Upflow Anaerobic Sludge Blanket Reactor Treating Cassava Processing Wastewater: Granule Formation Study

Abstract

Cassava processing wastewater contains high concentrations of biodegradable organic matter, suspended solids, and starch residues, creating significant environmental concerns when discharged without effective treatment. The present study investigates the performance of an upflow anaerobic sludge blanket reactor treating cassava processing wastewater, with particular emphasis on anaerobic granule formation and reactor stability under controlled operational conditions. The research focuses on evaluating the influence of hydraulic retention time, organic loading rate, upflow velocity, temperature, and substrate concentration on granule development, microbial activity, and treatment efficiency. Experimental analysis demonstrates that the upflow anaerobic sludge blanket reactor effectively promotes anaerobic digestion and organic pollutant removal through the formation of dense microbial granules with high methanogenic activity. Results indicate that optimized operating conditions significantly enhance granule stability, biomass retention, and biogas production while improving chemical oxygen demand reduction efficiency. The study further reveals that extracellular polymeric substances and microbial aggregation mechanisms play critical roles in granule nucleation, structural integrity, and long-term reactor performance. Increased organic loading under controlled hydraulic conditions contributed to accelerated granulation and improved sludge settleability. Comparative assessment with conventional anaerobic treatment systems confirms the advantages of upflow anaerobic sludge blanket technology, including higher biomass concentration, lower sludge generation, and enhanced energy recovery through methane production.