Determinants of privatized solid waste management service provision in Lagos

The growing popularity of privatized solid waste management service in least developed countries warrants an exploration of factors that are likely to impact on its sustainability. This study takes integrated solid waste management approach by analyzing relevant issues on both market sides. We use a three step theme development sequence to analyze the data obtained on service providers through library research, observations and interviews. This was followed by an opinion survey on the demand side to elicit households’ support for service improvement. Findings show that source-separation issues, government enforcement, market segmentation, financial issues and waste disposal issues are key factors influencing improved service provision. Meanwhile, on the demand side, we found that households are willing to support proposed regulatory improvement in service provision. Thus, we suggest industrial stakeholders to consider the aforementioned supply side issues in designing future service improvements that will take advantage of existing demand side feasibility.     

Emerging drivers and business models for equipment reuse and remanufacturing in the US: lessons from the biotech industry

While regulations have advanced product take-back in some markets, challenges to increasing product reuse and remanufacturing remain. Most research to date has focused on original equipment manufacturers taking back and remanufacturing their products, which is often problematic. The present study demonstrates that there are emerging opportunities for small companies with innovative business models to enter the market and advance product end-of-life (EoL) management. The paper examines the biotechnology industry – a growing sector with high spending on lab equipment and relatively short lifespans of research and development instruments. Building on previous research and analysis of industry practices and emerging drivers for product reuse and remanufacturing, the authors propose a framework for sustainable EoL management that includes five managerial drivers: financial benefits, space, ease/convenience, information, and sustainability goals. The paper concludes with discussion of the lessons learned and practical implications for managers in charge of purchasing or disposing of surplus equipment.     

Integrating waste, manufacturing and industrial symbiosis: an analysis of recycling, remanufacturing and waste treatment firms in Texas

The continually increasing volume of the waste stream has led to numerous calls for strategies to close the loop on material use through industrial symbiosis strategies which direct used material and products (wastes) back to production processes. By use of a survey of recycling, remanufacturing and waste treatment firms in Texas, this paper asks if these firms can operate as a bridge between production and consumption/waste to efficiently increase the flow of used materials and products back to production processes at the local level. The results suggest that while most materials and used products are collected locally, only some can be re(consumed) locally. Moreover, the firms face negative perceptions about their activities from industry and the public at large that likely slow both the rate of entry of new firms into these markets and the expansion possibilities of existing firms. In addition, the types of conventions that characterize the interactions of more successful firms are not well developed in this sector(s). It is unlikely that recycling, remanufacturing and waste treatment firms can become central players in the production, consumption and waste cycle loop until society develops production design, marketing and consumption philosophies that include recycling and remanufacturing at a fundamental level.     

Integrating waste,manufacturing and industrial symbiosis: an analysis of recycling,remanufacturing and waste treatment firms in Texas

The continually increasing volume of the waste stream has led to numerous calls for strategies to close the loop on material use through industrial symbiosis strategies which direct used material and products (wastes) back to production processes. By use of a survey of recycling, remanufacturing and waste treatment firms in Texas, this paper asks if these firms can operate as a bridge between production and consumption/waste to efficiently increase the flow of used materials and products back to production processes at the local level. The results suggest that while most materials and used products are collected locally, only some can be re(consumed) locally. Moreover, the firms face negative perceptions about their activities from industry and the public at large that likely slow both the rate of entry of new firms into these markets and the expansion possibilities of existing firms. In addition, the types of conventions that characterize the interactions of more successful firms are not well developed in this sector(s). It is unlikely that recycling, remanufacturing and waste treatment firms can become central players in the production, consumption and waste cycle loop until society develops production design, marketing and consumption philosophies that include recycling and remanufacturing at a fundamental level.     

美国企业有毒废物排放管理现状及对中国的启示

工业生产中产生的有毒废弃物是我们生活环境的一大危险,每个企业都有责任安全有效地处理其在生产过程中产生的有毒废弃物。美国环保署通过《有毒物质释放清单》的方式,要求工业、企业每年上报其有毒废弃物的产生、管理、排放的详细情况。并对所有数据进行收集、整理、统计、分析后在美国环保署网站上公布。美国这种敦促工业、企业披露其废弃物管理方式的做法可以让公众知晓企业的排污行为,也可以促使企业采取更负责任的方式管理有毒废弃物质。在新形势下,中国即将迎来新一轮区域性结构调整的浪潮,各地政府在产业结构调整的过程中,必须全面考量未来重点发展的行业的环境可持续性。因此,继续建立一个类似于TRI的公开、便捷的各业企业污染物情况数据库,满足各地政府管理地区发展的需要。     

