Heavy Metals Biosorption from Aqueous Solution by Endophytic Drechslera hawaiiensis of Morus alba L. Derived from Heavy Metals Habitats

Abstract

The ability of dead cells of endophytic Drechslera hawaiiensis of Morus alba L. grown in heavy metals habitats for bioremoval of cadmium (Cd2+), copper (Cu2+), and lead (Pb2+) in aqueous solution was evaluated under different conditions. Whereas the highest extent of Cd2+ and Cu2+ removal and uptake occurred at pH 8 as well as Pb2+ occurred at neutral pH (6–7) after equilibrium time 10 min. Initial concentration 30 mg/L of Cd2+ for 10 min contact time and 50 to 90 mg/L of Pb2+ and Cu2+ supported the highest biosorption after optimal contact time of 30 min achieved with biomass dose equal to 5 mg of dried died biomass of D. hawaiiensis. The maximum removal of Cd2+, Cu2+, and Pb2+ equal to 100%, 100%, and 99.6% with uptake capacity estimated to be 0.28, 2.33, and 9.63 mg/g from real industrial wastewater, respectively were achieved within 3 hr contact time at pH 7.0, 7.0, and 6.0, respectively by using the dead biomass of D. hawaiiensis compared to 94.7%, 98%, and 99.26% removal with uptake equal to 0.264, 2.3, and 9.58 mg/g of Cd2+, Cu2+, and Pb2+, respectively with the living cells of the strain under the same conditions. The biosorbent was analyzed by Fourier Transformer Infrared Spectroscopy (FT-IR) analysis to identify the various functional groups contributing in the sorption process. From FT-IR spectra analysis, hydroxyl and amides were the major functional groups contributed in biosorption process. It was concluded that endophytic D. hawaiiensis biomass can be used potentially as biosorbent for removing Cd2+, Cu2+, and Pb2+ in aqueous solutions.

Molecular Identification and Nickel Biosorption with the Dead Biomass of Some Metal Tolerant Fungi

“…These results concur with the results of Shantha and Poonkothai who mentioned that biosorption is analogous to an ion exchange process and thus, pH of solution effects the nature of biomass binding sites and metal solubility and corroborative Rhizopus species to absorb the Ni 2+ over a extensive range of pH but the maximum uptake of Ni 2+ was found to occur at pH 6 [19]. The decrease in removal of Ni 2+ above pH 6 is because of the creation of Ni(OH) 2 . Effect of incubation time on Ni 2+ removal by both strains under study was in line with those obtained by Shantha and Poonkothai on Ni 2+ removal by Rhizopus species in which the degree of Ni 2+ uptake from the effluent by Rhizopus species exhibited a gradual increase with increasing incubation time to a point [19].…”

“…On the other side, A. terreus AHM21696 at 50 ppm Ni 2+ was totally removed after treatment for 24 h and at 100 ppm Ni 2+ was reduced by 99.65 and 100 after 2 and 4 h of treatments, respectively but 100 % Ni 2+ removal was observed at Ni 2+ concentrations of 150 ppm and 200 ppm (Table 4). Greater premier concentration affords improved leading impose to overcome all mass transmit tolerance of metal ions between the aqueous and solid phase, resulting in greater probability of collision between metal ions and sorbents [1,2]. In agreement with our results Shantha and Poonkothai suggested that the effectiveness of Ni 2+ uptake by Rhizopus species was evaluated after 7 days of fungal species inoculation in graded concentrations (25%, 50%, 75% and 100%) of the Ni 2+ electroplating effluent [19].…”

“…Maximal metal uptake values of Ni 2+ were reached in a culture medium containing 100% of effluent stream enhanced with 1% of glucose, after 6 days of incubation [5]. El-Gendy et al, mentioned that under improved conditions minor reduction in heavy metal ions observed in sorption potential from industrial effluents than from synthetic solutions could be because of different impurities existent in electroplating industrial effluents in the form of anions i.e., SO 4 2− , NO 3 − and Cl − that may contend for binding sites on the fungal cell walls and then decrease uptake of metallic ions from industrial wastewater by fungal strain [2].…”

“…The fungal strains may well suit this goal than other microorganisms; due to their great resistance toward most of heavy metals, wall binding ability and intracellular metals uptake abilities. Efficiency of biosorption response is improved by environmental conditions such as temperature, pH, ionic strength of the media and so on [2].…”

“…These heavy metals at elevated concentrations in the environment specifically in different water resources is of main concern in respect of their extremely toxicity to biological systems, bioaccumulation in them, non-environmental decomposable and menace to human, animal and plant life [1,2].…”