CONCURRENT REMOVAL OF ORGANIC AND HEAVY METAL CONTAMINANTS IN WASTEWATER: A CASE STUDY ON A PULP MILL EFFLUENT AND LEACHATE

Abstract

A continuous flow reactor (CFR) was designed, and its application was tested for para-nitroaniline (PNA) degradation and real environmental wastewater (i.e., Boat Harbour (BH) and leachate samples) treatment. Total organic carbon (TOC) mineralization efficiency of 73.2% and 92% discoloration was achieved at the optimized condition for PNA mineralization at a flow rate of 5mL min-1 (retention time of 20 min), applied potential of 2.5 V, and NaCl concentration of 29 g L-1. At this optimized experimental conditions, contaminated BH sample was passed through the CFR, and 76% degradation (initial TOC of 105.4 mg L-1) was achieved, and major organic compound (cresol) identified using gas chromatography-mass spectroscopy (GC-MS) was confirmed degraded. Also, a significant concentration reduction of heavy metals including As, Cd, and Pb, was achieved post-treatment at environmental pH, the energy consumption of 23 kWh (kg TOC)-1, and overall operational cost of 0.66 USD g-1 of carbon removed.