Shabbir H. Gheewala

Biodegradation of chlorinated phenolic compounds

Chlorophenolic compounds are generated from a number of industrial manufacturing processes including pulp and paper manufacture. These compounds are found to be toxic and recalcitrant and hence their discharge into the environment must be regulated. Slow and partial degradation of chlorophenols under aerobic and anaerobic natural environment has been observed. Aerobic biodegradation of chlorophenols proceeds through the formation of catechols while under anaerobic conditions, reductive dehalogenation is the preferred metabolic pathway. Number and position of chlorine substituents on the phenolic ring has influence on the rate and extent of biodegradation of chlorophenols. In engineered systems, acclimatization of biomass to chlorophenols markedly enhances the biodegradation ability by reducing the initial lag phase and by countering inhibition. Partial removal of chlorophenols between 40-60% is usually observed in aerobic and anaerobic processes. Removal can be enhanced by a combination of aerobic and anaerobic operations.

Estimation of construction waste generation and management in Thailand

This study examines construction waste generation and management in Thailand. It is estimated that between 2002 and 2005, an average of 1.1 million tons of construction waste was generated per year in Thailand. This constitutes about 7.7% of the total amount of waste disposed in both landfills and open dumpsites annually during the same period. Although construction waste constitutes a major source of waste in terms of volume and weight, its management and recycling are yet to be effectively practiced in Thailand. Recently, the management of construction waste is being given attention due to its rapidly increasing unregulated dumping in undesignated areas, and recycling is being promoted as a method of managing this waste. If effectively implemented, its potential economic and social benefits are immense. It was estimated that between 70 and 4,000 jobs would have been created between 2002 and 2005, if all construction wastes in Thailand had been recycled. Additionally it would have contributed an average savings of about 3.0 x 10(5) GJ per year in the final energy consumed by the construction sector of the nation within the same period based on the recycling scenario analyzed. The current national integrated waste management plan could enhance the effective recycling of construction and demolition waste in Thailand when enforced. It is recommended that an inventory of all construction waste generated in the country be carried out in order to assess the feasibility of large scale recycling of construction and demolition waste.

Global guidance on environmental life cycle impact assessment indicators: findings of the scoping phase

Olivier Jolliet & Rolf Frischknecht & Jane Bare & Anne-Marie Boulay & Cecile Bulle & Peter Fantke & Shabbir Gheewala & Michael Hauschild & Norihiro Itsubo & Manuele Margni & Thomas E. McKone & Llorenc Mila y Canals & Leo Postuma & Valentina Prado-Lopez & Brad Ridoutt & Guido Sonnemann & Ralph K. Rosenbaum & Tom Seager & Jaap Struijs & Rosalie van Zelm & Bruce Vigon & Annie Weisbrod & with contributions of the other workshop participants

Framework for life cycle sustainability assessment of municipal solid waste management systems with an application to a case study in Thailand.

At present, there are many environmental, economic and social problems associated with poor municipal solid waste (MSW) management in Thailand. The development of sustainable solid waste management systems is a crucial aspect and should be based on an integrated approach. Therefore, an integrated system was designed for Nonthaburi Municipality incorporating recycling, anaerobic digestion, incineration and landfill technologies. In order to assess sustainability, a clear methodology was developed via life cycle thinking and a set of endpoint composite indicators has been proposed considering the most critical ultimate damages/effects of MSW management on the environment, the economy and society. The results showed that the appropriate integration of technologies offers important prospects with regards to socio-economic and environmental aspects, contributing, therefore, to improved sustainability for the overall MSW management system. The methodology and the proposed indicators would be useful in strategic planning, including decision- and policy-making with respect to the development of appropriate sustainable MSW management systems.

Long-Term Bioethanol System and Its Implications on GHG Emissions: A Case Study of Thailand

The study evaluates greenhouse gas (GHG) emissions performance of future bioethanol systems in Thailand to ascertain whether bioethanol for transport could help the country mitigate a global warming impact. GHG emission factors of bioethanol derived from cassava, molasses, and sugar cane are analyzed using 12 scenarios covering the critical variables possibly affecting the GHG performance, i.e., (1) the possible direct land use change caused by expanding feedstock cultivation areas; (2) types of energy carriers used in ethanol plants; and (3) waste utilization, e.g., biogas recovery and dry distillers grains with solubles (DDGS) production. The assessment reveals that GHG performance of a Thai bioethanol system is inclined to decrease in the long run due to the effects from the expansion of plantation areas to satisfy the deficit of cassava and molasses. Therefore, bioethanol will contribute to the countrys strategic plan on GHG mitigation in the transportation sector only if the production systems are sustainably managed, i.e., coal replaced by biomass in ethanol plants, biogas recovery, and adoption of improved agricultural practices to increase crop productivity without intensification of chemical fertilizers. Achieving the year 2022 government policy targets for bioethanol with recommended measures would help mitigate GHG emissions up to 4.6 Gg CO(2)-eq per year.

