Assessment of Rice Husk-Based Activated Carbon as Adsorbent in Domestic Wastewater Treatment

Abstract

Indiscriminate discharge of wastewater into the environment is of utmost concern, especially in developing countries. This study evaluated the efficiency of rice husk based activated carbon in wastewater samples harvested from a students’ hostel and a restaurant within the Federal University of Technology, Akure. The adsorbent used was produced from rice husk using hydrogen tetraoxosulphate (VI) acid (H2SO4) as the activating agent. The aim of this study was to assess rice husk-activated carbon for the reduction of physicochemical parameters such as hardness, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), total dissolved solid (TDS), total suspended solid (TSS), and heavy metals which include chromium (Cr), lead (Pb), manganese (Mn), and iron (Fe). The wastewater samples were treated using activated rice hush ash of particle size (180 µm) at four different doses (30, 35, 40, 45 grams/400 ml). The results showed that the different doses of activated carbon had different removal efficiency. It was observed that the optimum dosage was 40g for DO, COD, BOD, and TDS while 30g was optimum for Hardness. It was also observed that an increase in the concentration of rice husk adsorbent led to an increase in the removal efficiency for the heavy metals (Cr, Mn, Pb, and Fe). The maximum percentage removal of DO, COD, BOD, TDS, and TSS, with rice husk was 21%, 58%, 72%, 21%, and 57% respectively. After the treatment of the domestic wastewater and comparing with the WHO standard, the treated wastewater quality was found to be safe for direct discharge into surface water bodies and irrigation purposes.