温度和停留时间对DDT污染土壤热脱附效果的影响

采用热处理方法分别对自配DDT及其衍生物(DDTs,包括p,p'-DDT、o,p'-DDT、p,p'-DDD和p,p'-DDE)污染土壤在5个温度(100,200,300,400,500℃),6个停留时间(5,10,20,30,40,50 min)下的DDTs去除率及热处理前后的DDTs残留浓度变化进行了研究。研究结果表明:热脱附对DDTs污染土壤修复效果显著。当温度达到300℃以上时,热脱附技术的优势开始显现。300℃下40 min时的DDTs去除率与400℃及500℃处理10 min时相当,均能达到97%以上。对热处理前后土壤中DDTs的残留浓度进行检测,结果表明:土壤中的主要污染成分p,p'-DDT在200℃以上时大量减少,主要转化为p,p'-DDE。p,p'-DDE在200～300℃时大量生成,400～500℃被去除。根据能耗分析结果得出较佳热处理条件为400℃,10 min。     

芹菜农药残留监测结果分析

为了解芹菜质量安全现状,对蔬菜批发市场、农贸市场、超市销售的芹菜进行了农药甲胺磷、氧乐果等50项农药的专项抽样调查分析,共抽检芹菜样本213个,通过采用GB2763--2012（食品中农药最大残留限量》进行判定,结果表明：引起芹菜农药残留超标的农药主要为毒死蜱、甲拌磷、多菌灵等,其中由这3种农药引起芹菜超标的比例占农残超标总批次的78．1％,芹菜质量安全状况还需进一步加强。     

60%唑醚·代森联水分散粒剂中吡唑醚菌酯在葡萄和土壤中的残留分析

建立了一种固相萃取-反相高效液相色谱检测60%唑醚.代森联水分散粒剂中吡唑醚菌酯在葡萄和土壤中的残留方法.方法的回收率为80.4%—98.4%,变异系数为1.8%—3.8%.最小检出量为2×10-10g,最低检测浓度为0.01mg·kg-1.消解动态研究表明,吡唑醚菌酯在葡萄和土壤中消解较快,其半衰期分别为3.7—3.8d和8.7—10.2d.最终残留试验表明,60%唑醚.代森联水分散粒剂900mg(a.i.).kg-1喷雾,4次药后7d,吡唑醚菌酯在葡萄和土壤中的最终残留量分别为0.1585—0.1886mg·kg-1和0.6935—0.7245mg·kg-1,低于CAC规定吡唑醚菌酯在葡萄中的最高允许残留量(MRL值)2.0mg·kg-1.     

南宁城市内河水体和表层沉积物中有机氯农药分布特征

采用改进的固相萃取、加速溶剂萃取和气相色谱-电子捕获检测器,对广西壮族自治区南宁5条城市内河的水体和表层沉积物样品中7种痕量有机氯农药(OCPs)的残留状况进行了分析测定. 结果表明,南宁城市内河水体有机氯农药以HCHs为主,ρ(OCPs)为nd～0.141 μg/L. 5个点位沉积物中w(总OCPs)为2.13～2.80 μg/kg,均检出4,4′-DDE和4,4′-DDD,w(DDD)/w(DDE)<1,且DDTs在沉积物中的含量普遍高于HCHs. 各点位沉积物中有机氯农药各组分含量均低于美国环境保护署采用的无毒害风险浓度.      

Anuran Development, Density and Diversity in Relation to Agricultural Activity in the Holland River Watershed, Ontario, Canada (1990–1992)

Significantly lower anuran species diversity and density was recorded in a vegetable growing area relative to upstream and downstream sites in the Holland River watershed, Ontario, Canada. Egg hatching success and tadpole deformity rates of American toads (Bufo americanus americanus), green frogs (Rana clamitans melanota) and northern leopard frogs (Rana pipiens) eggs in water from field sites and control water were assessed. Compared to the control and the upstream site, the total abnormality rate (unhatched eggs plus deformed tadpoles) was higher for American toads in water from the agricultural and downstream sites. Total abnormality was higher in green frog eggs in water from the agricultural site and a downstream site. Trace concentrations of organophosphorus pesticides were detected most often in agricultural zone water and sediments than in upstream and downstream sites. Organochlorine pesticide residues, especially in agricultural zone samples, exceeded the no effect level guidelines for the protection of aquatic life. Ammonia, phosphorus, particulates, BOD and TKN were highest in the agricultural zone. Significant correlations between these parameters and anuran development suggest nutrient run-off as a causal or contributing factor in lower anuran diversity, density and reproductive success of American toads and green frogs in the site dominated by agriculture.     

