Heavy metal speciation in the composting process

Composting is one of the more efficient and environment friendly methods of solid waste disposal and has many advantages when compared with landfill disposal on which the UK and Ireland are currently heavily dependent. Composting is a very complicated process involving intensive microbial activity and the detailed mechanisms of the process have yet to be fully understood. Metal speciation information can provide an insight into the metal-microbial interaction and would help in the evaluation of the quality of compost. This would facilitate the exploitation of composts in remediation of heavy metal contaminated land. In this work a systematic approach to metal speciation in compost has been taken by applying the three-step method for operationally defined metal speciation of soils and sediments, developed by the European Commission's Standards, Measurement and Testing Programme to monitor the change in metal speciation with time (up to 106 days) for four different waste composting processes. The results have shown that in general metals become less available for the first extraction step as the composting process proceeds. This implies that composting tends to redistribute the metals from more labile forms to more fixed forms which may explain why the application of composts could be useful for with heavy metal contaminated land. There are exceptions to this trend and in some cases, certain metals appear to behave differently depending on the source of the compost.     

长江经济带工业来源危险废物污染与处理特征分析及监管对策建议

依据2017年环境统计数据, 分析了长江经济带工业危险废物的污染及处理特征:长江经济带危废产生 量较大的省份是江苏、浙江、云南、湖南和四川;危废种类主要是来源于化工、钢铁、有色和造纸行业的废酸、有色金属冶炼废物、废碱和焚烧处置残渣;各地对危废的处理情况各有优劣。根据以上特征,提出加强对重点 区域的监管和调度,针对特定行业和危废种类,建议出台最佳可行的处理技术,建立区域之间危废管理大平台,促进区域危废处理优势互补和均衡发展,挖掘企业自行处理能力,减轻危废集中处理压力。     

Leaching Characteristics of Heavy Metals and As from Two Urban Roadside Soils

The leaching tests, including the Toxicity Characteristic Leaching Procedure (TCLP), EDTA extraction and BCR sequential extractions before and after EDTA treatments, were performed on two specific soils to elucidate heavy metal-associated mineral fractions and general leachability. The TCLP illustrated the low leachability of heavy metals in soils from two sites. EDTA is a strong chelator and therefore had higher extraction efficiency compared to that of TCLP. The lower extraction percentages by EDTA for As and Sb were found compared to the other heavy metals derived from anthropogenic sources. Sequential extractions showed that the importance of acid-extractable, organically-bound and Fe–Mn oxide fractions was identified for anthropogenic heavy metals with the exception of As and Ni while the importance of residual fraction was identified for endogenous metals. Changes in sequential fractions of heavy metals after leaching with EDTA are very complex and it is difficult to generalize on which fraction was more mobile than the others. These combined results are helpful in elucidating the association of heavy metals to soil fractions and the mobility characteristics of heavy metals under certain environmental conditions.     

固体废弃物浸出毒性特性及美国EPA的实验室测定(续完)

围绕固体废弃物浸出毒性特性这个中心，综述了它在有害废弃物的鉴别和管理，在执行陆地处置限制法规过程中的重要作用。以及在保护水资源，特别是地下水资源方面的重要意义，并简要介绍和评论了美国固体废弃物浸出毒性的实验室测定方法ETP和TCLP。     

固体废弃物浸出毒性特性及美国EPA的实验室测定(待续)

围绕固体废弃物浸出毒性特性这个中心,综述了它在有害废弃物的鉴别和管理,在执行陆地处置限制法规过程中的重要作用。以及在保护水资源、特别是地下水资源方面的重要意义。并简要介绍和评论了美国固体废弃物浸出毒性的实验室测定方法EPT和TCLP。     

中国固体废物的环境管理与环境监测技术现状

为加强中国固体废物的环境管理和环境监测技术,回顾了中国自１９８５年以来制定的固体放心物环境管理法规制度以及１９８４年至１９９８年颁布的２０多年家或行业的固体废物处置标准体系等固体废物的环境管理状况,着重论述了中国固体废物环境监测技术的发展历史与现状。指出经过２０多年的努力,在固体废物环境监测技术与方法上初步形成了该领域框架体系,有固体废物的采样与制样技术;危险废物的有害特性试验鉴别方法,固体废物具     

Municipal solid waste generation in growing urban areas in Africa: current practices and relation to socioeconomic factors in Jimma, Ethiopia

