新疆某油区土壤污染状况研究

对新疆某油区的土壤污染状况进行研究,以期为石油开采区土壤生态环境保护与治理提供基础资料。通过对新疆某油区内的土壤环境状况调查发现,油田开发过程中产生的钻井废水、原油脱出水、井下作业废水、钻井废弃泥浆、钻井岩屑、污水处理厂污泥、罐底油泥是土壤污染的重要来源;该油区土壤受油田开发活动的影响,石油类、铬、总盐的含量升高,土壤有机质含量降低,pH趋于弱酸性。油气田开发项目应加强对污染物的管理,及时完善环保措施,并建立有效的环境管理制度,将油气田开发活动对环境的影响降到最低。     

不同物质对垃圾渗滤液中腐殖酸的吸附研究

垃圾渗滤液是一种有毒有害的高浓度有机废水,其中含大量腐殖酸。腐殖酸具有离子交换能力、吸附能力和脱除杂质能力,因此在很多方面有实用价值。活性碳、土壤、堆肥对废水中的有机物有一定的吸附能力。本文采用正交设计的方法,研究了活性碳、土壤、堆肥在不同温度,液／固,腐殖酸初始浓度的条件下对垃圾渗滤液中腐殖酸的吸附效果。实验结果表明：四种实验因素对吸附剂的吸附能力的影响程度为：吸附剂类型〉腐殖酸的初始浓度〉吸附反应温度〉液固比。在温度为25℃,液固比为50／0．5（mL/g）,腐殖酸初始浓度为41．99（mg／L）,吸附剂类型为活性碳时,腐殖酸吸附量最大,为40．86mg。同时分析了响应指标随因素的变化趋势。     

原油污染对水中四氯化碳在土壤中吸附作用的影响

通过对水中四氯化碳在原油开采区土壤中吸附作用的研究,初步探讨了四氯化碳在不同程度受到原油污染的土壤中迁移的影响。结果表明:与未受到污染的土壤中四氯化碳吸附系数值相比,低原油含量污染土壤中四氯化碳吸附系数值较小,高原油含量污染土壤中四氯化碳吸附系数值较大,土壤中四氯化碳吸附系数值与土壤中原油含量呈线性相关关系。实验范围内,低含量的原油污染增加了四氯化碳在土壤中的迁移能力,而高含量的原油污染减弱了其在土壤中的迁移能力。     

钻井废水中主要污染物的研究

钻井废水是石油勘探企业中的主要污染源。本文分析了钻井废水的来源,经对川东钻探公司钻井废水进行全面监测,并应用等标污染负荷计算法,对钻井废水中的污染因素进行了初步研究,得出了其中主要污染因素及主要污染因素群,并对污染物的来源及危害作了初步分析,提出了相应的对策。     

洗井废水对土壤质量及作物的影响

通过测定受洗井废水影响的土壤及作物中的重金属、有机污染物以及作物的生长发育和籽实中的营养成分，并与大庆地区无此类污染的相应作物比较表明：土壤和作物中的石油污染物随洗井废水灌入量的增加而有增高的趋势，这种趋势尤以硫化物为重，而重金属和3，4-苯并芘（BaP）的含量水平均在本地区正常范围内。在试验浓度条件下，洗井废水对作物没有不良影响，各浓度组都有利于作物的生长和营养物质的合成与积累。     

蚯蚓有机废水土地处理试验研究

利用蚯蚓的有机废水土地处理是一种符合生态平衡的新的处理技术，在这种处理工艺中，含有蚯蚓的土壤对废水中的COD的吸附去除百分数和有机物负荷均比常规的污水土地处理高两倍以上。这一处理过程的机理符合吸附，再生过程的一级反应动力学。     

铀在土壤中的吸附动力学

以四川盆地红层丘陵区涪江河谷两岸广泛分布的第四系中更新统亚粘土为对象,用动态法测定了铀在该土壤中的平衡吸附量,为极低放废物的处置提供一些理论依据。研究了流速、土壤粒度及铀溶液初始浓度对土壤吸附铀的影响,并用常用的吸附动力学方程对实验数据进行了拟合。结果表明：土壤粒度小的平衡吸附量较大;流速越小、平衡吸附量越大;铀溶液的初始浓度越大,平衡吸附量越大;在用动力学方程拟合时,E lovich方程的拟合度最好;该土壤对铀的最大吸附率为61.1%,吸附性能较差。     

