Effectivity of activated charcoal as adsorbent for wastewater treatment

Abstract

The main purpose of this research was to study the optimum condition for production activated charcoal in a retort with 100 kg capacity and to apply the best activated charcoal as adsorbent for wastewater treatment. The raw materials used in this research were wood sawdust, mangium wood (Acacia mangium) and coconut shell. The charcoal was activated using the condition : activating temperature at 700 ºC continued by steaming with H2O for 1, 2, 3 hours and without steaming as a control. In Order to improve the qualities of the activated charcoal, further activation was conducted using H3PO4 solution at 5 % concentration. The possible changes in structure were evaluated using Infrared Spectrophotometry, X-ray Difraction and Scanning Electron Microscope. The results showed that the best quality of activated charcoal was achieved by Acacia mangium by soaking in H3PO4 5 % solution without steaming. The yield of activated charcoal was 40,54 %; moisture content 5,25 %; ash content 2,31 %; volatile matter 7,01 %; fixed carbon 90,69 %. Adsorptive capacity of iodine was 657,20 mg/g; metanol 7,13 %; CCl4 8,39 %; CHCl3 13,24 %; formaldehida 6,57 % and benzene 7,13 %. Degree of crystalinity 58,23 %; height of aromatic layers (Lc) 4,02 nm; width of aromatic layers (La) 4,22 nm; number of aromatic layers (N) 10,84 and distance of aromatic layers (d) 0,21 nm with pore diameter of 0,14 – 0,35 μm. The best concentration of activated charcoal as adsorbent for domestic wastewater treatment was 1 % concentration. It decreased Biological Oxygen Demand (BOD) 98,03 %; Total Suspended Solid 97,66 %; oil and grease 76,92 % and pH value increased 6,15 %. For hospital wastewater treatment, the best condition was achieved using activated charcoal at 2 % concentration. It could decreased pH value 17,50 %; Total Suspended Solid 93,06 %; ammonia 76,09 %, phosphat 33,06 % and coliform bacteri 90 %. BOD and Chemical Oxygen Demand (COD) increased 330,79 % and 135,91 %. The best concentration of activated charcoal as adsorbent for nicel coated industry wastewater treatment was 1 % concentration. It decrease Total Suspended Solid 84,72 %; Cr 39,50 %; Cu 66,67 %; Zn 91,50 %; Ni 73,75 % and Cd 71,43 %. pH value increase 242,84 %, but Pb value was not changed.