Solidification/Stabilization of Hazardous Wastes Containing Metals and Organic Contaminants

The potential of solidification/stabilization (S/S) technology for the safe disposal of hazardous wastes has wide spread recognition. The purpose of this study was to investigate the effectiveness of portland cement-based S/S technology for the safe disposal of hazardous wastes containing toxic metals and organic contaminants. As hazardous wastes, metal enriched mining residue, adsorbable organic halogens (AOX) containing pulp and paper sludge, and polychlorinated biphenyl (PCB) oil-contaminated soil were used. For S/S of waste, portland cement as a binding agent was mixed with wastes at different ratios. For initial waste characterization, contaminant concentrations and some physical waste characteristics such as particle-size distribution, Atterberg limits, specific gravity, and moisture content yielding the maximum compacted dry density were determined. Waste and cement mixtures were cured for 28 days after compacting the desired waste-cement mixtures at their predetermined optimum moisture contents yielding the corresponding maximum dry densities in cylindrical molds having a height of 71 mm and a diameter of 36 mm. At the end of the 28-day cure period, unconfined compressive strength and hydraulic conductivity measurements were conducted on the solidified samples. Subsequently, solidified samples were crushed for fractionation into two different aggregate sizes (between 1–2 and >2 mm) and subjected to the U.S. Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP). The effectiveness of S/S was assessed by comparing the chemical composition of leachates obtained from TCLP tests of untreated and treated, i.e., S/S waste samples, and comparing values of strength and hydraulic conductivity of solidified waste samples with regulatory requirements. For mining waste, effective application of S/S was achieved for most cases. AOX containing sludge yielded acceptable results in terms of strength and hydraulic conductivity but leachate AOX concentrations were above regulatory levels. The effectiveness of S/S for coarse textured-soils contaminated with a PCB oil was not satisfactory, especially at a cement:soil ratio less than 35%.     

典型固废资源化与无害化处置技术

2021年我国产出约110亿吨固体废弃物,其中40亿吨为工业固体废弃物,12亿吨不同程度含有价金属,具有一定的回收利用价值。重点针对复杂多金属典型固废,介绍了国内外资源化与无害化处置技术,包括铜冶炼过程含砷物料、铅锌冶炼渣、废锂离子动力电池、废催化剂、电镀污泥和氰化渣等典型固废。目前,我国已初步建立了典型固废特别是危废的处置体系,但存在处置能力不足、技术装备参差不齐、处理不彻底、经济性差等问题,未来发展趋势将向着规模化、高温无害化、协同冶炼等方向发展。     

金属矿山固体废物的鉴别与处置方法探讨

一般含硫较高的硫化金属矿山废石和尾矿属第Ⅱ类一般性固体废物,需要根据处置场的工程地质和水文地质条件确定其防渗结构;但废石及尾矿浸出毒性监测结果表明为第Ⅰ类一般性固体废物,实际设计时我国的废石场和尾矿库也均按第Ⅰ类一般性固体废物进行设计,不采取任何防渗措施,根据笔者长期的跟踪和调查,废石场和尾矿库工程设计未采取防渗措施,造成部分硫化金属矿山地下水和土壤受到不同程度的污染,鉴于目前毒性浸出鉴别标准的局限性,建议硫化金属矿山工程设计和环境影响评价时,应类比同类型矿山废石场淋溶水和尾矿库外排废水水质监测值,确定其废石场和尾矿库是否要采取防渗措施。     

核废物固化处理中的粉末冶金技术

本文简要评述了核废物固化处理中粉末冶金技术的若干应用和发展,描述了瑞典、澳大利亚、美国、西德和日本的制粉、冷压、热压或热等静压处理强放射性废物的状况,指出用粉末冶金工艺固定核废物已成为当前核废物管理中的一个重要发展趋势。     

熔渣法城市垃圾高温焚烧技术试验研究

介绍了应用冶金技术开发的一种熔渣法处理城市垃圾的新工艺。用该工艺处理垃圾,具有使垃圾彻底无害化、减容化、资源化等特点,尤其适合特种垃圾的处理。为我国城市垃圾处理开拓了一条新路。     

