Chin Siong Ho

Mobilising the potential towards low-carbon emissions society in Asia

Emission of CO2, CH4, and NOx is among the main sources of greenhouse gases (GHGs) emitted through human activities such as fossil fuels combustion for power, heat and transportation, industrial processes, and land-use change. Low-carbon emission has become synonymous with GHG emission, which is often expressed in t CO2 eq. as derived from the major GHG. However, CO2 emission from fossil fuel constitutes just about 2/3 of GHGs. Low-carbon emission has received high publicity in recent years as a major reason for the potential mitigation of climate change. Achieving low GHG emission targets while decoupling the economic growth from high emissions, pollution, and resource use is desirable. This paper reviews the low-carbon emissions initiatives to develop resilient growth strategies to reduce GHG emissions in Asia and beyond. Four major initiatives, including the modelling of GHG emission and mitigation initiative; sustainable energy systems; sustainable waste management; and education and community outreach, are reviewed for mobilising the potential towards low-carbon emissions societies in Asia. Cooperation from major stakeholders, e.g. government, policy makers, financial institutions, private investors, industrial, commercial sector, residential, has been needed towards realising the goal.

Towards low carbon society in Iskandar Malaysia: Implementation and feasibility of community organic waste composting

Rapid population growth and urbanisation have generated large amount of municipal solid waste (MSW) in many cities. Up to 40-60% of Malaysias MSW is reported to be food waste where such waste is highly putrescible and can cause bad odour and public health issue if its disposal is delayed. In this study, the implementation of community composting in a village within Iskandar Malaysia is presented as a case study to showcase effective MSW management and mitigation of GHG emission. The selected village, Felda Taib Andak (FTA), is located within a palm oil plantation and a crude palm oil processing mill. This project showcases a community-composting prototype to compost food and oil palm wastes into high quality compost. The objective of this article is to highlight the economic and environment impacts of a community-based composting project to the key stakeholders in the community, including residents, oil palm plantation owners and palm oil mill operators by comparing three different scenarios, through a life cycle approach, in terms of the greenhouse gas emission and cost benefit analysis. First scenario is the baseline case, where all the domestic waste is sent to landfill site. In the second scenario, a small-scale centralised composting project was implemented. In the third scenario, the data obtained from Scenario 2 was used to do a projection on the GHG emission and costing analysis for a pilot-scale centralised composting plant. The study showed a reduction potential of 71.64% on GHG emission through the diversion of food waste from landfill, compost utilisation and significant revenue from the compost sale in Scenario 3. This thus provided better insight into the feasibility and desirability in implementing a pilot-scale centralised composting plant for a sub-urban community in Malaysia to achieve a low carbon and self-sustainable society, in terms of environment and economic aspects.

Relationship between land use composition and PM10 concentrations in Iskandar Malaysia

Air pollution has always been a concern with increasing urbanization and poor land use planning adding to the problem. This study sets out to investigate the relationship between land use composition of an area and its ambient concentration of 10-μm-or-less particulate matter (PM10). For this study, Iskandar Malaysia has been chosen as the study area. To compensate for the limited number of air quality monitoring stations in the study area, Terra MODIS aerosol optical depth Level 2 products are used to assess PM10 concentration spatially. Land use data were developed from LANDSAT images used together with the land use database from the local authority. Finally, the relationship between land use composition and concentrations of PM10 in the study area are explained using contour ternary plots. The plots show how different compositions of three major urban land uses (residential, commercial, industrial) in an area results in different concentration levels of PM10. Concentrations of PM10 are evidently more affected by commercial land use, followed by industrial land use. Hence, responsible authorities in Iskandar Malaysia could control or reduce air pollution in an area by planning a better land use composition.

