Chelate-induced Phytoremediation Of Pb Contaminated Soil With Ornamental Plants

Today, the rapid development of urbanization across the globe. Urbanization in providingefficient and economical for the city dwellers living space, but also brought a series of urbanenvironmental issues. Numerous studies abroad showed widespread contamination of urbansoils heavy metals. Heavy metals and changes will not only affect the ecological functions ofurban soils, and can harm human health through direct contact or dust. Therefore, heavy metalpollution has become a major ecological problems affecting the health of urban residents.Therefore, the purpose of this study is that this will by soil culture experiment andhydroponic experiment, different kinds and dosage of chelating agent for flowers plant repairreinforcement effect of soil lead pollution research, chelating agent with different methods, andthe timing of flowers plant repair reinforcement effect of soil lead pollution research as well asCu, Pb, Cd and Pb composite under pollution stress to study the influence of concentration oflead, flowers in order to further explore the chelating flowers plant bioremediation technologymeasures to provide a scientific basis, at the same time for purification and beautify the urbanenvironment quality, and safeguard people’s health to provide the scientific basis, promoteecological development pattern of urban greening walk with local characteristics is of greatsignificance.This study obtained the main conclusions are as follows:1.Different kinds and dosage of chelating agent for flowers plant repair reinforcement effectof soil lead pollution research shows that compared with the control without adding a chelatingagent, adding different type and concentration of chelating agent on the indexes of abovegroundand underground part of mirabilis jalapa often have no significant effect, lead to stress withstrong patience. Compared different kinds of chelating agent, plant aboveground average lead,lead, lead enrichment coefficient and transfer coefficient are processed by adding EDTA is thehighest, followed by NTA processing, and the processing of other kinds of chelating agent islow. With the increase of concentration of chelating agent, plant aboveground to leadenrichment ability gradually improve, EDTA and NTA is added when the concentration of2000mg/kg of lead were353.4and311.0mg/kg, lead enrichment coefficient of0.35and0.31respectively, lead transfer coefficient were2.08and1.32respectively. Comprehensive this studyresult shows that EDTA and NTA chelated strengthen induction effect is better than that ofseveral other53chelating agent, however, considering the potential environmental risk is bigger,EDTA practice appropriate chooses NTA as strengthening mirabilis jalapa repair of soil leadpollution chelating agent. 2.Chelating agent under different fertilization way flowers of phytoremediation of soil leadpollution research results show that compared with the control without a chelating agent,chelating agent applied to flowers plant, plant height, stem diameter and dry weight usually hadno significant effect, but plant aboveground lead and lead enrichment coefficient increasedsignificantly. Compared with the Zinnia elegans, mirabilis jalapa aboveground average lead andlead enrichment coefficient is low, and its transfer coefficient is lead to significantly higher thanthe Zinnia elegans; Mirabilis jalapa lead transfer coefficient and its aboveground lead and leadenrichment coefficient of regularity, for one hundred days, the grass its regularity is different.Compared to a week before harvest to join chelating agent processing, two weeks before harvestto join chelating agent processing plant aboveground average lead and lead enrichmentcoefficient were higher, and specific treatment effect depends on the types of flowers plant aswell as the application of frequency and the concentration ratio of chelating agent.Comprehensive this study result shows that mirabilis jalapa adopts the following chelatinginduced measures for soil lead pollution can achieve the best effect of repair: harvest in the firsttwo weeks EDTA, applying NTA again after a week, and NTA: EDTA concentration ratio is1:2.3.Cu-Pb and Cd-Pb compound pollution impact on flowers plant lead enrichmentcharacteristic research shows that：（1）Cu-Pb compound contamination under conditions Calendula in Pb concentration was50and100mg L-1aboveground lead levels are the largest, showed Calendula has a hightolerance for lead and enrichment capabilities, as well as gold the ability to lead from the rootelement of light absorbed by the chrysanthemum shoots transit stronger. Three test the leadcontent in the roots of the plants flower Pb concentration was little difference when50mg L-1,and when the Pb concentration was100mg L-1, the roots of Panax lead levels weresignificantly lower than Calendula and spider plants. For Calendula, in the Pb concentration was50and100mg L-1enrichment factor of the ground rules and the regularity of the lead content ofaboveground is basically the same. When Pb concentration was50mg L-1, with an averagetransfer coefficient Calendula treatment (0.15), followed by as spider plants (0.14), and thesmallest is Panax (0.12); while Pb concentration was100mg L-1, with an average transfercoefficient Panax treatment (0.22), followed by as calendula (0.14), and the smallest is thespider plant (0.09).（2）Under Cd-Pb combined pollution in Pb concentration was50mg L-1was on earth androots lead levels were higher than the spider plant Calendula officinalis, Calendula describedunder such conditions lead to higher enrichment capability Chlorophytum; in Pb concentration was100mg L-1, the ground lead levels higher than the spider Calendula, and the roots of thelead content is less than the calendula. Calendula and spider plants in Pb concentration was50and100mg L-1enrichment factor of the law is consistent with the lead content of regularity.When Pb concentration was50mg L-1, with an average transfer coefficient Calendula treatment(0.22), followed by as spider plants (0.13); while Pb concentration was100mg L-1, the averagedeal with spider transfer coefficient (0.30), followed by as calendula (0.16).Comprehensive results of this study shows, Cu-Pb compound pollution stress shootCalendula maximum lead content of lead has a high tolerance and enrichment capabilities.Under Cd-Pb combined pollution stress, spider plants to absorb higher concentrations of leadand enrichment strongest.In the Pb concentration was100mg L-1when applied to the groundand roots chelator NTA lead levels after treatment were significantly higher than othertreatments, indicating that the chelator NTA applied three flowers can enhance the absorptionand accumulation of lead, and the effect is significant.