Method for preparing modified bentonite flocculating agent

The invention relates to a method for preparing natural mineral modified bentonite flocculating agent. A method for preparing the modified bentonite flocculating agent is characterized by comprising the following steps: firstly, preparing ferrous sulfate solution, secondly, preparing sodium bentonite suspension, thirdly, weighing ferrous sulfate solution and sodium bentonite suspension according to mass ratio between ferrous sulfate and sodium bentonite=1:0.08-1:140, dropping the ferrous sulfate solution into the sodium bentonite suspension, obtaining the solution, fourthly, filtering solution, removing filtrate, collecting solid materials in the solution, drying the solid materials under 50 to 400DEG C, disintegrating, obtaining disintegrated solid, fifthly, placing disintegrated solid into a micro-wave oven, radiating with micro wave for 0.5 to 60min under the power of 100 to 800W, and preparing the modified bentonite flocculating agent. The modified bentonite flocculating agent of the invention has high removal rate to suspended substances and total phosphorus in polluted water, and the removal rate reaches higher than 80%. The preparation technique of the invention is simple.