《海水水质标准(GB3097—1997)》定值的合理性浅析——以铅和甲基对硫磷为例

基于物种敏感度分布曲线法,推导了铅和甲基对硫磷的海水水质基准低值和高值,并与《海水水质标准(GB 3097—1997)》中铅和甲基对硫磷的相关标准限值进行了比较,结果表明目前尚缺乏充分的科学证据说明我国现行的海水水质标准可以为我国海洋环境中大多数水生生物提供适当的保护,不同污染物的标准定值存在着一定程度的"欠保护"和"过保护"的问题。此外,结合我国近岸海水水质监测资料,在剖析了海水水质标准定值的合理性的基础上,对我国今后的海水水质基准和标准的研究进行了展望,给出了相应的对策和建议。     

超声波/紫外线-Fenton反应联用去除克拉玛依土壤中石油类污染物

研究了超声波(ultrasonic)和紫外线(ultraviolet)-Fenton反应联用处理干旱区老化石油污染土壤。土壤TPH含量为30 470 mg/kg,pH值为3,H2O2与Fe比例为50∶1时,H2O2浓度为0.37%、0.74%、1.11%和1.85%在超声波处理6 h土壤TPH去除量分别为4 495、11 983、15 470和19 800 mg/kg;TPH去除量随H2O2/Fe2+增大而增大,H2O2/Fe2+为100∶1时,TPH去除量为12 699 mg/kg。溶液pH值接近中性,H2O2浓度为0.74%,H2O2/Fe2+为50∶1,超声波与UV共同作用2 h和4 h,TPH去除量分别达到14 824和21 821 mg/kg;UV单独作用2 h、4 h对土壤TPH去除量为9 253和12 845 mg/kg。超声波-Fenton反应对1,2-二甲苯降解效果最好,其次为C17-C28的直链及支链烷烃,最低为烃类衍生物。     

Gaps,biases, and future directions in research on the impacts of anthropogenic land-use change on aquatic ecosystems: a topic-based bibliometric analysis

Environmental Science and Pollution Research - Anthropogenic land use change (ALUC) satisfies human needs but also impacts aquatic ecosystems. Aquatic ecosystems are intrinsically linked with...     

把好进口关

化学性食物中毒指有毒的金属、非金属及化合物,农药、亚硝酸盐等化学物质污染的食物而引发食物中毒。如有机磷、亚硝酸盐、砷化物等。预防留存在蔬菜水果表面的农药,应用清水彻底冲洗     

New DDT inputs after 30 years of prohibition in Spain. A case study in agricultural soils from south-western Spain

This study provides information on the current status of contamination by DDT in agricultural soils in south-western Spain. A recent use of technical DDT in at least 17% of the soils was found based on the values (<1) of the ratio Rp,p^′/p,p^′=[p,p^′-DDE+p,p^′-DDD]/[p,p^′-DDT]. According to the ratio Ro,p^′/p,p^′=[o,p^′-DDT]/[p,p^′-DDT], a dicofol type contamination was detected in about 27% of the soils. A wide range of concentrations was observed (0.08-11.1 ng/g d.w.) regardless of the type of crop soil. Enantiomeric fractions (EFs), based on the chiral analysis of o,p′-DDT residues differed from the racemic value (0.500) in most soils but they were not correlated with the study variables [DDTs], SOM, Rp,p^′/p,p^′ and Ro,p^′/p,p^′. Given the health risks posed by DDT, our findings support how the environmental control of legacy pollutants such as DDT cannot be neglected.     

