Effects of stirring on cassava effluent treatment in an anaerobic horizontal tubular pilot reactor with support medium - A Review

The cassava starch industries generate wastewater which, when stabilized in ponds, wastes biogas and pollutes atmosphere. Aiming to change this reality, the research was developed in a one-phase anaerobic horizontal pilot reactor, at a cassava starch industry in Toledo, PR, Brazil. The stirring was done by biogas recirculation and the support medium was built with bamboo. The experimental design was completely randomized, with answers submitted to multivariate analysis. The average organic load rates (OLR) in chemical oxygen demand (COD) were 0.556, 0.670, 0.678, 0.770 and 0.902 g L−1, and average reductions for COD (CODR) were 88, 80, 88, 67 and 70. Although the volatile acidity/total alkalinity ratio (VA/TA) presented risk values, the reactor remained stable, thanks to the support medium presence.