Properties of alkali-activated fly ash: high performance to lightweight

Alkali ash material (AAM) concrete is a unique material that is sustainable and cost-effective because it utilises waste fly ash, and has properties superior to other concrete products. The AAM concrete described here is produced from the addition of inexpensive chemicals to fly ash. AAM can be used to create a wide range of materials including high performance concrete (HPC-AAM) and lightweight (LW-AAM). The high performance AAM provides rapid strength gain along with high ultimate strengths of more than 110 MPa (16000 psi). LW-AAM can produce materials with densities ranging from 1200 to 2200 kg/m³ and compressive strengths from 2 (290 psi) to 65 MPa (9500 psi). Both HPC-AAM and LW-AAM have far better environmental resistance than Portland cement concrete, resisting attack from sulphuric acid (H₂SO₄), hydrochloric acid (HCl) and organic acids. AAMs resists freeze–thaw attack and high abrasion, possesses low chloride permeability and does not exhibit alkali silica reactivity.     

OPTIONS FOR ENVIRONMENTAL SUSTAINABILITY OF THE CRUDE PALM OIL INDUSTRY IN THAILAND THROUGH ENHANCEMENT OF INDUSTRIAL ECOSYSTEMS

The crude palm oil industry plays an important role in the economic development of Thailand and in enhancing the economic welfare of the population. Despite obvious benefits of this industrial development, it also significantly contributes to environmental degradation, both at the input and the output sides of its activities. On the input side, crude palm oil mills use large quantities of water and energy in the production process. On the output side, manufacturing processes generate large quantities of wastewater, solid waste/by-products and air pollution. Current industrial wastes and recoverable materials are empty fruit bunches, fibers, shells and ash. It is estimated that in 2003, a total of 2.1 million ton of solid wastes/by-products and 2.5 million m³ of wastewater were generated. The concept of the industrial ecosystem points at the potential of industrial waste recycling resembling food chains, food webs and nutrient cycles of nature. Following the notion of industrial ecology crude palm oil mills can develop a number of waste recycling and reuse systems. This paper analyzes the nature of these industrial ecosystems, divided in in-plant ecosystems (clean technology options) and external waste exchange between crude palm oil industries and other economic activities in Thailand.     

China’s Import of Wastes and Its Implications

Abstract

The trade of wastes in the world has been increasing and China has become the largest importer of wastes. This paper examines the import trend of different wastes and finds out that the total import volume to China approved by the Chinese government keeps increasing and the illegal trade can not be banned despite repeated prohibitions; therefore, China is not only “a world factory”, but actually “a global garbage dump”. In order to well understand the implications of wastes import, this paper further analyzes the resource and environmental effects and risks of different wastes imports as well as the strong driving force of wastes imports. Based on these detailed analysis and solid data, policy recommendations are put forward to reduce the demand for raw materials, to further strengthen the inspection of and supervision over the international trade of the wastes that can be used as raw materials by using the life cycle analysis and risk analysis, to improve the environmental standards and strengthen the disposal capacity, to re-export the raw materials produced from the imported wastes, to develop the long-term planning for the import of wastes and to promote international cooperation.     

Comparative toxicity of solid waste leachates to Daphnia magna

The comparative acute and chronic toxicities of municipal, industrial, coal-fired power plant, and synthetic fuel solid waste leachates to the aquatic invertebrate Daphnia magna were determined. Seventeen leachates were laboratory-derived by extraction with 0.5 N acetic acid, and one, an arsenic-contaminated groundwater, was naturally derived. The acute toxicity 48-h LC₅₀ estimates (concentrations of the test materials that killed 50% of the test organisms in 48 h) ranged from 0.0005% for a dye waste leachate to > 100% (i.e., undiluted) for a coal gasification waste leachate. The most toxic leachates were derived from a dye waste, a plater's waste, and the arsenic-contaminated groundwater, and the least toxic were from a soybean process cake waste and a coal gasification waste. Of the 16 leachates used in the 28 day chronic toxicity tests, only the arsenic-contaminated groundwater and a municipal sewage sludge significantly affected D. magna reproduction. The former material at 1.0% concentration and the sludge at 0.1% caused about an 88% reduction in the numbers of young produced by exposed females compared with controls. Generally, the industrial waste leachates were more toxic than those from the power plant and synthetic fuel wastes. Because its presence in the test materials interfered with interpretation of the results, acetic acid may not be an appropriate extraction medium for preparation of leachates.     

