Current status and future focus of hazardous waste management in China

 Rapid social and economic development in China has caused the amount of hazardous wastes being generated to increase drastically. The necessary regulations and systems regarding the management of hazardous wastes are currently still not in place. Based on an analysis of the characteristics of hazardous waste pollution and pollution trends in China, this paper reports on China's current status regarding hazardous waste management, and introduces the main difficulties to be faced. The principles and objectives, and the action plan for hazardous waste pollution control in China are also explained in detail. These principles and objectives have been stipulated in the Technological Policies on Hazardous Waste Pollution Control, which is issued by China State EPA, State ETC, and the Science and Technology Ministry. Received: April 30, 2002 / Accepted: October 17, 2002     

中国危险废物产生特征与转移管理现状

论述了我国危险废物产生特征及处理现状,分析了我国危险废物转移流程及其转移规模和材料类型,提出合理布局危险废物处理产业,应用物联网和区块链等新兴技术,完善危险废物日常统计和监管.     

The current situation of solid waste generation and its environmental contamination in China

In China, controlling environmental pollution resulting from solid waste (SW) and hazardous waste (HW) has become one of the most pressing tasks in the field of environmental engineering. It is reported that the annual generation of industrial solid waste (ISW) in China exceeded 0.6 billion tons in the 1990s, and is increasing every year. Although ISW management has been strengthened in recent years, about 40% of SW is put in uncontrolled landfill without appropriate treatment. According to statistics from the national Environmental Protection Agency, the cumulative ISW uncontrolled landfill in China had reached 6.6 billion tons by the end of 1995, occupying around 55 000 hectares of land. Although some major uncontrolled landfills were constructed, nonetheless groundwater contamination resulted from the use of low-standard liners and poor management. Furthermore, about 20 million tons of ISW was discharged into the environment illegally, and a third of this waste was discharged directly into water bodies, making ISW one of the greatest pollution sources for surface water and ground water. Environmental pollution accidents resulting from SW occur about 100 times a year in China, and environmental issues frequently arise because of ISW pollution. The practices of SW management, treatment, and disposal started relatively late in China, and for a long time the management of SW pollution has received little attention compared with water and air pollution management. China faces problems such as the insufficiency of management laws and regulations, insufficient investment, inadequate treatment and disposal technology, and a lack of qualified technicians. At present, most treatment and disposal technology cannot meet the requests for solid waste pollution control. In order to protect, restore, and improve environmental quality in China and to realize sustainable development, the safe management and disposal of solid and hazardous wastes is a pressing challenge. In recent years, much attention has been paid to SW management in China, and investment to develop management and treatment technologies has increased. In 1995, the Law for Solid Waste Pollution Protection was issued, and work on solid waste treatment and disposal began to be legally managed. SW treatment and disposal facilities have been constructed, and now operate in some large and medium-sized cities. In particular, rapid improvements have been seen in ISW recycling, collection, and disposal of municipal solid waste and regional HW management. All the figures in this paper are from 1995, and represent the situation in China in that year. Received: April 18, 2000 / Accepted: May 15, 2000     

重庆市危险废物市场分析及预测

随着危险废物政策的不断完善,以及重庆市对环境监管力度的不断加大,危险废物收集体系日益健全,危险废物产生、收集、集中处置量将继续增长.现有利用处置设施能力不足,规划的利用处置设施能力与处置缺口出现结构不平衡问题.针对这些问题,对重庆市危险废物的产量及处置现状、现有及规划的危废利用处置设施进行了统计整理分析,并对未来产量进...     

危险废物焚烧厂烟气净化工艺设计与探讨

参考国内外已有的危险废物焚烧工程相关设计和研究资料,针对国内具有代表性的危险废物成分,采用设计计算得到危险废物焚烧烟气的污染物初始浓度,分析成熟的烟气净化工艺,对适合中国危险废物特点的危险废物焚烧厂烟气净化工艺进行了设计和探讨,为危险废物焚烧厂建设单位及设计单位等提供参考。     