As one of cities in the developing countries, a rapid population growth and industrial activities pose many environmental challenges for Jimma city, Ethiopia. One aspect of urban growth posing a threat on sustainable development is poor solid waste management, which results in environmental pollution. The purpose of this study is to evaluate the quantity, composition, sources of waste generated, their current disposal practices, and to recommend appropriate management technologies. The total waste generated daily in Jimma city was ca. 88,000 kg, and the average per capita generation rate was 0.55?±?0.17 kg/capita/day. Eighty-seven percent of the waste was produced by households and 13% by institutions, and a negligible fraction (0.1%) was generated by street sweepings. During the rainy season, 40% more waste was generated than in the dry season because of the increased availability of agricultural food product. Further analysis showed that biodegradable organic waste constitutes 54% by weight with an average moisture content of 60% that falls within the required limits for composting. The nonbiodegradable components constitute 46% of which 30% of it was nonrecyclable material. Only 25% of the community uses municipal containers for disposal at the selected landfill site. Fifty-one percent of the households disposed their waste in individually chosen spots, whereas 22% burned their waste. Finally 2% of households use private waste collectors. The socioeconomic analysis showed that higher family income and educational status is associated more with private or municipal waste collection and less with the application of backyard or open dumping. These insights into generated waste and management practice in Jimma city allow making suggestions for improved collection, treatment, and disposal methods. A primary conclusion is that the biodegradable waste is a major fraction having suitable properties for recycling. As such an economic benefit can be obtained from this waste while avoiding the need for disposal.     

An evaluation of alternative household solid waste treatment practices using life cycle inventory assessment mode

Waste disposal is an important part of the life cycle of a product and is associated with environmental burdens like any other life-cycle stages. In this study, an integrated assessment for solid waste treatment practices, especially household solid waste, was undertaken to evaluate the impact contribution of household solid waste treatment alternatives towards the sustainable development by using Life Cycle Inventory Assessment method. A case study has been investigated under various possible scenarios, such as (1) landfill without landfill gas recovery, (2) landfill with landfill gas recovery and flaring, (3) landfill with landfill gas recovery and electric generation, (4) composting, and (5) incineration. The evaluation utilized the Life Cycle Inventory Assessment method for multiple assessments based on various aspects, such as greenhouse gas emission/reduction, energy generation/consumption, economic benefit, investment and operating cost, and land use burden. The results showed that incineration was the most efficient alternative for greenhouse gas emission reduction, economic benefit, energy recovery, and land use reduction, although it was identified as the most expensive for investment and operating cost, while composting scenario was also an efficient alternative with quite economic benefit, low investment and operating cost, and high reduction of land use, although it was identified as existing greenhouse gas emission and no energy generation. Furthermore, the aim of this study was also to establish localized assessment methods that waste management agencies, environmental engineers, and environmental policy decision makers can use to quantify and compare the contribution to the impacts from different waste treatment options.     

Assessment of metal contamination using X-ray fluorescence spectrometry and the toxicity characteristic leaching procedure (TCLP) during remediation of a waste disposal site in Antarctica

The remediation of the Thala Valley landfill, Casey Station, East Antarctica, is part of efforts to clean-up contaminated sites associated with the Australian Antarctic Program. These sites, ranging from abandoned rubbish dumps to fuel spills, are contaminated principally with metals and petroleum hydrocarbons. Remediation success depends on accurate, cost-effective and timely--fit-for-purpose--chemical analysis of soil and water samples from the site, which is required to guide excavation, the in situ or off-site treatment and disposal of contaminated material, and to validate satisfactory remediation. Owing to the remote location of Antarctica, it is necessary to carry out chemical analyses on-site. Waste and soil contaminated with Pb, Zn, Cd, and Cu were excavated from Thala Valley for removal to Australia, treatment and disposal. Analysis of total metal concentrations in soil was performed at Casey Station with a transportable energy dispersive X-ray fluorescence (EDXRF) spectrometer. Soil samples were prepared using a simple size-fractionation method to expedite sample throughput. A method for assessing contaminant mobility in solid waste (toxicity characteristic leaching procedure, TCLP) was also used to characterise soil. Although this was more labour-intensive and time-consuming than the total metals analysis, it was of great utility because leachable metals were often significant determinants in the assessment of contaminated soil. The combined data helped managers during remediation, directing excavation and allowing waste to be classified for treatment and disposal before its return to Australia.     

