Application Of Composite Materials To Microbial Degradation Of Formaldehyde Wastewater

To remove formaldehyde wastewater by microbial method, immobilized microbes method is proposed in this paper, because toxicity of formaldehyde can impact on microbes and inhibit the activity of microbes. The microbes are domesticated and embedding to improve the ability of microbial degradation of formaldehyde. There are some conclusions:Contrasting adding Na2SO3 and without adding Na2SO3 microbes’ removal ability of formaldehyde, found that the microbes of adding Na2SO3 have a high removal rate of formaldehyde. According to microbial by adding Na2SO3 growth curve, it can conclude that microbial growth by adding Na2SO3 reach a stable condition from 7 days to13 days, selecting microbes for embedding in this period.To ensure the optimal composite materials, Polyvinyl alcohol, sodium alginate, activated carbon, titanium dioxide effect on the properties of gel ball, through the single factor experiment determine its concentration range, polyvinyl alcohol mass concentration range from 8% to 11%, sodium alginate mass concentration range from 0.5% to 1.5%, the mass concentration of the active carbon range from 1% to 3%, titanium dioxide(TiO2) mass concentration range from 0.5% to 1.5%.Activated carbon as composite materials additives, through the orthogonal experiment determined optimal materials additives rate, polyvinyl alcohol mass concentration 9%, sodium alginate mass concentration 1.5%, and the activated carbon mass concentration 2%. Under the optimal conditions, mass transfer performance of gel ball by adding active carbon is 17.3%. Titanium dioxide as composite materials additives, optimal materials additives rate is determined by orthogonal experiment, polyvinyl alcohol mass concentration 10%, sodium alginate mass concentration 1%, titanium dioxide(TiO2) mass concentration 1.5%. Under the optimal conditions, mass transfer performance of gel ball by adding titanium dioxide(TiO2) is 9.5%。The experimental studies of the formaldehyde wastewater treatment by immobilized microbial show that: adding activated carbon immobilized microorganism is greater than adding TiO2 on formaldehyde removal ability; The 50% embedding microbe amount is the best in experiment; By contrasting immobilized microorganisms and free microbial of degradation formaldehyde ability, the immobilized microbes is better; Tolerance of immobilized microbial on pH is greater than free microbes. Immobilized microorganisms are less influenced by temperature than free microbes.Three characteristics of formaldehyde concentration in industrial waste water is 3000mg/L, 5000mg/L and 7000mg/L, comparing formaldehyde degradation ability of immobilized microbes and free microbes, found that removal ability of formaldehyde immobilized microbes is obviously stronger than free microbes.Compared to fixed bed and fluidized bed reactor degradation of the same concentration of formaldehyde, when the formaldehyde is fully degraded, the ability of microbial degradation of formaldehyde in fluidized bed is stronger. When the ratio of immobilized microbes amount and wastewater amount is 10:50, the removal formaldehyde ability is stronger.