The mechanism of Cd（Ⅱ） uptake by the dead biomass of macrofungus Pleurotus platypus was investigated using different chemical and instrumental techniques. Sequential removal of cell wall components of the biosorben...The mechanism of Cd（Ⅱ） uptake by the dead biomass of macrofungus Pleurotus platypus was investigated using different chemical and instrumental techniques. Sequential removal of cell wall components of the biosorbent revealed that structural polysaccharides play a predominant role in the biosorption of Cd（Ⅱ）. The adsorption kinetics fitted well with the pseudo second-order model suggested that the adsorption of Cd（Ⅱ） on P. platypus involved a chemisorption process. Transmission electron microscopy of the cadmium exposed biomass confirmed the deposition of the metal mainly in the metal loaded biosorbent confirmed the participation of-OH, - the cell wall. Fourier transform infrared spectroscopic analysis of NH and C-O-C groups in the uptake of Cd（Ⅱ）. Energy dispersive X-ray analysis of the biosorbent before and after metal uptake revealed that the main mechanism of adsorption was ion-exchange. The effectiveness of CaCl2 in the desorption of cadmium perhaps suggested the exchange of Ca^2＋ with Cd（Ⅱ）.展开更多
Anthropogenic and geogenic activities release potentially toxic trace elements （PTEs） that impact human health and the envi- ronment. Increasing environmental pollution stresses the need for environmentally friendly...Anthropogenic and geogenic activities release potentially toxic trace elements （PTEs） that impact human health and the envi- ronment. Increasing environmental pollution stresses the need for environmentally friendly remediation technologies. Physico-chemical treatments are effective, but are costly and generate secondary pollution on- or off-site. Phytoremediation is a biological treatment that provides positive results for PTE eradication with few limitations. Mycoremediation, a type of bioremediation to use macrofungi （mushrooms） for PTE extraction from polluted sites, is the best option for soil cleanup. This review highlights the scope, mechanisms, and potentials of mycoremediation. Mushrooms produce a variety of extracellular enzymes that degrade polycyclic aromatic hydro- carbons （PAHs）, polychlorinated biphenyls （PCBs）, pesticides, dyes, and petroleum hydrocarbons into simpler compounds. Cadmium （Cd）, lead （Pb）, mercury （Hg）, chromium （Cr）, copper （Cu）, zinc （Zn）, and iron （Fe） have been effectively extracted by Phellinus badius, Amanita spissa, Lactarius piperatus, Suillus grevillei, Agaricus bisporous, Trieholoma terreum, and Fomes fomentarius, re- spectively. Mycoremediation is affected by environmental and genetic factors, such as pH, substrate, mycelium age, enzyme type, and ecology. The bioaccumulation factor （BAF） can make clear the effectiveness of a mushroom for the extraction of PTEs from the substrate. Higher BAF values of Cd （4.34）, Pb （2.75）, Cu （9）, and Hg （95） have been reported for Amanita muscaria, Hypholoma fasciculare, Russula foetens, and Boletus pinophilus, respectively, demonstrating their effectiveness and suitability for mycoremediation of PTEs.展开更多
文摘The mechanism of Cd（Ⅱ） uptake by the dead biomass of macrofungus Pleurotus platypus was investigated using different chemical and instrumental techniques. Sequential removal of cell wall components of the biosorbent revealed that structural polysaccharides play a predominant role in the biosorption of Cd（Ⅱ）. The adsorption kinetics fitted well with the pseudo second-order model suggested that the adsorption of Cd（Ⅱ） on P. platypus involved a chemisorption process. Transmission electron microscopy of the cadmium exposed biomass confirmed the deposition of the metal mainly in the metal loaded biosorbent confirmed the participation of-OH, - the cell wall. Fourier transform infrared spectroscopic analysis of NH and C-O-C groups in the uptake of Cd（Ⅱ）. Energy dispersive X-ray analysis of the biosorbent before and after metal uptake revealed that the main mechanism of adsorption was ion-exchange. The effectiveness of CaCl2 in the desorption of cadmium perhaps suggested the exchange of Ca^2＋ with Cd（Ⅱ）.
文摘Anthropogenic and geogenic activities release potentially toxic trace elements （PTEs） that impact human health and the envi- ronment. Increasing environmental pollution stresses the need for environmentally friendly remediation technologies. Physico-chemical treatments are effective, but are costly and generate secondary pollution on- or off-site. Phytoremediation is a biological treatment that provides positive results for PTE eradication with few limitations. Mycoremediation, a type of bioremediation to use macrofungi （mushrooms） for PTE extraction from polluted sites, is the best option for soil cleanup. This review highlights the scope, mechanisms, and potentials of mycoremediation. Mushrooms produce a variety of extracellular enzymes that degrade polycyclic aromatic hydro- carbons （PAHs）, polychlorinated biphenyls （PCBs）, pesticides, dyes, and petroleum hydrocarbons into simpler compounds. Cadmium （Cd）, lead （Pb）, mercury （Hg）, chromium （Cr）, copper （Cu）, zinc （Zn）, and iron （Fe） have been effectively extracted by Phellinus badius, Amanita spissa, Lactarius piperatus, Suillus grevillei, Agaricus bisporous, Trieholoma terreum, and Fomes fomentarius, re- spectively. Mycoremediation is affected by environmental and genetic factors, such as pH, substrate, mycelium age, enzyme type, and ecology. The bioaccumulation factor （BAF） can make clear the effectiveness of a mushroom for the extraction of PTEs from the substrate. Higher BAF values of Cd （4.34）, Pb （2.75）, Cu （9）, and Hg （95） have been reported for Amanita muscaria, Hypholoma fasciculare, Russula foetens, and Boletus pinophilus, respectively, demonstrating their effectiveness and suitability for mycoremediation of PTEs.