Implications of the biofuels policy mandate in Thailand on water: the case of bioethanol.

The study assesses the implications of the bioethanol policy mandate in Thailand of producing 9 M litre ethanol per day by 2021 on water use and water deprivation. The results reveal that water footprint (WF) of bioethanol varies between 1396 and 3105 L water/L ethanol. Cassava ethanol has the highest WF followed by molasses and sugarcane ethanol, respectively. However, in terms of fresh water (especially irrigation water) consumption, molasses ethanol is highest with 699-1220 L/L ethanol. To satisfy the government plan of bioethanol production in 2021, around 1625 million m(3) of irrigation water/year will be additionally required, accounting for about 3% of the current active water storage of Thailand. Two important watersheds in the northeastern region of Thailand are found to be potentially facing serious water stress if water resources are not properly managed. Measures to reduce water footprint of bioethanol are recommended.

A comparative LCA of rice straw utilization for fuels and fertilizer in Thailand.

Life cycle assessment of four rice straw utilization systems including; (1) direct combustion for electricity, (2) biochemical conversion to bio-ethanol and biogas, (3) thermo-chemical conversion to bio-DME, and (4) incorporation into the soil as fertilizer have been conducted to compare their environmental performances. The results showed that per ton of dry rice straw, the bio-ethanol pathway resulted in the highest environmental sustainability with regards to reductions in global warming and resource depletion potentials. Rice straw bio-DME was preferable vis-à-vis reduction in acidification potential. Rice straw electricity and fertilizer also brought about several environmental benefits. The key environmental benefit of rice straw utilization came from avoiding the deleterious effects from burning straw in situ in the field. Recommendations for enhancing environmental sustainability of rice straw utilization for fuels and fertilizer are provided.

Greenhouse gas emissions from the production and use of palm methyl ester in Thailand

This study compares the life cycle Greenhouse Gas (GHG) emissions from Palm Methyl Ester (PME) and conventional diesel (diesel hereinafter) used for transportation in Thailand. The life cycle GHG emissions from the production and use of PME were found to be 79.5% less than that from diesel production and use. Hence, a fuel switch from diesel to PME, according to the Thai governments plan of using a 10% blend of biodiesel countrywide by 2012, will contribute to reducing global warming potential by 7.8 million tonne CO2-eq per year as well as reducing crude oil imports.

Food, Fuel, and Climate Change

This study evaluates the sustainability of biodiesel for transport in Thailand in terms of the availability of fresh fruit bunches (FFB) and crude palm oil (CPO) supply to satisfy the future demands for food and fuel, and the contribution of palm biodiesel to mitigating climate change if biodiesel induces land‐use change (LUC). Five land conversions including rubber, cassava, paddy field, set‐aside land, and forest land to oil palm are considered along with their displacement effects to other land types to evaluate the greenhouse gas (GHG) emissions associated with the direct and indirect land‐use impacts. The net feedstock balance reveals that the policy to expand 0.4 million hectare (Mha) for new oil palm plantations accompanied with an increase of FFB yield to 22 megagrams per hectare (Mg/ha) by 2012 would help avoid a CPO shortage; however, this increase in land use needs to be strongly encouraged. The GHG analyses show a wide range of net GHG balances compared to diesel depending on which type of land is converted and which options are used to treat the oil palm wastes. Except for forest land conversion, direct LUC emissions from converting other lands to oil palm will render benefit to the GHG balance of biodiesel. Indirect LUC emissions through crop displacements, however, will generally worsen the balance. Several recommendations are therefore suggested for sustainable palm biodiesel production in the future.

Agrofuels in Thailand: Policies, Practices and Prospects

Agrofuels, defined here as agriculture-based liquid transportation fuels, have been widely promoted as a renewable, sustainable, energy source which could reduce dependency on fossil-fuel imports. But the evidence of current and potential future contributions to sustainability is modest and mixed, varying with crops, places, markets and societies.