Sirintornthep Towprayoon

Greenhouse gas mitigation in agriculture

Agricultural lands occupy 37% of the earths land surface. Agriculture accounts for 52 and 84% of global anthropogenic methane and nitrous oxide emissions. Agricultural soils may also act as a sink or source for CO2, but the net flux is small. Many agricultural practices can potentially mitigate greenhouse gas (GHG) emissions, the most prominent of which are improved cropland and grazing land management and restoration of degraded lands and cultivated organic soils. Lower, but still significant mitigation potential is provided by water and rice management, set-aside, land use change and agroforestry, livestock management and manure management. The global technical mitigation potential from agriculture (excluding fossil fuel offsets from biomass) by 2030, considering all gases, is estimated to be approximately 5500–6000 Mt CO2-eq. yr−1, with economic potentials of approximately 1500–1600, 2500–2700 and 4000–4300 Mt CO2-eq. yr−1 at carbon prices of up to 20, up to 50 and up to 100 US

Application of 'waste' metal hydroxide sludge for adsorption of azo reactive dyes.

t CO2-eq.−1, respectively. In addition, GHG emissions could be reduced by substitution of fossil fuels for energy production by agricultural feedstocks (e.g. crop residues, dung and dedicated energy crops). The economic mitigation potential of biomass energy from agriculture is estimated to be 640, 2240 and 16 000 Mt CO2-eq. yr−1 at 0–20, 0–50 and 0–100 US

Novel bulking agent from clay residue for food waste composting.

t CO2-eq.−1, respectively.

Effect of Moisture Content on Fed Batch Composting Reactor of Vegetable and Fruit Wastes

The capacity and mechanism of metal hydroxide sludge in removing azo reactive dyes from aqueous solution was investigated with different parameters, such as charge amount of dyes, system pH, adsorbent particle size, and adsorbent dosage. The three anionic dyes used were CI Reactive Red 2, CI Reactive Red 120, and CI Reactive Red 141, increasing in number of sulfonic groups, respectively. Only 0.2% (w/v) of powdered sludge (<75microm) achieved color removal from 30 mg l(-1) reactive dye solutions within 5 min without pH adjustment. The larger the charge amount of the dyes, the greater the adsorption (>90%) on the metal hydroxide sludge. The system pH played a significant role in the adsorption on metal hydroxides and formation of dye-metal complexes. The optimum system pH for dye adsorption was 8-9 which was close to the pH(zpc) of the sludge while the precipitation of dye-metal complexes occurred at system pH 2. The maximum adsorption capacity (Q degrees ) of the sludge for the reactive dyes was 48-62 mg dye g(-1) adsorbent. The Langmuir and Freundlich models showed that the higher charged dyes had a higher affinity of adsorption. The smaller particle size and the greater amount of adsorbent showed the faster process, due to an increase in surface area of adsorbent. Desorption studies elucidated that metal hydroxide sludge had a tendency for ion exchange adsorption of sulfonated azo reactive dyes. Leaching data showed that the treated water was nontoxic at a system pH above 5 or a solution pH above 2.

Investigation of CO2 adsorption by bagasse-based activated carbon

New granular material from clay residue was investigated as a bulking agent for food waste composting. Five mixing ratios of granule were conducted in a laboratory scale reactor at the desired low rate of air (0.05 l min(-1)). The evolution of temperature and the accumulative CO(2) emissions were monitored. Physical and chemical changes, N loss, and organic matter degradation of compost were also examined. Adoption of granules of 15% V/V (FAS 31.6%) enhanced the thermophilic composting and CO(2) emissions; thus satisfying the Process to Further Reduce Pathogens (PFRP, USEPA) as well as obtaining the highest rate constant of organic matter degradation (k=0.005 day(-1)). As the amount of granules was doubled (35% V/V), the temperature was not only cooled, but also promoted the substantial N loss (54%). It was suggested that bulking agent from clay residue can be used beneficially as reusable media for microbial inoculation as analyzed by SEM.

Greenhouse Gas Emission from Solid Waste Disposal Sites in Asia

Vegetable and fruit wastes mixed with sawdust were composted in a laboratory scale reactor by controlling the waste feeding rate at 21 kg m−3 day−1 and aeration rate at 10.6 l m−3 min−1. The effects of initial moisture content on organic matter degradation and process performance of fed batch composting were investigated. The absolute amount of removal, removal percentage, and removal rate of dry mass obtained were substantially different among the initial moisture contents. The rapid rise of moisture content and the lowest absolute amount of removal observed were achieved in the 50% condition. The initial moisture content yielding the largest absolute amount of removal in both feeding and curing stage was 30% whereas the removal percentage and rate constant of waste decomposition were highest in the 50% condition. Examined by traditional soil physics method, the moisture content at 50-55% was suitable for satisfying the degree of free air space (65-70%) of compost during the fed batch composting. Most degradable organic matter was mainly consumed in the feeding stage as indicated by a higher removal rate of dry mass in all cases. It is recommended that the initial moisture content of 30% and mode of aeration and agitation should be adopted for achieving practical fed batch composting of vegetable and fruit wastes. The study also demonstrated that the composting kinetics of vegetable and fruit wastes mixed with sawdust can be described by a first order model.

