Refine search
Results 1-10 of 2,097
Biosorption of Chromium by Fungal Strains Isolated from Industrial Effluent Contaminated Area
2022
Narolkar, Swati | Mishra, Arvnabh
The ability of fungi to act as bio-sorbent had been extensively evaluated and has shown excellent metal sequestering ability for heavy metals such as cadmium, copper, zinc, lead, iron, nickel, radium, thorium, and uranium from aqueous solution. In the present study, tolerance, removal efficiency and adsorption capacity of hexavalent chromium using isolated fungal strains were analysed. Total nine fungal isolates were obtained from organic pollutants and metals contaminated Gujarat Industrial Development Cooperation sites. Filamentous fungi isolated belonged to Aspergillus spp., Rhizopus spp., Trichoderma spp., and Penicillium spp. Chromium sorption experiments using isolated fungal strains were carried out to check adsorption capacity and adsorption intensity. At higher chromium concentration, removal efficiency and adsorption capacity were observed in the order of Aspergills candidus > Aspergillus ochraceus > Aspergillus flavus > Rhizopus spp. > Trichoderma spp. A. candidus showed higher adsorption capacity, 5.49mg/g with 98.75% chromium removal efficiency at 150ppm of hexavalent chromium. The observed RL value for Langmuir isotherm for all the three concentrations was less than 1, depicting favourable sorption and in Freundlich isotherm, the value of 1/n exceeds more than 1 showing co-operative or similar type of adsorption.
Show more [+] Less [-]Phytotoxicity of Lead and Chromium on Germination, Seedling Establishment and Metal Uptake by Kenaf and Mesta
2020
Sultana, R. | Islam, S. M. N. | Zaman, M. W. | Uddin, N.
Heavy metal contaminated soil raises major global environmental and agricultural concern. Recently soil pollution through lead (Pb) and chromium (Cr) becoming serious problem and remediation or utilization of those contaminated soil with potential crops is of the outmost importance. The objectives of present study were to examine the effects of Pb and Cr on three different kenaf and mesta varieties for seed germination, seedling establishment and amount of Pb and Cr uptake by tested varieties in laboratory condition. Three varieties were used for the study namely, HC-95 (kenaf), CPL-72126 (mesta) and Samu-93 (mesta) and the treatments were combination of Pb and Cr chemical at (0,0), (60,60), (80,80), (100,100) and (120,120) mg/L. Increased level of lead and chromium gradually reduced the germination percentage and primary growth parameters compared to control. The shoot and root lengths were affected only little, whereas, the biomass showed a considerable reduction with the increase of Pb and Cr toxicity. Stress tolerance indices showed a gradual and negative response by the plant with the increase of metal concentrations. However, in all the levels of Pb and Cr treatment, the seedlings were capable to tolerate the toxicity and seedlings were established. Bioaccumulation of Cr was higher than that of Pb in all varieties and in all treatments. The interaction of Pb and Cr reduced the toxic effect of both metals to the plants. The findings are helpful for selecting fiber crop varieties for cultivation in contaminated soils or phytoremediation of Pb and Cr from the contaminated soils.
Show more [+] Less [-]Public health risk assessment of chromium intake from vegetable grown in the wastewater irrigated site in Bangladesh
2016
Ahmed, Fahad | Hossain, Md. Shakhaoat | Abdullah, Abu Tareq | Akbor, Md. Ahedul | Ahsan, Md. Aminul
There are many potential risks to human health from heavy metal contamination of vegetables resulting from wastewater irrigated sites. This study was carried out to assess the concentration of chromium (Cr) and the risk to human health by chromium through the intake of locally grown vegetables collected from wastewater irrigated agricultural fields. Twenty-seven samples of 9 (nine) different types of vegetables were analyzed by an Atomic Absorption Spectrometer (AAS) (Varian AAS 240 F S). The range of chromium concentration in wastewater irrigated vegetables was ND (Not detected) -4.14mg/kg. The highest mean concentration of chromium (4.14 mg/kg) was detected in radish. The mean concentration of chromium in all the vegetables was within the safe limits of WHO/FAO except radish which was much higher than the standard. Health risk index for chromium contamination in all vegetables was less than 1 for both adults and children which cause no risk to the local population. Among all vegetables tested, the highest intake value of chromium was from consumption of radish for both adults and children. The lower values of health risk index indicated chromium contamination in the wastewater irrigated vegetables that cause less negative impact on human health.
Show more [+] Less [-]Potential of Lemna minor in Ni and Cr removal from aqueous solution
2015
Goswami, Chandrima | Majumder, Arunabha
Duckweeds are of special interest, as they are naturally growing weeds that have the capacity to tolerate and remove toxic pollutants, including heavy metals from the environment. Studies have revealed that duckweed (Lemna minor) can tolerate and remove heavy metals from aqueous solutions. In the present study, the efficiency of L. minor in the removal of Ni and Cr individually from aqueous solutions was investigated at concentrations of 3.05, 3.98 and 4.9 mg/L for Ni and 1.91, 2.98, and 4.2 mg/L for Cr. Experiments were run for 22 days, after which the metal content in the plant was estimated by atomic absorption spectrophotometer (AAS). The duckweed showed higher percentage of Ni removal than Cr. Specific Growth Rate (SGR) was found to be reduced at high concentrations of both Ni and Cr. Statistical analysis suggested that the growth of the plant was affected by the toxic effect of both Ni and Cr. Bioaccumulation of Ni was higher than Cr in L. minor. The mechanism of removal of both Ni and Cr followed second order kinetics. It is suggested that these duckweeds can remove Ni and Cr from aqueous solution and can also accumulate the same in considerable concentrations, at low initial metal concentrations.
