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91.
Chromium pollution were investigated by sampling the abandoned chromium contaminated sites in Chongqing. Its health risk was assessed following the procedures made by USEPA. The results showed that the most seriously polluted land was found at the former production area (G4) with average Cr(VI) concentration of 3369.2 mg kg-1 on the surface soil. The assessment indicated that there was high risk of non-carcinogens for children. The assessed risk of the first layer of office area (G1) for children, chromium slag transition (G2), drainage pipeline chromium slag transition (G3) and production area (G4) for both children and adults were not acceptable (〉1.00× 106). It was strongly suggested that the accessible measures of remediation should be taken for a portion of contaminated sites before the reuse of abandoned lands.  相似文献   
92.
As in many other areas, the perennial cord grass Spartina anglica C.E. Hubbard has been extremely successful at colonising the English and Irish south coasts, but it is dying back for reasons that are not completely understood. The present study considers the relationship between die-back and metal concentrations in estuarine sediment. No obvious impact of the metal contamination on the S. anglica growth/die-back could be detected in the study zone, Poole Harbour, although the die-back did seem to have substantially influenced the metal concentrations in the sediments of the estuary. Based on core profiles, the remaining patches of S. anglica still retain elevated concentrations and the overall cadmium concentrations in the sediments have risen since 1925. However, considerable quantities of the cadmium stored in the sediment by S. anglica appear to have been washed out rapidly in the die-back zones. Should serious erosion of the saltmarsh occur, triggered for example by sea-level rise, then sudden and high levels of cadmium release may cause harmful effects to marine biota.  相似文献   
93.
王588块钻井泥浆污染主要是固相入侵和滤液与地层水的不配伍性。通过实验,优选出了具有高效深穿透能力以及固相溶解量大的表面活性剂DS-101酸液复配体系。实验表明,该体系耐温性强,对油泥具有极强的分散和溶解作用,对泥浆污染有明显的解堵效果,岩心渗透率恢复率可达127%。  相似文献   
94.
山东铝业公司拟建第二赤泥堆场于母猪山石灰石采空区。该堆场运行后将对下游地下水体造成污染 ,pH值将达到 1 1 .3。为此 ,拟采用赤泥、石灰配比为 1∶9的抗渗垫层进行防渗。根据水流运移特征及防渗材料特征 ,评价满足堆场使用 2 0年的最佳垫层厚度为 1 .0m。  相似文献   
95.
This work reveals the usefulness of the GIS (Geographic Information Systems) mapping techniques to show the distribution of pollutants along an estuarine environment, as the final stage of a thorough study. In the case of study, the environmental quality of the sediments in the Guadiana river estuary was determined by means of a complete geochemical characterization consisting on the calculation of enrichment factors for the most important metals and metalloids (compared with the local background of non-contaminated sediments). The obtained results were depicted in “enrichment distribution maps” which evidenced a distribution of the elements in two groups: Group-I, elements with natural origin (Al, Fe, Mn, Co, and Cr) distributed homogeneously along the basin, and Group-II, elements associated to anthropic origin (As, Cd, Cu, Pb, Ni and Zn) with clear punctual sources besides a high concentration all over the estuary. The enrichment factors for the elements of Group-II are indicative of the existence of a noticeable diffuse historical mining pollution associated with the acid mine drainage generated in the internal zones of the basin, which could overlap minor pollution inputs from other human activities. The obtained results lead us to a reconsideration of the traditionally thought “unpolluted” environment when it was compared to nearby estuaries.  相似文献   
96.
