| With the river dredging work carried out in all parts of the country,the sediment disposal problem has become a common problem of each city.In this study,the phosphorus removal ceramsite made from the river sediment,which is one of the direction of sediment utilization.The optimum conditions for the preparation of the phosphorus removal ceramsite is determined by orthogonal experiment.The characteristics of phosphorus removal in simulated Phosphorus Wastewater and the efficiency of wastewater treatment in biological aerated filter are invested.the feasibility of sewage treatment is demonstrated.Firstly,phosphorus removal rate are used as evaluation indexes.The optimal technique conditions and batch formula for production of the phosphorus removal ceramsite is determined throuth orthogonal experiment,namely sediment:aquatic plant residue:coal:cement = 10:1:1:2,sintering temperature 1060?,and holding temperature 15 min.Its phosphate removal rate is 96.15%,porosity is 61.05%,hydrochloric acid soluble rate is 1.88%,water absorption rate is 40.25%,crushing rate and wear rate is 2.34%,mud content is 0.88%,the apparent density is 510 kg·m-3 and the bulk density is 1309 kg·m-3.At the same time,the effect of pore forming agent,cement,sintering temperature and holding temperature to the characters of phosphorus removal ceramsite,which are phosphate removal rate,prosity,hydrochloric acid soluble rate,water absorption rate,crushing rate and wear rate,mud content,apparent density and bulk density are studied.Secondly,the adsorption characteristics of the phosphorus removal ceramsite are studied with simulated wastewater.The results showed that the optimum dosage of phosphorus removal ceramsite is 3 g,6 g,respectively,when the initial phosphorus concentration is 2 mg/L and 10 mg/L;the adsorption behavior of phosphorus removal ceramsite is in accordance with Langmuir equation and Quasi-second order kinetic equation,the maximum adsorption capacity increased with the increase of temperature,and for the temperature 10?,20?,30?,the maximum adsorption capacity are 0.526 mg/g,0.605 mg/g,0.655 mg/g;The optimum pH of removal rate is 6,and with the increase of acidity and alkalinity,the removal rate of phosphate gradually decreases.pH between 4 to 8,the initial concentration of phosphorus Solution for 2 mg/L,10 mg/L respectively with 3 g ceramic and 6 g phosphorus removal ceramic,the phosphorus concentration of solution is lower than 0.5 mol/L after 24 h,pH is 3 or 10,the phosphorus concentration in solution is less than 1 mol/L;Desorption experiments show that phosphorus removal ceramsite are almost unburned in distilled water and desorbed in the strong acid and alkali.The effect of hydrochloric acid on the phosphorus desorption of the phosphorus removal is much better than that of sodium hydroxide,the higher the concentration of hydrochloric acid,the faster the desorption rate.0.3 mol/L hydrochloric acid can make the desorbed phosphorus concentration reached 42 mol/L after 29 h,which is conducive to recovery of phosphorus.Finally,biological aearted filters with biofilm midia of the phosphorus removal ceramsite and commercial ceramsite for comparison.The treatment efficiency of phosphorus removal ceramsite is investigated from two aspects of start-up stage and operation stage.The results show that phosphate removal ceramsite is easier to be hung than commercial ceramsite,the removal efficiency of COD,NH3-N and TP of the phosphorus removal ceramsite is higher than that of commercial ceramsite,and the influence of influent flow rate on the phosphorus removal of phosphorus removal ceramsite is less than that of commercial ceramsite,which is fully demonstrates the feasibility of phosphorus removal ceramsite used in biological aerated filter. |
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