scholarly journals Bioremediation of Toxic Heavy Metals Cr (VI) from Tannery Effluent using Micro-Organisms: Biotechnological Potential

2018 ◽  
Vol 4 (01) ◽  
pp. 41-48
Author(s):  
Madhu Prakash Srivastava ◽  
Nupur Srivastava ◽  
Neeta Sharma ◽  
Yogesh Kumar Sharma

Increased industrialization and human activities have impacted on the environment through disposal waste containing heavy metals. Heavy metals pollution of agricultural soil has been mainly due to the disposal of industrial wastewater, sewage and sewage sludge to agricultural land. Conventional methods for the removal of heavy metals from aqueous solutions are not economically and environmental friendly because it has produced massive quantity of toxic chemical compounds. Naturally fungi have a large variety of extracellular proteins, organic acids and other metabolites. Fungi can adapt in any ecosystems and any environmental conditions Interest in processes involving heavy metal uptake by microorganisms has increased considerably in recent years due to the biotechnological potential of micro-organisms in removing and/or recovery of metals.

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Zuolian Cheng ◽  
Annie Lai Kuan Tan ◽  
Yong Tao ◽  
Dan Shan ◽  
Kok Eng Ting ◽  
...  

This study investigated the applicability of maghemite (γ-Fe2O3) nanoparticles for the selective removal of toxic heavy metals from electroplating wastewater. The maghemite nanoparticles of 60 nm were synthesized using a coprecipitation method and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX). Batch experiments were carried out for the removal of Pb2+ions from aqueous solutions by maghemite nanoparticles. The effects of contact time, initial concentration of Pb2+ions, solution pH, and salinity on the amount of Pb2+removed were investigated. The adsorption process was found to be highly pH dependent, which made the nanoparticles selectively adsorb this metal from wastewater. The adsorption of Pb2+reached equilibrium rapidly within 15 min and the adsorption data were well fitted with the Langmuir isotherm.


1999 ◽  
Vol 39 (6) ◽  
pp. 175-181 ◽  
Author(s):  
Abdallah Shanableh ◽  
Pushpa Ginige

The biosolids industry in Australia is evolving around the beneficial use of biosolids as a resource. Phosphorus rich biosolids from biological nutrient removal (BNR) facilities are highly desirable for land application. However, the accumulation of toxic heavy metals and industrial organic contaminants may render the biosolids unsuitable for land application. The presence of toxic heavy metals has been identified by Local Authorities in Australia as a major constraint limiting the beneficial use of biosolids. The potential of off-site contamination due to the migration of nutrients is also a major concern especially when applying biosolids to acidic agricultural land. Accordingly, the relevant environment protection and conservation agencies are involved in either developing or finalising guidelines to control the beneficial use of biosolids products. Metals bioleaching is a process achieved through bio-acidification. Bio-acidification of biosolids prior to land application can be used to dissolve and remove a significant fraction of the heavy metals content of the product. However, the process also reduces the nutrients content of the resource. Bio-acidification of Loganholme (Queensland) BNR biosolids dissolved 76% of the total phosphorus and 38% of the TKN. The heavy metals solubilisation results reached 50% for Cr, 79% for Ni, 45% for Zn, 24% for Cu, 30% for Cd, and 82% for Pb.


2002 ◽  
Vol 82 (4) ◽  
pp. 433-438 ◽  
Author(s):  
M T Morera ◽  
J. Echeverría ◽  
J. Garrido

The recycling of sewage sludge to agricultural land results in the slow accumulation of potentially toxic heavy metals in soils. A greenhouse experiment was conducted to determine the bioavailability of Cu, Ni, Pb and Zn applied to soils in urban anaerobically stabilized sewage sludge. The soils were Lithic Haplumbrept (Lh), Calcixerollic Xerochrept (Cx1 and Cx2) and Paralithic Xerorthent (Px). Sunflower plants (Helianthus annuus L) were grown in the soils following amendment with the sludge. The addition of sewage sludge markedly increased the average dry weight of the plants in the soils that had lower yields without sludge addition (Lh, Cx2, and Px). The acid pH of the Lh soil favoured the bioavailability of Zn from sewage sludge. The bioavailability of Cu was greater in the alkaline soils than in the acidic soil (Lh), which can be attributed to the high organic matter content of the Lh soil which complexes Cu and impairs its uptake by the plants. The concentration of metals in the plants increased with the sewage sludge dose. The effect of the soil type on the metal concentration in plants was greater that the effect of the dose. Key words: Soils, sewage sludge, heavy metals, bioavailability, sunflower


Author(s):  
Affonso C. Gonçalves Junior ◽  
Ana P. Meneghel ◽  
Fernanda Rubio ◽  
Leonardo Strey ◽  
Douglas C. Dragunski ◽  
...  

This study evaluated the efficacy of moringa seeds (Moringa oleifera Lam.) as an adsorbent material for removing toxic heavy metals such as cadmium, lead, and chromium from contaminated solutions. The effect of the adsorbent mass was investigated at two pH conditions (5.0 and 7.0). The optimized conditions were 0.300 g of adsorbent at pH 5.0, used for the isotherms construction, and linearized according to Langmuir and Freundlich models. Results showed that cadmium adsorption was similar in both the models used. For lead, the Freundlich model had the best adjustment and chromium was better adjusted by the Langmuir model. It was concluded that the adsorbent was effective in the remediation of solutions containing cadmium, lead and chromium, thus, its use as sustainable alternative material is feasible, since it has low cost, does not need a previous treatment and it is a byproduct.


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