有色金属行业含砷废弃物处置技术的研究进展

介绍了有色金属行业中含砷废弃物的两种处理技术——资源化和稳定化-固化的研究进展。从含砷的烟灰、废水及废渣3个方向对资源化处理技术的研究进展进行了介绍，含砷废弃物经资源化处理后可得到As2O3和砷酸盐产品，但砷产品品种有限，应开发新的资源化途径和砷产品。此外，综述了含砷废弃物的稳定化-固化处置技术的研究进展，指出铁盐稳定化优于钙盐稳定化，特别是臭葱石形式的沉淀具有稳定性高、堆存时间长和无需再固化的优点；对比了包胶固化、火法固化及熔融固化3种固化技术的特点，其中水泥包胶固化法的成熟度较高，但仍有改进空间。     

日本生活垃圾焚烧灰渣的资源化利用

日本生活垃圾的焚烧率高达80%,对焚烧灰渣的处理也比较先进,其资源化利用方式主要有在熔融设施进行熔融处理后制成熔融灰渣、作为水泥原料及路基材料等。介绍了日本生活垃圾焚烧灰渣的产生及资源化利用情况,以期对我国处理焚烧灰渣有所借鉴。     

铬渣无害化处理技术研究进展

综述了铬渣无害化处理技术的研究进展,分析了各种技术在实际应用过程中的效果,指出各种处理技术的优缺点,详细介绍了固化法中水泥固化和药剂稳定化两种处理技术,提出开发重金属螯合剂是今后铬渣稳定化处理的研究方向.     

某污染场地含钒重金属土壤制砖工艺研究

以湖南省某钒工业废弃厂区为研究对象,研究重金属高温烧结深度固化技术,以含钒重金属污染土壤为原料制备烧结砖体。通过添加不同比例的含重金属土壤的处理方法,研究其重金属固化效果、砖力学性质并对比相关标准限值,从而筛选出最优的添加比例。结果显示,当重金属土壤含量达到40%时,固化稳定化效果变差,钒和铜的总量超过《水泥窑协同处置固体废物技术规范》(GB/T30760-2014)中规定的限值,故针对研究对象建议采用添加比例不超过30%进行烧结制砖,可保证资源化利用的同时,避免原位处理潜在的二次污染。研究结果为含钒重金属污染土壤建立了一套行之有效的资源化、无害化处置的工艺流程,为促进土壤污染修复产业的形成与发展提供借鉴。     

城市生活垃圾预处理和资源化研究

分析了国内外近期生活垃圾资源化技术的处理模式和存在的缺点,指出了我国城市生活垃圾资源化的有效途径是加强对垃圾的预处理,提出了基于垃圾预处理的城市生活垃圾资源化综合处理系统,介绍了废塑料制作建筑板材的工艺和技术指标.     

论龙岩市生活垃圾焚烧厂配套填埋场防渗工程施工管理

龙岩市生活垃圾焚烧厂为有效处理垃圾焚烧所产生的炉渣,以及经固化、稳定化处理后的飞灰,建设了配套填埋场。为杜绝填埋场渗沥液的外渗,同时防止地下水向填埋库区的渗入,并确保填埋场安全可靠的运行,减少渗沥液产生量,避免造成二次污染等问题,建设科学安全有效的防渗系统工程对于填埋场工程来说至关重要。通过对填埋场内部防渗系统的简要介绍及阐述,对适合此配套填埋场的防渗材料、衬层系统和衬层结构以及防渗材料铺设等问题进行了深刻的分析。     

热解炭化技术应用于工业污泥处理的研究

针对重金属含量超标的工业污泥,处理量大,污染物成分复杂,国内常规处理技术难以实现较为环保的资源化处理。针对该项目特点采用国内外较为先进的热解炭化技术,实现工业污泥由污染物转化为可利用资源。这种资源化利用方式,避免了污泥处理过程中的污染物二次转移达到稳定化、无害化、资源化处理的目的。     