The current situation of solid waste management in China

With economic development, the quantity of solid waste is increasing rapidly in China; the total quantities of municipal solid waste (MSW), industrial solid waste (ISW), and hazardous waste (HW) in 2002 were 136.5 million tons, 945 million tons, and 10 million tons, respectively. In 2002, the quantity of MSW disposed of was 74.04 million tons, 89.30% of which was landfilled, 3.72% was incinerated, and 6.98% was composted. There are currently 651 disposal facilities for MSW in China. Mining gangue is the largest component of ISW, making up 27.5% of the total. In the Chinese industrial sector, the coal mining and processing industry contributed most to the total quantity of ISW, with 16.0% of the total quantity of ISW generated by this sector. In total, 44% of HW was recycled, 27% was stored, 13.5% was disposed of, and 15.4% was discharged. Of the total HW generated, 40% was produced by the chemical materials and chemical products industry. Five categories of HW, i.e., waste alkali, waste acid, inorganic fluoride waste, copper waste, and inorganic cyanide waste, made up 57.8% of the total HW generated. Solid waste pollution has become a huge challenge faced by those involved in Chinese environmental management, but this can be seen as an opportunity to improve environmental quality. This article introduces the strategies taken to improve solid waste management in China.     

电解铝工业危险废物处理技术的发展方向

针对电解铝工业产生的大量含氟危险废物,综述了国内外该类危险废物处理技术的发展历程和研究进展,并就目前国内电解铝工业危险废物的两种典型处理工艺进行了对比分析。指出:分类处理和浮选—浸出是目前处理电解铝工业危险废物的最佳工艺;湿法处理是实现电解铝工业危险废物资源化的技术发展方向;有价元素的进一步高效回收需要对工艺条件进行精细控制,从理论层面和分子水平进行深入研究。     

The influence of additives on the steam gasification of PVC waste

This study is concerned with the influence of additives on the steam gasification of polyvinyl chloride (PVC) waste. Three types of PVC waste, namely pipe waste, cable waste, and flooring, were tested. The presence of additives proved to have a profound effect on the carbon-to-gas conversion. Plasticizers and other organic additives caused an increase in carbon-to-gas conversion. Inorganic additives, especially calcium, caused a decrease in carbon-to-gas conversion, resulting in an overall decrease in the yield of syngas for all three types of waste. This decrease is probably caused by the deposition of Ca on the surface of the alumina bed material. In addition, calcium reacts with the HCl formed to give CaCl₂. This results in a decrease in the recovery of hydrochloric acid. Received: July 19, 2000 / Accepted: October 9, 2000     

Mass balance of arsenic and antimony in municipal waste incinerators

The arsenic and antimony balance in two municipal waste incinerators was investigated. Initially, the production rates of ash and wet scrubber effluent were estimated. Then the arsenic and antimony in the ash and wet scrubber effluent were determined, which gave an estimate of the elemental balance. The total amounts of arsenic and antimony in the municipal waste were 0.9 g/t and 30–44 g/t, respectively. The distributions to fly ash were 45–47% and 33–74% for arsenic and antimony, respectively. The distribution mechanisms of arsenic and antimony are discussed from the viewpoints of their thermodynamics as well as their initial valencies, which greatly affect their behaviour. Received: July 2, 1998 / Accepted: February 27, 1999     

Conventional and alternative technologies for the treatment of infectious waste

 The limited scientific information about infectious waste, and the heightened public awareness of this special component of the waste stream, have contributed to the implementation or strengthening of the regulations in this area. This paper proposes a general working definition of infectious waste, and describes the systems used to limit its potential occupational and public health impacts. Although incineration and autoclaving are the most widely used methods of treating infectious waste, the introduction of more stringent air-quality standards for incinerators, and the inherent limitations to the application of autoclaves, have created a demand for other methods of processing this segment of the solid and liquid waste streams. These alternative technologies use one or more of the following methods: (1) heating the waste to a minimum of 90–95°C; (2) exposing the waste to suitable chemicals; (3) subjecting the waste to heated chemicals; (4) irradiating the infectious waste with ionizing sources. The advantages and disadvantages of each of these alternative forms of treatment are discussed in this paper. Received: April 22, 2002 / Accepted: October 14, 2002     

Chlorine promotes antimony volatilization in municipal waste incineration

Antimony volatilization in municipal waste incineration was studied. Two municipal waste samples and antimony(III) oxide (Sb₄O₆) were heated to 500°C and 700°C in an air stream in a quartz furnace. The volatilization of Sb₄O₆ occurred more at 700°C that at 500°C. Conversely, antimony volatilization form municipal waste was stronger at 500°C than at 700°C. This implies that antimony from municipal waste is volatilized as chloride instead of oxide. The chlorine sources for antimony chlorination, a gas-phase reaction involving hydrochloric acid and a solid-phase reaction of inorganic chlorine, e.g., CaCl₂, were compared. Only the solid-phase reaction could offer enough active chlorine to induce chlorination of antimony oxide. Received: July 2, 1998 / Accepted: January 28, 1999     

