Research On The Preparation Of Ceramsite From Papermaking Sludge And Its Adsorption Properties For Cu²⁺,Pb²⁺and PO₄^3-in Sewage

Water pollution always has attracted much attention.Among them,the treatment of heavy metal impurities and eutrophic ions has always been key issue in water treatment.At the same time,papermaking sludge,as a solid waste generated during water treatment,has the characteristics of high organic content,complex microorganisms and high moisture content.Its main treatment methods are sanitary landfills,incineration,and expanded use.If can't be properly handled,it will cause secondary pollution.In recent years,papermaking sludge,river sediment,etc.have been used as raw materials,and the research on the preparation of filter ceramsite has gradually increased.The sludge ceramsite can make full use of sludge,but the amount if ceramsite sludge with sludge as raw material is generally not high.In this paper,sludge is used as raw material to prepare filter ceramsite.The modification conditions of sludge ceramsite and the effect of adsorption on heavy metal ions and the removal effect of enriched phosphorus ions are discussed.Explore its adsorption mechanism.The main content and results of this paper are as follows:(1)Using papermaking sludge,bentonite,calcium carbonate,sodium silicate as raw materials,supplemented with a small amount of iron powder,and using water as a solvent,the manual ball forming method is used to control the volume of ceramists<5mm.get Filtered ceramsite(TL530)made by sintering method.Through orthogonal experiments,the best preparation process for obtaining TL530 is papermaking sludge:Bentonite:Calcium carbonate:Sodium silicate=5:3:1:1,Raise to 450°C at a heating rate of 15°C/min for preheating for 25min,sinter at 1000°C at a rate of 10°C/min for 20min,and then cool naturally.The ratio obtained is 11.43m2·g-1,The sludge filter ceramsite with a strength of90N.The heavy metal precipitation rate is in line with national standards.(2)Modified TL530 with 2.5mol/L Na OH solution for 6h to obtain modified ceramsite(GTL)for Cu²⁺adsorption.With the increase of the amount of GTL added,the Cu²⁺removal rate(R)increased first,then gradually balanced,and the adsorption capacity gradually decreased,the adsorption capacity gradually decreases,and the increase of R is98.13%when the dosage is 0.25g·L^-1.The removal rate of Cu²⁺is also related to the p H value.As the p H value increases,the better the GTL's adsorption effect on Cu²⁺,the subsequent experiments try to control the p H value between 5-6.The adsorption equilibrium time is about 8h.The adsorption of Cu²⁺by GTL conforms to the Langmuir equation,indicating that the adsorption is single-layer adsorption.The mechanism of GTL adsorption of Cu²⁺is mainly chemical adsorption because GTL prepared by modification with Na OH solution is rich in solid solution groups.Cu²⁺and hydroxyl can form stable complexes,which are fixed on GTL by chemical bonds.Achieve Cu²⁺removal effect.(3)Modified TL530 with 1mol·L^-1nitric acid solution for 8h can produce modified ceramsite(PBL)with a better adsorption effect on Pb²⁺.By adjusting the p H value of the simulated wastewater of Pb²⁺,we can know that the removal rate of Pb²⁺increases with the increase of p H value.The best removal effect is obtained at p H=5,and the removal correction is 96.76%.At this time,when determining the subsequent experiments,The dosage of PBL was 5g·L^-1,and the p H was controlled at 5.It is proved that when a Pb²⁺solution with a concentration of 100 mg?L^-1is selected,the concentration of ceramsite is controlled to5g·L^-1.Under the conditions of 293K and p H 5,the adsorption capacity of PBL for phosphorus ions varies with temperature.It has been proved by SEM,FTIR,XRD and other tests that lead ions first interact with other elements in TL530 through chemical action,thereby increasing the exploration of the mechanism of PBL adsorption by PBL.Combined to form a new substance,and then combined with solids by physical adsorption(electrostatic adsorption)and adsorbed on the surface of the PBL,and then stably adsorbed on the surface of the PBL,forming a large number of stable spherical particle structures on the surface.(4)The adsorption effect of PO₄^3-on TL530 was studied.Through the increase of the dosage,the PO₄^3-removal rate gradually increased and then reached an equilibrium of 97.85%.Dynamic experiments have shown that when a phosphorus solution with a concentration of 10mg?L^-1is selected,the concentration of ceramsite is controlled at 400 mg·L^-1,and the adsorption temperature of TL530 for phosphorus ions is transferred at a temperature of 293K and p H 6.Increase and increase,and the process is a quasi-second-order power through SEM,FTIR,XRD,and other tests to prove that phosphate ions are first absorbed by the surface of TL530 through physical adsorption(electrostatic adsorption),and then by chemical interaction with TL530,The other elements in the combination form a new one.In this experiment,TL530 with excellent performance for absorbing phosphate ions(with a phosphorus removal rate of 97.85%)was successfully prepared.When used for phosphorus adsorption,the minimum additional amount was 40 times the equivalent of the phosphorus solution(the maximum adsorption capacity reached 6.04 mg·g^-1).This shows that TL530can be used in areas such as sewage treatment.