土壤-水环境系统有机氯农药垂直分布与迁移特征

分析了四川绵竹和盐亭垂直剖面不同深度土壤和不同形式及用途的水体样品中有机氯农药(HCH和DDT)含量分布特征。HCH和DDT异构体比值关系分析表明,研究区主要为历史残留。在地表有机质含量高的土壤中,随深度增加有机氯农药含量减少;地表为砂土的土壤柱,有机氯农药随土壤优先水流进入深层土壤。有机质、土壤结构和孔隙度可能是影响土壤有机氯农药吸附的重要因素,土壤优先水流强弱会影响有机氯农药在垂直方向迁移。研究区地下水有机氯农药含量均在国家生活饮用水质量标准范围内,地表水中有部分样点超标。为了人体健康,应使用水质相对较好的地下水或对地表水集中或分散处理后再饮用。     

涕灭威对地下水污染敏感区的预测与区划试点

本文根据涕灭威在室内模拟试验与田间试验的结果，详细剖析了影响涕灭威农药在土壤中残留和移动的各种因子，建立了涕灭威农药对地下污染的敏感性模型，并就涕灭威农药在江苏使用后对地下水可能造成污染的情况进行了预测与区划试点，结果与用美国环保局提供的ＰＲＺＭ模型计算结果和田间实测结果基本一致，本模型可用于预测涕灭威农药在其它地区使用后对地下水可能造成污染的情况。     

农药对地下水污染影响与控制研究

该项主要研究了 :涕灭威对地下水污染及其污染敏感区的预测与区划试点 ;应用计算机评价涕灭威农药对地下水污染的影响 ;拉索除草剂对地下水影响研究 ;呋喃丹在棉田土壤中移动特性研究 ;米乐尔对地下水污染的影响研究 ;环嗪酮对生态环境影响研究。该课题研究密切注视国外该领域的研究动态 ,结合我国的具体条件 ,对农药污染地下水问题进行了广泛、深入的研究。并在我国的农药环境管理中得到了实际应用 ,对防止地下水污染取得了实效。对一些有潜在危害性的农药品种 ,提出了因地制宜安全使用的有关规定。从而避免了我国农药对地下水的污染 ,保护…     

美国农药和地下水的预防政策与方案

防止农药对地下水的污染是美国环保局保护地下水战略的中心内容。作为其防预战略的一部分,环保局将采用多种渠道去防止农药对地下水的污染,以免达到不可接受的程度。第一、环保局将对公众关注的农药问题在全国采取统一的行动。即不论各地区地下水的状况如何,环保局都对地下水有特殊威胁的农药的使用和处置作了规定。第二、环保局将对农药的使用和管理采取不同的方法。根据这种方法,结合各地区地下水的状况.制定可行的预防措施。此外,环保局还应制定现场特殊措施,规定使用者在某一给定地区,根据地下水的脆弱性,或是处于“地下水优     

有机氯农药在岩溶区上覆土壤中的垂直迁移特征及对地下水的影响

选取典型表层岩溶泉域内的土壤剖面和表层岩溶泉水为研究对象,采用气相色谱(GC-μECD)对土壤和地下水中的有机氯农药(organochlorine pesticides,OCPs)进行定量分析,研究了有机氯农药在岩溶区上覆土壤中的垂直迁移以及对地下水的影响.结果表明,研究区所有土壤剖面中,HCHs和DDTs均有检出.HCHs和DDTs的含量范围分别为:0.77~18.3 ng·g-1(平均5.16 ng·g-1)和0.34~226 ng·g-1(平均16 ng·g-1).研究区土壤中的HCHs和DDTs峰值主要出现在土壤亚表层.在一年的观测期间,4个表层岩溶泉中均有HCHs和DDTs检出.泉水中HCHs和DDTs的含量范围分别为:2.09~60.1 ng·L-1(平均12 ng·L-1)和N.D~79.8 ng·L-1(平均9.16 ng·L-1).后沟泉、柏树湾泉、兰花沟泉的HCHs和DDTs含量以及水房泉中的HCHs含量均呈现出雨季高于旱季的特点.泉水中的HCHs、DDTs含量与泉域内土壤中的HCHs、DDTs含量并没有很好的对应关系.研究表明,TOC、土壤含水量、黏粒含量、p H均对后沟泉域土壤中有机氯农药垂直迁移产生抑制作用,致使后沟泉域土壤中有机氯农药含量虽然在4个泉域中最高,但泉水中的含量却最低.而在水房泉泉域,这4个因素对有机氯农药的垂直迁移均没有抑制作用,因此水房泉泉域土壤中有机氯农药含量虽然最低,但泉水中有机氯农药的含量却较高.     

