一种集成工艺处理重金属废水工程实践

采用化学还原+重金属捕集+气浮过滤组合工艺处理重金属废水。结果表明:处理后的出水水质中重金属等各项指标均达到《污水综合排放标准》(GB8978—2002)所规定的一级水质排放标准,COD去除率达到40%以上,同时此工艺在工程实践中取得了最佳工艺参数,可为类似工程提供参考。     

外度水库底泥重金属的分析及潜在生态风险评价

对莆田市外度水库底泥中Fe、Mn、Cu、Zn、Ni、Cr、Pb、Cd、As的含量进行分析。采用潜在生态风险指数法,研究了底泥中重金属的污染水平及其生态危害。结果表明:莆田市Mn、Cu、Zn和Cd的含量高于福建省土壤重金属含量背景值。底泥中重金属的潜在生态风险评价显示:外度水库底泥中重金属具有轻微的生态风险。各种重金属的污染程度为:Cd>Cu>As>Ni>Zn>Pb>Mn>Cr>Fe。外度水库底泥的重金属潜在生态风险主要是由于底泥Cd的潜在生态风险系数过高所造成。在此基础上,对产生的原因进行了分析并提出了治理的建议。     

黄浦江表层沉积物重金属污染研究

用加拿大沉积物质量导则对黄浦江表层沉积物重金属污染进行评价,并对重金属、总有机碳、有机质和硫化物含量进行了相关性分析、主成分分析和聚类分析。结果表明,黄浦江表层沉积物重金属污染水平较低,工农业布局与重金属分布关系密切,苏州河对黄浦江下游重金属存在一定输入贡献,重金属之间有一定的相关性,重金属与总有机碳及硫化物的相关性较差,表明除受人类活动影响外,还受自然沉积过程的影响。     

秦岭安河矿区地表水、沉积物重金属污染研究

以秦岭安河铅锌矿开采区和选矿区为研究范围,通过现场调查和系统采集地表水、沉积物样品,借助原子吸收分光光度计测试样品中Cu、Pb、Zn、Cd、Cr 5种重金属全量,并对不同重金属的形态含量进行了测定,综合分析了各类重金属在地表水、沉积物中的富集迁移规律,实现了重金属污染程度的综合评价。结果表明:矿区沟道地表水、沉积物已受到严重的重金属污染,重金属元素自上游到下游呈累积现象。下游地表水重金属含量超出农田灌溉用水水质要求。中游、下游沉积物重金属污染指数达到Ⅲ级污染,主要污染物为Pb、Zn。沉积物中重金属的有效态所占比例较高,对周围环境直接威胁大,显示出外源重金属直接注入的特征。     

Environmental changes in Jiaozhou Bay of northern China during the past 90 years using metals and biogenic elements in sediments

Metals and biogenic elements were analyzed from surface sediments and a 100 cm core collected from Jiaozhou Bay in July 2009, to determine how the environment has changed over the past 90 years due to increasing anthropogenic influences in this region. High concentrations of biogenic silica (BSi) represented the dominance of diatoms in the bay. Most metals were lower than the marine sediment quality guidelines; however, Hg, Zn, and Mn were at polluted levels. The vertical profiles of biogenic elements and metals in the sediment core suggest that the most significant environmental changes occurred since the 1990s, and three stages could be defined: (1) before 1950, characterized by low concentrations of biogenic elements and metals; (2) between 1950 and 1990, displaying an obvious increase of Hg and a slow increase of biogenic elements; (3) after 1990, reflected by a significant increase of total organic carbon (TOC), total nitrogen (TN), total phosphate (TP), and most metals, but a decrease of BSi. Correlation and principal component analyses indicated that most metals originated from lithogenic sources, industrial and domestic discharges as well as maricultural activities.     