不同pH值、不同比例的添加剂对土壤吸附铯的影响

铯极易被粘土矿物和有机质吸附而且不易解吸,在示踪水土侵蚀、处置核废物方面有着积极的作用。不同的pH值、不同比例的添加剂都会影响土壤对核素铯的吸附,实验证明两种土壤对核素铯的吸附在pH=4～7时很大,pH=7时达到最大;四种添加剂粗沸石、人造沸石、Ca（OH）2、MnO2只有粗沸石的加入量与铯的吸附比成正相关关系,可以提高土壤对铯的吸附能力。     

pH值对土壤吸附二氯喹啉酸的影响研究

采用间歇平衡震荡法研究pH值对二氯喹啉酸在红土、黑土、潮土三种供试土壤中吸附特征。结果表明:二氯喹啉酸在不同土壤中的吸附特征存在差异,土壤的pH值影响二氯喹啉酸的吸附特征,当pH值趋近于二氯喹啉酸的pKa(4.35)时,容易被土壤吸附;pH值在较高情况下(pH=7.4),二氯喹啉酸大多呈离子状态,不易被土壤吸附;有机质含量降低将导致土壤对二氯喹啉酸的吸附能力下降。     

干旱半干旱地区湖泊沉积物对Cu2+的吸附-解吸研究

吸附-解吸是重金属在沉积物中迁移转化的重要过程。本文研究干旱半干旱地区湖泊———乌梁素海不同区域沉积物对Cu2+的吸附-解吸过程。结果表明,吸附过程中,pH值逐渐降低;沉积物TOC含量越高,其对Cu2+的吸附能力也越强;生活污水和工业废水影响的S1样点及受农田退水影响的S2样点对Cu2+的吸附量相对较低,而相对较洁净的S3和S4样点具有较高的Cu2+吸附量。4个样点吸附量能力大小为S3>S4>S2>S1。解吸实验显示,沉积物吸附的Cu2+大部分都不能被解吸。试验结果符合Langmuir和Freundlich等温吸附方程,Langmuir方程的拟合效果要好于Freundlich方程,Langmuir方程拟合的饱和吸附量分别为3.31 mg/g、4.84 mg/g、8.39 mg/g和7.75 mg/g。     

臭氧-活性炭工艺在炼化循环排污水处理中的应用＊

针对炼化企业循环排污水中有机污染物浓度不能满足脱盐处理工艺进水水质要求的问题,开展了臭氧氧化-活性炭吸附工艺去除循环排污水中有机污染物的研究。通过对两种处理工艺进行不同组合的实验结果得知:当反应时间控制在最佳值,臭氧氧化和活性炭吸附单独处理循环排污水时,COD去除率分别约为27%和20%,处理效率偏低;当两种工艺组合后,在臭氧浓度为12 mg/L、氧化时间20 min、吸附时间为10 min时,COD去除率则达到52%,组合工艺协同作用效果明显。     

Some properties of a granular activated carbon-sequencing batch reactor (GAC-SBR) system for treatment of textile wastewater containing direct dyes

Resting (living) bio-sludge from a domestic wastewater treatment plant was used as an adsorbent of both direct dyes and organic matter in a sequencing batch reactor (SBR) system. The dye adsorption capacity of the bio-sludge was not increased by acclimatization with direct dyes. The adsorption of Direct Red 23 and Direct Blue 201 onto the bio-sludge was almost the same. The resting bio-sludge showed higher adsorption capacity than the autoclaved bio-sludge. The resting bio-sludge that was acclimatized with synthetic textile wastewater (STWW) without direct dyes showed the highest Direct Blue 201, COD, and BOD(5) removal capacities of 16.1+/-0.4, 453+/-7, and 293+/-9 mg/g of bio-sludge, respectively. After reuse, the dye adsorption ability of deteriorated bio-sludge was recovered by washing with 0.1% sodium dodecyl sulfate (SDS) solution. The direct dyes in the STWW were also easily removed by a GAC-SBR system. The dye removal efficiencies were higher than 80%, even when the system was operated under a high organic loading of 0.36kgBOD(5)/m(3)-d. The GAC-SBR system, however, showed a low direct dye removal efficiency of only 57+/-2.1% with raw textile wastewater (TWW) even though the system was operated with an organic loading of only 0.083kgBOD(5)/m(3)-d. The dyes, COD, BOD(5), and total kjeldalh nitrogen removal efficiencies increased up to 76.0+/-2.8%, 86.2+/-0.5%, 84.2+/-0.7%, and 68.2+/-2.1%, respectively, when 0.89 g/L glucose (organic loading of 0.17kgBOD(5)/m(3)-d) was supplemented into the TWW.     

