Decisions on recycling: Construction stakeholders’ decisions regarding recycled mineral construction materials

Construction and demolition (C&D) waste, being already the largest waste fraction in industrialized countries, is expected to increase in the future. C&D waste recycling has been considered to be a valuable option not only for minimizing C&D waste streams to landfills but also for mitigating primary mineral resource depletion. Even though the use of recycled mineral construction materials (RMCM) is regulated and successful application examples are available, construction stakeholders do not yet broadly apply them. Although various criteria hindering a transition towards a broader application of RMCM have been identified, it is yet unknown how these criteria differ among decisions, stakeholders and applications. We therefore analyze construction stakeholders’ behavior, and decision-making regarding RMCM for the construction material market in Switzerland. Stakeholders’ decision-making was quantified with the analytical hierarchy process (AHP) in a survey in combination with their behavior. The results demonstrate the importance of stakeholder interaction, i.e. most stakeholders decide which material to apply based on interaction with other stakeholders e.g., recommendations and specifications. However, the initial general specification by awarding authorities that construction should be sustainable has little relevance to the subsequent material decisions. On the contrary the role of the recommendation of engineers, have a high impact on the subsequent decisions by the other stakeholders. Results also confirm that RMCM are broadly accepted in civil engineering (CE), whereas in structural engineering (SE) RMCM are still a niche product. The good alignment of the outcome of decision modeling with observed behavior shows the usefulness of analyzing decision-making with AHP.     

Integration of the recycling processes to the life cycle analysis of construction products

The life cycle analysis of a product enables one to assess its environmental quality. A simple, transparent method taking into account the processes of recycling in the life cycle is developed here. It permits dealing with all types of open loops of all sectors. The principles on which the proposed method is grounded are discussed.     

许昌市发制品行业的清洁生产调查

发制品行业是以人发、人造纤维等为原材料进行假发加工的行业。许昌市发制品的生产过程大致可分为两个阶段:漂染和前后处理。漂染过程用水量大,产生的废水难以处理。其中过酸、氧化、染色配置的溶液使用一次后直接排放,不符合清洁生产要求,且所排放的溶液可考虑中和多次利用。漂染过程水资源消耗量大,废水产生量大,没有考虑废水综合利用。按清洁生产的要求在以上环节可通过技术革新和设备改造得以改进。     

Review of sustainability management initiatives within Finnish forest products industry companies—Translating Eu level steering into proactive initiatives

Sustainability has become a major focus area within forest products industry. The European operational environment and national environmental steering in EU member states highlight the importance of sustainable development and the development of associated new management approaches to promote sustainability. This article reviews some key elements of sustainability management, covering examples of both Finnish forest products industry initiatives and public environmental steering at the European level. An assessment is made of the current situation and an outline of a future outlook for sustainability management, with special emphasis on bridging the gap between industry initiatives and environmental steering in the form of legislation, policies and strategies at the EU level.This study applied a hybrid approach comprising a review of EU sustainability initiatives, a policy and legal review and a questionnaire survey of forest industry actors. The results of the future outlook indicate that energy efficiency is perceived to be the most important focus area in addition to e.g. environmental and waste management and recycling. Less than half of the companies aim at applying sustainability management. Life-cycle management is also considered to be important whereas product-based approaches, climate change and local industrial symbiosis receive very little attention. All responding companies aim to integrate the principles of sustainability into their operations and most companies consider that life-cycle thinking, management and assessment are useful for them. Energy efficiency is identified as the most important focus area with energy and materials efficiency seen as the most crucial factors for the achievement of responsible competitive advantage and building of sustainable value-added. The findings indicate that sustainability and life-cycle management are not receiving enough management focus at the moment and neither is the industry receiving enough guidance at either the EU level or via national steering and regulatory frameworks.     

Overview of non-hazardous solid waste in the small island state of Mauritius

In Mauritius, solid waste disposal has been a cause for concern since the 1980s. Currently, there is no segregation of waste and some 1200 tonnes of solid waste are generated daily by the 1.24 million inhabitants of the island. As processes such as recycling and composting are still in their infancy stage, most of the waste generated have to be disposed of at the sole landfill. The solid waste management practices of 1980s and early 1990s are no longer compatible with the changing composition and quantity of wastes now generated. As a result, there is an urgency to review the whole waste management system and come forward with sustainable solutions.This paper presents an overview of the disposal of non-hazardous solid waste in Mauritius and provides recommendations for improving the current disposal system.     

