Enhanced Turbidity Removal from Petrochemical Wastewater: Experimental Evaluation of Chitosan and Metal-Based Coagulants

This study evaluated how well chitosan, a safe and natural substance, removes cloudiness from actual petrochemical wastewater. The study used jar tests to find the best settings for several factors: the amount of chitosan used (۱۵-۸۰ mg/L), the initial cloudiness of the water (۲۷.۵-۷۱.۳ NTU), the pH level (۴-۱۱), and how fast and long the water was mixed quickly (۱۰۰-۳۰۰ rpm for ۱-۳ min), and then, how fast and long the water was mixed slowly (۳۰-۹۰ rpm for ۵-۴۰ min), and how long the particles were allowed to settle (۵-۳۰ min). The best results were achieved with a pH of around ۷, ۳۵ mg/L of chitosan, quick mixing at ۲۵۰ rpm for ۲ minutes, slow mixing at ۶۰ rpm for ۲۰ minutes, and a settling time of ۱۵ min. Under these conditions, chitosan was removed up to ۹۶.۷% of the cloudiness. Chitosan worked better than standard chemicals like ferric sulfate and ferric chloride because it needed smaller amounts, created less sludge, and settled faster. Unlike metallic salts, chitosan did not increase treatment costs or make the water harder or more alkaline, and it eliminated the need to adjust pH levels before or after treatment. Furthermore, chitosan significantly lowered other measures of pollution, including BOD (۵۲.۹%), COD (۶۸.۲%), TDS (۱۴.۱%), hardness (۱۸%), and oil content (۶۵.۱%), demonstrating its wide range of treatment capabilities. Statistical tests confirmed that chitosan performed better under the best conditions. These results suggest that chitosan is a cost-effective and efficient option for treating petrochemical wastewater, offering both economic and environmental benefits.

کلیدواژه ها:

Chitosan ، Coagulation ، Petrochemical wastewater ، Turbidity removal ، Statistical analysis