水体低氧的早期暴露对青鳉(Oryzias latipes)后期的生长、性别比和繁殖能力的影响

水体低氧已是全球性生态问题,常以季节性、偶发性和昼夜间等不同形式存在于不同的水体中。长期低氧可影响鱼类正常的生长和繁殖,但鱼类早期生活阶段暴露于不同形式的低氧后,后期的生长和繁殖是否会受到不利影响,目前研究甚少。本研究在实验室模拟了连续低氧(2.8 mg·L~(-1)DO)(H1)、昼夜低氧(H2)和发生在胚胎器官形成时期的偶发性低氧(H3)等3种情景对青鳉胚胎的发育影响,评估了这一早期暴露对青鳉后期的生长、存活和繁殖的影响。我们发现,3种低氧方式都可以显著延长青鳉胚胎的孵化周期,引起胚胎卵黄囊吸收和鱼鳔发育异常;暴露结束120 d后,H1组青鳉成鱼的畸形率显著升高、存活率和生长速度都显著下降;H1、H2和H3组中成鱼的雌雄比都发生了改变,鱼群中以雄鱼为主,且产卵量和受精率都显著下降。结果表明,鱼类早期胚胎发育阶段所受到的低氧暴露可对后期生长和繁殖产生不利影响,对子代补充和种群稳定产生重要影响;鱼类关键发育期所经历的低氧事件,以及昼夜低氧事件所产生的生态后果不容忽视。     

Vertical distributions of soil carbon and nitrogen fractions as affected by land-uses in the Ili River Valley

In this study, soil samples were collected to a depth of 100?cm from different land-uses, including maize field (MZ), wheat field (WT), paddy field (PD), apple orchard (OC), grassland (GL) and wetland (WL) in the Ili River Valley in northwest China, to investigate the effects of land-use on vertical distributions of soil carbon (C) and nitrogen (N) fractions, and examine whether such effects were different between topsoil (0–40?cm) and subsoil (40–100?cm). The results showed that soil organic C, water-extractable organic C, microbial biomass C, total N and microbial biomass N of croplands (MZ, WT, PD and OC) were significantly lower than those of natural lands (GL and WL) in both topsoil and subsoil, indicating that contents of soil C and N fractions can be reduced by agricultural land-uses, and the reductions are not limited to topsoil. However, the contents of soil ammonium N and nitrate N showed complex trends under different land-uses, possibly due to that the plant species and agricultural practices (e.g. application rate of fertiliser and irrigation) are considerably different among land-uses. Therefore, we suggest that more nutrient inputs should be applied to croplands to improve soil fertility in the Ili River Valley.     

Occurrence of and risk posed by highly carcinogenic dibenzo[def,p]chrysene isomers in urban soil

Dibenzopyrene and its isomers are considered the most potent carcinogens of all polycyclic aromatic hydrocarbons tested to date. However, despite public concerns over their deleterious effects, they have not been extensively studied. The occurrence of four highly carcinogenic isomers of dibenzopyrene – dibenzo[def,p]chrysene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene in urban soil samples from Shanghai, China, have been determined in this study, as well as that of benzo[a]pyrene and coronene. A total of 14 peaks with ions at m/z 302 were detected by gas chromatography-mass spectrometry. Although the concentrations of benzo[a]pyrene and the sum of the 16 priority polycyclic aromatic hydrocarbons were greater than that of dibenzopyrene and its isomers, the carcinogenic potency of the latter was higher than that of benzo[a]pyrene. The results also indicate that the relative carcinogenic potency of the four dibenzopyrene isomers in the samples is higher than that of the 16 priority polycyclic aromatic hydrocarbons.     

A/O/O工艺处理含油污水的模拟评估

利用Bio Win 5.0软件建立了某炼油厂A/O/O工艺处理含油污水的数学模型,对其工艺参数进行了评估,并提出了改进建议。经调整部分动力学参数后,模拟结果与实测值吻合度较好,相关系数在0.75~0.81之间,建立的模型可较好反映工艺的运行工况。模拟优化主要针对一级处理装置,在仅考虑NH_3-N和COD去除的情况下,目前装置的工艺参数较合理,若考虑TN,无法实现TN和NH_3-N同时达标。对一级处理装置的模型进行改进后,出水模拟值中COD轻微上升2%,但ρ(NH_3-N)和TN分别下降83%和66%,可有效减轻后续处理装置负荷。     

Accounting for the Impact of Management Scenarios on Typha Domingensis (Cattail) in an Everglades Wetland

Environmental Management - The coupled regional simulation model, and the transport and reaction simulation engine were recently adapted to simulate ecology, specifically Typha domingensis...