The use of alternative biomass sources that are not competitive with food production is intended for sustainable management in biogas production through anaerobic digestion. This study investigates the Napier grass and cattle slurry-based biogas production application that could be applied more cost-effectively more sustainable production biogas. The laboratory-based biogas plant and a biogas plant in practice revealed that the results from the laboratory experiments were realistic and transferable into practice. The effect of feedstock screening on the biogas yield of Napier grass and cattle slurry was evaluated in batch digesters under mesophilic conditions. Moreover, highest methane content was reached 64.4%. The biogas from the co-digestion of Napier grass and cow farm slurry containing the higher calorific value was 25.69 MJ/m3, and the lower calorific value was 23.14 MJ/m3 . The results demonstrated that combining Napier grass with common cow farm slurry can accelerate the reaction, increase efficiency, and increase methane content. Therefore, the co-digestion of Napier grass and cow farm slurry was a promising method for increasing biogas production.

The wastewater concentration is commonly acceptable for macroalgae growth; this process consumes water and is applicable for bioremediation. This study evaluated biodiesel's potential production from freshwater macroalga, Nitella sp. using batch experiment. Algae were collected from wastewater saturated from irrigation canals. Water quality and algae growth environment characteristics were monitored and analyzed. COD and BOD values were 18.67 ± 4.62 mg/L and 5.40 ± 0.30 mg/L, respectively. The chemical composition contents were high, demonstrating that water quality and sufficient nutrients could support algae growth. Oil extraction was estimated by the room temperature and heat extraction methods. The biodiesel in room temperature treatment was 0.0383 ± 0.014%, and in heat, extraction treatment was 0.0723 ± 0.029%. Results confirmed that the heat extraction treatment gave a high amount of oil and biodiesel yield. Gas chromatography/mass spectrometry (GC/MS) was used to analyze fatty acid methyl esters (FAME). Results revealed that 9-octadecane was a major portion of the substance. The obtained results confirmed that the wastewater contains many elements that can be utilized for dual-mode like bioremediation and enhanced macroalgae growth for biodiesel production. Therefore, macroalgae grown in canal wastewater was high feasible to use for sustainable biodiesel production.

This research aims to estimate whether the WTP for fish conservation zones in terms of fish species protection areas. The authors used cross-sectional data that was collected from 369 respondents in 3 target villages in the Khong district of Champasak province Laos in 2021 and utilised WTP and maximum likelihood regression, marginal effect result for analysis. The estimate of the empirical model used for econometric analysis is based on the previously described model. This study finds that the average WTP households in target villages for fish conservation zones is 12.12 US $/household/year. The bid price, the recognition of the necessity of the fish conservation zones' knowledge, and average monthly income all positively impact WTP for fish conservation zones with a statistically significant impact. The authors conclude that the fish conservation zones might increase fish species in the study area. This valuation can be calculated as the cost to improve the quality of establishing fish conservation zones by multiplying the number of people in three villages of 768 households, which is the value expectation of the economy at 9,310 US $/year. However, improving public goods conservation now is the duty of everybody, so if we would like to strengthen fish conservation zones more efficiently than ever, we may find more suitable and sustainable alternatives.

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This study estimates the potential effects of climate change on GDP in the agriculture sector in the ASEAN region based on historic data from 1995-2018. An econometric panel model is applied to examine the impact of the changing climatic and non-climate variables AGDP. The empirical estimation results show that some significant and insignificant. Based on estimation results, if the policymaker is concerned about climate change actions, it helps more comprehensive risk decision-making, and policy exertions should be concentrated toward climate change to the total gross domestic product in the ASEAN region. Under projections of the future climate change, the simulation results reveal that the substantial change in GDP in agriculture in the ASEAN region arises due to the fluctuation of temperature and precipitation. For instance, GDP in the agriculture sector would be decreased by 0.27% to 0.90% in response to different scenarios over the century. Therefore, it is necessary to take immediate adaptive actions appropriately to mitigate the decrease in GDP in the agriculture sector in the ASEAN region.