污泥和粉煤灰的循环利用及其对石漠化土壤质量的改善

本文通过在石漠化土壤中添加不同配比的城市污泥—粉煤灰混合物,研究其对石漠化区域土壤理化性质、持水性能,及在该石漠化土壤上所种植的高羊茅生长和重金属积累的影响。结果表明:施用粉煤灰能显著降低污泥Cu、Mn、Zn和Cd等重金属的含量并使土壤的pH得到提高,明显改善土壤的理化性质;土壤饱和含水率比对照提高1.95倍,持水时间提高7d左右,能增加土壤的N、P养分,并显著提高高羊茅的生物量,不失为促进石漠化地区生态恢复治理的一种有效方法。但由于重金属在环境中半衰期长、彻底清除难和生态毒害大等特点,不宜长期反复施用富含重金属的城市污泥。      

关中娄土剖面中重金属元素的垂直分布规律研究

通过对关中平原西安污灌区、宝鸡峡灌区、交口灌区关中娄土剖面土壤样品的采集、监测,重点分析了对土壤环境及人体危害较大的Cd、Pb、As、Cr等重金属元素在土壤剖面中的垂直分布和淋失迁移的特征.结果表明:在长期污灌的条件下,关中娄土剖面中的Cd、Pb、As、Cr含量具有在土壤耕作层富集的特征,关中娄土剖面中的Cd、Pb含量具有从耕作层向土壤下层递减的趋势,As、Cr含量从耕作层向土壤下层递减的趋势不明显.关中娄土剖面中的Cd、Pb、As、Cr含量在80～100 cm土壤粘化层中均具有明显增高的趋势,为土壤剖面中重金属元素垂直分布的转折层.关中娄土剖面中重金属元素的淋失率具有CA>Cr>As>Pb的特征,且土壤剖面中重金属的淋失率具有从耕作层、犁底层、老耕层、古耕层、粘化层垂直递增的趋势.当污灌区土层中的重金属含量高时,土壤剖面中的重金属元素Cd、Cr、As、Pb均可向土壤下包气带土层淋虑迁移,对地下水的安全构成威胁.     

南京城市土壤某些元素的富集特征及其对浅层地下水的影响

本研究以南京市的公园、校园绿地、道路绿地和郊区菜地等不同功能区的土壤为对象,对土壤的磷素和重金属以及一些土壤剖面点位的地下水组成进行了分析.研究发现城市土壤构成了区别于自然背景的某些元素(如磷和重金属)的地球化学垒,形成了明显的元素富集区域,其中磷素含量是背景土壤的数倍甚至十数倍,Pb含量也远高出背景土壤,60%以上样品达到中等污染程度以上.从磷素在剖面中的积累模式可以看出,城市土壤中磷含量最高的层次出现在表层以下的不同深度,说明土壤经历了不同的扰动过程,这意味着在城市发展过程中,土壤的性质遭受强烈的人为活动影响,元素在土壤中的分布形态可以指示不同的利用历史.质量改变后的土壤对地下水等环境产生影响,使地下水的组成发生改变,其中磷素含量直接受到土壤的影响,效区菜地地下水中硝态氮含量极高,而本研究尚未发现地下水中的重金属含量与土壤有显著相关.     

华北平原某集约化种植区地下水污染探讨

以华北平原某集约化种植区为典型研究区域,通过对采集的8个地下水样品及11个土壤样品分析,探讨集约化种植区地下水的污染程度,解析其污染影响机制。结果表明:该集约化种植地区土壤中残留物主要为有机氯农药,多环芳烃及邻苯二甲酸酯类有机化合物。地下水中硝酸盐含量显著增加;重金属中以Cr含量最高,但均未超标;地下水并未受到有机氯农药的污染,但仍显示有多氯联苯的输入;半挥发性有机物检出种类较多,其中残留农膜释放的邻苯二甲酸酯类有机化合物浓度最高;地下水已受到较为严重的污染。集约化种植区大量施用化肥、农药和覆盖农膜,污染负荷严重,灌溉频繁且量大,污染质运移驱动力大是地下水污染的根本原因;当地包气带中黏性土厚度不均以及井孔止水不严等因素也成为了地下水受到污染的直接原因。     

重金属在干旱内陆盆地浅层地下水中的迁移特征——以石羊河流域昌宁盆地为例

在分析石羊河流域昌宁盆地水文地质条件基础上,系统采集了不同深度(0～140 m)的8组岩土样,进行了重金属及盐分含量分析和室内吸附实验,并对测试结果进行聚类分析.结果表明: 受区内包气带岩土层对废水中重金属的吸附作用的影响,废水对地下水的影响微弱,包气带对地下水起到了很好的屏障作用;重金属及盐分在地下岩土中的分布明显受地下水、岩性及颗粒大小等影响,并存在两个峰值,即地下水位变动带(地下65～85 m深)和多层粉土、粘土层区(地下130～140 m深).     

