MICROCOSM EXPERIMENTS ON A COCONUT-FIBRE BIOFILM TREATMENT SYSTEM TO EVALUATE WASTE WATER TREATMENT EFFICIENCIES

Abstract

Interest in utilization of locally available biomasses as biofilm support media for wastewatertreatment in developing countries is increasing. In this study, microcosm experiments on a coconut-fibrebiofilm treatment system were carried out to evaluate wastewater treatment efficiencies in the laboratory usingtwo wastewaters, synthetic sewage and leachate, with different pollutant loads. Three coconut-fibre conditionswere set as a single bundle (low fibre density: LFD), two bundles (high fibre density: HFD), and no coconutfibre (blank). The wastewater was first circulated in the system for six weeks (circulation stage) and thendischarged from the treatment tank for 7–24 weeks (treatment stage). Water quality parameters of effluents,pH, DO, EC, BOD, COD, TC, and TN, were measured at one-week intervals, and the sedimented sludge ineach treatment tank was collected to determine C, N, and P contents. Results showed effective reductions inBOD and COD in the LFD and HFD conditions for the synthetic leachate, indicating that the coconut fibrecontributed to the treatment of wastewater. On the other hand, the fibre density had less or no effect on thereduction of water quality parameters in the synthetic sewage. For both synthetic sewage and leachate, the Cand N consumptions generally increased in the order of blank, LFD, and HFD. In particular, sludgesedimentation contributed to C consumption under the HFD condition.