Study Of Sludge Recycling To Produce Heat Insulaitng Material

As the rate of municipal wastewater treatment going up in our country, the amount ofsludge produced in the treatment process increase a lot. The traditional sludge treatment, notonly consume large amounts of resources, but also damage to the environment. So sludgerecycle is a sustainable development way of sludge treatment. In recent years, Sludge wasused as a building material in foreign countries, not only can maintain the unique performanceof heat preservation material, also can effectively make use of the sludge. Developed a newkind of heat preservation material in this study, the process is adopted by the foaming process.sludge are added to the heat preservation material. Its main contents include:(1) Thepretreatment of the sludge;(2) The development of the heat preservation material;(3) Studythe performance of the heat preservation material;(4)The evaluation of the heat preservationmaterial.Experimental results show: Sludge pretreatment is mainly to remove odor, poisonous andharmful substances and organic materials. Purpose is deodorized by joining deodorant.Deodorant choose diatomite and fly ash, its adding amount was10%, the ratio of2:1, theprocessing time is5days; Anaerobic digestion process adopted by the temperature of35℃,the digestive days for10days, PH between7.0~7.4; The sludge drying at140℃and6hours,it can effectively remove odor and harmful substances. The process is foaming process bygypsum as main raw materials. Through the study on the properties of the heat preservationmaterial, The sludge content is25%; The foaming agent choose sodium dodecyl sulfate, itscontent is1.4%; The foam stabilizer choose polyacrylamide, its content is2.1%; The ratio ofwater and gypsum is1:1.2. Cement and fly ash is in order to improve the hardness ofmaterials, its adding amount was10%, The ratio of Cement and fly ash is6:4. Vac/E canimprove the waterproof performance of materials, its content is6%. Raw materials andauxiliary materials mixed in the mixing time of3min and mixing temperature28℃, Materialdrying under natural conditions. The performance of the heat preservation material isrelatively good on these conditions, As to meet the requirements of the performance for theheat insulating material, it’s the density is371.4kg/m3, the compressive strength is12.7MPa,the thermal conductivity is0.13W/mK and the water absorption is less than1.5%. The heatinsulating material has good performance.Using sludge to develop the heat preservation material, opened up a new road for sludgerecycling. It has a positive meaning, no matter in the comprehensive utilization or inenvironmental protection is of positive significance.