构建有色金属矿山二级生态工业研究

为了解决有色金属矿山所面临的环境污染和资源短缺的问题,提出了绿色矿山的发展模式,构建有色金属矿山二级生态工业体系是实现绿色矿山的重要途径。有色金属矿山二级生态工业体系依据工业生态学原理,以实现工业资源的有限输入和工业废物的有限输出为目的,具体通过矿山清洁生产、预防废物产生、废物循环利用及最小量废物必要处置等途径实现。     

含油污水中固体废物固化与燃煤混烧的可行性

在含油污水处理过程中易产生含油污泥、活性污泥及浮渣等固体废物,利用传统的焚烧法、分离法、填埋法、生物降解法处理这些废物具有一定的缺陷和局限性。为了利用这些废物中的油及有机质的潜在能量,大庆炼化公司对固体废物进行了脱水固化试验。结果表明,脱水后的废物可以达到较好的固化状态,并具有一定的热值。固化废物经粉碎处理后,可按一定比例与燃煤混烧。在正常生产状况下,热电厂可保证混合燃烧的效果,其总体热值不会降低。混烧后的灰渣和炉渣可作为水泥厂的原料。该方法有利于环境保护,但其工业化生产可行性有待于进一步证实。     

Critical review of industrial and medical waste practices in Dar es Salaam City

Industrial and medical wastes constitute a larger part on what is known as ‘hazardous wastes’. The production of these wastes is and will continue to be an on going phenomenon as long as human civilization persists. The health impacts of direct and indirect exposure to hazardous wastes include carcinogenic effects, reproductive system damage, respiratory effects, central nervous system effects, and many others. Today, many developed countries have legal provisions with regard to proper management of hazardous wastes. Tanzania, like many developing countries, has little emphasis on the proper handling and disposal of hazardous wastes. There is a serious inadequacy in handling industrial and medical solid wastes in the Dar es Salaam City. Improper waste deposition is increasingly becoming a potential public health risk and an environmental burden. Due to poor control of waste, industrialists and hospital owners are not well checked on how they handle and dispose of the wastes they produce with the result that many hazardous wastes reach the Vingunguti dumpsite without notice. Data on waste generation in Dar es Salaam is also inadequate, making it difficult to plan an efficient solid waste system. Promotion of public awareness, legislation and regulations enforcement and establishment of a proper sanitary landfill are considered to be principal remedial measures to ensure sound environmental maintenance. This paper summarizes the findings of the study on the practices of industrial and medical waste management in Dar es Salaam. The author aims to express the inadequacy in hazardous waste management and suggests possible measures to be applied in order to rectify the situation.     

Exergetic Sustainability Indicators as a Tool in Commercial Aircraft: A Case Study for a Turbofan Engine

This paper focuses on the exergetic sustainability indicators of a medium-range commercial aircraft engine for constant reference environment and ground running conditions. First, a detailed exergy analysis of turbofan engine have been performed based on engine test cell parameters. Starting from the sustainability considerations and the second law of the thermodynamics, the paper presents six exergy-based sustainability indicators. The indicators of the turbofan engine developed here in conjunction with exergetic analysis and sustainable development are exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental effect factor, and exergetic sustainability index. The investigated sustainable indicators have been calculated by using exergy analysis outputs for aircraft ground running condition. Results from this study show that values of exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental effect factor, and exergetic sustainability index of investigated turbofan engine are found to be 0.315, 0.685, 0.408, 0, 2.174, and 0.460, respectively. These parameters are expected to quantify how the turbofan engine and aircraft become more environmentally benign and sustainable.     

发达国家和地区危险废物名录管理实践

危险废物名录制度是危险废物环境管理的基础。2016年6月14日,环境保护部、国家发改委、公安部联合公布了《国家危险废物名录》(2016年版),对2008年版危险废物名录进行了调整。本文介绍了主要发达国家和地区危险废物名录制度的基本情况,对其优缺点进行了对比分析,以期为更好的理解新版危险废物名录提供参考。主要发达国家和地区的危险废物名录管理体系具有以下优点:一是完善的危险废物豁免排除制度加强了企业和管理部门的责任意识。二是危险废物和一般固体废物共享分类体系便于对废物的统筹管理,废物代码内容翔实,增加了名录的可操作性。三是基于不同处理责任主体进行分类,避免了名录方式或列举方式造成的"漏分"现象。四是根据环境风险实行分级管理,重点突出。同时存在几点不足:一是鉴别程序繁琐,降低了危险废物处置效率;二是存在部分行业产生的废物遗漏、同类危险废物分类过细等问题;三是部分国家危险废物分类过于笼统,不利于企业对危险废物种类及属性的识别。     

