Developing Abu Dhabi's solid waste sustainability index (ADSWMI)

Fast urbanization and population and economic growth led to increased solid waste generation in Abu Dhabi in the last decades. Abu Dhabi generates 5.8 kg of municipal waste per day per person. This is well above the world average of 1.2 kg per day per person. Treatment and destination of the municipal solid waste is also problematic. Only 3.5% of the total municipal solid waste generation is recycled, and the remaining waste is disposed in landfills which are technically not adequate. In this context, sustainability indicators can play an important role in supporting decision makers in planning and managing the solid waste system. In this study, the waste management system in Abu Dhabi Emirate was analyzed through the implementation of a set of proposed sustainability indicators. The DSR Driving force-State-Response approach was used as the methodology to develop a framework for the context of Abu Dhabi. Twenty indicators, based on literature review and benchmarking, were divided into five categories: quantity & composition, environmental controls & resource management, construction & demolition waste, financial sustainability, and governances & policies. These indictors can be a baseline to assist decision makers to develop an integrated waste management system able to meet the high international standards and target in the field.

Australian SMEs waste to landfill

Landfill waste has a negative impact on the environment and small and medium sized enterprises (SMEs) are believed to be significant contributors. There is little government or scholarly research, however, quantifying the collective volume of waste SMEs send to landfill. Where studies do exist they measure total volumes (landfill and recycling combined) and/or do not distinguish between specific waste streams (e.g. wood) and subcategories (e.g. dust). This paper contributes to knowledge by giving insight into the collective volume of waste of 404 SMEs, reconceptualising SME waste into subcategories and by measuring landfill volumes. It presents findings from these 404 Australian SMEs which found that, in descending order, cardboard, paper, plastic wrap, wood dust and particleboard were the subcategories these SMEs sent to landfill in the greatest volumes. It also argues that this reconceptualisation, and associated data collection protocols, have the potential to enable scholars and policy makers to determine the waste subcategories to which SMEs contribute most, formulate targeted interventions and research or evaluate environmental outcomes. © 2014 © 2014 Environment Institute of Australia and New Zealand Inc.

Major factors affecting waste generation on construction sites in Iran

Construction and demolition (C&D) waste account for a large share of total solid waste sent to the environment. As a result, effective C&D waste management has been treated as one of the available avenues towards sustainable development. Yet, C&D waste management within the Iranian construction industry has been literally overlooked by investigators. As one of the first studies in Iran, the main causes of generating C&D waste on construction projects have been identified through a review of literature. Afterwards, the list has been subjected to the scrutiny of 101 experts in the field deploying a questionnaire survey. The findings revealed that important causes of C&D waste generation on construction sites were all associated with lack of skills and experience of construction workers and lack of awareness of the concept of waste and values of construction materials. No discrepancy in terms of causes of waste generation was observed among different tiers of construction companies in the Iranian construction industry. The paper concludes with providing a number of guidelines to address the issues as identified for Iran and other developing countries suffering from the same problems.

Capacity building for post disaster construction and demolition waste management: a case of Sri Lanka

Purpose – The purpose of this paper is to present a theoretical framework for capacity building in post disaster construction and demolition (C&D) waste management at a national level to address the identified capacity gaps in managing disaster waste resulting from natural hazards.

Design/methodology/approach – Data were gathered through pilot interviews, case studies and expert opinion surveys representing government, non-government and other sector organisations involved in post disaster waste management.

Findings – The study revealed unavailability of a single point of responsibility and provision for disaster waste in existing policies and capacity constraints in prevailing peace time solid waste management practices which were identified as major capacity gaps. Establishment of a regulatory body and enforceable rules and regulations with necessary levels of capacities was identified and presented in a theoretical framework comprising of seven identified areas for capacity building in post disaster waste management.

Research limitations/implications – This study is limited to disaster C&D waste as debris generated from totally or partially damaged buildings and infrastructure as a direct impact of natural hazards or from demolished buildings and infrastructure at rehabilitation or early recovery stages. Waste generated during reconstruction phase of post disaster management cycle is not considered as disaster C&D waste for purposes of this study.

Originality/value – The research enabled analysis of existing capacities and presents approaches for capacity building for identified gaps in post disaster C&D waste management to attain sustainable post disaster waste management for future resilience.

Technical development for deconstruction management

The Australian construction industry, particularly in the area of demolishing existing facilities, is responsible for up to 40% of the country's enormous solid waste streams, totalling about 14 million tonnes annually. The recently created concept of deconstruction, rather than destruction for demolishing a constructed facility, came about because of the rapidly increasing number of demolished buildings and changes in levels of environmental awareness. However,  reconstruction processes are now seen as only an interesting concept for reducing waste through reuse and recycling, but they fail to achieve widespread understanding or acceptance. The challenges faced by deconstruction are significant and diverse. The maturity of deconstruction practice depends on not only on tlle development of deconstruction techniques and management, but also on the enhancement of deconstruction awareness by the owners, designers, and construction teams, as well as the development of environmental regulations. These practical limitations are interrelated and mutually promotional. The technical developments in deconstruction management resulting from this research will have direct effects on various aspects, including the development of design and construction for deconstruction, deconstruction technology, reused material certification, recycl ing technology, and a method by which to calculate environmental benefits so that deconstruction would be promoted from an interesting concept mainly in theory to wide acceptance in practice. 

Using geopolymer to minimise metals leaching from brown coal fly ash

Fly ash is generated from combustion of brown coal in power stations. The majority of fly ash is removed by electrostatic precipitators (ESP) and finally disposed into the landfill as prescribed wastes. A method was studied to add clay materials to the brown coal fly ash in order to form the so-called geopolymer network, which is effective at stopping the metal contents from leaching, and have minimum impact to the environment. The experiments were conducted parallel on leached fly ash and dry precipitator fly ash. The ratios of fly ash and added clay materials were varied to determine the effects of different compositions on leaching rates. Both X-ray diffraction analysis and scanning electron microscopy images showed that as the percentage of fly ash was increased, the formation of geopolymer is reduced. Eighteen metals and heavy metals were targeted during the leaching tests and the leachate samples were analysed using ICP-AES and ICP-MS. It was found that the reduction of metal leaching was achieved by adding up to 60% of fly ash to form the geopolymer like structure. Significant reductions were observed for calcium, strontium and barium. Leached fly ash achieved better stabilisation than dry precipitator fly ash for major elements. It's hard to quantify its effects on trace metals leaching due to their ultra low concentration in the fly ash. The samples spiked with trace metals of lead, zinc, mercury and barium showed remarkable reduction in leaching.

Acid induced degradation of the bentonite component used in geosynthetic clay liners

Bentonite is a natural clay mineral widely used in the mining and solid waste containment industry, for example, as a soil mixture for the construction of seepage barriers, or as a component of geosynthetic clay liners (GCLs), to provide low hydraulic conductivity. However, degradation of bentonites generally occurs when permeated with acid solutions, such as encountered in mining applications, which may influence physical properties, and particularly, the hydraulic performance of geosynthetic clay liners.In this paper, properties such as Atterberg limits, free swell index, and fluid loss of three bentonites were measured with different concentrations of sulphuric acid solutions. These properties were found to deteriorate even with low (0.015 M) sulphuric acid solutions; higher concentrations (up to 1 M) resulted in larger degradation. X-ray diffraction and infrared spectroscopy were used to monitor the change of bentonites after interaction with the acid solutions. Acid leachates in general result in the overall degradation of the hydraulic performance of geosynthetic clay liners and potentially, any bentonite-soil mixture.