The act of balancing between water demand and water supply in Phuket Island is facing challenges, suggesting water reuse options in various activities on the island should be properly promoted ...considering the potential benefits in a variety of dimensions. This research presented options to reuse effluent water from wastewater treatment plants for Phuket Municipality in 3 main activity groups, namely, domestic reuse, agricultural reuse, and raw water for water treatment plants (WTP). Water demand, additional water treatment trains, and the length of the major water distribution pipeline for each water reuse option were designed, and its cost and expenses were calculated. Multi-criteria decision analysis (MCDA) was used by 1000Minds internet-based software to prioritize the suitability of each water reuse option based on a four-dimensional scorecard, including economic, social, health, and environmental aspects. The decision algorithm for the trade-off scenario based on the government's budget allocation was proposed to obtain weighing without subjective expert opinions. The results revealed that recycling effluent water as raw water for the existing WTP was the first priority, followed by agriculture reuse for planting coconut, Phuket's economic crops, and domestic reuse. There was a significant difference in the total scores of economic and health indicators between the first- and second-priority options because of the difference in the additional treatment system in which the first-priority option applied the microfiltration and reverse osmosis system, which could effectively eliminate viruses and chemical micropollutants. In addition, the first priority option required a much smaller piping system than other water reuse options because it relied on the existing plumbing system of WTP, lowering the investment cost, which was a very important indicator for decision-making.
•Multicriteria analysis of preferred water reuse options for a tourist island.•Proposed decision algorithm for trade-off scenario based on the budget allocation.•The weighing approach without subjective expert opinions.•Reuse as raw water for water treatment plants was the first priority option.•Plumbing system cost was a significant factor for decision-making.
A feed-in tariff (FiT) framework has been implemented in Thailand since 2007 to encourage and stimulate the development of renewable energy. As a result, the capacity of solar photovoltaics (PVs) has ...increased significantly and has reached 1902MW. Nevertheless, the installation of PVs on rooftops in the residential sector accounts for only a minute percentage (0.003%) of the total capacity of installed PVs. In this paper, a feasibility analysis of grid-connected solar PV rooftops for households under the present feed-in tariff framework was performed. The results demonstrate that the current feed-in tariff is not sufficient to promote investment in PV rooftops in the residential sector under the current market situation. Moreover, in order to support the current framework, additional supportive measures including (1) an appropriate feed-in-tariff rate, (2) personal income tax exemptions, (3) carbon trading, and (4) low interest rate loans, were proposed, and their effects were evaluated. The low interest rate loan appears to be the best measure for promoting and stimulating investment in residential-scale PV rooftops without additional subsidy. The leverage effect of debt, with different debt portions, loan terms and interest rates, was investigated to suggest a suitable policy.
•Thailand's feed in tariff framework is not sufficient to promote residential PV rooftops.•The effects of proposed additional financially supportive measures are evaluated.•The low interest rate loan is suggested for promoting residential PV rooftops.•Appropriate loan conditions and fund raising mechanism are proposed.
Per- and polyfluoroalkyl substances (PFAS), persistent organic pollutants, have been found in landfill leachate (LL) and can lead to environmental contamination. Recently, more stringent global ...regulations to control the maximum levels of PFAS have forced landfill authorities to improve treatment technologies to meet higher effluent quality standards. This study analyzed the additional cost of the treatment process to remediate PFAS contamination from LL in Thailand using a two-pass reverse osmosis (RO) system, including pretreatment and the use of evaporation ponds. The total estimated LL volume from 111 sites of sanitary landfills was ascertained using the water balance method, and then the overall project cost in the form of the net present cost (NPC) was evaluated. The capital investment, expense, and related operating and maintenance costs over the project lifetime were taken into account. The results showed that the total estimated LL volume was 17.5 m3/yr. To handle this amount of LL, the NPCs of the RO system were found to be 577.9 mil. USD for the system with an evaporation pond and 391.9 mil. USD for the system without an evaporation pond. The treatment unit costs ranged from 1.72–2.71 USD/m3 for the system with an evaporation pond and ranged from 1.06 to 2.09 USD/m3 for the system without an evaporation pond, depending on the size of the landfills. Based on these results, technological, operational, financial, and regulatory policy recommendations are presented.
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•Implementation cost of RO to remediate PFAS from landfill leachate was analyzed.•The net present costs of the RO system were found to be 391–5789 mil.USD.•The treatment unit costs ranged from 1.72 to 2.71 USD/m3.•Policy recommendations are presented.
This research assessed the economic feasibility of recovering polyol from rigid polyurethane foam (RPUF) waste, collected from dismantled, discarded refrigerators, by a single-phase glycolysis ...recycling process using domestic crude glycerol (a byproduct of biodiesel production) as a transesterification agent. The study, conducted in Thailand, took into account benefits from the added value of the recovered product, the investment and related operating costs of the process, demand (the need for the recovered product) and supply (the amount of RPUF waste). The results showed that the production of recovered polyol from RPUF waste is economically feasible, with a net present value of 1,113,018 USD, an internal rate of return (IRR) of 22.9%, and a payback period of 4.4 years. Due to the high IRR, project investment should be attractive to both the government and private sector investors. In addition, a sensitivity analysis was conducted to assess the economic resilience of the process to uncertainties in key factors, including the prices of the machinery, recovered polyol, crude glycerol and stannous octoate, and the amount of RPUF waste available. The sensitivity analysis showed that the economic feasibility was most sensitive to the price of the recovered polyol, followed by the amount of RPUF waste and the prices of the machinery, crude glycerol and stannous octoate. Based on these results, technological, operational, financial, and regulatory policy recommendations were also presented.
