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Soil respiration plays a crucial role in the worldwide carbon cycle and displays great sensitivity to shifts in soil temperature and moisture levels. Accurate prediction of soil respiration under different ratios of food waste compost (FWC) amended soil in various variables requires a clear understanding of the processes involved. This research introduces an appropriate model aimed at estimating soil respiration. This paper employed three distinct regression models: multiple linear (Model 1), first-order polynomial (Model 2), and second-order polynomial (Model 3). These models were employed to predict soil respiration by assessing its relationship with various factors. The study examined several factors, including FWC amended ratio (A), pH (B), electrical conductivity (EC) (C), organic matter (OM) (D), carbon-to-nitrogen ratio (C/N) (E), moisture content (F), porosity (G), and microbial count (H). These factors were considered potential influencers of the CO2 efflux response. It was observed that A,B,C and E exhibited p-values below 0.05 signifying their significance in the context of the study. Among the regression models, Model 3 demonstrated the lowest mean squared error of prediction (MSEP) and root mean square error (RMSE), 1.142 % and 0.153, respectively. The suitability of Model 3 for predicting soil respiration was attributed to its capacity to account for interaction effects among independent variables. Conversely, the results indicated that a non-linear model provide a better understanding of soil respiration under different ratios of FWC amended soil due to the smallest MSEP and RMSE, suggesting that the predictive model for CO2 efflux aligned more with second-order behaviour. [ABSTRACT FROM AUTHOR]

Biohythane production via single‐stage anaerobic digestion (AD) is an effective way for sustainable energy recovery from lignocellulosic biomass. In this paper, biohythane was produced through the AD process from pineapple peel waste substrate using purely cultured Methanosarcina mazei with the enhancement of palm oil mill effluent (POME) sludge as the inoculum. This study focuses on the effects of the lignocellulosic pre‐treatment method, the addition of POME sludge into M. mazei culture medium as inoculum, and various operational conditions (food to microorganisms (F/M) ratios, temperature, pH) on gas production performances. The experimental results indicate that these parameters influenced the efficiency of biohythane production by producing the peak maximum biohythane production rate values (HPRmax) and (MPRmax), H2:CH4 = 1.93:0.67 L/L‐d, and biohythane yield (HY) and (MY), H2:CH4 = 1.18:0.55 mL/L‐substrate. This study demonstrates that biohythane gas (H2 + CH4 + CO2) production from pineapple waste can be accelerated by M. mazei only with the enhancement of POME sludge through single‐stage AD system under mesophilic batch process conditions. [ABSTRACT FROM AUTHOR]

The ability of soil to promote plant development is mostly governed by its hydraulic properties, namely its water retention capacity. Sandy soils are the least fertile because of their poor moisture capacity, high water permeability, and low nutrient concentration. Adding food waste (FW) compost to sandy soil can improve its water retention capacity. The FW compost can enhance soil organic matter, which improves water and nutrient retention in sandy soils for plant growth and health. This study aims to identify the best composition amendment for FW compost to enhance soil water retention in sandy soil (sand 76 %, silt 8 %, clay 10 %, pH 4.8, and EC 142.4 dS/m). Indigenous microorganisms (IMOs) collected from bamboo leaves (Gigantochloa albociliata) were added to the FW compost to supply nutrients and stimulate plant growth. Five treatments were applied experimentally, with FW compost amendment rates of (5,15, 25, 35 and 100) % w/w, compared to unamended sandy soil as the control. 100 % FW compost provided the largest increase (169 %) in the amount of readily accessible water in sandy soil, raised total porosity to 6 % and reduced bulk density by 64 %. The FW compost with 25 % w/w compost significantly increased the seed germination of Dwarf Pak Choy (Brassica campestris sp. chinensis) to 125 %. This short-term study highlights the benefits of using FW compost and its potential to improve water retention when a low amendment rate (25%) is used. [ABSTRACT FROM AUTHOR]

In an automotive industry, high thermal energy demand is required mainly due to processes in the Paint Shop which leads to high energy utilization. In order to improve energy efficiency, automotive industry is now looking into the application of Solar Assisted Heat Pump (SAHP). SAHP is identified as a suitable technology and, as it produces energy from solar, can save up in energy cost to operate the heat pump in a long term. This research specifically looks into the painting section of the industry focusing on DIP Phosphating and Electrodeposition process as it consumed the most thermal energy compared to the other processes. The potential cost-saving and payback period are identified through scenario analysis involving Scenario 1 (Existing system), Scenario 2 (Heat Pump), Scenario 3 (Solar Thermal + Heat Pump), and Scenario 4 (Solar Photovoltaic + Heat Pump). Based on the analysis, it is concluded that Scenario 4 resulted in the highest potential cost-saving of MYR 73,988. As for the shortest payback period, it is achieved by Scenario 2 with a payback period of only 3.5 y. [ABSTRACT FROM AUTHOR]

Hydrogen is regarded as the fuel of future by having greater heating value than the conventional fuels and with zero carbon emission. Most of the previous supply chain studies only consider the application of hydrogen as transportation fuel. Taking Johor as a case study, this paper aims to develop a holistic optimization model that exploits the use of hydrogen for vehicle fueling and electricity generation. Oil palm biomass and solar energy are used as the energy sources to produce hydrogen and electricity to satisfy the local energy demand. Through this study, the optimal configuration of hydrogen supply chain in Johor has been identified and the associated cost is found to be 3,644,800 USD/d. [ABSTRACT FROM AUTHOR]