The discursive framework of sustainability in UK food policy: the marginalised environmental dimension

ABSTRACT

In the context of food policy, sustainability functions as a normative principle but also constitutes a highly contested arena. The study presented in this paper establishes how discursive dynamics amongst professionals involved in matters of food distribution, retail, consumption and waste lead to food policy themes being framed as issues of sustainability. Analysing varied UK-based data (trade magazine articles, policy documents and interviews with retail, non-profit and consultancy representatives), three interpretative frames of sustainability are identified: consumer sovereignty, economic rationality and stewardship. Focusing on three themes of food sustainability – organic consumption, protein diversity and waste reduction – it is shown how these interpretative frames constitute the discursive framework relevant to food policy. Based on these findings, it is shown how in the analysed debates environmental concerns are sidelined.     

Utilization of waste foundry sand (WFS) in concrete manufacturing

Due to ever increasing quantities of waste materials and industrial by-products, solid waste management is the prime concern in the world. Scarcity of land-filling space and because of its ever increasing cost, recycling and utilization of industrial by-products and waste materials has become an attractive proposition to disposal. There are several types of industrial by-products and waste materials. The utilization of such materials in concrete not only makes it economical, but also helps in reducing disposal concerns. One such industrial by-product is waste foundry sand (SFS). Waste foundry sand is a by-product of ferrous and nonferrous metal casting industries. Foundries successfully recycle and reuse the sand many times in a foundry. When the sand can no longer be reused in the foundry, it is removed from the foundry and is termed as waste foundry sand.Published literature has shown that WFS could be used in manufacturing Controlled Low-Strength Materials (CLSM) and concrete. This paper presents an overview of some of the research published on the use of WFS in concrete. Effect of WFS on concrete properties such as compressive strength, splitting tensile strength, modulus of elasticity, freezing-thawing resistance, and shrinkage are presented.     

建筑废弃物再生利用的可行性技术研究综述

建材行业的发展为城市化建设提供了重要保障,在我国城市化快速发展、建筑材料需求旺盛的带动下,建材行业发展强劲,但大多属于高能耗高污染行业,加之城市拆迁改造产生大量建筑废弃物,环境压力十分巨大,必须加强建筑废弃物的环境管理。对建筑废弃物再利用、再循环以及减少建筑废弃物是解决建筑行业环境问题的重要方式,实施这些仍有很大的提升空间。本文回顾了近年来建筑废弃物再生利用方面的各种可行性技术。主要是针对沥青、砖、混凝土、金属、玻璃等几种物质再生利用的可行性技术进行综述,为未来建筑废弃物再生利用领域提供参考。     

产品的可回收性与再制造

再制造技术是先进制造技术21世纪发展的一个重要组成部分和发展方向。它可以更合理地开发利用资源，减少制造中能源与资源消耗，减少废弃物，保护环境。文章介绍了再制造的概念，并对产品的可回收性，再制造工程进行了探讨。     

Utilisation of high volumes of limestone quarry wastes in concrete industry (self-compacting concrete case)

In limestone quarries, considerable amounts of limestone powders are being produced as by-products of stone crushers. High amounts of powders are being collected and utilisation of this by-product is a big problem from the aspects of disposal, environmental pollution and health hazards. In conventional concrete, the introduction of high volumes of limestone quarry dust to concrete mixes is limited due to its negative effects on water demand and strength of concrete. However, these fines can be efficiently utilised as viscosity enhancer particularly in special concrete (like self-compacting concrete—SCC) applications. Thus, the successful utilisation of this quarry dust in SCC could turn this material into a valuable resource.In this paper the usability of a quarry dust limestone powder in self-compacting paste and concrete applications was investigated. In the first part, the physical and mechanical properties of cement pastes incorporating quarry waste limestone powder (QLP) and a powder produced by direct grinding of limestone (PLP) were compared. In the second part, the performance of quarry waste limestone powder in SCC applications were tested and discussed. Results showed that, it is possible to successfully utilise high amounts of quarry waste limestone powder in producing normal-strength SCCs. Among its observed mechanical advantages, employment of quarry waste limestone powders improved the economical feasibility of SCC production.     

