| Immobilization technology since inception, develop with unprecedented speed, there into the method of embedding immobilization choicing of embedding agents and embedding condition, wrapped in microbial gel network structure with the formation of immobilized microorganisms has been widespread concern. A great deal of study results show that compared with natural materials(such as agar, Kok Loi plastic fork, alginate, etc.), the organic synthetic polymers(such as polyacrylamide for short ACAM, PVA called PVA, sclerous resin), as embedded material have high mechanical strength, good resistance to biodegradation, lower toxicity and easier immobilized manipulation, and have the advantages of low price. Especially the embedding immobilization become one of the most commonly used method, but because of the resistance PVA gel to mass transfer is great, the substrate and oxygen transfer to a certain extent are impacted, thus affecting biological activity of immobilized microorganism. So it is important significance to improve mass transfer properties of PVA gel for raising immobilization of microbial activity and the efficiency of water treatment.This paper on the basis of understanding a great deal of information as well as access to immobilized biological treatment technology to a certain extent, doing exploratory experiments for improving embedded material capabilities. Mainly start from the most widely used method of PVA-H2BO3, researching on the impact with performance of embedding immobilized microorganism gel beads by adding adsorbent powdered, activated carbon and attapulgite. This experiment by the globle properties and biological activity(COD degradation rates) as a target, by orthogonal test to study the impact on properties of PVA for small immobilized gel ball adding activated carbon and attapulgite clay, and obtain the best recipe with adding activated carbon and attapulgite. On the base of the best recipe, keep on doing early dissolution process, impacting on biodegrade properties for size of gel ball and mass transfer properties experiments and then made a comparative study. The results show:1. It explains that with the globle properties and biological activity(COD degradation rates) as a target, by orthogonal experiments immobilized microbial gel beads adding activated carbon's best recipe is A1B3C3. Immobilized microbial gel beads adding attapulgite's best recipe is A1B2C2.2. Dissolving test results show: Whether adding activated carbon or attapulgite, in water aeration conditions for about 10 days, dissolution process will be basically completed.3. From two different best formula immobilized gel beads to remove ammonia test, we can see that NH4-N removal rate of adding attapulgite are higher about 3％～20％than adding activated carbon。Both of the best recipe's NH4-N removal rate of big size(5mm) balls is higher about 5％～10％than small size(3mm) balls'. This shows adding attapulgite clay material immobilized gel balls are better bioactivity.4. From the results of ratio aerobic rate(SOUR) can be seen, attapulgite gel beads' SOUR is bigger 1～10 mgO2/mgMLVSS h than activated carbon condensate, and large size balls'SOUR is relatively bigger 2～6 mgO2/mgMLVSS h than small diameter ball' SOUR。5. By texting two different optimal prescription, blank film and immobilized biological gel film diffusion coefficient find that: blank membrane diffusion coefficient change much more than biofilm with the aeration time changes, and biofilm's COD, NH4-N, NO3-N, NO2-N diffusion coefficients decrease after first showing increasing trend analyzing the reasons may be because the early dissolution of gel membrane material carbon's interference; texting diffusion coefficient after 30 days, finding attapulgite biofilm's NO2-N, NO3-N, COD, NH4-N mass transfer coefficients were respectively higher than activated carbon biofilm about 48％, 15％, 12％, 6％. This shows nano-attapulgite is better than activated carbon for PVA gel mass transfer performance improvement.
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