Adsorption of cadmium on biosolids-amended soils

Debate exists over the biosolid phase (organic or inorganic) responsible for the reduction in phytoavailable Cd in soils amended with biosolids as compared with soils amended with inorganic salts. To test the importance of these two phases, adsorption isotherms were developed for soil samples (nine biosolids-amended soils and their five companion controls) and two biosolids samples from five experimental sites with documented histories of biosolids application. Subsamples were treated with 0.7 M NaClO to remove organic carbon. Cadmium nitrate was added to both moist soil samples and their soil inorganic fractions (SIF) in a 0.01 M Ca(NO3)2 solution at three pH levels (6.5, 5.5, and 4.5), and equilibrated at 22 +/- 1 degrees C for at least 48 h. Isotherms of Cd adsorption for biosolids-amended soil were intermediate to the control soil and biosolids. Decreasing pH did not remove the difference between these isotherms, although adsorption of Cd decreased with decreasing pH level. Organic matter removal reduced Cd adsorption on all soils but had little influence on the observed difference between biosolids-amended and control soils. Thus, increased adsorption associated with biosolids application was not limited to the organic matter addition from biosolids; rather, the biosolids application also altered the adsorptive properties of the SIF. The greater affinity of the inorganic fraction of biosolids-amended soils to adsorb Cd suggests that the increased retention of Cd on biosolids-amended soils is independent of the added organic matter and of a persistent nature.     

Sorption of hydrophobic pesticides on a Mediterranean soil affected by wastewater, dissolved organic matter and salts

Irrigation with treated wastewaters as an alternative in countries with severe water shortage may influence the sorption of pesticides and their environmental effects, as wastewater contains higher concentrations of suspended and dissolved organic matter and inorganic compounds than freshwater. We have examined the sorption behaviour of three highly hydrophobic pesticides (the herbicide pendimethalin and the insecticides α-cypermethrin and deltamethrin) on a Mediterranean agricultural soil using the batch equilibration method. We considered wastewater, extracts from urban sewage sludge with different dissolved organic carbon contents, and inorganic salt solutions, using Milli Q water as a control. All pesticides were strongly retained by soil although some sorption occurred on the walls of the laboratory containers, especially when wastewater and inorganic salt solutions were used. The calculation of distribution constants by measuring pesticide concentrations in soil and solution indicated that pendimethalin sorption was not affected whereas α-cypermethrin and deltamethrin retention were significantly enhanced (ca. 5 and 2 times, respectively) when wastewater or salt solutions were employed. We therefore conclude that the increased sorption of the two pesticides caused by wastewater cannot be only the result of its dissolved organic carbon content, but also of the simultaneous presence of inorganic salts in the solution.     

Regeneration of spent organoclays after the sorption of organic pollutants: A review

Clay minerals modified with organic ions, also known as organoclays, have found applications in a wide range of organic pollution control fields because of their excellent sorption capacity towards organic pollutants. Regeneration of the spent organoclays after the sorption of organic pollutants is of great importance during their application in pollution control. In this review, the reported methods for the regeneration of the spent organoclays are summarized, including biological degradation, photo-assisted oxidation, chemical extraction/desorption, supercritical extraction, thermal desorption, et al. The characteristics and applications of these methods are briefly described. It shows that most of these methods have been developed for regenerating spent organoclays from wastewater treatment. The biological regeneration method, as an in situ, low cost and easy-operating method, is applicable for regenerating spent organoclays not only from wastewater treatment, but also from soil and groundwater remediation.     

