Vermiculite In The Sewage Treatment Process Applied Research

These years, the appliance of cheapness and high effect fillings to wastewater treatment has been investigated a lot. Vermiculite is one of soil minerals, and possesses better adsorption and ion exchange capacity for its sandwich structure, so exhibit wider application prospect in domestic sewage treatment. This paper study the possibility of vermiculite's appliance to crafts, and reach the practice reactor applying. The test results were manifested as follows:(1) During theory research, the effect of time, coexisting cations on the absorption of ammonia-nitrogen onto the vermiculite were studied, while the effects of vermiculite amount and particle size were discussed respectively. The tests show that the rate of vermiculite absorb ammonia-nitrogen is fast, and the adsorption' amount of ammonia-nitrogen in 30min may reach 60% compared with the amount in balance; coexisting cations have rather big impact on the adsorptive action, the sequence is as follows: Mg2+ > Ca2+ > K+ > Na+; by analysis, when apply to craft, the suitable solid/liquid is l:100(g/mL) and small particle size are better than big.(2) The characteristics of contaminated material removal were investment on vermiculite-SBR and SBR. The experimental results indicated that the vermiculite filling can accumulate nitrifiers, and by the nitrifiers' transformation, vermiculites accomplish the performance of adsorption. Compared with common SBR, vermiculite-SBR can increase NH4+-N removal efficiency by more than 20~30%. Nitrifiers may grow in the surface of vermiculites, though the grow rate of nitrifiers is slow , it can accumulate in the reactors. As the filling moves, the reactor has enhance the ability to transfer the materials and oxygen, and so CODCr removal efficiency increase by more than 5%.(3) Among many factors that impact system .temperature has little effect on the removal of CODCr, Compared with common SBR, vermiculite-SBR has better capacity of resisting the low temperature; when temperature is suitable, pH is an important factor that constraint the rate of nitrification. By regulating the pH during the process of treatment, the system may reach hige NH4+-N removal efficiency. When other factors are finable, 15L/h is the suitable amount of aeration.By analysis, the excessive aeration amount will destroy the capacity of sludge, and so decrease the removal efficiency of CODCr,and the 15L/h aeration amount is enouge for the demand of nitrification.(4) The vermiculite apply to the system of intensified bio-flocculation and adsorption primary treatment technology was also study in this paper. Compared with normal treatment system, vermiculite system can not increase CODCr removal efficiency, but can increase greatly NH4+-N removal efficiency by more than 30% The suitable adsorption time of activated sludge removal CODCr by adsorption and the time of renew the activated sludge were studied respectively.This paper put forward innovatively to add vermiculite to SBR and the system of intensified bio-flocculation and adsorption primary treatment, and compared with common system, draw the conclusion that applying the vermiculite fillings to treatment systems could increase the capacity of system removal contaminating materials.