Preparation Of Modified Bentonite Adsorbent And Phosphorus Removal In Addition To Chromium

In recent years, the rich nourishment caused by phosphorus almost spread over each lake, and this trend is turning worse, and it stimulates the alage in the water growing quickly, the ability of water body purification by itself will be break. Industrial sections which make chromic sewage distribute everywhere, the amount of sewage which drained off is larger, and six-price chrome has terrible toxicity, even the pimping density will take a great harm to environment and human body. Therefore, nowadays, water resource increasingly polluting, this experiment which researchs disposing of phosphoric sewage and Cr⁶⁺ sewage and productes valid adsorbent for them is necessary, meanwhile it is very urgent of this experiment.This experiment makes use of advantages of bentonite. Bentonite has specific structure, and it has rich reserves, so it has objective conditions to be a cheap and valid adsorbent, we put forward a new method to turn bentonite into valid adsorbent by using microwave heating way which make staff modify between organic and inorganic each other. Compared to traditional way, the outstanding advantage is that there is a high heat rate in heating materials, it can shorten reaction time from several hours to several minutes, and it shortens processing time of sample consumedly.The best condition in preparation process for bentonite with lanthanum as follows: the density of the sulfuric acid is 15%, soaking density of chlorinated lanthanum is 0.4%, and the pH is above 10 in the soakage, and microwave radicating power is 340 watts, radiating time is 5 minutes. In the applied experiment, the best applicable condition is as follows: the pH of the solution which is the most important is from 3 to 6, oscillation time is 60 minutes, at this time removing ratio for phosphorus has reached 99.96%, and adsorbing capacity for phosphorus is 24.99 mg/g, and surplus density for phosphorus of the solution is 0.02 mg/L, and among of all the factors.The best preparation condition for bentonite modifid lanthanum in the organic process is as follows: the water bath temperature is 60℃, and the modified density of CTMAB is 5%, microwave radiating power is 166 watts, radiating time is 6 minutes. In the applied experiment to phosphorus, the optimum pH which is the most important is from 3 to 4,oscillation time is 60 minutes, at this time removing ratio for phosphorus has reached 99.95%, and adsorbing capacity is 41.64 mg/g, and surplus density for phosphorus is 0.0262 mg/L, among of them,. After modification, adsorbing efficiency for phosphorus improved about 60%.The best preparation condition for bentonite with lanthanum and titanium in inorganic way is as follows: the density of the sulfuric acid is 15%, molar ratio between lanthanum and titanium is 6, and molal quantity is 2.53, and the pH is above 10 in the soakage. In the applied experiment, the best applicable condition for Cr⁶⁺ is as follows: the pH which is most important is from 4 to 6, oscillation time is 80 minutes, and removing ratio for Cr⁶⁺ is 87.64%, and adsorbing capacity is 4.38 mg/g, and surplus density for Cr⁶⁺ is 3.71 mg/L, among of them.The optimum preparation condition for modified bentonite with lanthanum and titanium in organic way is as follows: the water bath temperature is 60℃, and the modified density of CTMAB is 6%. In the applied experiment for Cr⁶⁺, and the optimum pH of solution which is most important is 6, radiating time is 80 minutes. At this time, removing ratio for Cr⁶⁺ has reached 90.72%, and adsorbing capacity is 6.80 mg/g, and surplus density for Cr⁶⁺ is 2.78 mg/L, among of them. After modification, adsorbing efficiency for Cr⁶⁺ improved about 30%.