云南临沧盆地地下水环境脆弱性评价

地下水脆弱性研究是合理开发利用和保护地下水资源的有效技术措施。本文根据临沧盆地水文地质条件,应用美国环保署(USEPA)的地下水脆弱性DRASTIC评价方法,考虑地下水位埋深、含水层净补给量、含水层介质、土壤包气带、地形地貌、包气带介质和水力传导系数等7个评价因子,结合GIS技术,对该区的地下水脆弱性进行了评价。结果表明,临沧盆地地下水脆弱性高区为主城区和主要农田分布区,要严格控制工业废水、生活污水的排放量和农药、化肥的施用量,防止地下水受到污染,确保地下水资源的可持续开发利用。     

农业活动与水质的关系研究综述

农业活动与水质的关系十分密切。过量施用化肥、农药等不合理的农业活动常引起氮、磷等营养元素在土壤中富集,进而导致地表水富营养化和地下水硝酸盐污染。     

采用AF参数评价农药对地下水的污染

由农药在非饱和土壤中运移的一维弥散方程简化,得出衰减因子——AF参数模型．评价了应用范围广、用量大、毒性高的7种农药对地下水污染的潜能,顺序为：乐果〉甲胺磷〉甲草胺〉丁草胺〉敌敌畏〉甲基对硫磷〉对硫磷,“有可能污染”的深度分别为：乐果〉2m、甲胺磷2m、甲草胺1．5～2m、丁草胺1m、敌敌畏0．5m、对硫磷和甲基对硫磷不污染地下水。     

土壤和地下水耦合数值模拟研究进展

土壤和地下水在水分运移、污染物迁移转化等方面高度相关,基于数值模拟预测土壤和地下水耦合污染趋势可以为土壤与地下水污染协同防治工作提供定量化技术支撑。文章综述了土壤和地下水数值模拟方法,总结了土壤和地下水中水流和溶质运移的耦合数值模拟研究进展,并对耦合数值模拟研究的未来发展趋势进行了展望。     

农用化学物质、有毒化学物质污染及其防治

常数依次为0.012 gh一’和o.0231h一’,再次证明土壤有机质对7一肠6的光解有明显抑制作用。图2表4参14x5922仪曰卫210有机氯类农药在包气带及地下水中长期残留研究/刘广民(吉林大学朝阳校区化学系)…//农业环境保护/中国农业生态环保协会一2(X)1,20(6).一408一410环图X一15 采用现场采样及室内测试分析方法对吉林省西部松原地区农田一水田、早田种植类型下的包气带及地下水中有机氯类农药的长期残留进行了研究。结果表明,在研究区包气带土壤的各个取样层位都检测到了有机氯类农药,均为六六六,滴滴涕,在地下水中检测了p体六六六。同时解释了…     

GIS based ArcPRZM-3 model for bentazon leaching towards groundwater

Groundwater contamination due to pesticide applications on agricultural lands is of great environmental concern. The mathematical models help to understand the mechanism of pesticide leaching in soils towards groundwater. We developed a user-friendly model called ArcPRZM-3 by integrating widely used Pesticide Root Zone Model version 3 (PRZM-3) using Visual Basic and Geographic Information System (GIS) based Avenue programming. ArcPRZM-3 could be used to simulate pesticide leaching towards groundwater with user-friendly input interfaces coupled with databases of crops, soils and pesticides. The outputs from ArcPRZM-3 could be visualized in user-friendly formats of tables, charts and maps. In this study we evaluated ArcPRZM-3 model by simulating bentazon leaching in soil towards groundwater. ArcPRZM-3 was applied to 37 sites in Woodru County, Arkansas, USA to observe the daily average dissolved bentazon concentration for soybean, sorghum and rice at a depth of 1.8 m for a period of two years. Nineteen ranks of bentazon leaching potential were obtained using ArcPRZM-3 for all sites having di erent soil and crop combinations. ArcPRZM-3 simulation results for bentazon were compatible with the field monitored data in term of relative ranking and trend, although some uncertainties exist. This study indicated that macropore flow mechanism would be important in analyzing the e ect of irrigation on groundwater contamination due to pesticides. Overall, ArcPRZM-3 could be used to simulate pesticide leaching towards groundwater more e ciently and e ectively as compared to PRZM-3.     

