Development of a Wastewater Treatment System Using Local Materials to Improve Effluent Quality from Food Service Establishments along the Wang River, Lampang Province Wastewater Solutions

Abstract

Wastewater contaminated with grease and oil from food service establishments along the Wang River in Lampang Province is a significant contributor to the deterioration of water quality. This research, therefore, aims to develop a low-cost wastewater treatment system and evaluate the efficiency of local materials, namely charcoal and diatomite, for oil removal. A 100-liter mobile treatment system, equipped with PVC pipes and flow-control valves, was designed, and laboratory experiments were conducted to determine the optimal conditions for oil absorption. The results revealed that 2-mm charcoal demonstrated the highest oil absorption efficiency, absorbing up to 91.17 g (63.09%). In contrast, diatomite showed significantly lower efficiency, with 5-mm particles absorbing only 26.52 g. The investigation of contact time showed that charcoal's absorption efficiency remained relatively stable, despite variations in soaking duration (60.73% - 63.09%), whereas diatomite reached its peak efficiency (32.56%) at 12 hours. Regarding adsorbent quantity, 150 g of charcoal achieved an oil removal rate of 99.98%, outperforming diatomite at all tested quantities. For material mixtures, a 4:1 ratio of charcoal to diatomite yielded the highest efficiency (99.82%). Finally, an analysis of the restaurant effluent, which revealed pollution levels exceeding established standards, confirmed the necessity for this research. The collective results unequivocally demonstrate that employing charcoal as the primary material in the treatment system is a highly effective and suitable solution to this problem.