Summary: | 碩士 === 國立屏東技術學院 === 環境工程技術研究所 === 85 === The objective of this study is to develop an upflow
biofilter in combination with a leaching system treating
groundwater and soil contaminated with petroleum hydrocarbons
simultaneously, and enhancing the efficiency of in situ
bioremediation. In the preliminary studies, results tested by
respirometer showed over 80% of 104mg/L BTEX(Benzene, Toluene,
Ethylbenzene, and Xylene)was biodegraded in 142 hours at 20C
under aerobic conditions. Under the same temperature, over 98%
of a solution containing 12mg/L BTEX was biodegraded in 169
hours with the addition of 50mg/L H2O2. An abiotic test showed
that 11mg/L of BTEX was not transformed at all by chemical
reaction with the addition of 333mg/L H2O2 under 20C and 100rpm
shaking for 36 hours. In this
study, a reducing agent, Na2SO3 was used to help maintain the
DO<0.2mg/L for anaerobic conditions. In an experiment to test if
the addition of a 700mg/L of Na2SO3 would have impact upon the
microorganisms, it was found that over 98% of a 10mg/L BTEX was
degraded under 20C for 15 days anaerobically, with or without
adding 700mg/L Na2SO3. The results of laboratory-scaled upflow
biofilter system experiments evidenced that, over 98% of a
solution containing 13mg/L BTEX was biodegraded with HRT(
Hydraic Retention Time)=1 hour and adding of H2O2=33mg/L in 240
minutes. It was also found that the efficiency was maintainable
in a lower HRT of 0.5 hour.
Furthermore, the soil leaching experiment was tested with three
different leachates(from distilled water, effluent from an
aerobic upflow biofilter , and effluent from an anaerobic upflow
biofilter , respectively). The calculated result of mass balance
showed that it would take only about 65 days to remedy soil
contaminated with BTEX (4000mg/kg dry soil) by leaching with
effluent from the aerobic upflow biofilter. With the results
showed from these studies, feasibility of developing an upflow
biofilter system treating groundwater and soil contaminated with
petroleum hydrocarbons simultaneously was demonstrated.
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