中国钢铁企业固体废弃物资源化处理模式和发展方向

 论述了中国钢铁企业可持续发展的建设理念和绿色环保的新特点,讨论了钢铁厂从焦化、球团、烧结、炼铁、炼钢和轧钢及配套系统全工序产生的固废产物种类和相关冶金特性,研究了不同种类固废产物的处理模式。重点针对工程堆放和外销类固体废弃资源,深入探讨 “含有害元素除尘灰处理方式”、“危险废弃物处置”和“冶金渣高温转换与余热回收方式”的难题,并围绕这些难题创造性地提出了钢铁企业固废产物大平台处理的总体技术发展路线,希望能为今后中国的钢铁企业固体废弃物实现“零排放”起到促进作用。     

固体废物处理技术进展

系统地论述了我国固体废物目前的现状、产量，分析了医疗废物、生活垃圾焚烧厂飞灰、生活垃圾和工业固体废物处理过程中存在的主要问题和解决办法，提出了深入开展固体废物处理与资源化研究的方向，特别是有关生活垃圾深度分选技术研究和应用、危险废物的预处理技术等。     

稀土生产中的“三废”治理及环境保护

本文概述了我国稀土生产中的“三废”及其治理状况。主要内容包括三废来源及性质，三废治理方法及效果，稀土冶炼厂应贯彻“三同时”的三废治理方针，并提出了一些问题的讨论。     

危险废物安全填埋热干化预处理技术研究

危险废物在最终处置前实现减量化对于提高安全填埋场的库容利用率、降低渗滤液产生量具有重要意义。简述了安全填埋预处理常用技术,介绍了热干化工艺及设备特点,并对热干化应用于危险废物安全填埋预处理做出了技术建议。     

垃圾焚烧飞灰熔融无害化及资源化研究现状

垃圾焚烧飞灰因含二噁英和重金属被列为危险废物（HW18）,存在环境污染风险,2020年全国生活垃圾焚烧量高达14607.6万吨,以焚烧量5%（质量分数）计算,全国垃圾焚烧飞灰的产生量为730.4万吨。目前垃圾焚烧飞灰以固化填埋为主,占用土地资源,且堆存量与处理量严重失衡,无法实现资源化,因此垃圾焚烧飞灰的无害化及资源化已成为绿色发展的瓶颈课题。本文详细介绍了垃圾焚烧飞灰经熔融无害化及资源化的研究现状,阐述了熔融处理垃圾焚烧飞灰的重金属固化、二噁英降解机理,结合熔融形成的玻璃渣分析了制备微晶玻璃、泡沫微晶玻璃、胶凝材料的资源化技术,并指出现有玻璃化虽能固化重金属,但在后续资源化以及产品服役过程,重金属的迁移规律、浸出性需要进一步研究,为垃圾焚烧飞灰的综合利用提供了参考。      

我国工业危险废物产生现状及产量预测

根据1998～2004年工业危险废物的产生量和贮存量的统计数据,分析了我国工业危险废物产生和流向现状以及行业和地域分布特点,同时建立GM模型对未来工业危险废物产生的动态变化进行预测。研究结果表明:我国工业危险废物的产生量有逐年上升的趋势,预测到2015年工业危险废物需处理量将达到2709×104t,建议我国应前瞻性地扩建或新建工业危险废物处理设施,同时现有处理模式和工艺单一,在处理设施建设中优先考虑采用多功能综合处理厂建设。     

锑冶金固废处置现状

目前锑火法冶金主要采用传统鼓风炉和反射炉技术,冶炼过程产生大量冶金固废,如熔炼渣、砷碱渣、除铅渣,其危害性大,难以资源化回收和无害化处理,已成为制约锑冶炼企业发展的瓶颈问题。文中溯源了锑冶金固废产生途径,分析了固废处理工艺现状:熔炼渣堆存量大,烟化处理能耗高,分离效果不理想;砷碱渣以湿法处理为主,浸出实现锑、砷分离,含砷浸出液固化处理后堆存或填埋;除铅渣火法处理工艺铅、锑元素分离不彻底,未实现对磷酸盐的回收,湿法处理工艺流程长,工业化应用较少。因此迫切需要开发锑绿色冶金与固废资源化新方法,实现锑清洁高效提取及冶金固废源头减量与资源化回收。      

