共查询到19条相似文献，搜索用时 250 毫秒
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底泥修复技术与资源化利用途径研 总被引：2，自引：0，他引：2
阐述了当今污染底泥修复技术方法，以及污染底泥资源化利用途径。目前物理修复主要有疏浚、掩蔽和引水等方法，化学修复和生物修复方法。物理修复效果明显，但投入大；生物修复投入低，修复面积大，但速度慢等特点。底泥资源化利用途径有土地利用，填方材料，建筑材料，污水处理材料等。并且对各种修复技术和资源化利用途径进行了比较探讨，分析了各种技术方法的优点与不足。 相似文献
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由于长期大量的工农业污水排向河道,河道底泥中重金属污染严重超标,如何高效经济地修复污染底泥,并拓展资源化利用路径是个难点问题.目前采用的传统的底泥重金属稳定化技术大多借用污泥处置或者土壤修复方面的经验和技术,有pH值偏高等固有的弱点.本次实验研究采用了新型改性剂,对重金属稳定后,浸出浓度达到地表Ⅲ类水标准,修复后土壤偏中性,表明产品适合在工程中推广应用. 相似文献
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研究不同pH条件下低温强化混凝对某水源水中有机物的去除效果和去除机理，为微污染水源水饮用处理工艺在低温条件下达标提供方法和参数。采用烧杯混凝试验，测定混凝对高锰酸盐指数（CODMn）、紫外吸光度（UV254）的去除率，分析强化混凝去除有机物的分子量范围和有机物类型。通过降低pH，强化混凝可明显提高对CODMn和UV254的去除效率，特别提高了对分子量在1k~4k范围的溶解性有机物的去除率；被强化混凝去除的有机物主要是可被活性炭吸附和难生物降解的部分；由此得出强化混凝是低温条件下去除水中有机物和消毒副产物（DBPs）前质的有效手段。 相似文献
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石油类污染地下水土环境的曝气修复实验研究 总被引：1，自引：0，他引：1
曝气修复是一种去除水土环境中挥发性污染物的高效技术,具有良好的工程应用前景,但其机理有关的工作仍有进一步研究的空间。以石油类污染的饱和地下水土环境为研究对象,选取柴油作为代表性污染物,建立一维土柱模拟装置,开展地下水曝气修复技术的实验研究。通过5个土柱曝气系统的运行与监测,分析不同土壤介质、曝气流量条件对曝气过程及污染物去除效率的影响。结果显示:利用曝气修复技术可有效去除挥发性污染物,且增加曝气流量有利于提高污染物去除效率,高渗透率介质中污染物去除效率要高于低渗透率介质。此结论可为曝气修复技术的其他研究工作提供依据。 相似文献
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生物慢滤技术的应用与发展 总被引：2，自引：1，他引：2
随着慢滤技术的改进与发展，预处理技术如粗滤、预臭氧处理等使得慢滤可适合处理不同的水源水，而且可去除更多的污染物。在慢滤池中加入一层活性炭可以提高其去除人工合成有机物的能力。介绍了传统慢滤池和改进型慢滤池的一些设计参数，讨论了最近几年来研究人员对慢滤技术所做的改进以及慢滤技术的应用。 相似文献
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低温下强化混凝去除微污染水源水中有机物的研究 总被引：2，自引：0，他引：2
研究不同pH值条件下低温强化混凝对某水源水中有机物的去除效果和去除机理,为微污染水源水饮用处理工艺在低温条件下达标提供方法和参数。采用烧杯混凝试验,测定混凝对高锰酸盐指数（CODMn）、紫外吸光度（UV254）的去除率,分析强化混凝去除有机物的分子量范围和有机物类型。通过降低pH值,强化混凝可明显提高对CODMn和UV254的去除效率,特别提高了对分子量在1-4 k范围的溶解性有机物的去除率;被强化混凝去除的有机物主要是可被活性炭吸附和难生物降解的部分;由此得出强化混凝是低温条件下去除水中有机物和消毒副产物（DBPs）前质的有效手段。 相似文献
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寻找环境友好型的土地整治工程修复材料，已经成为国内外土地整治工程领域中的新热点。随着材料科学的飞速发展，有机材料、无机材料、纳米材料、复合材料和生物材料等在土地整治工程领域中的应用越来越受到重视，这些材料由于具有巨大的比表面积、微界面性质、吸附特性、重金属螯合作用和降解有机污染物等特性，在重金属污染、有机物污染物等污染土壤的治理中，以及土壤理化性质的改良中有望发挥重要作用。综述了目前有机材料、无机材料、纳米材料、复合材料和生物材料在土地整治工程领域的应用研究进展，并总结了应用研究的不足，指明了研究方向，为深入研究提供借鉴。 相似文献
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有机物污染土壤修复方法介绍 总被引：1，自引：0，他引：1
土壤中有机污染物种类繁多，强烈的疏水性，与土壤结合紧密不易被微生物降解，在食物链中易堆积且具有潜在的致癌风险，使得土壤中有机物污染的修复成为大家关心的热点。文章主要介绍溶剂萃取、化学氧化、电动力修复、生物修复、植物修复法、热解法在修复土壤中的有机污染物方法。 相似文献
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地下水中硝酸盐氮污染修复技术综述 总被引：1，自引：0，他引：1
介绍了地下水中硝酸盐氮的来源和危害,较全面地阐述了地下水中硝酸盐氮的物理、化学、生物修复技术的研究情况,比较了各种方法的优缺点,并对其发展趋势进行了简单的论述。 相似文献
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为了探究铜绿微囊藻对水环境的影响以及对沉积物中砷(As)和锑(Sb)迁移过程的影响,以沉积物/上覆水模拟柱为研究对象,监测不同浓度藻类衰亡过程中环境因素及物质浓度变化,分析藻类对沉积物中As和Sb迁移的影响.结果表明:在铜绿微囊藻活动的影响下,上覆水中溶解氧浓度和氧化还原电位均发生显著降低,为沉积物颗粒溶解提供了有利条件.渗透入沉积物中的铜绿微囊藻适应期间促进了As和Sb的迁移,二者的释放率均于投加藻细胞后第2天达到峰值,此时As在低藻组(LAD)和高藻组(HAD)中的最高释放率出现在沉积物-4 cm处,分别可达2.20和3.67,Sb的释放率在-2 cm处达到最大,分别为1.01和1.21,推测释放主要是由藻细胞在适应过程中对沉积物表面含As和Sb等营养物质的溶解作用导致的;藻类在衰亡阶段导致沉积物环境向还原性转化,此时As释放率再次增大,分别达到0.82和1.58,而Sb因还原性环境下的固化作用,释放率下降至0.13和0.12;HAD组中藻类活动对As和Sb迁移影响程度更大.研究表明沉积物中的藻类活动过程会影响As和Sb的迁移,为富营养化水体中重金属污染的控制提供依据. 相似文献
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《Agricultural Water Management》2005,71(1):19-32
