Innovative Coagulation Flocculation Strategies Using Chitosan Based Hybrids for Heavy Metal and Organic Pollutant Removal

Noman Basheer; Abdul Wasay; Fozia; Mahpara Akbar; Shay Chirag

Innovative Coagulation Flocculation Strategies Using Chitosan Based Hybrids for Heavy Metal and Organic Pollutant Removal

Authors

Noman Basheer Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan,
Abdul Wasay Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan,
Fozia Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan,
Mahpara Akbar Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan,
Shay Chirag Department of Entomology, University of Agriculture, Faisalabad, Pakistan,

Keywords:

BOD, COD, Chitosan, Heavy metals, Polyacrylamide, Sodium alginate, TDS, Turbidity , Wastewater treatment

Abstract

In Pakistan, municipal and industrial effluents which have a high concentration of organic pollutants and heavy metals like lead (Pb) and cadmium (Cd) have become a menace to the freshwater resources in the country. The paper compared the performance of chitosan, polyacrylamide (PAM) and sodium alginate as an individual and combination of 25 and 50 mg L^-1 in removing the BOD, COD, turbidity, TDS, electrical conductivity (EC) and heavy metals in sewage wastewater in Quetta. Jar tests were performed in controlled conditions (pH 5, 30 °C, rapid mixing of 15 min at 250 rpm, slow mixing of 30 min at 50 rpm and 1h settling). Application of chitosan as a single polymer showed the highest efficiencies with a maximum reduction of 86% BOD, 78.9% COD, 66% Cd removal, 73.5% Pb removal and 44.75% TDS reduction at 50 mg L^-1 and combined polymer showed even better removal efficiencies with the PAM50+Chit50 combination achieving 98.13% BOD, 91.1% COD, 98.4% turbidity 91%. The complementary actions are the reason of better performance of combined treatments, chitosan neutralizes the charges, binds the metal, stabilizes the flocs, PAM increases polymer bridging and aggregates the particles. The removal of heavy metals was always greater with Pb compared to Cd as a result of chitosan affinity to Pb 93.99%. An increase in polymer dose enhanced the removal without destabilizing flocs which is a sign that the treatment conditions were optimal. These findings substantiate that biopolymer engineered hybrid systems especially chitosan PAM and chitosan alginate hybrids are a sustainable, biodegradable and economical method of municipal wastewater treatment which will serve as an effective technology to enhance the quality of water in the growing cities.

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Innovative Coagulation Flocculation Strategies Using Chitosan Based Hybrids for Heavy Metal and Organic Pollutant Removal