Activated carbon as a filter media in a communal toilet water supply system: Analysis of water quality and potential social return on investment

This article discusses the water supply system for communal toilets located in the Citarum watershed in Rengasdengklok District, Karawang Regency. This research is an applied experiment with a single treatment design with two stages of research, namely the synthesis of activated carbon and the preparation of water treatment. Applied research is carried out to design (scale up) and implement water treatment facilities to meet the needs of public facilities (communal toilets). A survey has also been carried out to collect potential impact data and calculate financial feasibility with a social return on investment framework. This study achieved success to find local, cheap, frequent and available materials as filter media. Moreover, rice husk and rice straw that was used in filtration still can be used as animal food or may be mixed to be at the allowable safe limit to the animals. The present study shows that rice straw is effective adsorbents for the removal of Fe (III) and Mn (П) from river water. The findings show that operational parameters such as rate of filtrations, contact time and initial concentrations of contaminants, have a great effect on the adsorption efficiency. The amount of Fe (III) and Mn (П) adsorbed increased with the decrease of rate of filtration because of increase of contact time. Rice husk is the best filter media in removing iron and manganese from groundwater, but it needs a very good wash and rinses before use else it will increase the concentration of dissolved salts. This method saves all chemicals used in oxidation of iron & manganese. The rice husk filter media saturation time decreased with the increase of initial contaminant. Furthermore, numerous studies have been conducted to determine the effect of straw activated carbon on water treatment process. As for financial proxy, the water treatment project using activated carbon of rice straw will achieve a return on investment of a ratio of 1: 4.7 (every 1 rupiah invested will generate a potential benefit of 4.7 rupiah). All researchers hope to discover the simplest and least expensive method for preparing the most efficient filter media in water treatment process.