Cost-Benefit and Greenhouse-Gases Mitigation of Food Waste Composting: A Case Study in Malaysia

Waste generation nowadays is rising in the world and it seems hard to prevent it. Municipal Solid Waste (MSW) has been a major problem worldwide, especially in the fast growing cities and towns in the developing countries. This study aims to estimate the cost benefit and mitigation of greenhouse gases (GHGs) by converting the on-campus food and green waste generated in Universiti Teknologi of Malaysia (UTM) campus to compost. This study calculated the costing which includes the transportation, operating and equipment costs if green and food waste were converted into compost. The analyses were made with the basis of the pilot scale operation in Phase I operation. Extrapolation was made to project the further four phases of composting with higher amount of waste to estimate the potential profit. The results obtained from this study indicated that composting has the potential to generate a significant profit of Malaysia Ringgit (MYR)1.6 M/y based on 2,700 t/y of food and green waste composted. At the same time, the total solid waste supposedly to be sent to the landfill can be reduced by at least 47 %. Moreover, this study revealed that the composting process is able to reduce the GHGs emission rate by 90 %, i.e. the GHGs produced by the composting process is shown to be only 10 % of the total GHGs produced by landfill dumping given the same amount of solid waste to be disposed at the landfill site.

Efficiency of microbial inoculation for a cleaner composting technology

AbstractThere are contrasting opinions on the utilisation of microbial inoculant (MI) as a bioremediation technology for composting. The effectiveness can be affected by a diversity of factors, and the reproducibility of results can be a great challenge. This study aims to review the effectiveness of MI, specified as isolated or cultured single and consortium micro-organisms, for composting, with the main component of lignocellulosic waste (LW) and the organic portion of municipal solid waste (OPMSW). The potential for the enhancing effect of each parameter, i.e. compost quality parameters: pH, germination index, nitrogen content, phosphorus content, potassium content, C/N ratio; composting parameters: temperature, odour, enzymatic activities, organic matter content, microbial population, volume reduction, humification, is discussed and evaluated. Based on 13 analysed parameters, the use of MI tends to exert a significant positive effect on the composting of LW compared to that of OPMSW. There has not been a full consensus on the efficiency of MI for composting as it varies on a case-by-case basis. A decision framework is required for the application of MI for different composting scenarios. This overview proposes MI technology, which has been generally less practical than optimising the physicochemical parameters of the composting due to the higher variation in the composting efficiency. Comprehensive comparison studies between the two approaches are needed for further verification which can contribute to the support of composting as a clean technology. The unnecessary uses of resources (e.g. MI, electric, fuel) can consequently be avoided for environmental footprint minimisation.

Evaluation of Microbial Inoculation Technology for Composting

Utilisation of microbial inoculant (MI) in composting is a bioremediation technology aiming to enhance the degradation rate and the compost quality. There is a diverse opinion about the effectiveness of MI in composting. The reproducibility of the results is a great challenge notably for an open composting system compared to a closed in-vessel system. Its efficiency is expected to be affected by the starting materials and the operating conditions. Optimising the physicochemical parameters during composting, i.e. the initial C:N, pH values, moisture content and aeration during composting was reported to be more crucial than the role of MI. This study aims to review the effectiveness of MI for the composting of two types of starting materials, i.e. the organic portion of municipal solid waste (OP-MSW) and lignocellulosic waste (LW). The potential effects of MI to enhance the composting parameters are presented. It is found that the effectiveness of MI to facilitate the composting process is depending on the type of wastes to be managed and the aims to improve the targeted quality of composting. The use of MI tends to exert a more significant positive effect on the composting of LW than the OP-MSW. There is no absolute consensus on the efficiency of MI for composting as it varies on a case-by-case basis. A decision framework is needed for the application of MI for different composting scenarios.

Carbon emission pinch analysis for sustainable landfill

Renewable energy, energy efficiency and carbon capture and sequestration, are among several initiatives to reduce global carbon emission as an effort to mitigate global warming. Apart from reducing carbon footprint, another alternative to combat global warming is through effective solid waste management for landfill. While landfill is the most common solid waste treatment options in most parts of the worlds, however in densely populated area, as land availability may be scarce, careful planning and targeting is therefore required to reduce the landfilling rate. It is envisaged that an effective solid waste management strategy can reduce the amount of waste channeled to landfill. Since different waste management technologies requires different size of land area and have different carbon emission reduction impact, question that are often asked in correspond to this aspect includes; What is the suitable waste management technology that should be practiced to reduce the carbon footprint? How much land footprint is reduced? What are the carbon emission intensity of a landfill and how much it may contribute to global warming? In order to answer these questions, a new targeting technique based on carbon emission pinch analysis is developed. This technique aims to identify the optimal landfill waste management technologies based on specify carbon emission reduction target. It can also target the footprint of landfill area through graphical representation.