铬渣中Cr(Ⅵ)的浸出及强化研究

采用ICP-OES,XRD,SEM,EDX和电导率在线监测等手段分析铬渣浸取前后的变化及各种元素浸出量随pH值的变化,考察了添加化学悬浮剂、浸取体系和超声处理对铬渣中Cr(Ⅵ)浸出行为的强化作用.结果表明,浸取过程基本不改变铬渣的结构;pH为5—7,使用合适的浸取介质有利于Cr(Ⅵ)的溶出,通过添加化学悬浮剂APG650可提高浸取效率3倍,超声处理可提高浸取效率70多倍.     

Use of whole-body and subcellular Cu residues of Lumbriculus variegatus to predict waterborne Cu toxicity to both L. variegatus and Chironomus riparius in fresh water

We tested the use of whole-body and subcellular Cu residues (biologically-active (BAM) and inactive compartments (BIM)), of the oligochaete Lumbriculus variegatus to predict Cu toxicity in fresh water. The critical whole-body residue associated with 50% mortality (CBR₅₀) was constant (38.2-55.6 μg g⁻¹ fresh wt.) across water hardness (38-117 mg L⁻¹ as CaCO₃) and exposure times during the chronic exposure. The critical subcellular residue (CSR₅₀) in metal-rich granules (part of BIM) associated with 50% mortality was approximately 5 μg g⁻¹ fresh wt., indicating that Cu bioavailability is correlated with toxicity:subcellular residue is a better predictor of Cu toxicity than whole-body residue. There was a strong correlation between the whole-body residue of L. variegatus (biomonitor) and survival of Chironomus riparius (relatively sensitive species) in a hard water Cu co-exposure. The CBR₅₀ in L. variegatus for predicting mortality of C. riparius was 29.1-45.7 μg g⁻¹ fresh wt., which was consistent within the experimental period; therefore use of Cu residue in an accumulator species to predict bioavailability of Cu to a sensitive species is a promising approach.     

青岛近海沉积物中多环芳烃、多氯联苯和有机氯农药的含量和分布特征

利用气相色谱/质谱方法对青岛近海表层沉积物中多环芳烃(PAHs)、多氯联苯(PCBs)和有机氯农药(OCPs)进行了测定,并分析了PAHs、PCBs和OCPs的分布特征.结果表明,PAHs、PCBs和OCPs的均值分别为684.80、6.87和13.52ng·g-1,含量变化均呈近岸高、远岸低的分布规律.燃料的高温燃烧排放对本研究海域沉积物中PAHs有较大贡献;PCBs主要来源于工业及生活排放,但已受到控制;沉积物中HCHs存在工业和农业双重污染源输入,DDT主要是由于历史上使用农药造成,且在表层沉积物中受到好氧微生物降解.与国内外同类研究结果相比,调查海域沉积物中PAHs、PCBs和OCPs的污染程度及生态风险均处于较低水平.     

太湖沉积物柱状样中有机氯农药的垂直分布特征

采用气相色谱质谱法测定了太湖沉积物柱状样品中有机氯农药(OCPs)含量,探讨了沉积柱中有机氯农药的垂直变化特征及可能的来源.研究结果表明:沉积柱中OCPs浓度为0.88 4.73 ngg-1(干重),平均值为2.17 ngg-1;DDTs 、HCHs、六氯苯的残留量均较高,其中 DDTs为0.101.32 ngg-1,平均值为0.57 ngg-1;HCHs的浓度为0.251.99 ngg-1,平均值为0.65 ngg-1;六氯苯为0.501.35 ngg-1,平均值为0.92 ngg-1.3个湖湾的沉积柱表层DDTs含量最高,有明显的表面富集现象,成分分析表明,太湖可能着存在着DDTs类物质的输入.     

Organochlorine Pesticide Residues in Milk and Blood of Women from Anupgarh, Rajasthan, India

Anupgarh is the most fertile area of Rajasthan state where a variety of seasonal crops are grown. The availability of three manmade canals has enhanced the agricultural activities in this area. The farmers use huge amounts of pesticides to increase the crop productivity. Exposure of humans to these hazardous chemicals occurs directly in the fields and indirectly due to consumption of contaminated diet, or by inhalation or by dermal contact. The organochlorine pesticides are reported to be lipophilic and their presence in human milk and blood has been documented in different parts of the world. Blood and milk samples were collected from lactating women who were divided into four groups on the basis of different living standards viz residence area, dietary habits, working conditions and addiction to tobacco. The level of total organochlorine pesticides in blood ranged from 3.319mg/L—6.253mg/L while in milk samples it ranged from 3.209Mdash;4.608 mg/L. The results are in concurrence with the reports from other countries.