沙蚕暴露于石油烃、Cu2+和Cd2+毒性效应及乙酰胆碱酯酶活性的响应

采用浓度梯度污染暴露室内模拟方法,研究了沙蚕（Perinereis aibuhitensis Grube）暴露于不同浓度的石油烃和重金属Cu²⁺、Cd²⁺的毒性效应及乙酰胆碱酯酶活性的响应.结果表明,石油烃和Cd²⁺、Cu²⁺对沙蚕均具有较强的毒性效应.暴露4 d和10 d后,石油烃LC₅₀分别为440和110 μg·L^-1,Cu²⁺分别为1 150和570 μg·L^-1,Cd²⁺分别为5 090和2 500 μg·L^-1,相应的生态毒性大小为：石油烃＞Cu²⁺＞Cd²⁺.在Cd²⁺、Cu²⁺污染暴露条件下,沙蚕体内乙酰胆碱酯酶活性受到一定程度的抑制,但抑制率均低于50％.而在石油烃污染暴露条件下,沙蚕体内乙酰胆碱酯酶活性受到显著抑制,最高抑制率可达90％以上;而且,其乙酰胆碱酯酶活性的变化与石油烃的浓度显著相关.可见,乙酰胆碱酯酶活性的变化可以作为生物标志物,较灵敏地反映出石油烃对沙蚕的污染效应及其毒害作用.     

炼焦过程排放挥发性有机物的排放特征和组成分布研究

为控制炼焦排放以及为预防城市大气污染提供可靠的污染源数据支持,利用不锈钢采样罐和全自动预浓缩/GC/MS系统,研究了58-Ⅱ型和JN43-80型焦炉在装煤时刻和炼焦过程(包括装煤时刻)中挥发有机物(VOCs)的排放特征及其组成分布,分析了焦化行业排放VOCs的反应活性。研究发现,在装煤时刻和炼焦过程中,58-Ⅱ型焦炉产生的总挥发性有机物(TVOCs)浓度分别为7022μg/m~3和6266μg/m~3;JN43-80型焦炉产生的TVOCs浓度分别为4185μg/m~3和3298μg/m~3。装煤时刻产生的TVOCs浓度明显高于炼焦过程产生的。炼焦过程无组织排放的VOCs包含烯烃、烷烃、芳香烃、卤代烃以及少量的醛和酮,其中乙烯、乙烷、丙烯、苯、甲苯等为主要成分。这些产生的VOCs反应活性各不相同,活性最大的是烯烃类物质,其活性占TVOCs反应活性比重为(86.2±2.1)%;其次是芳香烃类物质,其活性比重为(9.2±3.1)%;反应活性最大的5个物种分别是丙烯、乙烯、1,3-丁二烯、1-丁烯以及苯乙烯。     

WPSTM-TEOMTM-MOUDITM的对比及大气气溶胶密度研究

通过对2005年夏季上海、北京地区大气气溶胶观测中3种不同原理气溶胶分析及采样仪的对比,考察了颗粒物个数浓度粒径分布仪（WPS^TM）、锥形元件振荡微量天平（TEOM^TMTM）在运行中所得数据的可比性.其中TEOM^TM测量PM_2.5质量浓度与WPS^TM计算PM_2.5质量浓度数据的相关系数分别为0.77和0.79,并发现在粗粒子颗粒物比例较高的时段二者相关性分别提高为0.91和0.84.MOUDI^TM分级质量浓度与WPS^TM计算分级质量浓度数据对比显示,除最小粒径分级外其他分级均有较好相关性（R分布在0.76～0.92）.应用2组不同对比数据推测了上海和北京观测点PM_2.5颗粒物密度,研究发现上海采样点颗粒物密度约为1.70 g·cm^-3,而北京采样点颗粒物密度约为1.50 g·cm^-3.     