Phosphorus (P) losses from agricultural lands degrade surface waters due to anthropogenic eutrophication. Previous studies focused on plot-to-field scale P loss and reductions from best management practices (BMP's), little information in intense agricultural catchments has been gathered on the dynamics influencing P beyond the edge of the field. This study was conducted to examine the phosphorus equilibrium between the water column and sediments in three tile fed drainage ditches in Northeast Indiana. Surface water and sediment samples were collected and analyzed for organic carbon (C), particle size and P from sites along three ditches with similar soils and land use at sites within each watershed draining approximately 300 and 1500 ha on each ditch. Organic C, silt and clay fractions of the bottom sediments decreased with increasing drainage area. Soluble P concentrations were low in Ditch A, but increased with increasing drainage area (0.02–0.05 mg P L−1). Overall, the P concentrations were higher in the Ditches B and C (0.06–0.09 mg P L−1). Exchangeable P, P partitioning index and equilibrium P concentrations (EPCo) decreased with increasing drainage area by as much as 95, 93 and 100%, respectively, except in one catchment area with a confined animal feeding operation between sampling points, where ExP and EPCo increased by 4 and 116%, respectively. Aluminum sulfate and calcium carbonate treatment of ditch sediments reduced exchangeable P and sediment EPCo in this study. Results from this study indicated some watershed characteristics, as well as sediment physiochemical properties, affect ditch sediment and water P equilibrium and buffering capacity. Furthermore, this study demonstrated that managers could potentially use chemical treatment of the ditches to increase the temporary retention of P in ditches and maybe reducing sediment P availability. 相似文献
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《Agricultural Water Management》2005,74(1):77-85
Water diverted from rivers to canals and then to fields brings along a heavy sediment load. According to estimates, the elevation of irrigated fields in the Indus Basin has increased up to 8 cm due to deposition of sediment from irrigation water. The deposition of sediment in the canals, distributaries and watercourses is a common concern. Each year during the winter, the canals are closed for desilting the conveyance system. Sediment deposited in the farmer-managed watercourses is piled along the watercourse banks, which takes fertile land out of production. This study was conducted to evaluate the possibilities of preparing cement blocks with soils and with sediments removed from the watercourses and using them in low cost linings to decrease losses from watercourses. Soil–cement and sediment–cement blocks were prepared, and tested for strength, durability and ability to reduce losses from watercourses. Compositions of the soil and of the sediments removed from the channels were determined. Blocks mortared into walls lining the sides of these channels reduced losses to less than 20% of losses in unlined old channels. Plastering the inside of these walls reduced water losses to less than 1% of the losses occurring in old unlined channels. Sediment–cement blocks were easier to make and they develop greater strength than soil–cement blocks. Cost of channel lining, using these blocks, appears to be about 2/3 of costs using fired brick masonry. 相似文献
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《灌溉排水学报》2019,(Z1)
【目的】从微观层面研究不同治理措施整治前后盐碱土结构变化,土壤结构与土壤性质相互作用,微结构变化对土壤性质的改善作用。【方法】对渭南市富平县褚原村"对流弥散"和"覆沙改良"试验小区的原状土进行采集,采用扫描电镜及能谱仪对采取"改排为蓄"和"覆沙改良"法整治前后的盐碱土进行微观形貌观测和元素组成分析。【结果】整治前盐碱土板结较严重,孔隙结构差,经淡水洗盐并经合理蓄水处理后的盐碱土颗粒变小,结构上呈片层状,利于水盐向下运移并有利于阻止返盐,"覆沙改良"法随着覆沙厚度的增加(5～15 cm),非毛管孔隙增多,土壤孔隙结构逐渐改善。【结论】对比"改排为蓄"和"覆沙改良"法整治后盐碱土微结构,"覆沙改良"法使土壤结构发生的变化较大。 相似文献
