| The process of urbanization and the demand for water supply is accelerating day by day,which has generated a large number of water purification sludge.If it is improper to dispose these sludge,it can cause secondary pollution.Based on the concept of sustainable development,water purification sludge with auxiliary materials can be made of ceramic to absorb phosphorus,which has turned waste into treasure to reduce the pressure on the environment.It is a win-win environment and development.According to the analysis results of the nature of water purification sludge,the bentonite,shell powder and starch were chosen as excipient to produce ceramiste,which was from the requirements of the ceramic composition about the making principle.Taking the amount of phosphorus adsorption and specific surface area as the evaluation index,the optimum ratio was obtained by orthogonal experiment,namely water purification sludge:bentonite:shell powder:starch=80:10:7:3.And the best making process was that the preheating temperature:300?,the preheating time:20min,the burning temperature:700?,the burning time:15min.At the same time,it can be seen from the orthogonal experiment that the burning temperature>the preheating time>the ratio of the raw materials>the preheating temperature>the burning time.The ceramiste made in the best making process can be in line with the standards of CJ/T 229-2008 The artificial ceramist filter to water treatment.The SEM analyses have showed that there are micropore structures of the aggregation on the surface of the good ceramiste in adsorption.The XRD analyses can be seen calcium body active ingredients of providing more adsorption sites and increasing the strength.The ceramic leaching heavy metal content is much lower than the standard of GB5085.3-2007 Hazardous waste identification criteria leaching toxicity identification.In this study,the adsorption reaction time,the initial solution concentration,the dosage of ceramsite and the pH of solution on the adsorption of phosphorus in water were investigated by using the control variable method in static experiment.The results showed that the adsorption time reached the equilibrium at 15h and the adsorption capacity increased with the increase of the initial concentration.With the increase of the dosage,the adsorption capacity decreased but the removal rate increased gradually.Under the acidic condition,the phosphorus removal effect is better.The adsorption process is in accordance with the quasi-second-order kinetics model and the Langmuir adsorption isotherm model,respectively.At 308K,the maximum adsorption capacity of water purification sludge can reach 6.881mg/g.The results of adsorption thermodynamics show that the reaction is spontaneous,endothermic,and the degree of freedom of the system on the increase.The temperature increase can improve the adsorption performance and the disorder after adsorption.The results of dynamic adsorption to removal phosphorus have showed that the penetration time and depletion time was proportional to the adsorbent bed height.With the increase of the flow rate of the phosphorus solution into the adsorption column,the breakthrough time was shorter.The R2 from Thomas and Yoon-Nelson are both above 0.95,which can describe the process of adsorption well.The rate constants(kT and kYN)are inversely proportional to the height of the packing in the column,proportional to the liquid flow rate.Through the experiments of regeneration and reuse,it is a reusable adsorption material.At the same time,the economic and environmental social benefits of the ceramsite are discussed,and the value of resource utilization is further explained.The application suggestion is put forward to improve the water quality,which not only realized the utilization of waste but provided a feasible measures. |
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