Evaluation of human urine purification using rice husk charcoal as the adsorbent

Abstract

Abstract The abundant amount and availability of human urine potentially can be re-used for water and nutrient resources. Nutrient content in urine, primarily nitrogen and phosphorus, can cause eutrophication in waters and worsen the environment. Urine is not easy to be managed separately because it is usually integrated with black water or domestic wastewater that flows to the sewer from households or other public facilities. The decline in water quality and the increase in water consumption by the global community have given many driving forces to technological breakthroughs that can recover important nutrients from waste for reuse. In addition, the high-water content of urine also provides an incentive to reuse or recycle most of the water contained in urine for public purposes. Rice husk charcoal is a waste product from burning husks used as fuel in the tofu-making process. It is usually used for poultry bedding or soil enhancer in gardening. This research aimed to characterize the utilization of rice husk charcoal as an adsorbent to treat urine to obtain clean water. The urine was processed using 30-mesh rice husk charcoal as an adsorbent. The soaking time and hose type were varied to identify the effect on the adsorption performance. The urine absorption using rice husk charcoal with 60 minutes soaking time showed the highest removal based on the absorbance value of 27.18% at 487 nm wavelength and 28.25% at 668 nm wavelength. On the other hand, the adsorption using a curved hose showed better performance than the straight hose. The adsorption using the curved hose could decrease the urine concentration by 25.30-29.24% at 487 nm wavelength and 28.50-30.19% at 668 nm wavelength. In addition, the urine total dissolved solids (TDS) decreased by 73-76%. Therefore, rice husk charcoal could be used as the adsorbent in the adsorption of human urine.