Study On Heavy Metals Cadmium And Lead Accumulation By Macro Fungus

For the past few years,with the acceleration of industrialization progress,plenty of heavy metals enters into our natural environment by means of many kinds of approaches and forms with humans industrial acctivities.As a result,it brings about serious environmental pollution problems of heavy metal.Since the seventies of last century,some reseachers began to discover that many kinds of macro fungus fruiting body had well ability of accumulation for heavy metals,especially which grew neighbouring pollution source of heavy metals.Compared with some inventional treatments,such as physical method,chemical method and phytoremediation technology,treating heavy metal pollution with macro fungus has obvious superiority.Starting the study on heavy metal accumulation by macro fungus has important pratical significance for ecological remediation of heavy metal pollution.In this work,30 kinds of macro fungi strains was alternative and they were inculated on the culture medium which contained lead and cadmium to enhance their tolerance of heavy metals.At last,Ganoderma sinensis and Oyster mushroom were chosen for the study on the removal of cadmium and anthracene from aqueous solutions and the study on the accumulation of lead and cadmium with bag cultivation respectively.The results indicated that Ganoderma sinensis had the function of accumulation for cadmium and degradation for anthracene.However,it could accumulate cadmium and degade anthracene simultaneously.When there were 10 mg/L cadmium and 10 mg/L anthracene in the medium simultaneously,the removal rate of them were 22.66% and 22.19% respectively.The accumulation for cadmium was closely related to metallothionein in the mycelium.Laccase and its enzyme activities played an important role for anthracene degradation of the strain.Moreover,bran could promote laccase enzyme activities of the strain obviously,while cadmium could inhibit laccase enzyme activities.And the inhibition of cadmium was much powerful than the promotion of bran for laccase enzyme activities.The accumulation abilities for lead and cadmium of oyster mushroom were investigated with bag cultivation.The result indicated that lead and cadmium had inhibition for Oyster mushroom fruiting body biomass.Oyster mushroom fruiting body biomass was decreased with the increasing of their concentration in composts.Furthermore,when the increasing of their concentration in composts increased,Oyster mushroom fruiting body heavy metal concentration also increased,but their accumulation coefficient of Oyster mushroom fruiting body decreased.