Treatability studies of naphthalene in soil,water and air with persulfate activated by iron(Ⅱ)

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO₄], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO₄] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.     

表面活性剂增强修复地下水中PCE的砂箱实验及模拟

在石英砂充填的二维砂箱中开展表面活性剂（Tween 80）冲洗四氯乙烯（PCE）的修复实验,基于图像分析技术监测不同污染源区结构条件下NAPL相的去除过程.由于实验条件限制,实验中缺乏溶解相浓度数据.为此进一步基于UTCHEM数值模拟方法来理解NAPL相和溶解态之间的质量传输过程,并探讨表面活性剂浓度、注入速率等因素对修复效率的影响.综合砂箱实验和数值模拟结果表明：介质均质和非均质条件下会形成不同类型DNAPL污染源区结构,表现为离散状PCE与池状PCE体积比（GTP）差异.由于离散状污染物与表面活性剂的接触面积更大,更易被优先去除;初始GTP值越高,污染物的修复速率和修复效率也越高.增大表面活性剂浓度或提高表面活性剂的注入速率,虽然能提高DNAPL的修复速率,但会明显降低表面活性剂的修复效率,实验过程中修复效率降幅可达93%.线性驱动溶解模型可以有效地模拟表面活性剂修复DNAPLs过程,基于数值模拟方法选择合适的表面活性剂配比可有效的节省实际污染场址修复经费和时间成本.     

多环芳烃的几种理化参数与LC_(50)的相关性研究

对多环芳烃(PAHS)4种理化参数(K;W、Sw。X Vv。)与 LCO的相关关系进行了研究,建立了 4种一元线性回归方程。结果表明,4种参数的相关系数分别为:0.刀66、08083、09488、0.9570,经r检验,后两种属高度显著相关.用所建立的一元线性回归方程对7种PAHS的LC。进行估算,估算值与实测值相比,平均相对误差分别为58.84％、32.23％、1761％、198％,用l和V＊.H对LClj进行估算的估算精度也较高。经比较,提出用(。估算P＊比对麦穗鱼＊CO的新方法。     

土壤对六价铬的还原容量初步研究

提出并讨论了土壤的潜在还原容量、有效还原容量和条件还原容量等概念，通过对采用北京和唐山地下水饮用水源区３个包气带土壤样品的土柱淋滤实验，研究了土壤对水溶液中六价铬的还原作用，研究了上述土壤各种还原容量之间的关系及影响因素，探讨了向土壤中投加适量常见，无毒，价廉的还原性物质以提高土壤还原能力的方法和将其应用于去除灌溉用污染地下水中六价铬的可能性，实验结果表明，在正常环境条件下，土壤的有效还原容量比土     

VOC removal from contaminated groundwater through membrane pervaporation. (Ⅱ): 1,1,1-trichloroethane-SDS surfactant solution system

IntroductionTheconventionalmethodforsubsurfaceremediationofgroundwatercontaminationwithVOCsistheso called“pump and treat”technology .Thelimitationofthisapproachistheprohibitivelylongtreatmenttimeforremediatingthegroundwatercontaminatedwithcommonchlorinatedsolventsthathavedensitiesgreaterthanthatofwater(classifiedasDNAPLs densenon aqueousphaseliquids) .Thisislargelyduetotheverylowwatersolubilityandlowbiodegradabilityofthisclassofsolventsandthetendencyofthesolventssettlinginthebottomofanaqu…     

活性炭吸附与生物活性炭脱臭效果的比较研究

针对污水收集与处理系统中恶臭气体的组成与特性,比较分析不同情况下活性炭吸附与生物活性炭的脱臭效果。当干活性碳总处理气量达到1.3m~3/g时,出现穿透。将吸附饱和的活性炭填料塔转为生物滴滤反应器后,仍能较快的实现挂膜生长,达到满意的处理效果。直接运行的生物活性炭滴滤器对H_2S的处理效率在95％以上,并具有较强的恢复能力。H_2S平均出口浓度为0.052mg/m~3。循环液pH值与盐度在一定范围内对系统影响不大。     

受污染地表水体生物修复技术研究进展

主要介绍了受污染地表水体生物修复技术的类型及特点,综述了国内外关于受污染地表水体生物修复技术研究及应用的现状,并对生物修复技术的研究及应用进行了展望.     

湖泊富营养化的防治对策与展望

由于工业化的发展和人类生产活动的加剧,大量有机污染物不断排入湖泊并在其中积累,致使湖泊产生了富营养化现象,已成为日益突出的环境问题.文中论述了湖泊富营养化的现状及危害,分析了产生的原因,并概括和比较了现有的国内外的防治措施,指出生态修复是治理的最佳出路.结合国内外湖泊的治理经验,并对今后的发展方向进行了展望.     

Water solubility enhancements of pyrene by single and mixed surfactant solutions

ＩｎｔｒｏｄｕｃｔｉｏｎＳｕｒｆａｃｔａｎｔｓｅｎｈａｎｃｅｔｈｅｒｅｍｅｄｉａｔｉｏｎｏｆＮＡＰＬ ｃｏｎｔａｍｉｎａｔｅｄｓｉｔｅｓｂｙｉｎｃｒｅａｓｉｎｇｔｈｅａｑｕｅｏｕｓ ｐｈａｓｅｃｏｎｃｅｎｔｒａｔｉｏｎｏｆｔｈｅＮＡＰＬｖｉａｍｉｃｅｌｌｅｆｏｒｍａｔｉｏｎ ,ｍｉｃｒｏｅｍｕｌｓｉｆｉｃａｔｉｏｎ ,ｏｒｍｏｂｉｌｉｚｉｎｇｔｈｅＮＡＰＬｐｈａｓｅ (Ｋｉｌｅ ,1989;Ｅｄｗａｒｄｓ,1991;Ｇｕｈａ ,1998ａ ;Ｋｏ ,1998;Ｚｉｍｍｅｒｍａｎ ,1999;Ｂｅｔｔａｈａｒ,1999;Ｗｉｌｌｓｏｎ ,1999;Ｐａ…