Study On Preparation Ceramsite In Water Supply Sludge And It's Application Of Phpsphorus Removal

As Chinese population continues to increase and the process of urbanization accelerate,the number and scale of water supply plants are expanding,and the amount of sludge produced by the water supply plants will also increase.Such a large amount of water supply sludge needs to be rationally planned and integrated utilization.If the sludge was dealt with simply or directly,the sludge would not only waste a lot of water and energy,but also pollute the environment seriously.Therefore,how to deal with these sludge become the current urgent need to be solved.Since the aluminum phosphate sludge can be used in phosphorus adsorption,explore the methods of water plant sludge treatment for treating domestic sewage,can save the cost of sludge treatment,reduce environmental pollution,make the sludge harmless and reduced.As a result,it is of great significance to save water resources,achieve the recycling of domestic sewage,improve the living environment,and promote the sustainable development of water environment.The main material of the sludge was taken as the main raw material in this paper,the main factors and the optimum technological conditions for the calcination of the ceramsite were determined.The process reference and technical support are provided for the development of ceramsite.The effects of the dosage of ceramsite,the reaction time,the initial phosphorus concentration,the pH and the temperature on the phosphorus adsorption were studied.The kinetic equation was used to linearly fit the kinetic equation and the isothermal adsorption model.The growth situation on the surface of the sludge of denitrification strains XP-1,CL-1,CL-3 and activated sludge were studied.In addition,the experiment was carried out to study the effect of HRT and the height of the filler layer on the actual adsorption of the ceramsite,and provide the basis for the application of ceramsite in water treatment.The main conclusions in this paper are as follows:(1)The ceramsite prepared in this paper is made from the sludge of Jinan Yuqing Waterworks as the main raw material,the content of sludge is 75%-80%and the calcination time is 1150?.The calcination time is 8-10 minutes.The drying conditions were 105? for 2 hours.Preheat conditions:300-400 ?,20-30 minutes.The optimum control conditions for stabilizing the ball were determined by the exploration of the pelletizing stage.The feeding time interval was 15 minutes to ensure that the powder was fully adhered,the speed was controlled to 30-40 r/min,the raw material and the binder are alternately added.(2)Through the performance test of ceramsite,the average size is 6?8mm,the specific surface area is 4.55?4.85 m2/g,the porosity is 48%-52%,and the performance indexes of the finished product can reach National standard "light aggregate and its test method"(GB/T17431.1-1998)standard requirements.The ceramic surface is rough and has a rich microporous structure with a large pore gap(1-5 ?m),which has strong adsorption capacity,and meets the requirements of sewage treatment.(3)By examining the effect of different reaction conditions on the phosphorus absorbsion performance,it can be seen that the adsorption capacity decreases with the increase of the dosage of the ceramsite.The adsorption capacity and the phosphorus removal rate increased gradually with the increase of the reaction time,and the adsorption process was the highest at the time of 6-8d.And the adsorption capacity increases gradually with the increase of the initial phosphorus concentration.When the initial phosphorus concentration is 30 mg/L,the adsorption capacity is up to 2.2 mg/g,and the removal rate is up to 91.2%.The adsorption capacity decreases with the decrease of the pH value of the solution.The pH value of the solution is neutral which is favorable for the adsorption of phosphorus and the removal of phosphorus.(4)When the HRT is 42 h and the packing height is 80 cm,the three indexes of effluent can meet the requirements of Grade A of the Standard for Pollutant Discharge in Urban Wastewater Treatment Plant(GB18918-2002).The HRT of TP is shortest to 24 h,and the COD and TP increase with the increase of HRT,and the removal rate increases first and then stabilizes.The effluent TN decreases slowly with the increase of HRT.COD removal efficiency in the near-water end is high;TN is high in the aerobic stage;the removal of TP is mainly achieved by the adsorption of the filler.(5)Using sludge to produce ceramsite to deal with sewage,can make the sludge harmless,it is conducive to the protection of land resources,construction of investment and operating costs,etc.It is a kind of technically and economically sludge treatment measures,which is in line with the requirements of the development of human and natural harmony.It is conducive to promoting the construction of benign ecological environment and has significant social,environmental and economic benefits.