The Effects on Solubility of PCP by Sunflower (Helianthus Annuus) Root Exudates in Different Environmental Conditions

The characteristics of sunflower (Helianthus annuus) root exudates and their effects on solubility of PCP in different environmental conditions were investigated by the indoor simulation cultivating methods. The results indicated that contents of high-molecular-weight and polarity fractions were very high; the biodegradating percentage increased with time elapsed, and the biodegradating percentage reached 56.50% on the 5th day. Root exudates can enhance solubility of PCP. The effects on solubility of PCP by root exudates obtained in different conditions were different obviously. There were the greatest values in the effects of solubilization of root exudates obtained at experimental illumination times and temperatures to PCP; the effects on solubility of PCP by root exudates obtained at experimental illumination intensities and gradient of KH2PO4 nutrition were very complex; the effects of solubilization of root exudates obtained at Pb contamination to PCP increased with increasing concentration of Pb.