Environmental and economic assessment of combined biostabilization and landfill for municipal solid waste

Biostabilization can remove considerable amounts of moisture and degradable organic materials from municipal solid waste (MSW), and can therefore be an effective form of pretreatment prior to landfill. The environmental and economic impacts of two combined processes, active stage biostabilization + sanitary landfill (AL), and active and curing stage biostabilization + sanitary landfill (ACL), were compared with sanitary landfill (SL) for MSW with high moisture content. The results indicated that land requirement, leachate generation, and CH(4) emission in the ACL process decreased by 68.6%, 89.1%, and 87.6%, respectively, and the total cost was reduced by 24.1%, compared with SL. This implies that a combined biostabilization and landfill process can be an environmentally friendly and economically feasible alternative to landfill of raw MSW with high moisture content. Sensitivity analysis revealed that treatment capacity and construction costs of biostabilization and the oxidation factor of CH(4) significantly influenced the costs and benefits of the AL and ACL process at an extremely low land price. When the land price was greater than 100 USD m(-2), it became the dominating factor in determining the cost of treatment and disposal, and the total costs of ACL were reduced to less than 40% of those of SL.     

Analysis of the implementation of effective waste management practices in construction projects and sites

In this paper, the implementation of effective waste management practices in construction projects and sites is analyzed, using data from a survey answered by 74 Spanish construction companies based in Catalonia. Most commonly implemented practices were found to be on-site cleanliness and order, correct storage of raw materials, and prioritization of the nearest authorized waste managers. The least widespread practices were the use of a mobile crusher on site, the creation of individualized drawings for each construction site, and the dissemination of the contents of the waste management plan to all workers, to help them to meet its requirements. Waste regulations for construction and demolition, and the corresponding construction waste management facilities, were designed before the recession in the Spanish construction sector. Current waste generation rates are still below predicted levels, and the infrastructure was designed for five times more waste generation. Even so, the percentage of reused and recycled waste currently amounts to 43%. Survey respondents highlighted various instruments and measures that would make the management of construction and demolition waste more sustainable. Most of the opportunities identified by construction firms are within the scope of government and related to a combined system of bonus and penalties and the establishment of environmental awareness and training programmes for all the stakeholders. Within the scope of authorized waste managers, firms suggested improvements such as the standardization of fees, a reduction of the time until the issue of waste management certificates, a higher number of inspections, and a change in the current model of a few large construction waste management facilities. This research is useful to better understand the current status of construction and demolition waste management in construction projects and sites. Thus, the results of this research will guide policy makers and relevant stakeholders such as contractors, clients, architects and engineers to achieve the EU target of recovering 70% of construction and demolition waste in 2020. In this sense, reliable information can help governments and professional associations to set future C&D waste management regulations, training programmes and dissemination tools, inspections, etc.     

Assessing the accumulation of construction waste generation during residential building construction works

The difficulty of dealing with construction and demolition waste (CDW) on construction sites is not new and continues to be an environmental problem. Understanding the waste generated in a construction work is essential to optimize CDW management. Therefore, any tool used for establishing an estimation of the CDW that will be generated should be considered as an alternative to achieve real solutions pursuing sustainability. This paper presents the evolution of CDW flow generation in the construction of new residential buildings, and has identified that the construction activity is increasing the waste generation. In an attempt to find some solutions and provide improved alternatives, several building sites have been analysed in order to quantify the estimation of CDW generated. Results show that when using plasterboard walls the CDW generation, per m² of built surface can be reduced up to 15.94% compared to the use of traditional brick partitions. In addition, a model describing the accumulation of CDW throughout the project duration is proposed. This model states that CDW mainly accumulates in the middle stages of the project. This study allows an estimation of the amount of CDW to be generated in a building construction site, helping to plan the number and size of containers required at any moment of the construction process, as well as the space required for a proper CDW management.     

Efficient water use in industries: cases from the Indian agro-based pulp and paper mills

Agro-based pulp and paper mills in India are one of the most polluting industries; in addition, they are high consumers of raw water. Growing scarcity of high quality freshwater as well as stringent regulatory standards is compelling these units to explore appropriate water management options. Based on data obtained through a questionnaire survey and plant visits, this work provides an overview of the water use and effluent treatment status in Indian agro-residue and recycled pulp and paper mills. The challenges faced by this sector are reviewed and practices adopted by progressive units to minimize freshwater use are illustrated through case studies.     