Phosphorus recovery and recycling from waste: An appraisal based on a French case study

Phosphate rocks, used for phosphorus (P) fertilizer production, are a non-renewable resource at the human time scale. Their depletion at the global scale may threaten global food and feed security. To prevent this depletion, improved P resource recycling from food chain waste to agricultural soils and to the food and feed industry is often presented as a serious option. However, waste streams are often complex and their recycling efficiency is poorly characterized. The aim of this paper is to estimate the P recovery and recycling potential from waste, considering France as a case study. We assessed the P flows in food processing waste, household wastewater and municipal waste at the country scale using a substance flow analysis for the year 2006. We also quantified the P recycling efficiency as the fraction of P in waste that ultimately reached agricultural soils or was recycled in the food and feed industry. Efforts were made to limit data uncertainty by cross-checking multiple data sources concerning P content in waste materials. Results showed that, in general, P recovery in waste was high but that the overall P recycling efficiency was only 51% at the country scale. In particular, P recycling efficiency was 75% for industrial waste, 43% for household wastewater and 47% for municipal waste. The remaining P was discharged into water bodies or landfilled, causing P-induced environmental problems as well as losses of nutrient resources. Major P losses were through food waste (which amounted to 39% of P in available food) and treated wastewater, and the findings were confirmed through cross-checking with alternative data sources. Options for improving P resource recycling and, thereby, reducing P fertilizer use were quantified but appeared to be less promising than scenarios based on reduced food waste or redesigned agricultural systems.     

Sustainable management of demolition waste—an integrated model for the evaluation of environmental, economic and social aspects

A model is presented for evaluating waste management systems for their contribution to a sustainable development, including environmental, economic and social aspects. The model was tested in a case-study, where groups of long-term unemployed people were offered both education on environmental issues and practical work with the recovery and recycling of building and demolition waste as a form of vocational development. Application of the suggested model revealed the overall effects on sustainability of different methods of waste management. In addition, negative aspects of the systems analysed were identified, which led to discussions about possible improved practices within the waste management systems. Two of the waste management systems investigated (the recycling of steel and re-use of sanitary porcelain) showed a potential contribution to sustainable development in all of the aspects studied. Preparing bricks for re-use showed the largest potential for eco-efficiency, but had negative effects on sustainability from the social perspective of health and the working environment. The possibility of further use of the model and the remaining obstacles to such analyses are discussed. One observation is that the data collection needed to perform this kind of sustainability analysis is resource-demanding, and that it would therefore be better to identify a smaller number of key indicators.     

Utilisation of high volumes of limestone quarry wastes in concrete industry (self-compacting concrete case)

In limestone quarries, considerable amounts of limestone powders are being produced as by-products of stone crushers. High amounts of powders are being collected and utilisation of this by-product is a big problem from the aspects of disposal, environmental pollution and health hazards. In conventional concrete, the introduction of high volumes of limestone quarry dust to concrete mixes is limited due to its negative effects on water demand and strength of concrete. However, these fines can be efficiently utilised as viscosity enhancer particularly in special concrete (like self-compacting concrete—SCC) applications. Thus, the successful utilisation of this quarry dust in SCC could turn this material into a valuable resource.In this paper the usability of a quarry dust limestone powder in self-compacting paste and concrete applications was investigated. In the first part, the physical and mechanical properties of cement pastes incorporating quarry waste limestone powder (QLP) and a powder produced by direct grinding of limestone (PLP) were compared. In the second part, the performance of quarry waste limestone powder in SCC applications were tested and discussed. Results showed that, it is possible to successfully utilise high amounts of quarry waste limestone powder in producing normal-strength SCCs. Among its observed mechanical advantages, employment of quarry waste limestone powders improved the economical feasibility of SCC production.     

活性污泥法处理工业废水有关指标的控制

独山子炼油厂的工业废水处理采用活性污泥法，处理工艺是鼓风曝气。本文就有关操作情况以及活性污泥法的指标要求进行了论述，结论是只有控制好指标才能取得良好的处理效果。     

Waste management issues for the UK ready-mixed concrete industry

The UK government has recognised the vital contribution that the construction industry has to play in contributing towards sustainable development. While the issue of hardened concrete waste has received considerable attention, process waste arising from the manufacture of ready-mixed concrete is relatively unexplored. It is apparent that initiatives such as the landfill tax have encouraged UK ready-mixed concrete manufacturers to reduce substantially the amount of waste they produce. Environmental pressures continue to increase and ready-mixed concrete producers are being forced towards a closed loop production system.