Ammoniacal nitrogen, chemical oxygen demand, and color reduction in rubber processing industry effluent using zeolite

The effluent from the rubber processing industry usually contains a high concentration of organic compounds, suspended solids, color, nitrogen, and other pollutants. If an excessive amount of ammonia nitrogen is discharged into bodies of water, it may cause eutrophication and the death of various aquatic creatures. The goal of this experimental design was to investigate the effectiveness of zeolite for ammoniacal nitrogen, chemical oxygen demand (COD), and color removal from rubber processing industry effluent. The samples of rubber processing industry effluent for this study were acquired directly from the discharging point of a manufacturer in Kluang, Malaysia. The effects of optimal adsorbent dose, shaken speed, contact time, and pH were determined for ammoniacal nitrogen, COD and color removal. The obtained result reveals that the best batch adsorption experiment of ammoniacal nitrogen, COD, and color removal was attained at pH 7, ZEO dosage 4.0 g, contact time 120 min, and shaken speed 200 rpm respectively. The best efficiency removal of ammoniacal nitrogen, COD, and color was achieved based on dosage generally in the range of 75% for ammoniacal nitrogen, 69% for COD, and 79% for the color of all batch experiments conducted. The kinetic equilibrium model data fitted well with the pseudo-first and second model. The pseudo- second-order better fitted the equilibrium data over the entire concentration range studied. The pseudo- second-order described the best coefficient of determination compared to the pseudo-first-order. The coefficient of determination for pseudo-second-order was generally in the range of 0.9958 for ammoniacal nitrogen, 0.9978 for COD, and 0.9984 for the color of all kinetics studies conducted.