A critical review of the influence of effluent irrigation on the fate of pesticides in soil

The impact of effluent irrigation on the transformation and mobility of organic contaminants is poorly understood. The objectives of this review paper are: (i) to discuss the fundamental processes influencing the transformation and transport of pesticides in soil; (ii) to present a critical analysis of the impact of effluent irrigation on the transformation and transport of pesticides in soils; (iii) to suggest research areas that need attention. Effluent irrigation affects the fate of pesticides through its direct effect on the transformation and transport of pesticides that are already present at the irrigation sites, and its indirect effect on soil properties that are important in controlling the transformation and transport of organic contaminants. It has often been noticed that the effluent-derived dissolved organic matter (DOM) facilitates the movement of soil-borne pesticides by forming soluble pesticide complexes, and enhances their biodegradation by providing energy sources for the microorganisms that are involved in pesticide degradation. However, the results of field and laboratory experiments that examined the effect of effluent irrigation on the fate of pesticides are inconsistent; in some cases reduced mobility resulting from enhanced pesticide sorption has been observed, but enhanced pesticide mobility has also been reported. The inconsistency may be related to the inherent spatial variability of soil properties and/or the heterogeneity of effluent quality. For example, effluents vary in the nature and concentration of DOM that play a vital role in the degradation, sorption and transport behaviour of pesticides. Similarly, they vary in the concentrations of solvents and surfactants that have been shown to impact sorption and transport of organic contaminants. Field-based investigations on the impact of effluent irrigation on pesticide fate coupled with an accurate characterisation of the effluent are urgently required to assess the long-term risk associated with effluent irrigation in relation to pesticide transformation and transport.     

三唑磷在土壤中的降解与吸附特性

三唑磷农药在江西红壤，河南二合土和东北黑土中均具易降解性，其土壤降解半衰期分别为28．3，3．75、3．28d，降解速率次序为东北黑土〉河南二合土〉江西红壤。土壤对三唑磷的吸附性能强弱次序为：河南二合土〈江西红壤〈东北黑土。其Freundich吸附常数分别为2，17．6，70．100。尽管河南二合土对三唑磷农药的吸附性弱（koc〈300）．且三唑磷的水溶解度〉30mg／kg，但由于三唑磷农药的易土壤降解性，正常施用，其对地下水的实际污染风险较小。     

广东省荔枝园土壤农药残留现状研究

荔枝收获完毕后在广东省荔枝主产区采集208个荔枝园土壤样本,检测了9种荔枝常用农药甲霜灵、代森锰锌、多菌灵、溴氰菊酯、氯氰菊酯、三氟氯氰菊酯、敌百虫、乐果和敌敌畏的残留含量.结果表明,农药检出率为氯氰菊酯(59.1%)多菌灵(51.0%)代森锰锌(11.1%)甲霜灵(6.7%)三氟氯氰菊酯(3.4%).乐果和敌敌畏仅在个别果园检出,溴氰菊酯和敌百虫均未检出.土壤同时检出不同种类农药果园的百分数为只检出1种农药(40.4%)同时检出2种(31.3%)未检出(18.8%)同时检出3种(8.2%)同时检出4种(1.4%).检出的7种农药中,代森锰锌残留平均含量最高达39.05μg·kg-1,氯氰菊酯次之为7.83μg·kg-1.其它5种农药平均含量为0.19～1.65μg·kg-1.整体上广东省荔枝园土壤农药残留状况较轻.     

The profiles of chiral pesticides in peri-urban areas near Yangtze River: Enantioselective distribution characteristics and correlations with surface sediments

Chiral pesticides account for 30% of pesticides. Pesticides are inevitably leached into the groundwater by runoff. At the watershed level, the distribution characteristics of enantiomers in sediments collected from the river network of an agricultural area near the middle and lower reaches of the Yangtze River were tested, and their potential correlations with the physicochemical properties and microbial communities of the sediments were analyzed. The sediment pollution was serious at sites 8 and 9, with their pollution source possibly being agricultural or industrial sewage. Moreover, there were higher cumulative contents of pesticide residues at sites 4, 8, and 9. Specifically, Cycloxaprid was the most detected chiral pesticide in the study area, followed by Dinotefuran and Diclofop-methyl. Additionally, Ethiprole and Difenoconazole had strong enantioselectivity in the study area. Interestingly, the enantiomers of some chiral pesticides, such as Tebuconazole, had completely different distributions at different sites. Pearson correlation analysis showed that sediment catalase and microbial biomass carbon were important factors for enantioselectivity of chiral pesticides. The effect of sediment physicochemical properties on enantioselective distribution was achieved by influencing the microorganisms in the sediment. Furthermore, the enantioselective distribution of Tebuconazole was closely related to the genus Arenimonas. Overall, the enantioselective distribution of most of the chiral pesticides was positively correlated with the prokaryotic microbial community. This study provides empirical support for agricultural non-point source pollution caused by chiral pesticides, and also lays a research foundation for exploring the factors that affect the fate of chiral pesticides in the environment.     

