LABORATORY-SCALE EVALUATION OF FLUIDIZED-BED REACTOR TECHNOLOGY FOR BIOTREATMENT OF MALEIC-ANHYDRIDE PROCESS WASTE-WATER

Fluidized bed reactor (FBR) technology has emerged in recent years as an attractive approach for the biotreatment of chemical industry waste streams. A laboratory-scale FBR study was conducted to investigate the feasibility of utilizing FBR technology for the biotreatment of malei c anhydride wastewater generated during manufacturing operations. The maleic anhydride wastestream contains a mixture of maleic acid, fumari c acid, phthalic acid and di-n-butylphthalate (DBP). The FBR removed > 98% of chemical oxygen demand (GOD) and total organic carbon (TOC) fro m the wastewater at a chemical loading rate of 4.86 kg of COD m(-3) be d day(-1). Maleic acid, fumaric acid or phthalic acid were not detecte d in the FBR effluent indicating removal of these diacids, Residues of DBP adsorbed to granular activated carbon (GAG) stabilized at low lev els indicating that the >99% removal efficiency for DBP in the FBR res ulted from microbial degradation, Solids measurements showed microbial biomass levels on the GAC ranging from 10500 to 32400 mg L(-1) and ef fluent solids production ranged from 0.027 to 0.041 kg solids kg(-1) C OD treated. This laboratory-scale study demonstrated that FBR technolo gy was highly effective for the biotreatment of the maleic anhydride w astestream and may offer several advantages over traditional activated sludge systems.