Heavy Metals Removal from Automotive Wastewater using Chemically Modified Sand

The effectiveness of the automotive industry wastewater treatment has been determined by fixed-bed adsorption study. Two mathematical models which are Thomas model and Yoon and Nelson model were used to determine the maximum adsorption capacity of ammonia. Percentage of removal of ammonia using chemically modified sand indicate the removal percentage range of 43.68% to 96.55% compared to raw sand, which indicate the range of 0% to 89.66%. Zinc, manganese, chromium, copper, arsenic, nickel, cobalt and iron have been recorded to give removal percentage of 93% to 100% by using chemically modified sand compared to the raw sand which recorded the range of removal percentage of 0.8% to 100%. The analysis using Thomas model shows the maximum adsorption capacity; q(o) of ammonia using chemically modified sand (8.80 mg/g) was four times higher than normal sand (2.57 mg/g). Meanwhile, the time for 50% adsorbent to breakthrough, t(0.5) determined by Yoon and Nelson model showing that the chemically modified sand obtained the time of 30.18 min compared to raw sand which is 9.57 min. This study indicated that the removal percentage and the adsorption capacity of ammonia and the selected heavy metals such as zinc, manganese, copper, arsenic, nickel, cobalt and iron were higher in chemically modified sand compared to pristine sand fix-bed column.