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Activated carbon (AC) was prepared from the carbon residue of Lugi pressurized gasifier (LPG) slag with a microwave-assisted activation process using potassium hydroxide (KOH) as the activating agent. The effects of various factors such as the heating behavior of the microwave, power of the microwave, activation time and ratio between LPG slag and KOH on the activation have been studied. The surface property of the AC was characterized by BET. The optimal activation conditions were 900 W of microwave power, 9 min of radiation time and 1:1 ratio of KOH and carbon. The surface area of prepared AC was 1061 m² .g–1, and a carbon yield of 42% could be reached. The iodine value was 1082.2 mg g–1. When compared with the traditional method, the microwave-assisted activation process demonstrated faster rate of activation and higher carbon yield. Microwave-assisted AC removed phenols and chromaticity from the wastewater obtained from the Coking Plant in Kunming efficiently. [ABSTRACT FROM AUTHOR]

The removal of lower molecular weight organic compounds (LMWOC) from water is of increasing concern. While, nano-filtration (NF) is a good option, it removes only a fraction of the LMWOC. In this paper, NF experiments were conducted to remove oxalic acid and diuron in combination with coagulation using poly-aluminum chloride (PAC) as the coagulant. The results showed that this hybrid treatment system was effective in removing oxalic acid where almost a 100% removal efficiency of oxalic acid was achieved. However, using PAC as coagulant to remove diuron from water was not effective. In order to improve the removal efficiency of diuron, 0.02 M NaCI was added to diuron and a 40% increase in the removal of diuron was achieved. Higher removal of diuron was achieved when the solution was treated with reverse osmosis (RO) when compared to the nano-filtration. [ABSTRACT FROM AUTHOR]