重金属污染场地风险评估与治理技术体系研究

在对发达国家污染场地风险评估与治理修复技术方法进行分析的基础上,针对我国重金属污染场地的实际特点,通过调查、分析、实践、优化等方式,对风险评估与治理修复技术开展了系统研究,对风险评估技术在我国的实际应用以及治理修复技术体系的构建提出了模型优化、技术路线优化等相关建议,提出了以浸出浓度为基础依据初步构建重金属污染场地理修复技术体系,并针对治理修复技术的国内产业化分析了技术标准、技术开发应用、市场引导、政府监管等关键影响因素。     

Spatial Trends of Trace-Element Contamination in Recently Deposited Lake Sediment Around the Ni–Cu Smelter at Nikel, Kola Peninsula, Russian Arctic

A large copper–nickel smelter complex is located at the Kole Penninsula, Russia, close to the Norwegian border. Trace-element concentrations in surface sediments (0–0.5 cm) and pre-industrial sediments from 45 lakes in the region were used to uncover spatial deposition patterns and contamination factor of sediments. Elevated concentrations were found, especially for Ni and Cu, but also for Pb, Co, Hg, As, and Cd. Highest concentrations were found up to 20 km from the smelter, but the concentrations decreased exponentially with distance from the smelter. Increasing Ni, Cu, As, and Hg concentrations from sub-surface to surface sediments were found for lakes at intermediate distances (20–60 km). This may reflect recent changes in atmospheric depositions, as shown in nearby Norwegian areas. However, we cannot rule out that this also may have been caused by diagenetic processes, especially for the most redox-sensitive elements such as As.     

Limitations of applying life cycle assessment to complex co-product systems: The case of an integrated precious metals smelter-refinery

Integrated smelter-refineries play an important role in the recovery of multiple metals from complex primary and secondary materials, and hence in closing metals cycles. Processes in these facilities are strongly interconnected, dynamic, and multifunctional, which challenges a typical representation in life cycle assessment (LCA). This is especially true when LCA is applied to calculate the environmental profile of single metals products.This study examines methodological requirements for assessing complex co-product systems using attributional LCA through a static, gate-to-gate inventory model that quantifies the environmental impacts of each of the metal products of an integrated precious metals smelter-refinery. The model is based on a large number of subprocesses and is formulated using detailed industry data, which allows quantification of the sensitivity of the results with respect to allocation rationales and the data collection period.The results within one impact category vary strongly among metals (up to four orders of magnitude for copper compared to rhodium). Moving from mass- to value-based allocation changes the result for a given metal by up to two orders of magnitude. If value-based allocation is used, the selected reference year for metals prices influences the results by up to a factor of two.Allocation rationales are critically analyzed, and it is shown that none reflect the business model or other system drivers. While the model is focused on quantifying environmental impacts of metal outputs, the actual process is economically driven to efficiently treat a continuously changing feed mix. The complexity of a smelter-refinery cannot be captured by static, attributional inventory models, which is why the choice of allocation rationale remains arbitrary. Instead, marginal, parameterized models are needed; however, such models are substantially more time and data intensive and require disclosure of more detailed, process specific data.     

Effects of Metal Mining and Milling on Boundary Waters of Yellowstone National Park, USA

/ Aquatic resources in Soda Butte Creek within Yellowstone National Park, USA, continue to be threatened by heavy metals from historical mining and milling activities that occurred upstream of the park's boundary. This includes the residue of gold, silver, and copper ore mining and processing in the early 1900s near Cooke City, Montana, just downstream of the creek's headwaters. Toxicity tests, using surrogate test species, and analyses of metals in water, sediments, and macroinvertebrate tissue were conducted from 1993 to 1995. Chronic toxicity to test species was greater in the spring than the fall and metal concentrations were elevated in the spring with copper exceeding water quality criteria in 1995. Tests with amphipods using pore water and whole sediment from the creek and copper concentrations in the tissue of macroinvertebrates and fish also suggest that copper is the metal of concern in the watershed. In order to understand current conditions in Soda Butte Creek, heavy metals, especially copper, must be considered important factors in the aquatic and riparian ecosystems within and along the creek extending into Yellowstone National Park.KEY WORDS: Mining; Metals; Toxicity; Biomonitoring; Copper; Yellowstone National Park     

Species analysis methods for hydrolysis polymerization of aluminum

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