Toxicological effects of major environmental pollutants: an overview

The last quarter of the twentieth century had witnessed a global surge in awakening against the unabated menace of environmental pollution. Among the various types of environmental pollution, water pollution is an age-old problem but it has gained an alarming dimension lately because of the problems of population increase, sewage disposal, industrial waste, radioactive waste, etc. Present scenario of water pollution calls for immediate attention towards the remediation and detoxification of these hazardous agents in order to have a healthy living environment. The present communication will deal with the toxicological effects of major environmental pollutants, viz. heavy metals, pesticides, and phenols.     

印染废水处理污泥危险废物鉴别过程中有毒污染物的迁移转化及鉴别因子筛选

简述了印染废水处理污泥危险废物鉴别过程中有毒污染物的迁移转化及鉴别因子筛选。以采用活性染料的印染企业为例,从常用的原辅材料、使用的生产工艺、常用的废水处理工艺等几个方面来对印染废水处理污泥危险废物鉴别过程中有毒污染物的迁移及转化进行分析。提出危险废物鉴别工作任重而道远,危险废物鉴别的关键在于日常监管。     

Municipal solid waste management in Thailand and disposal emission inventory

The increasing municipal solid waste (MSW) generation along with the high fraction of organic waste and a common disposal of open dumping is the current scenario in many areas in Thailand. As a response to this problem, the country’s Pollution Control Department (PCD) aims to reduce the MSW generation rate to less than 1 kg/capita/day, increase the collection efficiency, and improve the recovery of recyclables. For many years, more than 60% of the solid waste disposal system in Thailand has been carried out by open dumping. According to the survey conducted by this study, in 2004 there were 425 disposal sites (95 landfills; 330 open dumps) in Thailand and an estimated methane emission of 115.4 Gg/year was generated based on this practice. It has been estimated that the anticipated methane emission in Thailand will rise from 115.4 Gg/year to 118.5 Gg/year if the largest open dumpsites in provinces with no existing landfill are upgraded to sanitary landfill; and it will increase to 193.5 Gg/year if the existing sanitary landfill is upgraded to integrated waste management facilities. Moreover, Bangkok metropolitan have the highest methane emission (54.83 Gg/year) among all the regions in Thailand. The methane emission forecast of 339 Gg/year by 2020 (based on LandGEM methodology) provides a stimulus to create a comprehensive plan to capture and utilize methane as an energy source.     

Organic interference of solidified/stabilized hazardous wastes

Liquid hazardous waste disposal in landfills is usually allowed only after solidification/stabilization. Although various procedures are commonly practiced, little is known about the mechanism(s) of the processes. A particular problem is the interference of organics. Small amounts of organics can interfere with the reaction between inorganic sludges and cementitous matrices. The present communication reports studies of the interaction between selected organic hazardous wastes and Type I Portland cement. Microscopic studies of the structural differences between cements set with water and those set with water plus organic liquids are discussed. In these studies the scanning electron microscope is used to observe samples fractured at 78K. The results provide technical background data on the ultimate stability of critical waste constituents solidified by various binding agents.     

电石法生产聚氯乙烯行业危险废物判定要点分析

聚氯乙烯树脂是用途极广的热塑性高分子材料,然而,电石法生产聚氯乙烯树脂(PVC)的过程中会产生大量的危险废物,如处置不当会对环境造成严重污染。本文对电石法生产聚氯乙烯树脂(PVC)过程中产生危险废物的类型、环节和产生特性进行了分析,以供环保部门和相关企业作为针对危险废物环境管理的判定依据。     

基于健康风险的危险废物智能化分级分类研究

在分析国内外危险废物分级管理经验的基础上,结合健康风险的评估步骤,提出了基于全过程危险废物污染物释放情景的精细化-动态健康风险评价方法。充分考虑处理利用工艺、企业管理水平等因素对于危险废物中污染物释放概率和能力的影响,并基于污染物向环境介质的迁移转化,定量评估危险废物的健康风险。基于危险废物污染特性数据库和事故情景数据库,结合全过程信息采集技术,构建危险废物分级分类管理平台,进行涉废企业的风险级别划分,实施差异化管理,形成更加科学有效的危险废物全过程精细化管理体系。     

水处理污泥处理处置研究进展

污水污泥是城市废水处理后的终端产物,既是一种生物质原料,可以被有效地资源化和能源化,同时又含有大量有毒有害物质,如何妥善地处理处置污水污泥,已成为全社会关注的课题。浅析了污水污泥的处理处置方法以及当前的研究热点和新技术。污泥处理处置的发展方向为减量化、稳定化,以及在无害化前提下的资源化、能源化。     

