Variant Of The Yanshan Bentonite And Its Adsorption Of Phosphorus Wastewater

The primary bentonite which is from Yanshan county in Yunnan province was purified and re-modified by one-step. Using single factor and orthogonal experiment, the ethylene blue absorbed as evaluation index, optimize the one-step process conditions; The Yunnan Yanshan bentonite after purification was modified by aluminum salt to obtain Al-bentonite prepared to do deal with wastewaterincluding phosphorus. In the modified process, the removal rate of phosphorus as the evaluation index, the best modified aluminum salt was filtrated, the optimum conditions of Preparation Al-modified were obtained by orthogonal experiment method. Final the content of remaining phosphorus and aluminum as common evaluation index, the optimum adsorption conditions were obtained; then study on the adsorption mechanism using SEM, XRD et al test means. The researches showed that:1. The optimum conditions of purification and sodium modified by one-step were: bentonite dosage 40g, ratio of liquid to solid at 16:1, soaking time 24h, the addition amount of dispersant 30mL, the addition amount of sodium salt 10%, the time of sodium modified 1.5h, the temperature at 70℃, time of stirring 30min; The four physical capability were: expanding content is 93.00mL/g,colloid content is 48.9mL/g, ethylene blue absorbed is 1.356mmol/g and CEC is 3.3113mmol/g, montmorillonite content 96.2%, has reached the grade of nanometer bentonite; With step-by-step process, the less dry, a smash and a separation step, to shorten the process, saving time for modifications, but also a reduction of wastewater discharges, for energy saving and environmental protection as well.2. The purification bentonite was modified by AlCl3, Al(NO3)3, A12(SO4)3, KAl(SO4)2. The best modified aluminum salt KAl(SO4)2 has been filtrated by parallel experiment. Use the Al-bentonite which was prepared under the optimum conditions to deal with the including phosphorus wastewater, phosphorus removal rate reached 98.4 percent, the content of remaining phosphorus is smaller than 0.5mg/L, has reached the first class standard that the wastewater of our country discharges synthetically.3. The content of remaining phosphorus and aluminum as common evaluation index, through the single-factor method of Al-modified soil phosphorus adsorption conditions were optimized, at optimum conditions, after the wastewater treatment content of remaining phosphorus 0.1897mg/L, level lower than the first class standard that the wastewater of our country discharges synthetically (0.5mg/L); content of remaining aluminum 0.8372mg/L, reaching the power plant boiler water standard at 0-150 atmospher-ic pressure (2.68mg/L).4. Using SEM, XRD analysis of Al-bentonite phosphorus removal mechanism was discussed. Preliminary view is that:After Al-modified, with increased surface area of bentonite, improve the adsorption properties.