Primary Study on Phytodegradation of Bisphenol A by Elodea nuttallii

In a microcosm system where Elodea nuttallii and Bisphenol A （BPA） coexist, with the help of Liquid chromatography-mass spectrometer （LC-MS） and gas chromatography-mass spectrometer （GC-MS）, the dynamics of phytodegradation of BPA with concentration 1-20 mg/L and the products of phytodegradation was studied. Antioxidation activity and phospholipids fatty acids were measured to evaluate the effects of BPA on E.nuttallii. The results showed that the half life period of phytodegradation of BPA was less than 15 days. 2-（4-hydroxypheny）-2-（3,4-o-dihydroxypheny） propane and 2, 2-bis（4-hydroxypheny） propyl alcohol were identified to be as two possible products of BPA. The peroxidase （POD） activity of E.nuttallii decreased by 50% to 100% compared with that controlled at the end of the experiment. The fatty acid methanol esters （FAMEs） changed obviously too. It showed that oxidation stress and membrane damage would be the two effcting aspects of BPA on E.nuttallii.

Effects of humic acid on phytodegradation of petroleum hydrocarbons in soil simultaneously contaminated with heavy metals

The use of humic acid （HA） to enhance the efficiency of phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel was evaluated in this study. A sample of soil was artificially contaminated with commercially available diesel fuel to an initial total petroleum hydrocarbons （TPH） concentration of 2300 mg/kg and four heavy metals with concentrations of 400 mg/kg for Pb, 200 mg/kg for Cu, 12 mg/kg for Cd, and 160 mg/kg for Ni. Three plant species, Brassica campestris, Festuca arundinacea, and Helianthus annuus, were selected for the phytodegradation experiment. Percentage degradation of TPH in the soil in a control pot supplemented with HA increased to 45% from 30% without HA. The addition of HA resulted in an increases in the removal of TPH from the soil in pots planted with B. campestris, F. arundinacea, and H. annuus, enhancing percentage degradation to 86%, 64%, and 85% from 45%, 54%, and 66%, respectively. The effect of HA was also observed in the degradation of n-alkanes within 30 days. The rates of removal of n-alkanes in soil planted with B. campestris and H. annuus were high for n-alkanes in the range of C11–C28. A dynamic increase in dehydrogenase activity was observed during the last 15 days of a 30-day experimental period in all the pots amended with HA. The enhanced biodegradation performance for TPHs observed might be due to an increase in microbial activities and bioavailable TPH in soils caused by combined effects of plants and HA. The results suggested that HA could act as an enhancing agent for phytodegradation of petroleum hydrocarbons in soil contaminated with diesel fuel and heavy metals.