摘要：Twenty samples of polluted water were collected from Damietta's canals and drainages located near the industrial area of New Damietta. Initial concentrations of heavy metals including (zinc, copper and lead) in the polluted water were determined. Fourty–five fungal species were isolated . Mucor racemosus, Aspergillus flavus, A. niger, A. fumigatus, Trichoderma koningi and Rhizopus oryzae were isolated frequently. On the basis of its frequency, Mucor racemosus was chosen for biosorption studies. Free and immobilized biomass of Mucor racemosus sequestered ions in this decreasing sequence Cu > Zn > Pb. The effects of biomass concentration, pH and time of contact were investigated. The level of ion uptake rose with increasing biomass till 200 mg and then decreased with increasing biomass. The maximum uptake for Cu (60.13 mg/g), Zn (57.67 mg/g) and Pb (21.97 mg/g) respectively occurred at 200 mg/l biomass. The uptake rose with increasing pH up to 5 in the case of Zn and Cu and 4 in the case of Pb. Maximum uptake for all metals was achieved after 15 minutes. Ion uptake followed the Langmuir adsorption model, permitting the calculation of maximum uptake and affinity coefficients. Treatment of Mucor racemosus biomass with 0.1 M NaOH at 120°C for 6 h improved biosorbent capacity, as did immobilization with alginate. Immobilized biomass could be regenerated readily with treatment with dilute HCl. The biomass-alginate complex efficiently removed Zn, Cu and Pb from polluted water samples. Therefore, Mucor racemosus could be employed either in free or immobilized form as a biosorbent of metal ions in waste water
关键词：alginate – alkali treatment – biosorption – copper – free and immobilized biomass – lead – zinc