有色冶炼含砷危废玻璃固化技术研究进展

介绍了砷资源的供需情况及有色冶炼含砷物料的走向及含量分布情况。综述了含砷危废无害化处置技术及工业应用情况，详细介绍了国内外含砷危废玻璃固化技术研究现状，指出玻璃固化技术是含砷危废处理的最佳技术，并从政策管理、标准制定、技术研发及污染治理等角度指明了砷玻璃固化技术的发展方向。     

水滑石类材料在废水处理方面的应用进展

简要介绍了水滑石的结构、性质和水滑石类化合物的制备方法,并介绍了水滑石类化合物在印染废水、含磷酸根富营养废水、含卤素元素离子废水、含重金属离子废水及难降解有机物废水处理领域的应用情况。其中,含重金属离子废水处理方面的研究较深入系统,不仅有助于提高含重金属离子废水的资源化处理和回收水平,而且能够降低废水处理成本,在冶金、制革等行业具有较广阔的应用前景。最后,对水滑石类材料的应用现状及发展趋势进行了展望。     

Characterisation of dusts and sludges generated during stainless steel production in Brazilian industries

Abstract

During the stainless steel production process, wastes are generated at the electric arc furnace (EAF) and at the converters. These wastes are a problem for stainless steel industries, for they must be disposed of in controlled landfills. Finding areas to make more landfills is becoming difficult, and new landfills are being placed far from the industries. This leads to an increase in disposal prices and, furthermore, in production prices. Recycling of these wastes, besides solving the disposal and environmental problems, makes it possible to recover valuable metals such as iron, chromium, and nickel. These three metals are needed in stainless steel manufacture and could be returned to the production procedure, hence bringing profit to the industry. It is important, therefore, to develop a recycling process. Waste characterisation is an essential step in the definition of such a process. Four kinds of dust and two kinds of sludge, generated in stainless steel production, were characterised in the present work. The techniques used to characterise the waste were chemical analysis, size separation, density measurement, X-ray diffraction analysis, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) microanalysis. The largest proportion of the dust and sludge particles was of spherical shape. This kind of particle was composed mainly of iron and chromium in the form of a spinel, or of oxides. Precipitation of a secondary phase was identified in some particles.     

我国工业危险废物产生现状及产量预测

根据1998-2004年工业危险废物的产生量和贮存量的统计数据，分析了我国工业危险废物产生和流向现状以及行业和地域分布特点，同时建立GM模型对未来工业危险废物产生的动态变化进行预测。研究结果表明：我国工业危险废物的产生量有逐年上升的趋势，预测到2015年工业危险废物需处理量将达到2709×10^4t，建议我国应前瞻性地扩建或新建工业危险废物处理设施，同时现有处理模式和工艺单一，在处理设施建设中优先考虑采用多功能综合处理厂建设。     

医疗废物焚烧烟气污染物及其处理技术述评

在阐述我国医疗废物焚烧处置的基础上，论述了医疗废物焚烧烟气中污染物的来源、危害和净化技术，结合工程设计和生产实践，对目前国内应用的三种医疗废物焚烧烟气的处理工艺进行了介绍和评述。     

工业危险废物处理与处置工程的设计实践

介绍工业危险废物处理处置工程的主要设计内容和相关的工程措施，并对危险废物处理处置工程设计中应注意的问题提出了建议。     

镍冶炼厂的三废状况及治理

介绍了我国镍冶炼厂的生产简况,三废来源,三废治理方法及其效果。针对目前三废治理中存在的一些问题,提出了一些建议。     

Sustainable Disposal of Domestic Sanitary Waste

The study presented is an example of the assessment of the relative sustainability of either option for disposal of domestic sanitary waste, either via the toilet or via the solid waste route. This required an evaluation of the total (social, economic, environmental, and technical) benefit/cost of implementing and adopting the alternative routes and an assessment of public responsiveness to encouragement to change sanitary waste disposal practices. It illustrates how, even for an apparently straightforward either/or question, the assessment of relative sustainability is complex and the amount of data needed to quantify sustainability indicators is prodigious. The study also provides an appraisal of the effectiveness of public campaigns to reduce waterborne disposal. Important information regarding public attitude and behavior in relation to wastewater systems has been acquired and lessons for ways of encouraging behavioral change to more sustainable ways of living have been gleaned.