Preparation of decolorizing ceramsites for printing and dyeing wastewater with acid and base treated clay

• Published in: Applied clay science Vol. 40; no. 1; pp. 20 - 26
• Main Authors: Guo, Xiangli, Yao, Yadong, Yin, Guangfu, Kang, Yunqing, Luo, Yong, Zhuo, Lang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.06.2008; Amsterdam Elsevier Science; New York, NY
• Subjects: Clay minerals; Decolorization; Decolorizing ceramsite; Earth sciences; Earth, ocean, space; Exact sciences and technology; Mineralogy; Printing and dyeing wastewater; Silicates; Clay minerals; Printing and dyeing wastewater; Decolorization; Decolorizing ceramsite; adsorption; neutralization; palygorskite; metals; raw materials; flocculation; acids; solution; materials; sepiolite; temperature; clay minerals; sheet silicates; silicates; ions; reduction; performances
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2007.06.009

A new type of decolorizing ceramsites for printing and dyeing wastewater were prepared, by means of acid activation, base neutralization, granulation and heating treatment, by using palygorskite, Hangjin2# clay, bentonite or sepiolite as raw materials. The experimental results show that, the decolorizing ceramsites made of palygorskite have the best performances among different clay minerals in treating printing and dyeing wastewater. Its decolorizing amount is 635 mL g − 1 and the reduction in COD is 81%, after 5 min static treatment at normal temperature. After calcined at 700 °C for 1 h, the loss ratio of decolorizing ceramsites made of palygorskite is less than 5%. Treated with saturated (NH 4) 2SO 4 solution for 10 min, and then calcined at 300 °C for 10 min, the used decolorizing ceramsites can be reused for more than 15 times. The decolorizing effect of the decolorizing ceramsites is mainly attributed to the combined chemical flocculation reaction of various metal ions in the material, with minor physical adsorption involved.