The Preparation Of Microbial Immobilized Carrier From Attapulgite

Atapulgite is crystal hydrated magnesium aluminum silicate with a unique chain layer structure. It is so plentiful that the quantity is above half of the world in our country. It has excellent absorptive property which attracts many scholars studying and acquiring good effects as wastewater treatment adsorbents. There are some quartzes and dolomites in attapulgite, quartz has small specific surface area and it is difficult to molding. It will influence mechanical intensity, adsorptive property and resist water property of attapulgite granules with so many quartzes.We purify the attapulgite with two methods: Mechanical mix round purification with water and ultrasonic purification with sodium silicate dispersant, and it is found that the method purification with sodium silicate dispersant is better.The experiments for preparing carrier is to put montmorillonite, sodium carbonate, aluminum chloride and manganese sulfate into purified attapulgite by dry mixed way or wet mixed way, and then to dry and to calcine etc. The influence of mixed ways, mass and proportion of additives, calcined temperature and time for attapulgite's structure and capability is analyzed by TG-DTA, XRD, TEM and FT-IR etc. The conditions for preparing the attapulgite carrier are ascertained by testing dispersed ratio and immobilized effect. It is found that the best conditions of chemical additive are these: attapulgite: montmorillonite: Na₂CO₃: AlCl₃: MnSO₄ =100:10:1.5:1:1.5, and the calcined temperature is 450℃, and the calcined time of is 1h.Complex strains are immobilized on attapulgite carriers. It is used complex methods: First they are immobilized by adsorption, second joined together with glutaraldehyde. The effect of immobilized granules is tested by measuring the weight of dry immobilized cells and the activeness, and compared with dissociative cells. It is found that the effect of immobilized cells is better than dissociative cells.