A design for EoL approach and metrics to favour closed-loop scenarios for products

Recently, environmentally conscious design and extended producer responsibility have become key aspects for companies that need to develop products that are sustainable along their whole life cycle. Design for End of Life (EoL) is a strategy that aims to reduce landfill waste through the implementation of closed-loop product life cycles. It is important to consider disassembly and EoL scenario management as early as the design phase. For these reasons, this paper presents an approach to help designers in the evaluation and subsequent improvement in product EoL performance. The method is based on four innovative EoL indices that compare different EoL scenarios for each product component. In this way, the designer can modify the product structure or the liaisons to maximise the reuse and remanufacture of components as well as material recycling. The presented case studies confirm the validity of the approach in helping designers during the redesign phase of goods and products to reduce the quantity of materials and industrial wastes sent to landfill.     

Cost-effectiveness of recycling and recirculation of natural and energy resources based on the equality principle

A cost structure is proposed for optimizing the recirculation and recycling of commodities and energy usage considering regional, national and global operating scales. The methodology proposed involves business administration theory and economics and employs the previously introduced equality principle and the model for efficient use of resources for optimal production economy (EUROPE) to impose shadow costs on unwanted material wastes and energy residuals that produce economic incentives to reduce such wastes at the source. A case study presents the practical application of the proposed theory in a national and a global context. It is concluded that the presented methodology is useful for increasing the cost-effectiveness and optimizing recirculation and recycling in the usage of energy resources and natural resources in general. Profitability increases, technology is advanced and environmental conditions improve simultaneously through the application of the EUROPE model to analyze government policy related to the recirculation and recycling of solid wastes and energy. Furthermore, the equity of the distribution of such recirculation and recycling facilities is improved. The developed methods are useful information support tools for decision-making in the management of energy and other natural resources with emphasis on the economics of recirculated and recycled residuals.     

Industrial complexes and their relevance for pulp and paper mills

Advantages and disadvantages of the concept of an industrial complex are discussed. From an environmental standpoint an ideal industrial complex is one containing a group of compatible industrial plants utilizing completely each other's wastes and products as raw materials and manufacturing products with no adverse environmental impact and at a minimum of cost. A typical complex centering about a pulp and papermill is pictured in this paper. This complex produces six products for external sale and four products for internal use. In addition, all major wastes of suspended solids, cooking liquor, fillers, heat and bark are reused within the complex in the manufacture of these products. A literature review evolved typical concentrations of recoverable suspended solids in various process effluents. A mass balance was prepared assuming that the total production of fine paper is 907.2 kg × 10³ (1000 tons) per day. Little or no air or water pollution results from this complex. In addition, it is anticipated that no expensive waste-water treatment plant would be required for this complex. Ten additional practices are described which, when used, will reduce operating costs even further. A continuing study with more precise data on the production requirements for the service plants in the complex will yield a more balanced and realistic system.     

Recycling – the importance of understanding the complexity of the issue

Natural resources and raw materials such as metals and minerals are often taken for granted in today’s society. Without them, the offerings of an enormous variety of modern conveniences, including computers and mobile phones, would not be possible. The production of these everyday items depends on a secure, sustainable, and reliable supply of critical raw materials. In addition, product development also requires new hybrid materials when targeting lightweight structures, etc. However, the mandatory recyclability of new products or materials is not obligatory or even prevailing practice in present manufacturing business. Therefore, the main research question in this article is: “how to solve the challenge of recycling in industrial system?” In this article, a comprehensive approach to recycling based on the findings of research projects is presented. Simplified, this involves moving the challenge from the end of the product’s life cycle to the beginning, to the design or even to material development phases. Life cycle and system thinking and material know-how in the design phase are found to be essential elements of a new approach to recycling. This approach stems from the material development and market economy perspectives. Furthermore, the vulnerability of the industrial system to create uncertainty to recycling is also demonstrated.     

Identification of potential applications for recycled polymeric multi-material

Abstract

This research aims to characterise a recycled polymeric multi-material, explore potential areas of application for it and analyse the eventual impacts of the introduction of this new recycled material (NRM) on end-of-life activities. Thus, this research presents a practical study regarding recycled polymeric multi-material from toothbrushes. A preliminary characterisation (via density determination, tensile test and dynamic mechanical thermal analysis – DMTA) and data analysis using the Cambridge Engineering Selector (CES-Edupack 2013) software have been done. The study also presents an analysis of the impacts of introducing the NRM into end-of-life activities. Results shows that, based on the properties considered in this study, NRM may have potential for new applications. The impact on recycling networks indicates that it is a positive solution that would improve process variable efficiencies, maintaining material value as long as possible in industrial closed-loop life cycles. However, an in loco analysis of the treatment of waste containing the NRM is necessary.     