•The economic feasibility of rigid polyurethane foam (RPUF) waste recovery by glycolysis technology was assessed.•Recovery is economically worthwhile and the price of polyol is the most sensitive factor to the return.•Two strategies for glycolysis plant location: centralized plant and distributed regional plants were suggested.•Technological, operational, financial, and regulatory policy recommendation was presented.
This research is aimed to estimate energy consumption and the greenhouse gases emission from olefins production process in Thailand and to analysis its correlation between energy intensity and carbon ...intensity. The results of five olefin case study plants showed that direct energy use of olefins production was about 87% of total energy consumption. The greatest amount of energy demand was supplied for fuel combustion in manufacturing processes. The olefin plants using gas feedstock could operate with less amount of energy consumed as the average energy intensity (EI) of 23.88 GJ/ton of olefin produced, whereas plants of olefin produced from steam cracking of liquid feedstock had the average EI of 33.21 GJ/ton of olefin produced. Greenhouse gas emission from olefin plants using gas feedstock were consistent with the result of EI. The carbon intensity (CI) from olefin plants using gas feedstock (0.98 tCO2-eq./ton of olefin produced) was lower than the plants using liquid feedstock (2.01 tCO2-eq./ton of olefin produced). The T-test function used to reflect the correlation between EI and CI emphasized that the carbon intensity was significantly correlated with the intensity of energy (r = 0.9564 and p = 0.05).
This research assesses the appropriate options for managing rigid polyurethane waste (RPUW) remaining from refrigerator/freezer dismantling in Thailand by analyzing the impacts on environment, energy ...and economic aspects. There are four options for RPUW management: option 1 – landfill; option 2 – incineration; option 3 – hydrolysis + landfill; and option 4 – production of lightweight concrete (LWC) mixed with RPUW (LWC-RPUW). From environmental and energy perspectives using Life cycle assessment (LCA) by Simapro software, the results showed that option 4 had the lowest human toxicity, followed by option 3, option 1 and option 2, respectively. On the other hand, option 1 had the lowest climate change and fossil depletion impacts, followed by option 2, option 3 and option 4, respectively. However, without considering energy consumption during the use phase of LWC as wall material in building, option 4 has the least energy and environmental impact. Regarding economic impact, option 4 is the only one option that can make a profit, and its net present value (NPV) is positive. In other words, it is worth refrigerator recyclers investing in a LWC-RPUW production plant. Option 4 is feasible to perform practically without subsidizing from any organization, while the other options are costly to carry out. To promote option 4, which is more appropriate considering all three kinds of impact studied here, it will be necessary to improve option 4 in terms of the insulation properties of the LWC-RPUW products to reduce the environmental impact from energy consumption during the product use phase.
Purpose
Urbanization and industrial development intensify water utilization and wastewater generation. The efficiency of wastewater treatment systems varies and depends on system design and ...wastewater condition. The research aims to examine seven existing centralized municipal wastewater treatment plants (WWTPs) in Bangkok to discover which system configuration yields the best environmental and economic performance. The degree of environmental impact and operational costs from different system designs were investigated to help select future wastewater treatment systems.
Methods
Life cycle assessment (LCA) has been conducted to evaluate environmental impacts from centralized municipal wastewater treatment systems. Life cycle impact assessment method based on endpoint modeling (LIME) was applied, with three major potential environmental impact categories including eutrophication, global warming, and acidification. All seven centralized municipal WWTPs in Bangkok were investigated as case studies. The system configurations are classified into five types of activated sludge (AS) systems. The contribution of impacts from individual processes in each type of AS system was analyzed. The methodology covered major on-site and off-site operational processes excluding construction and maintenance phases. Average annual data were calculated to develop an inventory dataset. JEMAI-Pro software was utilized in this study to analyze the life cycle impact of the systems.
Results and discussion
The level of environmental impact from a WWTP depends on the configuration of the AS system. The highest potential environmental impact from a municipal WWTP is eutrophication, which is obviously affected by ammonium and phosphorous discharges into water bodies. The vertical loop reactor activated sludge (VLRAS) system yielded the best treatment performance among the five AS sub-systems. The consumption of electricity used to operate the system contributed significantly to global warming potential and correlated considerably with operating costs. Comparing among three system sizes, the large-scale WWTP revealed inefficient electricity consumption, whereas the medium plant provided better performance in chemical use and operating costs.
Conclusions
Centralized municipal WWTPs with capacities ranging from 10 to 350 × 10
3
m
3
/day were evaluated with respect to environmental performance and costs during the operating phase. Among all case studies, a medium-scale WWTP with a VLRAS system offered the best operating performance in terms of low environmental impact, resource consumption, and cost. To enhance WWTP management, it is vital to improve the efficiency of electricity consumption in primary and secondary treatment processes and increase wastewater collection efficiency to maximize the plant operating capacity and minimize overall environmental impacts.
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