Study On Phosphorus Adsorption In Tail Water Of Biochemical Treatment By ZnO-ZnAl Hydrotalcite(ZZA)

In this paper, ZnO-ZnAl(ZZA) is a kind of layered double metal oxide, which has the properties of anion exchange, acid and alkali, thermal stability, memory effect and catalysis. Widely used in catalysis, adsorption, medicine, preparation of composite materials and other fields.In this paper the ZZA of X ray powder diffraction analysis(XRD), infrared spectrum analysis(FT-IR) and scanning electron microscopy analysis(SEM); a detailed study of the simulation the effect of phosphate from wastewater by adsorption ZZA; on the basis of, increase the the wastewater treatment effect of research and study.ZZA were prepared by the is the new centrifugal method preparation technology, the preparation of the ZZA powder crystal to the nanometer level, and compared with other methods of preparing class hydrotalcite less impurity, the processing effect is better, a more regular structure. ZZA adsorption of phosphate in wastewater process is divided into two stages, the former 10 h happen fast adsorption, phosphate removal rate reached 53.45%, after 10 h slow adsorption, phosphate final removal rate steady at 55.68%. The process is in accordance with the pseudo two order kinetics model. The study of ZZA adsorption of phosphate in wastewater by adsorption temperature is set to 15 DEG C and 25 DEG C and 35 DEG C, the maximum adsorption capacity were 30.54mg/g, 32.40mg/g and 33.54mg/g, so that within a certain range of temperature, with increasing adsorption temperature, ZZA maximum adsorption volume volume also increased. This is because the temperature increase of the adsorption rate, thereby increasing the adsorption capacity, show that the ZZA simulations of the adsorption reaction of phosphate in wastewater may is an endothermic reaction. The adsorption process accord with the Langmuir equation, which indicates that the adsorption process may be homogeneous monolayer chemical adsorption. Thermodynamic study of ZZA adsorption index phosphate in simulated wastewater, the adsorption process is an endothermic and entropy increase and spontaneous process. This study investigated the effects of pH, coexisted ions, adsorption time and adsorption temperature on the adsorption of ZZA phosphate from simulated wastewater.In addition, in order to make the study more practical value, increase the adsorption of the wastewater ZZA, ZZA adsorption the best dosage of phosphate in wastewater is 50mg/L, the phosphate removal rate can reach 70%, the treatment effect is better. This chapter also increased the ZZA sodium based modified bentonite, zeolite and coal cinder adsorption experiments of real wastewater. Experimental results show that ZZA adsorption effect of actual wastewater phosphate is the best. It is proved that ZZA can be used for the treatment of sewage treatment plant tail water low phosphorus, and can get a better treatment effect, has good application prospects.