共查询到18条相似文献,搜索用时 125 毫秒
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不同赋存形态重金属的环境行为和生态效应不同,水体沉积物中重金属的迁移转化及其潜在环境危害更大程度上取决于其赋存形态。本研究在西湖和东苕溪设置12个采样点采集沉积物样品,采用改进BCR分步提取法,提取了重金属污染物的4种化学形态,分别为弱酸提取态、可还原态、可氧化态及残渣态。结果表明:沉积物中Cd以弱酸提取态为主,对外界环境的变化极其敏感,并易于发生迁移转化,生态风险较高。Cu离子对有机质表现出极强的亲和力导致Cu的可氧化态含量较高也有一定的生态风险。Pb会被Fe-Mn氧化物所吸附导致Pb的可还原态含量较高,存在较高的潜在生态危害。Mn的弱酸提取态、可还原态和残渣态含量都较高,在迁移的过程中变化地较快,能够逐渐降低Mn对自然环境的危害。其他各重金属(As、Cr、Zn)则都以残渣态为主,潜在危害较低。 相似文献
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全氟化合物的分布、累积及生态毒理学效应 总被引:1,自引:0,他引:1
全氟化合物(Perfluorinated compounds,PFCs)污染在全球范围内已普遍存在,其在环境中的浓度增长迅速,受到人们越来越多的关注。环境中PFCs的迁移转化规律决定其环境效应,是进行环境和健康风险评价的基础。目前关于PFCs的研究主要集中于水体及生物体内PFCs的分析检测,对其生态毒理效应的研究尚处于初步阶段。本文介绍了PFCs研究现状,综述了PFCs在环境中的分布模式、生物体内的蓄积规律以及环境中PFCs的生态毒理效应等方面的最新研究进展,同时也阐述了PFCs污染对人体健康的影响,并提出了未来PFCs研究亟待解决的问题。 相似文献
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抗生素被长期大量地使用于人和动物的疾病治疗,同时作为饲料添加剂长期使用于畜牧业及水产养殖业。然而,大部分抗生素不能完全被机体吸收,大量的抗生素以原形或代谢物形式经由病人和禽畜粪尿排入环境,经不同途径进入土壤和水体,从而造成环境污染。多项研究显示在城镇废水和地表水中检测到了抗生素的存在,但关于抗生素在环境中的迁移转化及生物效应等研究资料很少。环境中的抗生素会对微生物、水生生物、土壤生物和植物等产生危害,并产生大量耐药菌,影响禽畜等的正常生长,进而对人类健康及整个生态系统构成威胁。为评估抗生素在环境中潜在的危害,本文就抗生素在环境中的迁移转化以及生物效应等多方面进行综述,并提出了今后研究的方向。 相似文献
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《中国环境管理干部学院学报》2018,(1)
正渤海湾滨海湿地土壤微生物实验室以渤海湿地"水体-土壤-生物"生态环境系统为主体研究对象,围绕该环境中污染物在环境介质中的迁移、蓄积、代谢和转化过程,借助现代分析表征手段和方法,研究污染物的环境化学行为和生态毒理效应,以及土壤微生物在转化过程中的响应及作用。实验室依托国家自然科学基金(项目编号:41201244)及河北环境工程学院实验中心,以研究污染物在海洋-河流-土壤-生物等介质间的传输和转化途径及由此导致的生态环境危害机制为主要研究内容,研究方向和相关内容如下:(一)滨海湿地系统中土壤微生物的环境生物化学 相似文献
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壬基酚在活性污泥系统中的去除研究进展 总被引:3,自引:0,他引:3
壬基酚是一种持久性有毒的内分泌干扰物,它会对生物系统产生有害影响。本文介绍了壬基酚的来源、物化性质、化学结构、城市污水处理厂和实验系统中的迁移转化及去除,以及壬基酚在活性污泥分离的菌种中的降解。最后分析了目前研究中存在的问题并提出了相应的解决方法。 相似文献
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External loading of phosphorus (P) from agricultural surface discharge (tailwater) is the main cause of excessive algae growth and the eutrophication of the Salton Sea, California. Continuous polyacrylamide (PAM) applications to agricultural irrigation water inflows were evaluated as a means of reducing sediment and P in tailwater. Zero (control) and 1 mg L(-1) PAM (PAM1) treatments were compared at 17 Imperial Valley field sites. Five and 10 mg L(-1) PAM treatments (PAM5, PAM10) were conducted at one site. The particulate phosphorus (Pp) fraction was determined as the difference between total phosphorus (Pt) and the soluble phosphorus (Ps) fraction. We observed 73, 82, and 98% turbidity reduction with PAM1, PAM5, and PAM10 treatments. Although eight field sites had control tailwater sediment concentrations above the New River total maximum daily loads (TMDL), all but one were made compliant during their paired PAM1 treatments. While PAM1 and PAM10 reduced tail water Pp by 31 and 78%, none of the treatments tested reduced Ps. This may have been caused by high irrigation water Na concentrations which would reduce Ca adsorption and Ca-phosphate bridging on the PAM. The PAM1 treatments resulted in <0.5 mg L(-1) drain water polyacrylamide concentrations 1.6 km downstream of PAM addition, while PAM5 and PAM10 treatments produced > 2 mg L(-1) drain water polyacrylamide concentrations. We concluded that, although PAM practically eliminates Imperial Valley tailwater sediment loads, it does not effectively reduce tailwater Ps, the P fraction most responsible for the eutrophication of the Salton Sea. 相似文献