危害电工电子产品的生物霉菌

本文分析了霉菌对电工电子产品的影响,并指出预防方法。     

Guided group discussion and the reported use of toxic products: The persuasiveness of hearing others’ views

Guided group discussion ( [Lewin et?al., 1952], [Werner, 2003] and [Werner and Adams, 2001]) was used to persuade groups to replace their toxic home and garden chemicals with nontoxic alternatives. We hypothesized that discussion would allow participants to hear others endorse the new information, and this normative information would facilitate persuasion. Approximately two months after the group discussion, we obtained questionnaires from the organizer of the meeting and a member of the group who had missed the meeting because of another obligation (i.e., not because of disinterest in the topic). Most organizers were female and analyses were limited to females. This quasi-experimental matched control group design indicated that those who attended the meeting were more favorable towards using nontoxics and more interested in sharing leftover toxic products with friends (instead of discarding them). Path and mediation analyses showed that the organizer’s evaluation of the meeting predicted her final attitude, and perceptions that the group endorsed the material (perceived group norm) partially mediated this relationship. A second mediation analysis showed that evaluation of the meeting predicted intention to share leftover toxics and this relationship was fully mediated by the organizer’s impression that the group would also share leftovers. The results support the idea that persuasion is based both on individual evaluation and normative influence, especially when people are not confident others will accept the behavior, such as sharing leftover toxic products.     

旅游开发中典型土地利用问题及对策探讨

旅游用地是一种特殊的土地资源类型，一直没有得到应有的重视。在实际利用中存在着许多突出问题，如旅游景点的土地利用规划与旅游规划不协调，旅游用地中的景观设计的人为性，旅游用地资源环境污染和破坏，旅游用地中的产权关系混乱，以及打生态旅游牌搞房地产开发等。研究提出了加强旅游用地立法，做好土地规划与旅游规划，对旅游用地进行估价，实行用地来源的多途径化与统一管理等对策。它是一项探索式研究，具有开创性，旨在为旅游资源的可持续发展做初步探讨。     

垃圾填埋场选址与风水选址浅析

通过对风水理论中关于选址要素的科学阐述,从自然环境和社会环境两个方面分析了风水选址和垃圾填埋场选址的共通与不同之处,并根据风水理论中“天人合一”的和谐理念,提出了在填埋场选址过程中,应该融入崇尚自然,尊重自然;结合实际,因地制宜;整体系统;以人为本,和谐构建等原则。     

垃圾填埋气中微量挥发性有机物的净化技术

垃圾填埋气中存在的多种微量挥发性有机物(VOCS),既造成二次污染,影响了人类健康;又对填埋气的回收利用产生了不利影响。本文综述了几种VOCS常规净化技术的基本原理、优势及限制,介绍了几种新兴技术,并预期有效的联合工艺是净化填埋气中微量VOCs的研究方向。     

浅谈钢铁企业工业污水处理现状和存在的问题

文章对钢铁企业工业污水处理现状和存在的问题进行了初步的分析和探讨。指出我国钢铁工业要进一步降低钢铁企业吨钢耗用新水量、提高钢铁企业水的重复利用率,需要积极推广应用少水或不用水的工艺技术装备,并应强化合理串级用水,以及加强工业污水的综合处理回用。     

Economies of scale in global iron-making

In this paper, we investigate the presence of economies of scale in the global iron-making industry for integrated steel plants, iron making being the first stage in the steel-making process. Iron making depends on basic commodities, such as iron ore, coke and various forms of energy, required in the operation of the blast furnace, which can be classified as essential inputs and used in fixed proportions to produce iron. A generalized Leontief cost function is estimated using panel data for 69 integrated plants, such a specification being appropriate for technologies with essential inputs that are used in fixed proportions in production. A significant scale effect is observed due to the existence of fixed costs and a linear dependence of the cost function on production. Under a simple linear cost function, a rough estimate of the breakeven scale of plant, where costs equal revenue, is 4.5 Mt per year. Competitiveness, as measured by the ratio of plant average cost per tonne to best practice cost per tonne, can be shown to be positively related to the scale of production as well as the cost of essential inputs. Therefore, low-cost producers are also often producers with low raw material costs and production levels below the estimated breakeven scale of operation. Labor costs, although significant, are comparatively less important as a driver towards low costs.