Pretreatment of Herbal, Tofu and Fertilizer Waste Using UV/Ozon Technique and Its Utilization for Spirulina sp Cultivation

Abstract

The herbal, tofu and fertilizer industries contribute considerable waste to the environment. The waste contains COD and organic substances which should be reduced before it is discharged to the environmental body. One of methods is by using Advanced Oxidation Processes (AOPs) degradation method. The process of AOPs in this study used a combination of UV irradiation and ozone to produce hydroxyl radicals. This study was aimed to investigate the degradation of Chemical Oxygen Demand (COD) by using AOP techniques and to evaluate the treated waste for microalgae growth. This research consists of two steps: (1) the initial COD degradation using UV-Ozon. (2) utilization of the treated waste for microalgae cultivation by combining a mixed nutrient of waste and 10 mg/L TSP, 10 mg/L Urea, 80mg/L NaHCO3. The results showed that the COD degraded by UV/Ozone follows the first order equation by k value of 0.082/day, 0.223/day and 0.436/day for tofu, herbal and fertilizer waste respectively. The growth rate of Spirulina cultivated in waste medium was in comparable with the one cultivated in control medium.