Performance of precast anaerobic digestion tank combined with a food waste disposer system. A case study of household food waste in Thailand

The actual sizes of precast anaerobic digestion tanks (600 dm3) combined with food waste disposer systems (PAD-FWD) were selected to investigate efficiency under actual use conditions. The effects of organic loading rates (OLRs) and the presence of linear alkylbenzene sulfonate (LAS) surfactants in dishwashing liquid on the organic removal efficiency and biogas generation of PAD-FWD were studied. According to the findings, the PAD-FWD at an OLR of 0.13 kg VS/(m3·day) and hydraulic retention time (HRT) of 12 days could be applied to treat food waste without adding any nutrients to the system to effectively produce biogas. Under operating conditions of the LAS concentration of 63.4 mg/dm3, PAD-FWD was able to reach a steady-state condition with a performance similar to the system without added LAS. The quality of effluent from the PAD-FWD system was unable to meet the effluent standard for households; thus, this effluent should be collected for treatment in a secondary wastewater treatment plant (WTP) before release into the environment. The effluent quality at an OLR of 0.13 kg VS/(m3·day) was in the range of the influent properties of the central WTP, which ensures that the pollutants in the effluent do not increase the overall burden on the WTP. The bio-sludge from PAD-FWD was not a sufficient nutrient source for the growing plants. However, the germination index (GI) of the effluent at an OLR of 0.13 kg VS/(m3·day) did meet the fertilizer standard. The results of this study can be applied to develop self-management of food waste technology to encourage the separation of food waste at the origin within households

Recycling of non-metallic powder from printed circuit board waste as a filler material in a fiber reinforced polymer

Rapid growth in the electricity and electronics industry in Thailand has resulted in numerous problems with electrical waste management. Printed circuit board (PCB) components contain copper in an amount of approximately 10 wt. % and approximately 90 wt. % of non-conductive substrate made from fiberglass resin. In the recycling process, after copper is physically separated from PCB, only nonmetallic powder (NMP) will be left; that needs to be properly disposed of and managed. Therefore, this study is a proposal of suitable choices for NMP management. The results showed that NMP can be disposed in hazardous waste landfill. Furthermore, NMP can be recycled as a component in fiber- -reinforced polymer (FRP) of the following composition: coarse NMP 25%, fine NMP 25%, polyester 38.8%, hardener (Butanox type) 0.6%, catalyst (cobalt type) 0.6%, styrene monomer 10%. This FRP mixed with NMP can be properly processed into an artificial wall tile product in terms of mechanical properties, manufacturing processes and conditions of use

Evaluation of emission and reduction of greenhouse gases from upstream petrochemical industry in Thailand

The study aimed to determine the baseline and indicators for the emission of greenhouse gases (GHG) and to evaluate the effectiveness of GHG mitigation measures in Thai upstream petrochemical plants. During 2005–2010, the upstream production had an annual demand for energy in the range of 110 000–150 000 TJ, ca. 5–6% of the total Thailand energy consumption. The proportion of energy consumption for producing olefin and aromatic products is 73 and 14%, respectively. The amount of GHG emissions equalled approximately 7–9 Mt CO2 eq. This represents a 3% portion of the total GHG emissions of Thailand, separating into the olefin and aromatic products, around 69 and 18%, respectively. The ratios of GHG emission came from fuel combustion of 59%, steam consumption (28%), electricity consumption (10%) and flare (3%). The carbon intensity of upstream products in the olefins and aromatics’ groups had the range of 1.125–1.309 and 0.518–0.667 t CO2 eq/t, respectively. It was likely that the carbon intensity during the period of 2005–2010 was lowered as the industry sector took measures to improve energy conservation and developed their production processes. The GHG mitigation measures by energy conservation were already implemented including fuel saving (67%), steam saving (23%) and electricity saving (10%)