Development of microalgae and agrobost mutualism symbiotic technology in the aerobic treatment of sago refinery wastewater

Abstract

Sago wastewater is 94% of the water produced from the sago processing that could pollute the environment. One of the biological treatments to solve this problem is the use of mutualism symbiotic between the microalgae Chlorella sp. and agrobost with the addition of 5.000 lux constant light. The purpose of this research was to develop symbiotic technology for microalgae and aerobic bacteria in the decomposition of liquid sago waste, in particular for optimizing the photosynthesis process. Furthermore, the reduction of BOD, COD, and organic content could be fast and effective. The research applied a Completely Randomized Design (CRD) with five treatments and three replications. The treatments were addition of 800 ml/l (7.595 log cell/ml) as much to sago waste at variation of concentrations (0% v/v,1% v/v, 2%v/v, 3% v/v, 4%v/v). Data were statistically analyzed using the Analysis of Variance, followed by Duncan’s New Multiple Range Test (DNMRT) at the level of 5%. The result showed that the addition of agrobost microorganisms significantly affected BOD, COD, DO, and pH of sago wastewater. The treatment selected from the results of this study was the P4 treatment with the highest reduction on day 7 with a BOD value of 116.06 mg/l, COD 200.90 mg/l, DO 6.62 mg/l, and pH 8.90.