The mobility, bioaccessibility and transfer pathways of metals and metalloids in estuarine sediments have been the focus of much detailed research. However, to date, few studies have examined the mineralogical siting of metals and metalloids in such sediments. This is despite the fact the mineralogy of sediments is an important factor that controls which and how much of a particular metal is released to pore waters and overlying water columns. This study reports on the mineralogical siting of metals in contaminated estuarine sediments, Hobart, Australia, and aims to evaluate the mobility of metals in the contaminated substrates. Mineralogical, mineral chemical and bulk chemical analyses demonstrate that the sediments contain very high levels of several metals and metalloids. The contaminated sediments have concentrations of zinc (Zn), lead (Pb), copper (Cu) and cadmium (Cd) ranging from 0.55 to 4.23 wt%, 0.16 to 0.70 wt%, 415 to 951 mg/kg and 23 to 300 mg/kg, respectively. Franklinite and lesser sphalerite are the main repositories of Zn, whereas much of the Pb and Cu is hosted by sulfides, organic matter and undetermined iron (Fe) oxides. While the release of contaminant loads from franklinite through dissolution is likely to be insignificant, even small releases of metals from the highly contaminated sediments can still cause the deterioration of local water quality. The contaminated sediments represent long-term sources of metal pollutants, particularly Zn, to local waters. This study demonstrates that mineralogical analyses are a vital tool to recognise the potential mobility of trace metals in estuarine environments.  相似文献   
97.
A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient (ADC) of Japanese flounder (Paralichthys olivaceus). The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences (P 〉0.05) in growth performance among the treatments fed with 0% -60% MBM replacement of fishmeal, while the percent weight gain (WG, % ), body length gain (BLG, % ) and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences (P 〉0.05) in growth performance and ADC among all treatments fed with the diets with 0% -80% replacements of fishmeal with PBM.  相似文献   
98.
 Anthropogenic activities create various contaminated leachate, which can migrate downward from the vadose zone to groundwater, transferring contaminants, including some hazardous ones. When these various sources of contamination influence the groundwater aquifer simultaneously, the effects of contamination are enhanced. The major concern of this study has been to determine whether the shape of a groundwater chlorograph might be the result of such deterministic effects as accumulation of one or more particular processes of groundwater contamination, and how this might relate to specific hydrological situations. This study proposes a classification of groundwater contamination on the basis of properties of the main components of groundwater quality graphs and the corresponding hydrogeological/environmental situation. The study further suggests that contamination of groundwater in any hydrogeological situation (e.g. sea water) may be graphically expressed. A variety of chlorographs and nitrographs, representative of various groundwater aquifers sampled from a number of wells throughout Israel attest to this. The study thus indicates that groundwater quality graphs may be considered as a complementary tool for groundwater quality control and better understanding aquifer situations.  相似文献   
99.
胡秀艳  谢红青  景山 《江苏地质》2023,47(4):412-419
选取扬州邵伯地区作为研究区,根据评价标准(GB 15618—2018)对其农田土壤环境质量及生态风险进行评价。研究区农田土壤中8种重金属元素平均含量均低于农用地污染风险筛选值,除Ni外其余7种重金属元素的平均含量均超过江苏土壤平均背景值,其中Hg含量均值为江苏土壤平均背景值的2.16倍;通过对比内梅罗指数法和综合指数法评价结果,认为综合指数法能更客观准确地反映研究区农田土壤环境质量状况,结果显示研究区农田土壤轻度污染以上样本占总样本的2.35%;研究区农田土壤属中度生态风险,综合潜在风险指数平均值为200.56,主要贡献因子是Hg。  相似文献   
100.
为了解江苏某材料厂金属冶炼活动引发的重金属污染风险,采集周围农田土壤、小麦和水稻籽实样品,确定Mo含量及其在土壤中的形态,采用地质累积指数和富集因子指标评价土壤中钼的污染风险,采用健康风险指数评价小麦、稻米中Mo的健康风险。结果表明,农田土壤中Mo含量在0.50~63.2 mg/kg之间,其平均值5.70 mg/kg远高于全省平均值0.65 mg/kg,表层土壤出现了中度—高度富集,近70%的样点受到不同程度的钼污染,污染范围距该厂300 m,污染深度>1.5 m。土壤中的Mo具有较高的生物有效性,在小麦、水稻籽实中显著富集,主要与土壤具有较高的全Mo含量以及土壤呈碱性有关。基于EPA的健康风险评估方法,食用当地稻米、小麦会产生较大的健康风险。  相似文献   
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