城市污泥太阳能光热干化技术研究进展

污泥干化是城市污泥无害化处置和资源化利用的前提和关键工序,需要消耗大量能源。将太阳能应用于城市污泥干化,可大幅度减少污泥干化过程对常规能源的依赖,经济高效地实现污泥的稳定化、减量化及资源化。对国内外城市污泥的处理处置和太阳能污泥干化技术的研究现状进行综述。     

城市生活垃圾处理技术和资源化应用探讨

介绍我国城市生活垃圾处理技术和城市垃圾资源化现状,对北京阿苏卫生活垃圾综合处理进行详细分析,为城市生活垃圾的处理工艺选型和垃圾处理发展前景提供了参考依据。     

废聚丙烯塑料的回收利用技术

介绍了废聚丙烯塑料能源化的方法(焚烧、无氧及有氧条件下的热分解)与资源化回收利用技术(简单再利用、改性再生利用),并对国内外相关方面的研究和应用情况进行了报道。     

Use of detoxified MSWI fly ash for cement stabilized macadam mixture: mechanism,mechanical and environmental considerations

Journal of Material Cycles and Waste Management - In order to realize the recovery and stabilization of detoxified municipal solid waste incineration fly ash (DIFA) in roadbases, the synergetic...     

Improving immobilization efficiency and mechanism analysis of sodium hexametaphosphate on MgO-based cementitious material solidified MSWI FA

Journal of Material Cycles and Waste Management - MgO-based cementitious material (MCM) is a potential green substitute for solidifying municipal solid waste incineration fly ash (MSWI FA). Sodium...     

Comparing urban solid waste recycling from the viewpoint of urban metabolism based on physical input-output model: A case of Suzhou in China

Investigating impacts of urban solid waste recycling on urban metabolism contributes to sustainable urban solid waste management and urban sustainability. Using a physical input-output model and scenario analysis, urban metabolism of Suzhou in 2015 is predicted and impacts of four categories of solid waste recycling on urban metabolism are illustrated: scrap tire recycling, food waste recycling, fly ash recycling and sludge recycling. Sludge recycling has positive effects on reducing all material flows. Thus, sludge recycling for biogas is regarded as an accepted method. Moreover, technical levels of scrap tire recycling and food waste recycling should be improved to produce positive effects on reducing more material flows. Fly ash recycling for cement production has negative effects on reducing all material flows except solid wastes. Thus, other fly ash utilization methods should be exploited. In addition, the utilization and treatment of secondary wastes from food waste recycling and sludge recycling should be concerned.     

Accelerated carbonation of municipal solid waste incineration fly ashes

As a result of the EU Landfill Directive, the disposal of municipal solid waste incineration (MSWI) fly ash is restricted to only a few landfill sites in the UK. Alternative options for the management of fly ash, such as sintering, vitrification or stabilization/solidification, are either costly or not fully developed. In this paper an accelerated carbonation step is investigated for use with fly ash. The carbonation reaction involving fly ash was found to be optimum at a water/solid ratio of 0.3 under ambient temperature conditions. The study of ash mineralogy showed the disappearance of lime/portlandite/calcium chloride hydroxide and the formation of calcite as carbonation proceeded. The leaching properties of carbonated ash were examined. Release of soluble salts, such as SO4, Cl, was reduced after carbonation, but is still higher than the landfill acceptance limits for hazardous waste. It was also found that carbonation had a significant influence on lead leachability. The lead release from carbonated ash, with the exception of one of the fly ashes studied, was reduced by 2-3 orders of magnitude.     