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聚丙烯酰胺类絮凝剂的制备及应用研究 总被引:2,自引:0,他引:2
为了研究絮凝效果与絮凝剂分子结构的关系,实验中制备了聚丙烯酰胺(PAM)、阳离子化聚丙烯酰胺(CPAM)和部分水解聚丙烯酰胺(PHP),将其分别与FeCl3复配后处理钻井废水。实验探讨了絮凝剂的分子量、PHP的水解度及阳离子度对絮凝作用的影响。实验结果表明:PAM、CPAM、PHP与无机混凝剂复配使用处理钻井废水时,最佳分子量是500万,处理效果依次为PHP>PAM>CPAM。 相似文献
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聚丙烯酰胺降解菌的分离和鉴定 总被引:1,自引:0,他引:1
三次采油产生的大量含聚丙烯酰胺(PAM)的污水急需处理,其核心问题是PAM的生物化学降解。文章叙述了从含聚合物油田污水中分离到七株PAM降解菌的过程,并对其营养物体系进行了初步研究及分子生物学鉴定。结果表明,分离到的七株菌可以以PAM为唯一氮源和碳源进行生长,但是生长速度较慢,添加液蜡或酵母膏等可导致微生物菌群的共代谢,能加快PAM的生物降解。七株菌分别归类于放线杆菌纲和α-变形菌纲及芽孢杆菌,与数据库中已知菌的同源性均超过98%。 相似文献
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Paz Pérez-Sangrador M Cristina León-Cófreces M Acítores-Benavente M Cruz García-González M 《Journal of environmental management》2012,93(1):67-70
Most of the organic nutrient elements (nitrogen and phosphorus) and carbon compounds in liquid swine are contained in fine suspended particles. Flocculation treatment with polyacrylamide (PAM) followed by screening is one the best methods to separate the liquid fraction from the solid fraction in swine manure, and thus to eliminate nutrient elements associated with solids. In this study, the efficiency of a synthetic polyacrylamide to treat swine manure was evaluated. After polymer treatment samples were sieved and the filtrated liquid was analyzed. TSS, VSS and COD concentrations in the liquid fraction were 2.17, 1.93 and 16.42 g/L respectively, accounting for 94, 94 and 77% removal percentages for TSS, VSS and COD using 30 mg/L of PAM. 相似文献
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Polyacrylamide distribution in columns of organic matter-removed soils following surface application
Knowledge of how polyacrylamide (PAM) penetrates and distributes in a soil profile after application in irrigation water is important for understanding PAM conditioning depth and evaluating its environmental effects. Little is known, however, about PAM distribution in soil because of the difficulty in quantifying PAM content in natural soils. By using a recently modified substrate-borne PAM quantification method, PAM distribution in columns of organic matter-removed soils was determined. Results showed that penetration of PAM into the soil was affected by salt level of irrigation water, soil texture, initial soil water content, water application method, and other factors. Polyacrylamide penetration depth was about one-eighth to one-half of the water penetration depth, with a particularly high PAM retention in the top few centimeters of the soil. Under different experimental conditions, the PAM retained in the top 0 to 2 cm of soil ranged from 16 to 95% of the total applied amount. More favorable solution-soil contact conditions, longer solution-soil contact time, and lower initial soil moisture caused much more PAM retention in the top few centimeters of the soil. High sorptive affinity of PAM on soil is the main reason for its low penetration into the soil. Although these results were not obtained from natural soils, they are still helpful in improving our understanding of PAM transport behavior in soils. 相似文献