应用自动识别和定量系统评价两种污水再生工艺对微量有机污染物的去除效果

采用气质联用分析,并结合自动识别与定量系统(AIQS-DB)考察2种再生水厂采用的深度处理工艺对微量有机污染物的去除效果。结果表明,以污水为原水的膜生物反应器(MBR)+臭氧氧化+生物活性炭滤池(BAC)工艺用于再生水生产,MBR工艺对有机污染物的去除起主要作用;城市污水厂二级出水为原水的混凝沉降+浸没式超滤(SMF)/连续微滤(CMF)+部分反渗透(RO)+臭氧氧化工艺用于再生水生产,其SMF和CMF工艺段的膜截留作用均可有效消减有机污染物含量,SMF的效果优于CMF;2种工艺中采用的臭氧技术都能进一步加强部分物质的去除效果。气质联用结合AIQS-DB可用于再生水中污染物的筛查和不同污水再生工艺对微污染物消减效果的评价。     

利用发光菌和大型蚤对北方某城市再生水急性毒性的调查

利用发光菌和大型蚤作为受试生物测定了北方某城市5个再生水原水(城市污水厂二级出水)和2个再生水处理系统的各工艺出水的急性毒性.结果表明,各再生水原水对大型蚤和发光菌具有不同程度的毒性效应,其中工业废水占较大比例的K和B厂再生水原水的大型蚤48 h总抑制率分别高达90%和100%,发光菌发光抑制率分别达到74.2%和46...     

基于Landsat TM/ETM+/OLI遥感大数据分析南京市1984—2015年大气能见度变化趋势

对南京市1984—2015年Landsat 4／5／7／8卫星TM／ETM＋／OLI传感器获取的遥感数据,利用ENVI遥感软件的FLAASH大气校正模块,进行了区域大气能见度（ VIS）遥感反演。结果表明,时间跨度达30余年的Landsat卫星遥感数据影像序列反演的VIS呈明显的下降趋势,20世纪80年代数值较高,“差”能见度（＜10 km）的观测率不到6％,21世纪以来VIS下降明显,“差”能见度的观测率为20％～25％。与2010—2015年南京市PM10、PM2．5监测数据进行了对比,在城市空气清洁及污染较轻时,星地监测结果有较好的一致性,但中到重污染天气时FLAASH算法反演VIS偏高,侧重于代表离主城区距离远的偏远乡野山林地区的能见度状况。     

The concentrations, distribution and sources of PAHs in agricultural soils and vegetables from Shunde, Guangdong, China

The concentrations, distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in 30 agricultural soil and 16 vegetable samples collected from subtropical Shunde area, an important manufacturing center in China. The total PAHs ranged from 33.7 to 350 μg/kg in soils, and 82 to 1,258 μg/kg in vegetables. The most abundant individual PAHs are phenanthrene, fluoranthene, chrysene, pyrene and benzo(b)fluoranthene for soil samples, and anthracene, naphthalene, phenanthrene, pyrene and chrysene for vegetable samples. Average vegetable–soil ratios of total PAHs were 2.20 for leafy vegetables and 1.27 for fruity vegetables. Total PAHs in vegetable samples are not significantly correlated to those in corresponding soil samples. Principal component analyses were conducted to distinguish samples on basis of their distribution in each town, soil type and vegetable specie. Relatively abundant soil PAHs were found in town Jun’an, Beijiao, Chencun, Lecong and Ronggui, while abundant vegetable PAHs were observed in town Jun’an, Lecong, Xingtan, Daliang and Chenchun. The highest level of total PAHs were found in vegetable soil, followed by pond sediment and “stacked soil” on pond banks. The PAHs contents in leafy vegetables are higher than those in fruity vegetables. Some PAH compound ratios suggest the PAHs derived from incomplete combustion of petroleum, coal and refuse from power generation and ceramic manufacturing, and paint spraying on furniture, as well as sewage irrigation from textile industries. Soil PAHs contents have significant logarithmic correlation with total organic carbon, which demonstrates the importance of soil organic matter as sorbent to prevent losses of PAHs.     

Concentrations and distributions of 18 organochlorine pesticides listed in the Stockholm Convention in surface sediments from the Liaohe River basin,China

Organochlorine pesticides (OCPs) were analyzed in 26 surface sediment samples from the Liaohe River basin, and the distributions of and potential environmental risks posed by OCPs in the basin were evaluated. Eighteen OCPs listed in the Stockholm Convention were determined using isotope-dilution gas chromatography–high resolution mass spectrometry. This is the first study of hexachlorobenzene (HCB) in the Liaohe River basin sediments. The total OCP concentrations were 0.39–68.06 ng g^?1 dry weight. The total α-, β-, γ-, and δ-hexachlorocyclohexane (HCH), the total dichlorodiphenyltrichloroethane (DDT – p,p′-dichlorodiphenyldichloroethane (DDD), p,p′-dichlorodiphenyldichloroethylene (DDE), o,p^'-DDT, and p,p′-DDT), and the HCB concentrations in the sediment samples were 0.1–28.48 ng g^?1 (mean 4.01 ng g^?1), 0.08–6.52 ng g^?1 (mean 3.07 ng g^?1), and 0.18–24.8 ng g^?1 (mean 4.38 ng g^?1), respectively. The HCB concentrations were higher than the concentrations of the other OCPs, and the HCHs and HCB together were the dominant OCPs. β-HCH was the most abundant HCH isomer. The concentrations of DDTs and other OCPs were relatively low, and the (DDE+DDD)/DDT ratios (>0.5) and DDD/DDE ratios (<1) indicated that no recent DDT inputs had occurred in the Liaohe River system. The main sources of HCHs were probably the historical production and agricultural use of HCH in the study area. The DDT and HCH concentrations were generally below or similar to the concentrations that have been found in other parts of the world. An ecotoxicological evaluation indicated that HCHs in surface sediments pose slight risks to human and ecological health in the Liaohe River basin.     