The German packaging ordinance: the questionable effects of a fragmentary solid waste management approach

Germany seems to be one of the leading nations in solid waste management, especially in the case of packaging waste; success stories about the ongoing increase in recycling strengthen this impression. However, enormous costs and questionable ecological benefits are the result of Germany's packaging ordinance and the formation of the recycling organization Duales System Deutschland (DSD). This article shows that similar progress in the reduction and recycling of packaging could have been realized without the packaging ordinance and dual system, with lower costs. This regulatory impact analysis of the German packaging ordinance covers all the effects on the different life-cycle stages of packaging, from production to recycling or disposal. The conclusion is that a fragmentary solid waste management approach – one that is based, like the German packaging ordinance, more on ideology than on facts – leads to enormous costs and questionable ecological benefits. To improve this situation, there is a need for an integrated solid waste management approach, based on evaluation of the economic, environmental, and social effects of different waste management options for the materials involved. Received: February 4, 1999 / Accepted: April 30, 1999     

Optimization of regional hazardous waste management systems: an improved formulation

The planning and design of regional hazardous waste management system (RHWMS) involves selection of treatment and disposal facilities, allocation of hazardous wastes and waste residues from generator to the treatment and disposal sites and selection of the transportation routes. An improved formulation based upon multi-objective integer programming approach is presented to arrive at the optimal configuration of RHWMS components. This formulation addresses important practical issues like unique characteristics of the hazardous wastes reflecting on waste–waste and waste–technology compatibility. A utility function approach is presented to integrate both cost and risk related objectives. An illustrative case example is presented to demonstrate the usefulness of the improved formulation as a tool which can be used by environmental planning agencies in regional planning for hazardous waste management.     

An evaluation of landfill disposal of asbestos-containing waste and geothermal residues within a risk-assessment framework

 The public perception of risks related to waste disposal facilities appears to reflect general societal anxieties and fears, which may not have a reasonable basis. A three-tier risk assessment study was therefore conducted to evaluate the landfill disposal of asbestos-containing waste (ACW) and geothermal residues. From the tier-1 analysis, the dominant asbestiform phase was identified as chrysotile, that is tightly bound in the matrix of calcite, while arsenic, cadmium, chromium, and lead were identified as the chemicals of potential concern associated with geothermal residues. From the tier-2 analysis, none of the possible exposure pathways associated with the landfill disposal of ACW was found to be potentially significant. On the other hand, there were potentially significant pathways associated with landfill disposal of geothermal residues because of the considerable potential pollution impact of leachate on soil and groundwater quality. From the tier-3 analysis, the health risk associated with landfill disposal of geothermal residues was found to be time-dependent, since the contributions to risk from water-dependent and water-independent pathways occur at different times, as indicated by RESRAD–Chem simulations. Component pathway analyses were performed to identify critical exposure pathways. The results from model sensitivity analysis have identified the input parameters that have the most influence on the time of peak risk, and the cancer risk associated with water-dependent and water-independent pathways. Received: July 9, 2002 / Accepted: October 17, 2002     

Factors affecting the concentration of bisphenol A in leachates from solid waste disposal sites and its fate in treatment processes

 The concentrations of bisphenol A (BPA) contained in landfill leachates from solid waste disposal sites were measured. The concentrations of BPA contained in leachates from industrial waste sites were in the range below the detection limit to 2800 μg/l, while those from municipal sites were in the range 26–8400 μg/l. The leachates from ash-rich sites contained relatively lower concentrations of BPA compared with organic-rich leachates. It is suggested that BPA concentration increases with time after the completion of reclamation in the case of ash-rich sites, whereas the concentration of BPA decreases with time in the case of organic-rich sites. A 7-year survey on a site in Japan showed neither a decrease nor an increase in the concentration of BPA during on-going reclamation. A leachate from a site in the Philippines contained high concentrations of BPA. A slight positive correlation was found between BPA concentrations and total organic carbon (TOC). A major portion of the BPA in leachates was found in dissolved and organic unassociated fractions, which cannot be precipitated by coagulation. More than 99.9% of the BPA contained in raw leachates was removed by a conventional series of treatment processes consisting of biological treatment, coagulation, sedimentation, sand filtration, and activated carbon adsorption. Received: May 29, 2002 / Accepted: October 17, 2002     

