Preparation and Physical Properties of Ceramsite Filter Media for Water Treatment Obtained from Municipal Solid Wastes

Sludge,solid waste of sewage treatment plants,poses a threat as a secondary pollution if it is not handled properly.In this study,artifical ceramsite filter material(ACFM)for water treatment,was obtained from sludge by high-temperature sintering process,and then it’s physical properties,leaching toxicity and sintering mechanisms were investigated.The results showed that the preferred conditions for the preparation of ACFM were that the mass ratio of sludge,river sediment and fly ash was 5∶4∶1,preheated at 400℃for 20 min and sintered at 1 150℃for 5 min.After the optimal sintering conditions treatment,the physical properties of the rate of breaking and wear,solubility in hydrochloric acid,silt carrying capacity,void fraction and Brunauer-Emmett-Teller(BET)specific surface area of ACFM were 0.2%,0.01%,0.2%,71.1%and 0.75×104cm2/g,respectively.The results confirmed that the ACFM’s physical properties were totally aligned to the requirements of China’s industry standard(CJ/T 299—2008).The leaching toxicity results indicated that the leaching contents of heavy metals,such as Cr,Zn and Cu,were much lower than the thresholds of China’s national standards(GB 5085.3—2007 and GB 8978—1996).

Sludge, solid waste of sewage treatment plants, poses a threat as a secondary pollution if it is not handled properly. In this study, artifical ceramsite filter material （ACFM） for water treatment, was obtained from sludge by high-temperature sintering process, and then it＇s physical properties, leaching toxicity and sintering mechanisms were investigated. The results showed that the preferred conditions for the preparation of ACFM were that the mass ratio of sludge, river sediment and fly ash was 5 ： 4 ： 1, preheated at 400 ℃ for 20 min and sintered at 1 150 ℃ for 5 min. After the optimal sintering conditions treatment, the physical properties of the rate of breaking and wear, solubility in hydrochloric arid, silt carrying capacity, void fraction and Brunauer-Emmett-Teller （BET） specific surface area of ACFM were 0. 2%, 0. 01%, 0. 2%, 71. 1% and 0. 75 × 10^4 cm2/g, respectively. The results confirmed that the ACFM＇s physical properties were totally aligned to the requirements of China＇s industry standard （ CJ/T 299-2008 ）. The leaching toxicity results indicated that the leaching contents of heavy metals, such as Cr, Zn and Cu, were much lower than the thresholds of China＇s national standards （ GB 5085.3-2007 and GB 8978-1996）.