不同母质土壤重金属含量与生态风险评价

为防治土壤重金属污染,建设绿色无公害农业产业基地,在黔东南黄平县分别采集典型砂页岩、老风化壳、石灰岩、页岩、河流冲积物、泥岩6种不同母质发育的土壤样品257个,测定土壤中Cr、Cd、Pb、As、Hg的含量及pH值,对比分析不同母质发育的土壤重金属含量差异性和与pH的相关性,采用Hakanson潜在生态风险指数法对研究区进行土壤重金属风险评价。结果表明,不同母质土壤Cd含量大小为石灰岩>河流冲积物>老风化壳>泥岩>砂页岩>页岩,Cr含量为老风化壳>泥岩>页岩>石灰岩>砂页岩>河流冲积物,Hg含量为石灰岩>泥岩>砂页岩>河流冲积物>老风化壳>页岩,As含量为泥岩>石灰岩>老风化壳>砂页岩>页岩>河流冲积物,Pb含量为泥岩>老风化壳>石灰岩>砂页岩≈页岩>河流冲积物。不同母质发育的土壤重金属含量均存在显著性差异(p<0.05),表现为Hg>As>Cd>Pb>Cr。不同母质发育的土壤重金属与pH相关性研究表明,砂页岩土壤C...     

镇江谏壁热电厂煤灰库对周边土壤硒的环境影响

镇江谏壁热电厂始建于1959年,是华东电网的主力电厂之一,已创下发电量连续26年超100亿kW/h的非凡业绩,产生了大量的粉煤灰.选取龙山煤灰库和贞观山煤灰库作为研究对象,对煤灰库区的粉煤灰、地表水及其周边水系沉积物、岩石、土壤、水稻籽实等不同类型样品进行分析,发现表层土壤受粉煤灰影响存在Se富集,按照谭见安的划分标准,足Se和富Se土壤分别占总面积的32.96%和43.08%;Se不足和Se缺乏土壤分别占总面积的7.86%和6.76%%;Se过剩土壤占总面积的9.34%,主要分布在煤灰库下游附近,最大值达14.7×10-6.调查表明,离煤灰库较远的农田Se主要来自高Se含量灌溉水,离煤灰库较近的农田除受高Se含量灌溉水影响外,同时还受到随水迁移的粉煤灰沉积物的叠加影响.根据Se与重金属元素聚类树状图判断,土壤在输入Se的同时亦输入了一定量的Cd、Hg和Pb,从输入量看Hg>Cd>Pb.总体上,表层土壤As、Cd、Cr、Cu、Hg、Ni、Pb和Zn等重金属元素含量多小于相应的土壤环境质量一级标准(自然背景值),浓度未达到污染水平,只有Cd和Hg的最大值接近农田土壤二级标准.受土壤环境影响,区内存在富Se大米,且大米中As、Cd、Cr、Hg、Pb等重金属元素的含量没有出现超标现象,表明该地区具备生产富Se大米的潜力.建议在该区域利用不同水源进行灌溉,从而调整土壤中Se含量,即对土壤Se缺乏区域灌溉高Se含量水,使富Se土壤区域扩大,对已存在Se过剩的土壤引用一般水源灌溉,使之范围缩小,含量降低.通过该项研究得出一个结论:粉煤灰中含有较高的Se,而有害重金属含量甚少,因此可提取Se或将粉煤灰直接添加到肥料中制成富Se肥.     

用若干固体废弃物改衣土壤的可行性研究

合理利用粉煤灰、水库淤积物和污泥三种废弃物对保护环境有重要意义。选择干旱－半干旱地区，联合施用上述三种废物进行土壤改良，兼有建设生态环境的作用，盆栽试验结果表明：粉煤灰、水库淤积物、污泥按适当比例配合施用，对改良贫瘠土壤、促进植物生长有明显效果。     