Show more [+] Less [-]Trace elements in vegetables grown in an industrial area in relation to soil and air particulate matter.
1996
Voutsa D. | Grimanis A. | Samara C.
Fluxes of Cu, Zn, Pb, Cd, Cr, and Ni in temperate forest ecosystems. A literature review.
1989
Bergkvist B. | Folkeson L. | Berggren D.
A reconstruction of emission, flow and accumulation of chromium in Sweden 1920-1980.
1989
Bergbaeck B. | Anderberg S. | Lohm U.
Physicochemical and biological characterisation of different dredged sediment deposit sites in France
2006
Capilla, Xavier | Schwartz, Christophe | Bedell, Jean-Philippe | Sterckeman, Thibault | Perrodin, Yves | Morel, Jean-Louis | Laboratoire des Sciences de l'Environnement ; École Nationale des Travaux Publics de l'État (ENTPE) | Laboratoire Sols et Environnement (LSE) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL)
Physicochemical and biological characterisation of different dredged sediment deposit sites in France
Show more [+] Less [-]Efficacy of marigold (Tagetes erecta L.) for the treatment of tannery and surgical industry wastewater under citric acid amendment: a lab scale study.
2023
Fatima, Arooj | Farid, Mujahid | Asam, Zaki Ul Zaman | Zubair, Muhammad | Farid, Sheharyaar | Abbas, Mohsin | Rizwan, Muhammad | Ali, Shafaqat
peer reviewed | Contamination of land and aquatic ecosystems with heavy metals (HMs) is a global issue having the persistent potential to damage the quality of food and water. In the present study, Tagetes erecta L. plants were used to assess their potential to uptake HMs from wastewater. Plants were grown in soil for 20 days and then transplanted in hydroponic system containing Hoagland nutrient solution. After more than 15 days of growth, plants were then subjected to wastewater from tannery and surgical industries in different concentrations ranging from 25 to 100% in combination of citric acid (5 and 10 mM). After 6 weeks of treatment, plants were collected and segmented into roots, stem, and leaves for characterizing the morphological properties including plant height, roots length, fresh and dry mass of roots, stem, and leaves. For evaluation of the effect of wastewater on the plants, photosynthetic pigments; soluble proteins; reactive oxygen species (ROS); antioxidant enzymes SOD, POD, CAT, and APX; and metal accumulation were analyzed. Application of industrial wastewater revealed a significant effect on plant morphology under wastewater treatments. Overall growth and physiological attributes of plant decreased, and metal accumulation enhanced with increasing concentration of wastewater. Similarly, the production of ROS and antioxidant enzymes were also increased. Chlorophyll, protein content, and enzyme production enhanced with CA (5 and 10 mM) mediation; however, ROS production and EL were reduced. Metals analysis showed that the maximum accumulation of Pb was in roots, while Cr and Ni in the stem which further increased under CA mediation. Overall, the metal accumulation ability was in the order of Pb > Ni > Cr under CA.
Show more [+] Less [-]Effects of tannic acid on the transport behavior of trivalent chromium in soils and its mechanism
2022
Xu, Teng | Jiang, Xiaofeng | Tang, Yuling | Zeng, Yunhang | Zhang, Wenhua | Shi, Bi
Trivalent chromium [Cr(III)] and tannins serve as necessary substances in leather processing and coexist in tannery site, which lead to the chromium contamination in site soil when disposed improperly. However, coexisting tannins are very likely to complex with Cr(III) and affect its properties, ultimately changing the mobility of chromium in soil. In this study, tannic acid (TA) was selected to investigate the complexation with Cr(III) and the influence on the solubility and sorption of Cr(III) in soils. Then, the transport behavior and mechanism of Cr(III)-TA complexes in soil was clarified. Dialysis results showed that the increase of TA concentration and solution pH promoted the formation of complexed Cr(III). The results of UV–Vis absorption spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations indicated that the adjacent ionized phenolic hydroxyls in TA functioned as the binding sites with Cr(III) to form the Cr–O bonds and the degree of complexation increased with pH. The Cr(III)-TA complexes had higher solubility than free Cr(III) at pH ≥ 6.0. Batch sorption experiments demonstrated that the sorption capacity of Cr(III)-TA to soils with different pH was always lower than that of free Cr(III). These reasons led to the stronger mobility of Cr(III)-TA in soil columns than Cr(III). Our research reveals that the enhanced mobility of Cr(III) in soils coexisting with TA.
Show more [+] Less [-]