The model test of leaching behaviour of trifluralin, lindane and aldicarb through the plough layer in three types of soil

A study on the leaching behaviour of trifluralin, lindane and aldicarb in three different types of soil was performed using soil column method. Leaching of trifluralin was not much influenced by soil types. Organic matter content showed an apparent influence on the leaching of lindane and aldicarb. Leaching depth of the pesticide was found to be negatively related to the organic matter content of the soil under study. It was also found that hydrophobic property of the pesticide increased the tendency of adsorption of the chemical to soil particles and hence reduced its leaching tendency. Thus, the leaching depths of the three pesticides in each of the three soils were observed in the order: aldicarb >lindane> trifluralin. Leaching behaviour of the three pesticides was also predicted based on the adsorption coefficients of the chemicals. For trifluralin and lindane, the predicted results were considerably in line with the results of the experiment.     

4种农药流失性质的研究

对４种农药的流失性质，进行了实验室和田间的试验研究，结果表明，水溶性农药乐果和杀虫单，有较低的土壤水分配比，较强的渗滤性和淋洗性，较易流失并污染水环境。脂溶性农药氰戊菊酯易被土壤强烈吸附，较难渗及被淋洗，不易流失，对水环境污染较轻。丁草胺的流失性质介于水溶性农药与脂溶性农药之间。     

土壤中毒虫畏和倍硫磷复合污染物的降解规律

采用土壤室内培养,气相色谱仪测定的方法,研究了毒虫畏和倍硫磷2种有机磷杀虫剂的复合污染物在红壤中的降解规律.结果表明:在复合污染下,倍硫磷的降解显著快于其在单一污染下的降解;土壤水分饱和条件下,倍硫磷的降解与对照差异不大,而毒虫畏的降解量在加入农药后的前21d比对照高33.3%～1 250%;在土壤干旱条件下,倍硫磷的降解量比对照略有降低,而毒虫畏的降解量在前期则比对照显著增加;施用氮肥能促进复合污染物的降解;在去除有机质的红壤矿物中,倍硫磷的化学降解量比对照降低22.4%～30.8%,而在加入农药后的前21d,毒虫畏的化学降解量比对照增加42.1%～2 370%,随后又下降.因此,复合与单一农药的污染物在土壤中的降解规律是不同的,复合污染的有机磷农药在土壤中的降解是相互影响的.     

某污灌区污水-土壤-地下水污染物分布特征

通过对某污灌区灌溉水、土壤及地下水的取样分析,研究了灌区污染物的分布特征。结果表明:灌区主要污染物为重金属Zn、多环芳烃和农残六六六。不同污染物分布特征不同。重金属主要富集于土壤表层,如Zn大部分富集于耕植层中(0～30cm),但浓度过高,其可向深部迁移。多环芳烃按分子量可分为三类,小分子量芳烃迁移过程中降解转化显著;中分子量芳烃迁移至深部土壤和地下水,土壤各深度吸附量几乎相同;大分子量芳烃化学性质稳定,易吸附沉积于表层土壤和底泥中。农残六六六迁移深度至少可达50m。     

江汉平原典型土壤环境中有机磷农药的分布特征及影响因素

为了研究江汉平原土壤中有机磷农药（OPPs）的分布特征,项目组于2015年9月在地下水监测场所在区域,采集了78个剖面土和7个表层土土样,通过气相色谱-氮磷检测器（GC-NPD）分析OPPs的含量,研究江汉平原土壤中OPPs的分布特征.结果表明,研究区土壤普遍存在OPPs,其中地表土中OPPs的含量范围为89.80~193.85 ng·g^-1,平均值为140.05 ng·g^-1;剖面土中OPPs的整体含量范围为19.81~138.28 ng·g^-1,平均值为40.99 ng·g^-1.地表土和剖面土中OPPs主要检出成分均为甲胺磷、氧化乐果、二嗪农和喹硫磷等,并且根据美国土壤农药残留限量标准,研究区土壤中10种OPPs的残留量已对农产品的安全构成威胁.研究区剖面土中∑OPPs分布为：水平方向,沿河农田剖面土 > 沿河非农田剖面土 > 中部农田剖面土,即：GS1-1 > GS4 > GS2 > GS3;垂直方向,大部分剖面土随着深度的增加整体上呈先减小后增大的趋势;研究区土壤中OPPs的分布受多种因素的影响：农业生产过程中施用OPPs的量、土壤对OPPs的吸附、解吸附作用、地下水的垂直运动、研究区的地形环境、土壤有机质的含量等.