粉煤灰土壤及所产蔬菜的有害元素含量变化和环境意义

利用南京第二热电厂湿排的粉煤灰,进行了改良蔬菜土壤的试验,并对试验用的粉煤灰、不同施灰量的土壤及所产蔬菜共３８ 个样品的有害元素和放射性元素含量进行了系统的测定。结果表明：这些元素在土壤中的含量与粉煤灰施用量无明显相关性;在本次试验范围内施用粉煤灰没有造成土壤的污染;其所产蔬菜的这些元素含量也均低于国家卫生标准限值,食用是安全的。     

陕西省渭河扩建电厂粉煤灰处理场土壤对Cr（Ⅵ）的吸附作用

粉煤灰处理区的环境地质调查表明:由于受地面排放的粉煤灰的影响,地下水中Cr（Ⅵ）浓度高出背景值4⁵倍.野外现场试验对Cr（Ⅵ）监测结果显示:在2m厚的灰体底部,下渗水中的Cr（Ⅵ）浓度已高达0.701ppm,超标14倍.很明显,Cr（Ⅵ）是粉煤灰中的主要污染质之一.老灰场的环境地质调查还发现:土壤对Cr（Ⅵ）的迁移有很大的阻滞作用.作者对此进行一系列野外及室内试验来研究粉煤灰中Cr（Ⅵ）的解吸,迁移及其与土壤之间的相互作用和有关的化学机理,并且评价了渭河扩建电厂新灰场区土壤包气带对粉煤灰中Cr（Ⅵ）的净化能力.     

Characteristics of heavy metal accumulation on fly ash- and sewage sludge-amended calcific soil

Land disposal of fly ash(FA)and sewage sludge(SS)is a major problem due largely to their potentially harmful constituents.In this paper,a potting experiment was performed to evaluate the effects on the plant growth and to discuss in particular the potential hazard to soils and plants according to the characteristics of heavy metal accumulation and migration when FA and SS are used as the amendments of calcific soil in a limestone mining area. The results showed that the application of FA-SS mixture is capable of accelerating the growth of plants and improving the biomass production at either 1:1 or 1:2 FA-SS mixture:soil(w/w).The highest yields were obtained at 1:1(w/w)mixing ratio.When compared with the Element Background Values of Soils in China,the analysis on heavy metals indicated that the contents of Pb,Cr,Hg,Cd,As,Ni,Cu and Zn in the amended soils came up to the second-class environmental quality standards,only Hg and Cd showed significant accumulation.At the same time, though the metal concentrations in roots were higher than those for the control,the concentrations except Cu,Zn in shoots were lower.And all the heavy metal contents in the plants were substantially lower than the toxicity limits. The results indicated that the combined use of FA and SS at a rational rate of application should pose no danger to both soil and food chain based on the characteristics of the FS and SS,heavy metals and calcific soil.     

Effects of poor quality irrigation waters on the nutrient leaching and groundwater quality from sandy soil

Sodium (Na⁺) in poor quality irrigation water participate in ion-exchange processes results in the displacement of base cations into solution and a raised concentration in groundwater. Knowledge of the rate of decrease of nutrients from soils resulting from poor water quality application is essential for long-term planning of crop production while minimizing the impact on groundwater quality. In this study, we examined the effect of sodium adsorption ratio (SAR) of irrigation water on nutrients leaching and groundwater quality in columns of sandy soil. Three types of irrigation waters at three NaCl–CaCl₂ solutions with the following levels of SAR (5, 15, and 30) were synthesized in laboratory. With the application of solutions, exchange occurred between solution Na⁺ and exchangeable cations (Ca²⁺, Mg²⁺, and K⁺), resulting in the displacement of these cations and anions into solution. Increasing the level of SAR from 5 to 15 and 30 resulted in increase in the average exchangeable sodium percentage (ESP) of the soil from 10.4 to 20.3, and 32.5, respectively. Adverse effect of high Na⁺ concentration in the solutions on raising ESP was less pronounced in solution having low SAR. Leaching of Ca²⁺, Mg²⁺, K⁺, and P from soil with the application of solutions represents a significant loss of valuable nutrients. This sandy soil showed the high risk for nutrients transfer into groundwater in concentrations exceeding the groundwater quality standard. Irrigation with poor quality water, which is generally more sodic and saline than regional groundwater, increases the rate of sodification and salinization of shallow groundwater.     

