Preparation of Sulfur-Impregnated Carbonaceous Filter with High Heavy Metal Adsorption Capacity

The adsorption method for heavy metal removal from wastewater is focused because of its simplicity and high versatility, and sulfur-impregnated carbonaceous adsorbent is expected as heavy metal adsorbent with high performance at low cost. In this study, sulfur-impregnated carbonaceous filter for removing heavy metals were prepared by pyrolysis of cotton immersed in sulfur solution, K2S, Na2S and NaHS, and the adsorption behavior of nickel was investigated. A nickel adsorption experiment was carried out using a syringe. The sulfur-immersed carbonaceous filter was prepared from cotton via pyrolysis at 400 °C for 1 h after immersing to sulfur solution for 12 h. In the experiment, a syringe which filled with 1 g of the obtained filter and glass wool was used, and a nickel solution was passed through the syringe. The filter with nickel adsorption can be prepared using all sulfur solutions, especially the product prepared by using Na2S has higher adsorption ability than the products using K2S and NaHS. The product obtained using over 0.4 M K2S solution was effective for nickel adsorption. The equilibrium data of nickel adsorption on the product using 1 M K2S was found to Langmuir isotherm model better than Freundlich, and the calculated maximum adsorption capacity is 0.215 mmol/g.