Trends in waste plastics and recycling

Zero emission is an ambitious project aimed at the conversion of the conventional top-down or one-directional flow type production systems of modern society to those of a recycling type. The basic idea underlying this project is to understand in detail the material flow mechanism in a particular segment of society and to evaluate the transformability of the hitherto one-directional types of process into recycling types. The authors, members of the Zero-Emission Research Group of Japan, are investigating the material flow of plastics in Japan. The present work describes the features of this project, as well as the results obtained so far. Received: May 28, 1998 / Accepted: October 16, 1998     

Investigation of hydrogen generation from municipal solid waste incineration fly ash

Hydrogen generation from municipal solid waste incineration fly ash was investigated to understand the influences of contacting method, kinds of contact solution, liquid to solid ratio, and particle size distribution of materials. Redox properties of materials and hydrogen generation were also studied. The largest quantity of gas generated in contact with water was 29.1 ml/g-ash, most of which was hydrogen. Fluidized bed fly ash generated more gas than stoker fly ash. In order to calculate the hydrogen generation potential (the maximum quantity of gas generated in contact with water), a novel system using a Y-shaped test tube and NaOH was utilized. This method gives values which are related to the quantity of generated gas in contact with water. A relationship between the aluminum content and hydrogen generation potential was observed, especially for fluidized bed fly ash. The reducing potential of fluidized bed fly ash was higher than that of stoker fly ash. Only fluidized bed fly ash showed a positive correlation between aluminum content and reducing potential, and between reducing potential and hydrogen generation potential. These results suggest that fluidized bed fly ash contains more Al⁰ than stoker fly ash. Received: September 11, 1998 / Accepted: March 19, 1999     

Substance flow analysis of coplanar PCBs released from waste incineration processes

Previous reports have focused on the emission of coplanar polychlorinated biphenyls (Co-PCBs) which have a toxic mechanism similar to that of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/DFs) released from municipal solid waste (MSW) incineration. Such emissions accounted for a small percentage of all the dioxins (PCDDs/DFs and Co-PCBs) recorded at the toxicity equivalent (TEQ) level. There is, however, very little information about Co-PCBs, such as the quantities being released and their effect on overall environmental pollution. The aim of this research has been to clarify the substance flow of Co-PCBs from MSW incineration processes. The results reveal that whereas the input of Co-PCBs into the MSW incineration facilities in Kyoto City was 0.13–0.29 μg-TEQ per ton waste, the total output of Co-PCBs (the sum of Co-PCBs released from emission gas, fly ash, and bottom ash) was 4.9 μg-TEQ per ton waste. The total output was therefore found to be higher than the total input. Over 90% of the total PCBs were decomposed in the incineration process. In comparing the profiles of congeners and homologues, those in the MSW were found to be similar to those detected in the atmosphere and products containing PCBs, but different from those in the MSW incineration gas. Received: August 26, 1998 / Accepted: March 2, 1999     

The Teshima Island industrial waste case and its process towards resolution

 The worst case of illegal dumping of industrial waste in Japan occurred on Teshima Island. The disputes concerning the removal and treatment of waste material were completely resolved. An outline of the process of arbitration and the terms of the agreement are given. A technological examination committee was organized to resolve the problem of environmental pollution caused by industrial wastes. An impermeable wall has been constructed on the north coast of the disposal area to prevent polluted water from flowing out to sea. A total of 600 000 tons of industrial waste will be excavated and moved to Naoshima Island. This material will be melted down and transformed into slag at a new melting furnace in Naoshima, with a capacity of 200 tons per day. The slag will be reused as aggregate in concrete. Comprehensive environmental preservation measures and full environmental monitoring of sewage and emission gas are planned in Teshima and Naoshima. Received: June 10, 2002 / Accepted: June 10, 2002     

European Union waste management strategy and the importance of biogenic waste

In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills. The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries have already enacted respective national regulations and their realization shows that recycling and incineration are not in competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative fuel. Hence part of the CO₂ released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual CO₂ emissions if energy from MSW replaced that derived from fossil fuel.