苏州市工业用地地表径流污染特性研究

对苏州新区枫桥工业园湘江路段的10场有效降雨事件的地表径流污染特性进行了研究.研究表明.地表径流水质参数COD、SS、NH3-N、TN、TP均服从对数正态分布,在95%置信水平下,SS与COD、TP、TN之问存在线性相关性(R=0.45～0.72).统计了污染物事件平均浓度(EMC),COD、SS、NH3-N、TN、TP的EMC中值分别为213、491、2.65、5.19、1.07 mg/L,相对应的单位面积污染物负荷分别为1 898、4 375、24、46、10 kg/(hm2·a).与韩国Chongju工业区和上海市相比,SS负荷高是苏州新区枫桥工业园地表径流水质的主要特点,削减SS负荷对控制其非点源污染具有重要意义.     

制备方法对MgAl水滑石衍生氧化物负载钯催化剂丙烷完全氧化活性的影响

以沉积沉淀法(DP)、浸渍法(IM)和共沉淀法(CP)制备MgAl水滑石衍生氧化物负载钯催化剂,用ICP、XRD、SEM、TEM、EDS、TPR以及比表面测定等手段对催化剂进行了表征.ICP和XRD数据表明用上述3种方法均可成功制备水滑石为前体载钯催化剂.SEM、TEM、EDS数据表明不同方法制备的样品具有不同的形貌以及钯在其中的分散度.综合各类表征数据可知Pd在催化剂中暴露的活性位是影响其活性的主要因素.     

曝气条件对浸没式膜生物反应器内流场的影响

为深入研究流场动力学特性对浸没式膜生物反应器系统内膜面污染的控制,应用fluent软件对浸没式膜生物反应器内气液两相流动进行了三维数值模拟研究。采用标准k-ε湍流模型和欧拉多相流模型,考察了改变曝气条件对膜面气液速度场及气含率分布的影响。模拟结果表明,在相同曝气强度下,1 mm曝气孔径下膜面气液两相的速度增加较孔径2mm、3 mm的快;曝气孔径为1 mm时,膜面的液相速度随着曝气强度的增加逐渐增大;曝气孔径为1 mm时,曝气量为5.5m3/h所形成的漩涡区较大,膜面气含率值较高且分布较均匀,气液两相接触面积较大,膜面冲刷效果较好;模拟观察到反应器底部靠近壁面局部气含率较低,不利于活性污泥中微生物的生长,需要进一步优化曝气和反应器结构。     

好氧颗粒污泥自生动态膜生物反应器处理碱减量印染废水

自生动态膜生物反应器(SFDMBR)接种颗粒污泥启动,研究溶解氧浓度和水力停留时间对该反应器处理碱减量印染废水的影响。自生动态膜生物反应器形成稳定的动态膜后,出水浊度小于10 NTU,系统对浊度的去除率在90%以上,溶解氧和水力停留时间对反应器出水浊度基本无影响。系统对废水色度的去除率随着溶解氧浓度的提高和水力停留时间的延长而增加,但是系统对色度的去除效率一般不超过40%。溶解氧浓度由0.3 mg/L逐渐增大至2.4 mg/L,COD的去除率由40%提升至80%,而当溶解氧浓度大于1.0 mg/L后,UV254的去除率达到95%。水力停留时间在8~48 h时,COD去除效率由65%逐渐上升至85%左右;水力停留时间在8~32 h,UV254去除效率为68%~93%,超过32 h后水力停留时间对UV254去除效率的影响已不明显。     

厌氧氨氧化（ANAMMOX）生物滤池反应器的启动特性

采用平行对比实验,讨论不同实验条件下上向流厌氧氨氧化（ANAMMOX）滤池反应器的启动特性。对比条件为温度、接种污泥、联氨和羟胺。结果表明：温度是影响厌氧氨氧化细菌活性的主要因素;接种200mL具有活性的厌氧氨氧化污泥后,在避光、加热38℃、不控制联氨和羟氨的条件下,45d可成功启动厌氧氨氧化滤池反应器;反应过程NH4^＋N：NO2^-·N：NO3-N的化学计量摩尔比为1：1．17：0．30,其总氮去除率达到87．38％,总氮容积去除负荷可达到1．41kg／（m^3·d）。