Effectiveness of coagulants in removing selected microbiological and physicochemical contaminants from fruit and vegetable industry wastewater

Wastewater from the fruit and vegetable industry was treated by coagulation, using variable doses of Al PAX 18 and Fe PIX 113 coagulants (2-10 mL/L) and neutralized with a 10% soln. of lime milk. The PAX 18 was more effective in removing microbiol. contaminants in the entire range of doses used. No enterococci or Escherichia coli were detected, and the total no. of microorganisms was reduced by more than 99%. The COD value was reduced by a max. of 67% using an Al coagulant (dose 2 mL/L) and by 72% using an Fe coagulant (dose 6 mL/L). The color of the treated sewage was reduced from 88 to 97%, and the turbidity was almost completely reduced (< 1 NTU).