The formal electronic recycling industry: Challenges and opportunities in occupational and environmental health research

BackgroundE-waste includes electrical and electronic equipment discarded as waste without intent of reuse. Informal e-waste recycling, typically done in smaller, unorganized businesses, can expose workers and communities to serious chemical health hazards. It is unclear if formalization into larger, better-controlled electronics recycling (e-recycling) facilities solves environmental and occupational health problems.ObjectivesTo systematically review the literature on occupational and environmental health hazards of formal e-recycling facilities and discuss challenges and opportunities to strengthen research in this area.MethodsWe identified 37 publications from 4 electronic databases (PubMed, Web of Science, Environmental Index, NIOSHTIC-2) specific to chemical exposures in formal e-recycling facilities.DiscussionEnvironmental and occupational exposures depend on the degree of formalization of the facilities but further reduction is needed. Reported worker exposures to metals were often higher than recommended occupational guidelines. Levels of brominated flame-retardants in worker's inhaled air and biological samples were higher than those from reference groups. Air, dust, and soil concentrations of metals, brominated flame-retardants, dioxins, furans, polycyclic-aromatic hydrocarbons, or polychlorinated biphenyls found inside or near the facilities were generally higher than reference locations, suggesting transport into the environment. Children of a recycler had blood lead levels higher than public health recommended guidelines.ConclusionsWith mounting e-waste, more workers, their family members, and communities could experience unhealthful exposures to metals and other chemicals. We identified research needs to further assess exposures, health, and improve controls. The long-term solution is manufacturing of electronics without harmful substances and easy-to-disassemble components.     

China’s Import of Wastes and Its Implications

The trade of wastes in the world has been increasing and China has become the largest importer of wastes. This paper examines the import trend of different wastes and finds out that the total import volume to China approved by the Chinese government keeps increasing and the illegal trade can not be banned despite repeated prohibitions; therefore, China is not only ＂a world factory＂, but actually ＂a global garbage dump＂. In order to well understand the implications of wastes import, this paper further analyzes the resource and environmental effects and risks of different wastes imports as well as the strong driving force of wastes imports. Based on these detailed analysis and solid data, policy recommendations are put forward to reduce the demand for raw materials, to further strengthen the inspection of and supervision over the international trade of the wastes that can be used as raw materials by using the life cycle analysis and risk analysis, to improve the environmental standards and strengthen the disposal capacity, to re-export the raw materials produced from the imported wastes, to develop the long-term planning for the import of wastes and to promote international cooperation.     

Processes for sustainable development using high-intensity electric fields

Intense electric fields up to 10⁷ V/m generate very interesting and useful applications for the environment. Several processes using high electrical voltage for environment preservation were developed in the laboratory. The purpose of this study was to review these applications, highlighting their economic and environmental benefits: (1) electrostatic separators of particles used in industrial wastes recycling; (a) role-type electrostatic separator for granular mixtures of plastic–metal particles; (b) free-fall and rotating belt triboelectric separators for mixtures of plastic–plastic particles; (c) plate-type electrostatic separator for mixtures of metal–metal particles, (2) electrostatic precipitators for gas cleaning and (3) ozone generators for air and water treatment.     

Health and environmental impacts of a fertilizer plant--Part I: assessment of radioactive pollution

The aim of the first part of this investigation is to assess the radioactive pollution caused by a production plant of complex fertilizers (that is to say containing nitrogen, phosphorus and, in some cases, potassium). Firstly, the authors determine the concentrations of natural radioactivity present in raw materials, end products and wastes of the industrial plant. Then, they carry out an assessment of radioactive releases into the atmosphere, hydrosphere and lithosphere as well as of their significance from the environmental point of view. The second part of the investigation will be aimed at assessing the annual effective doses to plant workers and to members of the population surrounding the industrial site.     

高科技污染问题及驱动力模型研究

高科技产生的污染包括产品生产、消费过程中及废弃时产生的污染。这些特点又加重了高科技的污染程度。高科技污染的各种特点，包括扩散快、产品回收难、污染类型多及隐蔽性强等。以江苏省高科技企业为例，研究企业隶属、资产组成以及经营能力和科技水平等企业性质指标与企业有毒有害原辅料消耗量的相关性，并做出高科技企业污染的驱动模型。根据所得研究结果，分析总结影响高科技企业有毒有害原辅料消耗量的主要因素，认为企业的性质间接作用于企业，最终形成了高科技污染。并据此提出治理高科技污染的建议，即完善污染治理法律体系、探索废旧产品回收途径、发展清洁生产技术、探索针对高科技企业的环境管理模式。     

How does government environmental regulation “unlock” carbon emission effect?—evidence from China

ABSTRACT

The disordered emission of carbon dioxide is an important sign of market failure, making it a must to “unlock” the high emission effect of carbon dioxide by effective means. From the perspective of technological innovation, on the basis of the data of time series from 1985 to 2014 in Beijing, China, this article empirically analyzed the relationship between environmental regulation and carbon emissions through VAR model, impulse response function, and variance decomposition. It is concluded that in a short term, environmental regulation has an inhibitory effect on carbon emissions and technological innovation and has a positive effect on industrial structure. In a long term, environmental regulation can enhance the technological innovation and reduce the effect of carbon emissions, which may even eliminate it. Generally, environmental regulation and technological innovation have a greater impact on carbon dioxide emissions, while the industrial structure has a relatively small effect. Finally, the targeted countermeasures and suggestions are put forward.     

