title: Moisture distribution in sludges based on different testing methods.
abstract: Moisture distributions in municipal sewage sludge, printing and dyeing sludge and paper mill sludge were experimentally studied based on four different methods, i.e., drying test, thermogravimetric-differential thermal analysis (TG-DTA) test, thermogravimetric-differential scanning calorimetry (TG-DSC) test and water activity test. The results indicated that the moistures in the mechanically dewatered sludges were interstitial water, surface water and bound water. The interstitial water accounted for more than 50% wet basis (wb) of the total moisture content. The bond strength of sludge moisture increased with decreasing moisture content, especially when the moisture content was lower than 50% wb. Furthermore, the comparison among the four different testing methods was presented. The drying test was advantaged by its ability to quantify free water, interstitial water, surface water and bound water; while TG-DSC test, TG-DTA test and water activity test were capable of determining the bond strength of moisture in sludge. It was found that the results from TG-DSC and TG-DTA test are more persuasive than water activity test.
authors.affiliation: School of Environmental Science and Engineering, Donghua University, Shanghai 201620, China. dengwy@dhu.edu.cn
authors.forename: Wenyi
authors.initials: W
authors.lastname: Deng
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yan
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Chi
authors.forename: Kefa
authors.initials: K
authors.lastname: Cen
mesh_terms: D002152:Calorimetry, Differential Scanning; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002947:Cities; D004396:Coloring Agents; D003890:Desiccation; D006813:Humidity; D007220:Industrial Waste / Q000032:analysis; D010209:Paper; D011327:Printing; D012722:Sewage / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D012722:Sewage; D014867:Water