Study On The Performance And Microbial Ecology Of Biotrickling-filter For Odor Removal

Biological trickling filter deodorant technology has much Advantages, such as cost-effictive and without secondary pollution, but the operating conditions such as inlet concentration, pH value, packing material, temperature, as well as the microbial community structures will affect the biological trickling filter deodorizing efficiency. Using biological trickling filter for hydrogen sulfide(H2S) waste gas removal will produce sulfuric acid so that the packing environmental pH would decreased, resulting in microbial community structure change of the biological trickling filter.Field test for biological trickling filter is a useful way to provide adequate data for the design and operation of a full-scale system. In this study,two laboratory scale biotrickling filter (bed volume is15L and empty bed residece time is10s) and two pilot scale biotrickling filter (bed volume is650L and empty bed residece time is25s were set up to investigation the removal capabilities,under the concentration from1-640mg m-3H2S. The removal efficiency of H2S in the start-up period,inlet concentration fluctuations and stable stages and at low temperature of two laboratory scale biotrickling filters(named as BTFp filled with polyurethane foam (PU) and BTFcfilled with ceramic granule), were studied. In order to reduce the running costs of the biological trickling filter, two pilot scale biotrickling filters(named as BTF1and BTF2), filled with ceramic granule, were employed to verify whether the effluentfrom secondary sediment tank of the wastewater treatment plant could be used as nutrient for bio filtration treatment of H2S-containing airstream.Using the polymerase chain reaction (PCR) amplified16S rDNA V6variable region, combined with denaturing gradient gel electrophoresis (DGGE) the microbial community structure at different spatial and temporal were researched. Phylogenetic of dominant microorganisms were analyzed by excising gel and cloned into T vector and sequencing. Results of the experiment were achieved as follows:1. In start-up period the data showed that H2S removal efficiency of BTFc was maintained at above80%, while H2S removal efficiency of BTFp reach80%after6days. Both biotrickling filters could efficiently removal the H2S when the inlet concentration was lower than200mg m-3. The maximum removal capacities for BTFp was80.6g m-3h-1(inlet loading rate81.7g m-3h-1), and for BTFc was77.2g m-3h-1(inlet loading rate79.8g m-1), respectively. The performance of both BTFs was severely affected when temperature dropped to lower than14℃. The results showed that use secondary sediment tank effluent as the nutrient liquid, BTF1and BTF2only suitable for handling the H2S concentration less than of10mg m-3.2. PCR-DGGE analysis demonstrated that BTFc (spray liquid was made from tap water and inorganic salts) operating in early period the microbial community structure diversity is higher than the late period, but BTF1and BTF2microbial community structure diversity in start up period is lower than the late period. The structural diversity of microbial communities on the upper packing was higher than those from the lower location. The predominant bacteria have highly similarity with Acidithiobacillus thioocidans ATCC19377by sequencing Verified which are acidophilic bacteria and have highly relative abundance in the lower location.Volatile organic compounds (VOCs) waste gas emitted from paint manufacture plant. In this study, a pilot-scale biological trickling filter (BTFV), inoculated with laboratory accumulated microbial consortium, was set up to remove the organic waste gas from a paint manufacturing plant packaging workshop. Polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) technologies were used to reserch the microbial community structure at different spatial and temporal. The results showed that the major pollutants in organic waste were toluene, ethylbenzene, mixed xylene (m/p-xylene, o-xylene), and the maximum removal rate were88.8%,83.7%,86.3%, respectively. DGGE analysis demonstrated that the structural diversity of microbial communities on the lower part of the filter higher than those from the upper part of the filter. BTFV microbial community structure diversity in early operation period is higher than the late period.