Environmental fate of triasulfuron in soils amended with municipal waste compost

The amendment of soil with compost may significantly influence the mobility and persistence of pesticides and thus affect their environmental fate. Factors like adsorption, kinetics, and rate of degradation of pesticides could be altered in amended soils. The aim of this study was to determine the effects of the addition of compost made from source-separated municipal waste and green waste, on the fate of triasulfuron [(2-(2-chloroethoxy)-N-[[4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzenesulfonamide], a sulfonylurea herbicide used in postemergence treatment of cereals. Two native soils with low organic matter content were used. A series of analyses was performed to evaluate the adsorption and degradation of the herbicide in soil and in solution after the addition of compost and compost-extracted organic fractions, namely humic acids (HA), fulvic acids (FA), and hydrophobic dissolved organic matter (HoDOM). Results have shown that the adsorption of triasulfuron to soil increases in the presence of compost, and that the HA and HoDOM fractions are mainly responsible for this increase. Hydrophobic dissolved organic matter applied to the soils underwent sorption reactions with the soils, and in the sorbed state, served to increase the adsorption capacity of the soil for triasulfuron. The rate of hydrolysis of triasulfuron in solution was significantly higher at acidic pH and the presence of organic matter fractions extracted from compost also slightly increased the rate of hydrolysis. The rate of degradation in amended and nonamended soils is explained by a two-stage degradation kinetics. During the initial phase, although triasulfuron degradation was rapid with a half-life of approximately 30 d, the presence of compost and HoDOM was found to slightly reduce the rate of degradation with respect to that in nonamended soil.     

Assessment of properties of Tunisian agricultural waste composts: Application as components in reconstituted anthropic soils and their effects on tomato yield and quality

Organic soil improvers are mainly used for their potential for preventing soil losses. This study investigates the physicochemical properties of six different organic soil improvers and their effects on the properties and productivity of reconstituted anthropic soils during short-term application compared to farm manure. Treatment materials were obtained from Tunisian agricultural waste composts (almond shell (AS), sesame bark (SB), olive cake (OC), olive mill wastewater sludge (OMWS) and poultry manure (PM)) as well as mixtures of compost-manure (CM). The characterization of soil conditioners shows that (i) nitrogen contents are higher in olive wastes and PM-based composts; (ii) carbon/nitrogen ratio (C/N) and the organic matter (OM) contents are in the ranges of 14.1-29.7 and 19.3-64.5%, respectively; (iii) the electrical conductivity (EC) is higher in manure (M) and compost-manure mixture (4.8-10.4 mS/cm) and (iv) pH values are alkaline (8.2-8.8). Treatments were applied as components of a reconstituted soil at a rate of 14 kg/m². Except for the manures, the mixtures of soil and treatment material (in a ratio of 600 L/28 kg) were placed in metallic basins to form the reconstituted anthropic soil. Plot areas of 2 m² were used for each treatment and 2 × 2 m² for the control. An assessment of the geochemical properties of soils during the cultivation period reveals variations in soil organic matter (SOM) contents as well as pH and EC values. Soil productivity is determined by quantitative and qualitative comparison of tomato fruits obtained from each plot amended with manure-treated soil.     

有机肥结构特征对污染土壤Cd形态的影响

研究了以污泥和鸡粪为主要来源的两种不同有机肥主要组分和结构特征差异,结合吸附和土壤平衡试验,探讨了各组分对Cd吸附反应特征和土壤Cd形态分布的影响。结果表明:供试污泥有机肥含有较多的羧基,其最大络合量大于鸡厩肥;同时能更有效降低NH4NO3提取态Cd,但因为结合形态相对不稳定,因此导致EDTA提取态Cd有明显增加。而鸡厩有机肥含有更多π键,芳香化和腐熟化程度较高,与Cd吸附更稳定,在降低NH4NO3提取态Cd的同时也能降低EDTA提取态Cd。研究表明有机肥腐殖化、芳香化程度是影响其对重金属污染土壤修复与改良效果的主要因素。