The use of vetiver grass (Vetiveria zizanioides) in the phytoremediation of soils contaminated with heavy metals

Recent research has shown that phytoextraction approaches often require soil amendments, such as the application of EDTA, to increase the bioavailability of heavy metals in soils. However, EDTA and EDTA–heavy metal complexes can be toxic to plants and soil microorganisms and may leach into groundwater, causing further environmental pollution. In the present study, vetiver grass (Vetiveria zizanioides) was studied for its potential use in the phytoremediation of soils contaminated with heavy metals. In the pot experiment, the uptake and transport of Pb by vetiver from Pb-contaminated soils under EDTA application was investigated. The results showed that vetiver had the capacity to tolerate high Pb concentrations in soils. With the application of EDTA, the translocation ratio of Pb from vetiver roots to shoots was significantly increased. On the 14th day after 5.0 mmol EDTA kg⁻¹ of soil application, the shoot Pb concentration reached 42, 160, 243 mg kg⁻¹ DW and the root Pb concentrations were 266, 951, and 2280 mg kg⁻¹ DW in the 500, 2500 and 5000 mg Pb kg⁻¹ soils, respectively. In the short soil leaching column (9.0-cm diameter, 20-cm height) experiment, about 3.7%, 15.6%, 14.3% and 22.2% of the soil Pb, Cu, Zn and Cd were leached from the artificially contaminated soil profile after 5.0 mmol EDTA kg⁻¹ of soil application and nearly 126 mm of rainfall irrigation. In the long soil leaching experiment, soil columns (9.0-cm diameter, 60-cm height) were packed with uncontaminated soils (mimicking the subsoil under contaminated upper layers) and planted with vetiver. Heavy metal leachate from the short column experiment was applied to the surface of the long soil column, the artificial rainwater was percolated, and the final leachate was collected at the bottom of the soil columns. The results showed that soil matrix with planted vetiver, could re-adsorb 98%, 54%, 41%, and 88% of the initially applied Pb, Cu, Zn, and Cd, respectively, which may reduce the risk of heavy metals flowing downwards and entering the groundwater.     

Transport,fate, and infectivity of <Emphasis Type="Italic">Cryptosporidium parvum</Emphasis> oocysts released from manure and leached through macroporous soil

A major mode of transmission of Cryptosporidium parvum, a widespread waterborne pathogen, is via contaminated drinking and recreational waters. Oocyst transport to surface water can occur by deposition of manure directly in the water or by wash off in surface runoff. Oocyst transport to groundwater is less straightforward and requires that the oocysts move through soil and bedrock to reach the water table. The purpose of this study was to determine the relative concentration and infectivity of C. parvum oocysts released from manure and leached through columns of undisturbed, macroporous karst soil. Modeling the fate of oocysts in this system over time can provide baseline data for evaluating real world events. Substantially more oocysts leached from undisturbed soil columns than disturbed soil columns. Oocyst survival studies using BALB/c neonatal suckling mice showed that about 85% of oocysts were infective at the beginning of leaching experiments. The oocyst infectivity decreased to about 20% after 12 weeks of leaching from soil columns maintained at 10°C. Cool (10°C) temperatures appear to increase survivability and maintain infectivity of many oocysts for 3 months or longer. Cool temperatures also appear to increase rates of release of oocysts from manure and leaching through soil. This study demonstrated that leaching is an important mechanism of oocyst transport in karst soils where infiltration capacities are high and long, continuous macropores exist. Karst groundwater systems might be especially vulnerable to contamination by leached oocysts, because of the prevalence of shallow soils and rapid groundwater movement. Oocysts leaching from soils into the epikarst could accumulate and remain viable for months until hydrological conditions are right for flushing the oocysts into the conduit flow system.     

Evaluation of fertility indicators associated with arsenic-contaminated paddy fields soil

Emerging environmental issues related to heavy metal contamination in rice draw great concern about the soil quality of paddy farming lands irrigated with groundwater. Investigating the functioning of soil microorganisms exposed to heavy metal contamination is imperative for agricultural soil manipulations. The current study accentuates the influence of heavy metals on microbial activity and community composition in arable soil of West Bengal State of India. The result revealed that the fertility indicators (activity of all soil enzymes) and growth-limiting factors (soil N and P) were negatively correlated with the heavy metal stress except the soil total organic content which demonstrated significant positive correlation with the heavy metals. In case of functional diversity of soil, all the considered diversity indices exhibited no specific pattern along with the availability of heavy metals. Further, despite the heavy metal contamination, we observed a very complex and indifferent pattern of bacterial community composition along the heavy metal contamination sites. Overall, we found that γ-Proteobacteria had been the most abundant bacterial community followed by Actinobacteria, Firmicutes, β-Proteobacteria and α-Proteobacteria. Commemorating all the results, we can infer that arsenic and other heavy metal contamination is deteriorating the soil quality and hence warrants immediate attention of concerned soil scientist and agronomists.     

