Distribution Of Heavy Metals In Contaminated Sediments, Plant, Acrida Cinerea And Treatment Of Polluted Sediment By Activated Carbon

It is well-known that heavy metal pollution has reached to a promising toxiclevel due to consequences of anthropogenic activities and industrialization. Eventhough some heavy metals are essential elements for a wide range of organisms andplay structural roles in many proteins, excess in sediment has caused detrimentaleffects damaging plants, animal and human health. Heavy metals such as cadmium,chromium, lead, etc. have been classified as carcinogenic to humans and wildlife byInternational Agency for Research on Cancer. Heavy metals not only affect plantgrowth and productivity but also enter the food chain through water and contaminatedplant products, as the plants easily become biomagnified in these organisms.The shore sediment in Zhuzhou section of the Xiang River in China wascontaminated with significant heavy metals by industrial wastewater from ZhuzhouSmelter, Zhuzhou Chemical Industry Plant, Zhuzhou Electricity Plant, et al. Industrialactivity has resulted in significant heavy metal pollution, with the consequence thatheavy metal concentrations in water and locally grown vegetables and crops greatlyexceed accepted standards and thus threaten the health of human beings. Recently,public concern over heavy metal soils and their bioaccumulation in living beings hasbeen growing. However, few metal-tolerant and metal hyperaccumulator plants in thiscontaminated area have been reported. The grasshopper Acrida cinerea was chosenfor this study because it is feed on various weeds. Soil contaminants are accumulatedby terrestrial receptors through their diet. A survey of bioaccumulation andtranslocation related to heavy metal, in this polluted area, is important to assessecological risk of heavy metals to plants, insects, and human and provide asignificative basis and foundation.The concentrations of Zn, Pb, Cu and Cd in plants, sediments, and grasshoppersfrom the shore of the junction between the Xiang River and the Xiawan River of theQingshuitang district in Zhuzhou city were determined using FAAS. Theconcentrations of Zn in sediment collected from the sites varied from423to1992mg·kg-1. Total Pb and Cu concentrations of the five soil sample sites ranged from165to390and76to147mg·kg-1, respectively. Total concentrations of Cd in soils rangedfrom14to31mg·kg-1. Considering Translocation Factor (TF) and BioaccumulationFactor (BAF), Rumex crispus (Polygonaceae), Rumex dentatus (Polygonaceae) and Lagopsis Supina (Labiatae) could be potentially useful for phytostabilization ofmetals. R. crispus can be considered potentially useful for phytoextraction of Cd. Inlight of the biomagnification factors, grasshoppers are deconcentrators for Pb and Cd,microconcentrators for Zn and macroconcentrators for Cu to the plants, respectively.To the our knowledge, the present study is the first report on Zn, Pb, Cu and Cdaccumulation in R. crispus and L. supina, providing a pioneer contribution to the verysmall volume of data available on the potential use of native plant species fromcontaminated sediments in phytostabilization and phytoremediation technologies.The concentrations of Zn2+, Pb2+, Cu2+and As3+in porewater of sediments weredetermined using ICP-AES before and after the adsorption of activated carbon.200μm-300μm activated carbon has good effect in adsorbing Cu2+and the removal rate is100%after5days. It has better effect in adsorbing Pb2+and the removal rate is over88%after8days. The best time in adsorbing Cu2+and Pb2+is6days. It has mediumeffect in adsorbing As3+and the removal rate is77%after8days. It has bad effect inadsorbing Zn2+and the removal rate is below50%.