Environmental monitoring of offshore drilling for petroleum exploration (MAPEM Project): shallow waters

This paper deals with the characteristics and composition of municipal solid waste (MSW) generated in Sangamner city. The composition of solid waste was studied by segregating it into different component, i.e., kitchen waste, paper, earth and fine material, slaughter house waste, leaves, metals, etc. These components were categorised into organic waste and inorganic waste. It was observed that Sangamner city produces around 61% organic waste, and the rest is inorganic waste. The characteristics of organic solid waste, i.e., pH, electrical conductivity, moisture content, organic carbon, nitrogen, phosphorus and potassium were evaluated. The analysis of organic content of MSW indicates that it is good source of nutrients for the agriculture sector whereas inorganic material can be used for landfill.     

Detection of metal contamination in wild asparagus near a waste disposal site

Estimating contaminant distributions in environmental media is necesary to evaluate human and ecological hazards. Because of uncertainties in release histories and transport, traditional sampling and statistical techniques applicable to the experimental sciences may not be suitable for exploratory studies at hazardous waste sites. An approach that relies on cluster analysis of principal components (PCA) was used to identify contaminated wild asparagus (Asparagus officinalis) growing in the vicinity of waste disposal sites along the Columbia River at the U.S. Department of Energy's Hanford Site in southeast Washington state. Metals in soil samples taken from the sites contained elevated levels of Ag, Al, Ba, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Zn, and V. Samples of asparagus tissue were collected from the river near the waste site, from Hanford old fields abandoned 52 years ago, and from commercial fields in the neighboring communities. Dried tissues were analyzed for metals content by ICP-mass spectrometry, furnace AA, and cold vapor AA. Tissue concentrations of elements varied over 5 orders of magnitude, from K at 46 900 ppm to As and Ag at maximum concentrations below 1 ppm. PCA produced four components that accounted for 66.2% of the metals variance. Subsequent cluster analysis using Ward's minimum variance separated the data into Columbia River and old-field groups, with the River group further divided into three clusters: plants primarily upriver from the waste sites, plants primarily downriver, and plants growing in or near the waste sites. The clustering showed that the more soluble components of the discharges (Ba and Ca) showed a pattern of distribution in the asparagus plants consistent with the ground water flow pattern, in that these elements were found far downriver of the disposal sites themselves. In contrast, the less mobile elements Al, Cd, Cr, Fe, Mn, Tl, and Zn were elevated only near the most-recently used waste disposal area. Asparagus from agricultural fields, including fields abandoned 50 years ago, contained higher concentrations of Fe, Cu, Pb, K, and Ni than did the wild riverine plants.The U.S. Governments right to retain a non-exclusive royalty free licence in and to any copyright is acknowledged.     

Study on the law of heavy metal leaching in municipal solid waste landfill

Comparative leaching experiments were carried out using leaching medium with different pH to municipal solid waste in the landfill columns in order to investigate the mobility of heavy metals. The leachate pH and oxidation–reduction potential were measured by oxidation–reduction potential analyzer; the contents of heavy metals were measured by inductively coupled plasma mass spectrometry. It is very different in leaching concentrations of heavy metals; the dynamic leaching of heavy metals decreased with the rise of the leaching amount on the whole. Acid leaching medium had definite influence on the leaching of heavy metals in the early landfill, but it had the obvious inhibition effect on the leaching in the middle and late period of landfill; the neutral and alkaline leaching medium are more beneficial to the leaching of heavy metals. Due to the influence of the environment of landfill, the differences of the results in cumulative leaching amount, leaching rate, and leaching intensity of heavy metals are very big. The calculation results of the release rates of heavy metals prove that the orders of the release rates are not identical under different leaching conditions. Acid rain made heavy metals migrate from municipal solid waste to soil and detain in soil more easily; approached neutral and alkaline leaching mediums are more beneficial to leaching of heavy metals in the municipal solid waste and soil with leachate. The field verification of experimental data showed that the law of heavy metal leaching in municipal solid waste revealed by the experiment has a good consistency with the data obtained by municipal solid waste landfill.     

基于WebGIS的广东省危险废物登记交换平台的设计

选择广东省为研究区域,探讨危险废物信息化管理的建设目标,结合WebGIS技术开展广东省危险废物登记交换平台的设计,使广东省危险废物管理提升水平和效率.