基于地下管廊施工建筑垃圾产生特征的定量预测模型的建立

以浙江省宁波市地下管廊施工为研究对象,通过现场调研和建筑施工进度跟踪,建立了工程渣土、废弃混凝土、工程泥浆3种建筑垃圾的定量预测模型。结果表明:预计产生程渣土为83891.21 m3、废弃混凝土为4837.34 m3、工程泥浆为11435.27 m3。与真实值相比,模型的相对误差分别为8.6%,4.9%,3.5%,均低于20%,可认为三类建筑垃圾预测模型的建立有效。     

Responses of nitrification performance, triclosan resistome and diversity of microbes to continuous triclosan stress in activated sludge system

Triclosan(TCS) is commonly found in wastewater treatment plants,which often affects biological treatment processes.The responses of nitrification,antibiotic resistome and microbial community under different TCS concentrations in activated sludge system were evaluated in this study.The experiment was conducted in a sequencing batch reactor(SBR)for 240 days.Quantitative PCR results demonstrated that the abundance of ammonium oxidizing bacteria could be temporarily inhibited by 1 mg/L TCS and then gradually recovered.And the abundances of nitrite oxidizing bacteria(NOB) under 2.5 and 4 mg/L TCS were three orders of magnitude lower than that of seed sludge,which accounted for partial nitrification.When the addition of TCS was stopped,the abundance of NOB increased.The mass balance experiments of TCS demonstrated that the primary removal pathway of TCS changed from adsorption to biodegradation as TCS was continuously added into the SBR system.Moreover,TCS increased the abundance of mexB,indicating the efflux pump might be the main TCS-resistance mechanism.As a response to TCS,bacteria could secrete more protein(PN) than polysaccharide.Three-dimensional excitation-emission matrix revealed that tryptophan PN-like substances might be the main component in PN to resist TCS.High-throughput sequencing found that the relative abundances of Paracoccus,Pseudoxanthomonas and Thauera increased,which could secrete extracellular polymeric substances(EPS).And Sphingopyxis might be the main TCS-degrading bacteria.Overall,TCS could cause partial nitrification and increase the relative abundances of EPS-secreting bacteria and TCS-degrading bacteria.     

Ozone pollution characteristics and sensitivity analysis using an observation-based model in Nanjing, Yangtze River Delta Region of China

Ground-level ozone (O₃) has become a critical pollutant impeding air quality improvement in Yangtze River Delta region of China. In this study, we present O₃ pollution characteristics based on one-year online measurements during 2016 at an urban site in Nanjing, Jiangsu Province. Then, the sensitivity of O₃ to its precursors during 2 O₃ pollution episodes in August was analyzed using a box model based on observation (OBM). The relative incremental reactivity (RIR) of hydrocarbons was larger than other precursors, suggesting that hydrocarbons played the dominant role in O₃ formation. The RIR values for NO_X ranged from –0.41%/% to 0.19%/%. The O₃ sensitivity was also analyzed based on relationship of simulated O₃ production rates with reductions of VOC and NO_X derived from scenario analyses. Simulation results illustrate that O₃ formation was between VOCs-limited and transition regime. Xylenes and light alkenes were found to be key species in O₃ formation according to RIR values, and their sources were determined using the Positive Matrix Factorization (PMF) model. Paints and solvent use was the largest contributor to xylenes (54%), while petrochemical industry was the most important source to propene (82%). Discussions on VOCs and NO_X reduction schemes suggest that the 5% O₃ control goal can be achieved by reducing VOCs by 20%. To obtain 10% O₃ control goal, VOCs need to be reduced by 30% with VOCs/NO_X larger than 3:1.     

洱海北部入湖河流水质特征及其对北部湖区的影响

基于2016—2018年罗时江、弥苴河、永安江及洱海北部湖区监测数据分析,探讨洱海北部入湖河流污染变化特征及对北部湖区的影响。结果表明:1）"北三江"监测断面总磷、COD、氨氮浓度整体稳定在GB 3838—2002《地表水环境质量标准》Ⅱ—Ⅲ类标准限值内,年内污染物浓度变化表现出典型的农业面源污染特征,且受流域内产业模式等的综合影响;2）研究期间,河流首要污染物为TN,旱季次要污染物为COD,雨季为TP。雨季入湖负荷高于旱季,弥苴河污染负荷大于罗时江、永安江。"北三江"入湖TN和TP污染负荷分别占洱海允许负荷的50.1%和59.7%;3）入湖河流的磷元素输入是洱海北部湖区磷污染的重要来源。北部湖区污染物浓度对氮、磷入湖污染负荷相关性次月强于当月,响应存在延迟。筛选环境友好型种植模式,控制"北三江"氮磷入湖负荷,有利于保护洱海水环境。     

大气压纳秒负脉冲放电对水中大肠杆菌的灭活

采用自行研制的喷嘴-板-筒式反应器,研究了大气压纳秒负脉冲空气放电对水中大肠杆菌（Escherichia coli, E.coli）灭菌率的影响因素及规律。实验中空气自放电喷嘴电极进入反应器,气流带动放电生成的活性粒子流到达并作用于水中大肠杆菌。研究结果表明:本实验装置可有效实现对水中大肠杆菌的灭活,灭菌率随着放电电压和脉冲重复频率的增加、放电处理时间的延长而升高;随着鼓气速率的增大先增大后减小;随着喷嘴电极直径的增加先减小后增大。当采用1.30 mm喷嘴电极,在脉冲峰值电压为-32 kV、重复频率80 Hz,鼓气速率为80 mL/min时,连续放电处理12 min,灭菌率达到91%。