| Odors emerged from garbage compressing station do great harm to human healthand cause heavy air pollution, however, are hard to control, especially forlow-concentration and the complex of different pollutants. So an effective controlapproach is urgent. Comparing with the chemical methods or physicalmethods,biological methods are simple,cost-effictive,environment friendly with lowoperation costs and without secondary pollution. It becomes the mainstream researchand application methods to the odor treatment.Based on the investigation and analysis of odor from garbage compressing station,we selected hydrogen sulfide, ammonia, VOCs and odor concentration as the targetpollutants. A biotrickling filter which was packed with plastic striplike material,elasticity threadlike material and sponges was designed as the biofilm carryers toremove odor from garbage compressing station. After improving the structure of thebiotrickling filter, the odors elimination efficiency and microbial growthcharacteristics of the biotrickling filter under different conditions were investigated.The effect of nutrients supplied on elimination efficiency and biomass,microorganism activity was researched.The information provided can be able toapplied to improve the industrialized application of biotrickling filter. Results of theexperiment were achieved as follows:1. By examined the clearing efficiency of H2S, NH3 in each part of the reactorwhen non-nutrient liquid was applied and liquid was not recirculation. The resultsshown that the major function of pre-treatment phase is to remove the particulatedust matter.The clearing efficiency of the NH3 was 25% and had not clearingefficiency of H2S in the pre-treatment phase.The average of biofilm thickness was87.5μm～110μm . Microorganism activity was 1.5～4.3 TF/ g.h, the rate ofammonium oxidation was 12～21mg/g.d,, the nitrafication rate was 8～16mg/g.d.Theelimination efficiency of the NH3 was 78% and H2S was 100% in the whole reaction.The results shown most of the pollutants were removed by the main of thebiotrickling filter.2. Under the conditions which the inflow contained NH3 concentration at0.4mg/m3～1.2mg/m3 and H2S at 0.01～0.03 mg/m3, the clearing efficiency of theNH3 was 75% and H2S was 100%; When nutrient liquid recirculation was applied, the inflow concentration of NH3 concentration from 0.8mg/m3 to 1.5mg/m3, H2S from0.01 mg/m3 to 0.02 mg/m3 and the outflow concentrations of NH3 concentration about0.01mg/m3～0.03 mg/m3 ,H2S less than 0.005 mg/m3 were monitored. Theelimination efficiency of the NH3 was up to 90% and H2S was 100%.3. By applying nutrients recirculation the biomass increased 10% andmicroorganism activity increased 30%～40%, nitrafication rate increased 35%～40%,biofilm thickness increased 10%～20%, an increase of the elimination efficiency fromη=75% toη=90%. The effect of the addition of nutrient is mainly on the activity ofbiofilm.Nitrobacteria grown slowly. The high elimination efficiency of odorsdepended on the high microorganism activity.The results shown that plastic striplikematerial was the best carrier on which microorganism quantity and activity were thehighest.4. GC—MS was used to detect the odors emerged from garbage compressingStation .The major components detected were H2S, NH3, BTEX and VOCs. Comparethe elimination efficiency with biofilter which had achieved Industry scale, deal withthe kind of odors which contain very few microbe available nutrients, the addition ofnutrients to improve bofilm quantity and activity is necessary. In order to improvemicrobial cell binding and biofilm developing on the plastic surface, pretreatment forthe surface of the packing material is needed.
|
PDF Full Text Request