Effect of recirculation rate on methane production and SEBAR system performance using active stage digester

Bagasse-based activated carbon (BAC) and amine-modified BAC were prepared and investigated for CO2 adsorption capacity. Modifying BAC with amines resulted in a decrease of surface area, but the decreasing magnitude varied depending on type and loading rate of amines. At room temperature, the unmodified BAC was able to adsorb more CO2 than the amine-modified BAC. This ability was related to the higher surface area of unmodified than that of the modified BAC. When temperature increased, CO2 adsorption capacity of all absorbents was decreased. However, above 323 K and a concentration of CO2 lower than 30% v/v, the BAC modified with PEI at 5 and 25 wt% showed higher adsorption capacity. Among all adsorbents under 15% CO2 and 348 K, BAC-PEI25 showed the highest adsorption capacity (0.20 mmol/g).

Calculation and Mapping of Sulfur Critical Loads for Terrestrial Ecosystems of Thailand

1.1 Difficulties in estimating GHG emission from solid waste disposal sites (SWDSs) in Asian countries From the viewpoint of sustainable development, appropriate waste management is crucial for conserving the local and global environments. Improvement of waste management in developing countries is directly related to preventing environmental pollution and expanding public health services. Appropriate waste management contributes to reducing not only the emission of water/atmospheric pollutants and odors, but also the emission of greenhouse gases (GHGs). Those involved in international cooperation via technology transfer should take into consideration the potential for shared benefits in terms of “co-benefit” of waste management and climate change. The recent framework of Nationally Appropriate Mitigation Actions (NAMAs) indicated in the Bali Action Plan requires measurability, reportability, and verifiability of emission reduction in mitigation action. Therefore, researchers in the waste management field have focused on finding precise and practical methods for estimating GHG emissions. Solid waste disposal sites (SWDSs) that include both managed landfills and unmanaged dump sites were recognized as major GHG emission sources in developing countries. Although the Intergovernmental Panel on Climate Change (IPCC) released guidelines for estimating GHG emissions, there is still considerable uncertainty regarding emissions from SWDSs in Asian countries, because of the lack of data about the precise emission behavior and waste degradation kinetics, especially at waste disposal sites. In this chapter, authors are going to describe the current situation of the GHG emission estimation and mitigation action in the waste management field in Asia.

Evaluating the effects of alternate wetting and drying (AWD) on methane and nitrous oxide emissions from a paddy field in Thailand

A project was undertaken to examine the feasibility of treating organic wastes from Thai fruit and vegetable markets using the sequential batch anaerobic digester (SEBAR) approach. A key feature of the SEBAR system is the regular interchanging, or recirculation, of portions of leachate between each freshly filled digester and a support digester to which it is coupled until it is ready to operate independently. Leachate transfer from this support digester to the fresh waste digester provides additional alkalinity to help counteract the effects of early high acid release rates; it also helps build a balanced microbial population in the fresh waste digester. To optimize the leachate recirculation process, the effect of varying the quantities of leachate interchanged between freshly filled waste digesters and the still highly active support digesters to which they were coupled was studied. It was found that increasing the recirculation rate accelerated the onset of both waste degradation and methane production. The increasing of recirculation rate from 10% to 20% and 10% to 30% could reduce the SEBAR cycle period by approximately 7% and 22% without significant reduction in the amount of methane obtained from the systems. The methane yields were 0.0063, 0.0068 and 0.0077 l g—1 VS added in the NEW digester per day using leachate recirculation rates of 10%, 20% and 30%, respectively. This finding has potentially important practical and economic implications for those using the SEBAR system to add value to market waste.

Advancing low-carbon emissions in Asia: mitigation of greenhouse gases and enhancing economic feasibility for major sectors

The essential parameters needed for the calculation of critical load of sulfur, CL(S), are base cation weathering rate, base cation uptake, acid neutralizing capacity leaching and base cation deposition. These parameters are estimated and mapped for the most area of terrestrial ecosystems of Thailand using data of national data soil survey. The values of CL(S) range from <200 to 2,225 eq.ha-1yr-1 and about 70% of terrestrial ecosystems are characterized by low values (<200 eq.ha-1yr-1). These CL values reflect the sensitivity of Thai ecosystems to sulfur deposition.