Assessment of waste settlement models based on the long-term settlement data measured at a multi-stage MSW landfill in Korea

Journal of Material Cycles and Waste Management - An assessment of municipal solid waste (MSW) settlement models was carried out based on analyses of field-scale data measured at landfill #1 of the...     

Multi-response optimization of Fenton process for applicability assessment in landfill leachate treatment

Fenton process, as a pretreatment method, was found to be effective in the primary treatment of mature/medium landfill leachate. However, the main problem of the process is the large amount of produced sludge that requires an accurate feasibility evaluation for operational applications. In this study, the response surface methodology was applied for the modeling and optimization of Fenton process in three target responses, (1) overall COD removal, (2) sludge to iron ratio (SIR) and (3) organics removal to sludge ratio (ORSR), where the latter two were new self-defined responses for prediction of sludge generation and applicability assessment of the process, respectively. The effective variables included the initial pH, [H₂O₂]/[Fe²⁺] ratio and Fe²⁺ dosage. According to the statistical analysis, all the proposed models were adequate (with adjusted R² of 0.9116–0.9512) and had considerable predictive capability (with prediction R² up to 0.9092 and appropriate adequate precision). It was found that all the variables had significant effects on the responses, specifically by their observed role in dominant oxidation mechanism. The optimum operational conditions obtained by overlay plot, were found to be initial pH of 5.7, [H₂O₂]/[Fe²⁺] ratio of 17.72 and [Fe²⁺] of 195 mM, which led to 69% COD removal, 2.4 (l sludge/consumed mole Fe²⁺) of SIR and 16.5 (gCOD removed/l produced sludge) for ORSR in verification test, in accordance with models-predicted values. Finally, it was observed that [H₂O₂]/[Fe²⁺] ratio and Fe²⁺ dosage had significant influence on COD removal, while Fe²⁺ dosage and [H₂O₂]/[Fe²⁺] ratio had remarkable effects on SIR and ORSR responses, respectively.     

Optimization for MSW logistics of new Xicheng and new Dongcheng districts in Beijing based on maximum capacity of transfer stations

The new Xicheng and new Dongcheng districts of Beijing in 2010 were chosen as the research object. Based on the analysis of the current municipal solid waste (MSW) logistics system, the transfer station’s processing capacity and the terminal treatment facilities' conditions of the two new districts and other districts, a MSW logistics system was built using geographic information system (GIS) and analytic network process methods considering transregional treatment. The new logistics (MSW from new Xicheng was collected for Majialou. MSW from old Dongcheng and Xuanwu was collected for Datun and Xiaowuji, respectively) proved to be an improvement with a 10 % less collection fee, 111 % output–input ratio after transfer station (include) and 0.8:4.6:4.6 I:C:L (incineration:compost:landfill). After Nangong, Gaoantun II and Asuwei incineration are established, the output–input ratio of the new logistics will reach 114 %, and I:C:L will reach 3.6:4.2:2.2 which is environmentally friendly and nearer to the 4:3:3 Beijing government target. For a full load of every transfer station, the complement schemes were also presented and contrasted based on GIS analysis. The results have great theoretical and practical significance in transregional treatment and improving resource management level of MSW.     

费用效益分析法在火电厂脱硫工程经济评价中的应用

火电厂脱硫项目的投资一般以财务评价为主。以谋取利润最大化为目标，而忽略了二氧化硫排放所造成的社会环境效益的损害。介绍了一种以动态经济评价的费用效益分析法。举例说明其计算方法和评价效果，提出了相关的可行性建议，其评价结果能直观地反映企业环境治理投资的经济效益和社会效益。     

基于ANSYS的脱硫烟道结构有限元分析

利用ANSYS有限元数值分析软件,对章丘电厂二期烟气脱硫系统烟道结构进行3D数值计算,考察烟道结构受力和变形情况,从而对加固肋和内撑杆规格进行设计选型.结果表明,有限元分析方法对于脱硫系统结构的精准设计具有一定的指导意义.     

Comparisons of four categories of waste recycling in China's paper industry based on physical input-output life-cycle assessment model

Waste recycling for paper production is an important component of waste management. This study constructs a physical input-output life-cycle assessment (PIO-LCA) model. The PIO-LCA model is used to investigate environmental impacts of four categories of waste recycling in China’s paper industry: crop straws, bagasse, textile wastes and scrap paper. Crop straw recycling and wood utilization for paper production have small total intensity of environmental impacts. Moreover, environmental impacts reduction of crop straw recycling and wood utilization benefits the most from technology development. Thus, using crop straws and wood (including wood wastes) for paper production should be promoted. Technology development has small effects on environmental impacts reduction of bagasse recycling, textile waste recycling and scrap paper recycling. In addition, bagasse recycling and textile waste recycling have big total intensity of environmental impacts. Thus, the development of bagasse recycling and textile waste recycling should be properly limited. Other pathways for reusing bagasse and textile wastes should be explored and evaluated. Moreover, imports of scrap paper should be encouraged to reduce large indirect impacts of scrap paper recycling on domestic environment.     

An assessment on the recycling opportunities of wastes emanating from scrap metal processing in Mauritius

This paper presents an assessment on the wastes namely slag, dust, mill scale and sludge resulting from scrap metal processing. The aim of this study is to demonstrate that there are various ways via which scrap metal processing wastes can be reused or recycled in other applications instead of simply diverting them to the landfill. These wastes are briefly described and an overview on the different areas of applications is presented. Based on the results obtained, the waste generation factor developed was 349.3 kg per ton of steel produced and it was reported that slag represents 72% of the total wastes emanating from the iron and steel industry in Mauritius. Finally the suitability of the different treatment and valorisation options in the context of Mauritius is examined.     

Research on the recycling industry development model for typical exterior plastic components of end-of-life passenger vehicle based on the SWOT method

In-depth studies on the recycling of typical automotive exterior plastic parts are significant and beneficial for environmental protection, energy conservation, and sustainable development of China. In the current study, several methods were used to analyze the recycling industry model for typical exterior parts of passenger vehicles in China. The strengths, weaknesses, opportunities, and challenges of the current recycling industry for typical exterior parts of passenger vehicles were analyzed comprehensively based on the SWOT method. The internal factor evaluation matrix and external factor evaluation matrix were used to evaluate the internal and external factors of the recycling industry. The recycling industry was found to respond well to all the factors and it was found to face good developing opportunities. Then, the cross-link strategies analysis for the typical exterior parts of the passenger car industry of China was conducted based on the SWOT analysis strategies and established SWOT matrix. Finally, based on the aforementioned research, the recycling industry model led by automobile manufacturers was promoted.