Raw fruit juice processing wastewater treatment using electrochemical coagulation followed by synthesis of CuO Nano sorbents using leaf extract

Abstract

Stainless steel and aluminium electrode was utilized inside batch electro chemicals coagulations (BECCs) using current densities (CD) for the treatment of fruit juice processing wastewater (FJPW). During ECC, ~65-70% color removal and COD removal of ~55-60% was observed for CD 260 A/m2 at 75 min electrolysis time for both 4SS (four stainless steel) and 4Al (four aluminium) electrodes. In general, 4SS and 4Al electrodes had less influence on FJPW for all CDs. Therefore, to improve the quality of treatment of leftover color and COD by BECC treatment, the batch adsorption studies were conducted as secondary treatment by synthesis of CuO nanoparticles using Carica papaya, Centella asiatica (CA), Ocimum sanctum and 1:1:1 mixture of leaves. An effect of several operating parameters like adsorbent dose, pH, and contact duration on leftover color and COD removal was studied for optimal conditions to treat FJPW. The results showed that ~70% color and ~65% Chemical Oxygen Demand elimination at an optimal condition for adsorbent dosages 0.60 g/L, at pH 8.0 to 8.5 and contact time 40 min for CA and 1:1:1 mixture of leaves. Altogether, BECC - nanosorption, a dual treatment, effectively treated FJPW wastewater with clean water reclamations of up to 90%.