Mini- Review on Substrate and Inoculum Loadings for Anaerobic Co-digestion of Food Waste

Increasing production of food waste can lead to major environmental pollution if it is disposed without proper control in many countries. Food waste can be regarded as a resource rather than unwanted discard due to its high potential for resource recovery. Anaerobic digestion of food waste has shown promising potential for food waste treatment and valorisation by producing biogas as a renewable energy and digestate as fertiliser. Food waste has high biogas potential due to the presence of highly labile organic matter but this can lead to process instability. The process instability is often linked to the imbalance of process intermediates that affects the microbial community. Common parameters that are crucial for ensuring optimal metabolic activity of anaerobes includes temperature, pH, carbon-nitrogen ratio, organic loading rate, retention time and nutrient concentration. Co-digestion of food waste with other feedstocks are increasingly being practiced for better nutrient balance and reducing chances for rapid acidfication. The optimum conditions for the process has been shown to vary following different microbial inoculants and loadings of the respective substrates. This study aims to review only the effect of substrate and inoculum used during the AD of food waste, including the type of co-digested substrate, the mixing ratio, the microbial inoculant used and the substrate to inoculum ratio.

Sustainable and Low Carbon Practices at Schools in Iskandar Malaysia

In Malaysia, environmental education is not taught as a specific subject in the formal school curriculum; rather its general principles are embedded across the whole of the curriculum. Hence, informal education plays an important role in raising low carbon awareness. Schools in Malaysia organise various green projects but often these best practices were not shared nor recognised. This paper discusses the organising of a sustainable and low carbon schools exhibition. The objective of the exhibition is three-fold. First, from the research point of view, to understand green activities conducted at schools in Iskandar Malaysia; second to give recognition to schools that contributed to sustainable and low carbon Johor and third, to provide a platform for schools to showcase their effort and an opportunity to build network among them. This school exhibition was conducted for two consecutive years (2015 and 2016), inviting all primary and secondary schools to showcase their school effort in promoting sustainable and low carbon practices. For both years, 21 and 23 schools were accepted respectively into the exhibition after sending in their school profiles for preliminary screening. The profiles detailed the activities organised and participated by teachers, students and community around their school area. During the exhibition, each school presented one poster detailing their effort, followed by an oral presentation to a panel of judges. A group interview were conducted after the exhibition among committee members accompanying judges assessing school projects. Drawing data from these three sources (the school profiles, posters and group interview), several main themes of programmes emerged including 3R (Reduce, Reuse and Recycle), Reducing CO2, Indirect Programmes and Low Carbon Education Programme. Some of these activities are able to generate income to sustain the activities themselves or support other school projects.

Mitigation of Greenhouse Gases Emission Through Food Waste Composting and Replacement of Chemical Fertiliser

A pilot scale composting plant has been established on-campus in Universiti Teknologi Malaysia (UTM) to achieve the goal as a sustainable campus. Portion of organic wastes were diverted from landfilling by converting it into compost (organic fertiliser) for reducing greenhouse gases (GHG) emission at the landfill and the dependency on inorganic fertiliser. Composting has been reported as a sustainable approach to reduce the footprint of GHG as compared to the waste disposal through landfilling. However, the amount of GHG emitted during composting can vary due to localised condition. The aim of this study was to assess the potential of composting in mitigating GHG emission compared to the current waste management employed in UTM (Landfilling). A business as usual (BAU) scenario represents the current organic waste management practice in UTM was established. Composting was proposed as an alternative scenario. The amount of GHG emitted or reduced from different sources including for transportation, waste processing, waste treatment as well as downstream activities such as carbon sequestration and inorganic fertiliser substitution was estimated based on lifecycle inventory analysis. The result indicated that composting scenario offer a GHG reduction of 66.72 % as compared to the BAU scenario. The fugitive emission from biodegradation of organic waste contributed significantly to the GHG emission for both scenarios whereas the GHG emission from the fossil fuel combustion was considered as not significant. The overall result suggested the potential of composting as a viable technology for sustainable organic waste management in UTM.