Statistical characteristics of heavy metals content in groundwater and their interrelationships in a certain antimony mine area

In recent years, most of domestic and foreign researches about heavy metal pollutions of metal mine mainly focus on water, soil and plants on the surface. There is lack of researches about heavy metal pollution in groundwater of metal mine. In this research, a certain antimony mine area is selected as a typical study area. Also, the study about statistical characteristics of heavy metals in groundwater has been carried out. Furthermore, the interrelationships have been preliminarily discussed through related analysis, such as relevant analysis, cluster analysis and principle component analysis. The results show that: the excessive elements in groundwater of study area are Sb, As, Pb, Se, and Ni. The average mass concentration of Sb, As, and Pb is higher than that of drinking water standards (GB5749-2006). The concentration of most heavy metals in dry season is lower than or equal to that in wet season for groundwater. Zn is the only metal in groundwater showing a different pattern, the concentration of which in dry season is higher than that in wet season. Under the impacts of stratum leaching and absorption effect, the concentration of heavy metals (except Pb and Ba) in groundwater are lower than or equal to that in surface water. As and Se, the two heavy metals have a significant positive correlation, which shows the two elements might have gone through similar environmental geochemical effect. Also, the connection among Zn, Hg, Pb, and Mn is not obvious; therefore, the sources of those elements are quite different. In addition, the elements of Se and As have obvious positive interrelationship with elements of CO32- and F-. Also, the Pb has significant positive correlation with PO43-, H2SiO3 and oxygen consumption. The results of cluster analysis show that 9 different heavy metals in the study area can be divided into 3 categories: Zn, Cd, Mn, Hg, Cu, and Cr belong to the first category, Se and As belong to the second one, and the last category is Pb. Also, the principle component analysis divides 6 heavy metals (Zn, As, Hg, Pb, Mn, and Se) into 4 different principle components, which can be utilized to assess heavy metals pollution situations in groundwater. The reliability of this method is higher than 91%. Moreover, the research provides theory basis and models for establishing evaluation index system and exploring the evaluation method of heavy mental pollution in groundwater.     

人工回灌过程中富里酸和Cu(Ⅱ)对多孔介质悬浮物堵塞的影响

地下水人工回灌是解决地下水超采问题的有效措施,悬浮颗粒物堵塞是影响回灌进行的技术瓶颈。目前多数研究聚焦在悬浮物堵塞方面,然而地表回灌水中重金属离子以及腐殖质对多孔介质物理堵塞的影响缺乏研究。本研究采用室内渗流砂柱试验研究富里酸、Cu(Ⅱ)以及两者共存对多孔介质悬浮物堵塞的影响,分别采用高岭土（SS组）、富里酸+高岭土（SS+FA组）、富里酸+Cu(Ⅱ)+高岭土（SS+FA+Cu组）配置模拟回灌用水。研究结果表明：（1）回灌结束时,SS组、SS+FA组、SS+FA+Cu组多孔介质整体相对渗透系数K’分别降至0.233,0.095,0.182。SS组和SS+FA+Cu组在中上层（0~7.50 cm）相对渗透系数K’均降至0.28以下,而在底层（7.50~10.50 cm）相对渗透系数K’仅降至0.45左右,说明2组多孔介质中上层重度堵塞（0相似文献   

Environmental Mineralogical Materials

Basic properties, including surface absorption, porous filtration, ion exchange, heat effect and chemical solubility of environmental mineralogical materials, are widely applied to the pollution prevention environment improvement. The pollunian prevenition environmenr means the quality improvement of surface water, groundwater, river, lake and ground reservoir: the improvement of soil, the disposal of nuclear waste, the purification of domestic sewage, the collection of smoke and dust and the treatment of waste water. The prospective investigation and utilization of environmental mineralogical materials have been dealt with in more detail by the author of this paper with emphases on the prevention and control of soil contamination by heavy metals, on the quality im provement and treatment of surface water and groundwater,and on the collection of smoke and dust arising from burning coals.     

模糊综合评判法在淮南市浅层地下水评价中的应用

通过对淮南市浅层地下水水样进行测试、分析,选取氯离子、硫酸盐、硝酸盐氮、总磷、锰、铅等六项指标为评价指标,依据《地表水环境质量标准》(GB3838-2002),运用模糊综合评判法对研究区水质进行了合理评价。研究结果表明:淮南市浅层地下水综合水质较差,大部分地区浅层地下水已遭受到不同程度污染,多数水体不能直接作为饮用水。