Application of Sugarcane Bagasse and Peanut Shell in Natura as Bioadsorbents for Vinasse Treatment

Abstract

Abstract Vinasse is one of the most polluting effluents in the sugar-alcohol industry due to its physicochemical properties. It poses a threat to soil fertility and can contaminate groundwater if not appropriately handled. Therefore, it is important to evaluate more sustainable and comprehensive vinasse treatment strategies to safeguard environmental integrity. So, this work aims to evaluate sugarcane bagasse and peanut shell, as renewable adsorbents, for the removal of organic matter, pH, and turbidity found in vinasse effluent. Commercial activated carbon was used to compare the performances. Experimental assays were conducted using the adsorbents under three different concentrations (1: 12.5 g L-1; 2: 25.0 g L-1; 3: 37.5 g L-1) at 3, 6, 12, 24, and 48 hours of treatment, under controlled temperature (25°C) and rotation (200 rpm). The bioadsorbents were able to promote marked removal of organic matter, showing natural adsorbent properties without any previous activation. Major COD removal (63.88%) was observed for the commercial activated carbon after 48 hours of treatment and a concentration of 37.5 g L-1. For the peanut shell and sugarcane bagasse, the major COD removal was 50.94% and 45.35%, respectively, after 48 hours of treatment and a concentration of 12.5 g L-1. The final effluent exhibited high residual COD content, indicating the necessity to associate with another treatment state, such as biodigestion or ozonolysis, acting as a pretreatment or as a posttreatment.