Manufacture of artificial aggregate using MSWI bottom ash

This paper reports the results of an investigation on material recovery by stabilization/solidification of bottom ash coming from a municipal solid waste incineration plant. Stabilization/solidification was carried out to produce artificial aggregate in a rotary plate granulator by adding hydraulic binders based on cement, lime and coal fly ash. Different mixes were tested in which the bottom ash content ranged between 60% and 90%. To avoid undesirable swelling in hardened products, the ash was previously milled and then granulated at room temperature. The granules were tested to assess their suitability to be used as artificial aggregate through the measurement of the following properties: density, water absorption capacity, compressive strength and heavy metals release upon leaching. It was demonstrated that the granules can be classified as lightweight aggregate with mechanical strength strongly dependent on the type of binder. Concrete mixes were prepared with the granulated artificial aggregate and tested for in-service performance, proving to be suitable for the manufacture of standard concrete blocks in all the cases investigated.     

Crystalline phase evolution behavior and physicochemical properties of glass–ceramics from municipal solid waste incineration fly ash

Journal of Material Cycles and Waste Management - Appropriate management and treatment of fly ash from municipal solid waste (MSW) incineration plant have become an urgent environmental protection...     

Soluble salt removal from MSWI fly ash and its stabilization for safer disposal and recovery as road basement material

Fly ash from municipal solid waste incinerators (MSWI) is classified as hazardous in the European Waste Catalogue. Proper stabilization processes should be required before any management option is put into practice. Due to the inorganic nature of MSWI fly ash, cementitious stabilization processes are worthy of consideration. However, the effectiveness of such processes can be severely compromised by the high content of soluble chlorides and sulphates. In this paper, a preliminary washing treatment has been optimized to remove as much as possible soluble salts by employing as little as possible water. Two different operating conditions (single-step and two-step) have been developed to this scope. Furthermore, it has been demonstrated that stabilized systems containing 20% of binder are suitable for safer disposal as well as for material recovery in the field of road basement (cement bound granular material layer). Three commercially available cements (pozzolanic, limestone and slag) have been employed as binders.     

Reducing volatilization of heavy metals in phosphate-pretreated municipal solid waste incineration fly ash by forming pyromorphite-like minerals

This research investigated the feasibility of reducing volatilization of heavy metals (lead, zinc and cadmium) in municipal solid waste incineration (MSWI) fly ash by forming pyromorphite-like minerals via phosphate pre-treatment. To evaluate the evaporation characteristics of three heavy metals from phosphate-pretreated MSWI fly ash, volatilization tests have been performed by means of a dedicated apparatus in the 100-1000 °C range. The toxicity characteristic leaching procedure (TCLP) test and BCR sequential extraction procedure were applied to assess phosphate stabilization process. The results showed that the volatilization behavior in phosphate-pretreated MSWI fly ash could be reduced effectively. Pyromorphite-like minerals formed in phosphate-pretreated MSWI fly ash were mainly responsible for the volatilization reduction of heavy metals in MSWI fly ash at higher temperature, due to their chemical fixation and thermal stabilization for heavy metals. The stabilization effects were encouraging for the potential reuse of MSWI fly ash.     

Recycling MSWI bottom and fly ash as raw materials for Portland cement

Municipal solid waste incineration (MSWI) ash is rich in heavy metals and salts. The disposal of MSWI ash without proper treatment may cause serious environmental problems. Recently, the local cement industry in Taiwan has played an important role in the management of solid wastes because it can utilize various kinds of wastes as either fuels or raw materials. The objective of this study is to assess the possibility of MSWI ash reuse as a raw material for cement production. The ash was first washed with water and acid to remove the chlorides, which could cause serious corrosion in the cement kiln. Various amounts of pre-washed ash were added to replace the clay component of the raw materials for cement production. The allowable limits of chloride in the fly ash and bottom ash were found to be 1.75% and 3.50% respectively. The results indicate that cement production can be a feasible alternative for MSWI ash management. It is also evident that the addition of either fly ash or bottom ash did not have any effect on the compressive strength of the clinker. Cement products conformed to the Chinese National Standard (CNS) of Type II Portland cement with one exception, the setting time of the clinker was much longer.