低碳沼气工程建设的生态经济效益核算研究——以广西恭城瑶族自治县为例

在全球气候变暖和快速城市化的背景下,农村地区是能源集约消耗的薄弱区域,其经济、社会、生态的可持续发展一直受到制约。沼气工程作为一种清洁用能方式,在优化用能结构、减少环境污染、节约自然资源、增加农民收入和促进农村经济转型等方面具有较大优势。本文选择广西恭城瑶族自治县这一沼气工程建设全国示范县为案例,针对户用8m3沼气池,对施工建设、运营维护和消费利用全生命周期过程中的碳足迹、减排效益、经济收益和生态价值方面进行核算和评价。结果表明在沼气池的建设与正常使用年限内,该县农户通过替代燃煤、柴薪和秸秆等共可减排CO2约1.24×106t。从户用沼气池建设及生产过程的投入产出价值的来看,仅通过节约炊事燃料和沼液沼渣的回收利用就能为每户节约19 877元,为全县带来1.26亿余元的总收益。因此,沼气工程在该地区的建设普及是发展农村低碳经济、走富农之路的有效措施,可为广大西部地区新农村建设提供借鉴。     

Construction of Circular Economy Industrial System

Abstract

It is difficult to realize the transformation from traditional economy industrial system to circular economy industrial system. Regarding primary raw materials as the indicators, the industrial system has been specified according to the divergence among the indicators and the circular utilization modes. In comparison with the association among industrial systems, the relationship among industrial sub-systems is named as industrial cross-linking in this paper. The industrial system which could completely utilize and recycle the indicators should be increased and strengthened, and the circular economy industrial system with complete industrial association and industrial cross-linking should also be constructed. Taking the development of circular agricultural system basing on the traditional agricultural system as an example, the traditional agricultural products are regarded as the indicators which have been divided into foodstuff and crop straws which are used to produce food and articles for use, like fertilizer, energy and papers etc. The way to construct the circular agricultural industrial system is to increase the industrial systems that could utilize the products generated from crop straws, feces and other castoffs and transform the wastewater and other trucks into environmental friendly products. It has also been pointed out that the construction of circular economy industrial system is conducive to the foundation of circular industrial economics and the establishment of the construction layout of circular economy and the application schemes. Suggestions to the theoretical and practical work of the next step have also been brought forward in this paper.     

Recovery and recycling of post-consumer waste materials. Part 1. Generalities and target wastes (paper,cardboard and aluminium cans)

Recycling of post-consumer waste materials is gaining increased interest due to public awareness, legislative promotion and imposition, economic benefits and appropriate technologies being available. The present paper does not deal with municipal solid waste as such, but only with the recyclable constituents. The paper does not aim at presenting recycling process details and/or fundamental research results, but reviews the major recyclables with their reuse potential, recycling technologies used, problems, solutions and potential areas of future research and development. These target recyclables include paper and cardboard, aluminium cans, glass beverage bottles, scrap metal and steel cans, scrap tyres, batteries and household hazardous waste. The present paper sets the overall picture and deals with paper, cardboard and aluminium cans only. A second part of the paper assesses the other target recyclables. The assessment of the waste availability, the existing and currently developed recovery and recycling technologies, and the economically rewarding markets while recycling, stress the technical, economic and environmental importance of this waste management sector. The activities associated with the recovery and recycling of post-consumer wastes require a strong sustainable engineering input at all phases of the treatment, from input quality control, to the selection of the most appropriate technology and the delivery of the recyclables as readily reusable feedstock.     

Local Area Quotas for Industrial Emissions along Reaches of the Pearl River in Guangdong

Abstract

There is an obvious departure from the regional equilibrium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in “the effects of contra-geography-grads development”. It is mainly because the upriver mountainous areas have been deeply stuck in industrialization delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of “the vicious circle of poverty” by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environmental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called “the Local Area Quotas for Industrial Emis-sions along the Pearl River” is put forward supposed to give corresponding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.     

Construction and demolition waste generation in cities in India: an integrated approach

ABSTRACT

This paper quantifies construction and demolition waste (C&DW) generation rate in Indian cities using bottom-up material flow analysis approach. A dynamic model was applied to different classes of cities in India to investigate how C&DW generation rate varies across different classes of cities. The data on construction and demolition activities in different classes of cities were estimated from information reported in secondary literature. The results show that urban areas in India generated over 150 million tonnes of C&DW in 2016, and almost 50% of waste was generated in small to medium towns. The paper concludes with discussion on opportunities for recycling of C&DW and closing the material loops in Indian cities.