Study On The Production Of Ceramisite Using River Sediment

With the fast development of national industry and agriculture, the problem of river pollution becomes more and more serious, at the same time, a lot of river sediment polluted are producted. If not properly treated, the sediment may result in secondary pollution. At present, the disposal and recycle of river sediment mainly centers around bury and land use in our country, however, the drawbacks of these methods are obvious. Therefore, it is very important to develop a new way of the reutilization of river sediment.The chemical compositions, particle distribution, mineral component and heavy metals in the river sediment from Shanghai Xinjing Gang are analyzed. The result indicates that the main chemical compositions are similar to the one of clay raw materials, which provide possibility of reutilization river sediment. Heavy metals content in the river sediment and concentration in the leachate are very high but not reaching the level of hazard waste.Consider synthetically, river sediment , Sewage sludge, Guangxi Baini and water glass are chosen to be the raw materials of the ceramisite. Through orthorhombic experiment, the optimal technique conditions and batch formula for production of ceramisite is determined, namely river sediment: Guangxi Baini: Sewage sludge: water glass=100:20:15:6, sintering temperature 1140℃, sintering time 9 min. At the same time, effect of sintering temperature, sewage sludge content and adherent content to the characters of ceramisite , which are specific surface area, packing denisty, apparent denisty, porosity and water absorption rate, are studied through single factor experiment. In laboratory, high-quality sediment ceramisite have been successfully produced according to the optimal technique conditions. Its packing density is 710kg/m~3, apparent denisty is 1517kg/m~3, porosity is 53% and tube strength is more than 3.0Mpa. Compared with other ceramisite, it has remarkable advantages.The performances of river sediment ceramisite is tested and analyzed, which include in technical performance, morphology characteristics, extraction rate of heavy metals and adsorptive capacity. The results indicate that it can meet the requirements of biofilm carrier and can be applied widely to wastewater treatment. By high temperature sintering, heavy metals have already solidified in ceramisite, so it dose not result in secondary pollution. Moreover, it has also very good adsorptive capacity to organic matter and ammonia-nitrogen.Analysis of the production of ceramisite using river sediment show that it can bring remarkable economic benefits, environmental benefits and social benefits. Therefore, the production of ceramisite using river sediment is a new effective approach for disposal of river sediment.