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Summary Observations and studies were conducted on the origin and destination of sediment in irrigation water, and the effects of sediment adsorbed on the wetted perimeter of furrows on water intake and erosion. Fine sediment adsorbed on the perimeter reduced intake and increased soil water tension which was the primary mechanism holding the sediment on the perimeter. This self enhancing effect causes this thin seal to decrease erosion and intake rates. In contrast, removal of a few square centimeters of this seal by chance events after water velocities and shear forces have increased often causes reduced tensions, exfoliation of the surface seal and erosion pits which develop into head cuts. 相似文献
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河南人民胜利渠泥沙专题研究组 《灌溉排水学报》1987,(1)
本文系统地整理分析了引黄人民胜利渠灌区1982—1984年三年泥沙测验资料,定量描述了在目前引水引沙条件、工程现状和运行管理水平下,灌区内的水沙分配现状、泥沙淤积分布现状、灌区退水退沙现状及其泥沙颗粒组成分布现状,探讨了形成现状的主要因素和主要特点,指出了灌区现存的突出问题,并提出了可供灌区借鉴的泥沙处理和利用的六项措施。 相似文献
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In this study deterministic, multivariate and stochastic methods are applied to a combined temporal and spatial monitoring data set, in order to assess nitrate and pesticide levels and contamination risk in shallow groundwater. The case study involves an area in the Mondego River alluvial body in central Portugal, where agriculture is the main land use, with predominantly maize, rice and some vegetable crops supported by river water irrigation. Factorial correspondence analysis (FCA), reducing the original data matrix to a small number of independent orthogonal factors, is applied to detect associations between nitrate levels, land use (crop type), lithology and groundwater depth. Indicator-geostatistical techniques are used to create maps indicating the probability of nitrate concentrations in groundwater exceeding predetermined threshold values, including the drinking water standard (98/83/EC) and vulnerable zone designation criterion (91/676/EEC) of 50 mg/l NO3−. For pesticides the leaching potential is determined by calculating the Groundwater Ubiquity Score (GUS), based on the sorption coefficient and soil half-life for each pesticide compound. Results for nitrate show an overall very low risk of exceeding 50 or 25 mg/l, whereas the risk of exceeding 9.5 mg/l (third data quartile) is particularly high in areas where FCA shows correlation of nitrate contamination with vegetable and maize crops, aerobic conditions, lower groundwater levels and to some extent, coarser grained sediments. On the contrary, nitrate levels under rice are lowest and correlated to a reduced environment, finer-grained sediments and a higher water table. Denitrification is found to be an important attenuation process, as well as dilution by surface water irrigation and precipitation. Crop type and irrigation source are seen to have a large influence on the nitrate contamination potential of groundwater. Total concentrations of the analysed pesticide compounds above the regulatory limit of 0.5 μg/l are observed in 32% of the analysed water samples, with a maximum value of 16.09 μg/l. The probability maps provide a particularly interesting example of how multiple-well monitoring results over a certain period can be condensed into single maps and used by water engineers, managers and policy-makers. 相似文献
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2004-2010年黄河干流汛前水库群联合调度、人工异重流塑造进行了7次,小浪底水库各年份异重流排沙比相差很大,排沙效果并不理想。通过深入分析,得出小浪底水库入库水沙、悬沙细颗粒含量、河堤站水沙变化以及三门峡水库调度与潼关来水组成等因素对水库异重流排沙的影响。结果表明:①入库水沙对小浪底水库异重流塑造起着关键作用;②在异重流塑造期间,入库沙量中细颗粒泥沙含量越高,异重流排沙比就会越大。随着异重流排沙比的增加,分组沙的排沙比也在增大,细颗粒泥沙增加幅度最大;③三门峡水库在下泄大流量清水的过程中,河堤以上河段是冲刷的;在敞泄排沙的过程中,河堤以上河段有冲有淤,在实际操作时可适当控制三门峡出库高含沙水流,来减少河堤以上河段的淤积,提高小浪底水库异重流排沙效果。 相似文献