Pilot test of remediation of hexavalent chromium from soil by reducing bacteria strain Staphylococcus sp.
To investigate the application potential of microbial remediation in engineering,a pilot test of remediation of hexavalent chromium from the soil by reducing bacteria was studied.The polluted soil sample was collected from a bankrupt electroplate factory.After consecutive cultivation,a bacteria strain that could reduce hexavalent chromium was isolated.This strain was identified as Staphylococcus sp.through 16S rRNA sequencing.The influence of different factors on the remediation efficiency of Staphylococcus sp.was analyzed,including initial pollutant mass concentration,pH,and temperature.Staphylococcus sp.could survive in 200 mg/L hexavalent chromium solution during the experiment.When pH was 7 and temperature ranged from 25 ℃ to 35 ℃,the reduction rate of hexavalent chromium was highest.While the initial pollutant mass concentration in water was lower than 100 mg/L,Staphylococcus sp.could reduce all of the hexavalent chromium for 12 days.Under the condition that the initial pollutant mass ratio was 98.00 mg/kg,the water-soil ratio was 2∶1,and LB medium was added.Staphylococcus sp.could reduce all of the hexavalent chromium in the soil for 21 days.In the pilot test,200 kg of polluted soil was used to evaluate the remediation efficiency.The water-soil ratio was also adjusted to 2∶1,and the LB medium was added periodically.The initial mass ratio of hexavalent chromium in soil was 65.42 mg/kg,and Staphylococcus sp.reduced 92.59％of hexavalent chromium in 6 days.After that,the mass ratio fluctuated between 2.97 mg/kg and 10.85 mg/kg.These might be influenced by the heterogeneous distribution of hexavalent chromium in soil with large amounts.Besides,other bacteria strains in the soil could also impact the remediation efficiency of Staphylococcus sp.The results indicate that the functional bacteria strain Staphylococcus sp.isolated from the polluted site has potential application in remediation engineering.The relevant parameters used in the pilot test can provide technical support in future engineering.
environmental engineeringreducing bacteriahexavalent chromiumsoil remediationpilot test
NETL
NSTL
万方数据
维普
