[Biomass production and biological purification of distillation slops in a 2-step process]

In order to lower the chemical demand (COD) of slops from cane molasses alcohol a treatment of two steps which allows the production of single cell protein of Candida utilis and Paecilomyces variotii has been performed. Its use reduces the treatment cost. In the first step the slops without sterilization supplemented with ammonium sulphate (5 g.l-1) and dipotassium phosphate (0.5 g.l-1) was inoculated with C. utilis and P. variotii. The yield was 24 and 18 g.l-1 of dry biomass and COD reduction of 36 and 75% respectively. In the second step, the remainder effluents were treated with Aspergillus niger. The final COD reduction attained was 93 and 92% respectively.