内循环移动床生物膜反应器的研究与应用

对传统移动床生物膜反应器进行改进,开发了内循环移动床生物膜反应器,通过处理模拟生活污水的研究,考察了反应器去除有机物和脱氮的能力。结果表明,在填料投加率为35%、进水COD为200～800mg/L、HRT为6h、有机负荷为0.8～3.2kg/(m.3d)的条件下,系统COD的去除率在89%以上;同时反应器具有良好的同步硝化反硝化脱氮能力,在DO为2.0mg/L、C/N为25、HRT为6h的条件下,NH4-N和TN的平均去除率分别可以达到98%和93%。另外,内循环移动床生物膜反应器与移动床生物膜反应器的对比实验结果表明,前者对COD和氮的去除效果都优于后者。     

加速溶剂萃取法(ASE)测定土壤中酞酸酯类有机物

应用加速溶剂萃取法(ASE)对土壤样品进行前处理测定酞酸酯类有机物,根据溶质在不同溶剂中溶解度不同,在较高的温度和压力下选择合适的溶剂,高效、快速地萃取固体或半固体样品中的待测物.与传统萃取技术相比,ASE技术具有操作简单、萃取效率高、萃取时间短、回收率高、所需溶剂用量少、对环境二次污染小等优势.     

氯化对二级处理出水中溶解性有机物结构的影响

以哈尔滨市W污水处理厂污水为研究对象,利用XAD树脂对二级处理出水中的溶解性有机物(DOM)进行分级分离.按照DOM在不同树脂上的吸附特性将其分为5个部分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).考察了二级处理出水中有机组分的组成分布、三卤甲烷生成势、紫外光谱和红外光谱.结果表明,二级处理出水中的主要成分是HPO-A和HPI,两者含量之和达70.8%.HPO-A是加氯消毒时产生三卤甲烷的主要有机组分,其三卤甲烷生成活性(STHMFP)为232.9μg/mg.而HPO-N、TPI-A、TPI-N和HPI的STHMFP介于100～125μg/mg之间.氯化反应后,HPO-A、HPO-N、TPI-A和HPI的紫外-可见吸光度均降低,而TPI-N则相反.并且HPO-A、HPO-N、TPI-A和TPI-N中的O-H、C=C和苯环的含量降低,而C-O的含量升高,还生成了C=O和C-Cl.     

Decomposition of hexachlorobenzene over Al2O3 supported metal oxide catalysts

Decomposition of hexachlorobenzene(HCB)was investigated over several metal oxides(i.e.,MgO,CaO,BaO,La2O3,CeO2,MnO2, Fe2O3,and Co3O4)supported on Al2O3,which was achieved in closed system at a temperature of 300°C.Catalysts were prepared by incipient wetness impregnation with different metal oxides loading and impregnating solvents.The decomposition effciency of different catalysts for this reaction depends on the nature of the metal oxide used,and Al2O3 supported La2O3 was found to be the most active one.Pe...     

Treatment of tunnel wash waters-experiments with organic sorbent materials.PartⅠ:Removal of polycyclic aromatic hydrocarbons and nonpolar oil

Tunnel wash waters characterize all waters that run off after washing procedures of tunnels are performed.These waters represent a wide spectrum of organic and inorganic pollutants,such as polycyclic aromatic hydrocarbons(PAHs)and toxic metals.Removal of such contaminants from water runoff was investigated using laboratory tests after washing procedure was performed on two road tunnels in eastern Norway(Hanekleiv and Bragernes).Due to diverse character of both,treatment media and treated wash waters, the...     

Residues of organochlorine pesticides in surface soils from college school yards in Beijing, China

Organochlorine pesticides (OCPs) have been a major environmental issue, attracting much scientific concern because of their nature of toxicity, persistence, and endocrine disrupting effects. Soil samples were collected from ten college school yards in Beijing in 2006 and analyzed to determine fifteen OCPs. Dichlorodiphenyltrichloroethanes (DDTs) were found to be the main pollutants, accounting for 93.70% of total OCPs, followed by hexachlorohexanes (HCHs) (2.25%) and hexachlorobenzene (HCB) (1.82%). Content...     

Dissimilatory Fe(Ⅲ) reduction characteristics of paddy soil extract cultures treated with glucose or fatty acids

Dissimilatory Fe(Ⅲ) reduction is a universal process with irreplaceable biological and environmental importance in anoxic environments. Our knowledge about Fe(Ⅲ) reduction predominantly comes from pure cultures of dissimilatory Fe(Ⅲ) reducing bacteria (DFRB). The objective of this study was to compare the effects of glucose and a selection of short organic acids (citrate, succinate, pyruvate, propionate, acetate, and formate) on Fe(Ⅲ) reduction via the anaerobic culture of three paddy soil solutions with Fe...