scholarly journals Biosorption of Heavy Metals by the Bacterial Exopolysaccharide FucoPol

2020 ◽  
Vol 10 (19) ◽  
pp. 6708
Author(s):  
Patrícia Concórdio-Reis ◽  
Maria A. M. Reis ◽  
Filomena Freitas
Keyword(s):  
Heavy Metals ◽  
Binding Sites ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Chemical Methods ◽  
Ph Values ◽  
Bacterial Exopolysaccharide ◽  
Physical And Chemical ◽  
Specific Metal ◽  
Significant Health

Despite the efforts for minimizing the usage of heavy metals, anthropogenic activities still generate high amounts of wastewater containing these contaminants that cause significant health and environmental problems. Given the drawbacks of the conventional physical and chemical methods currently used, natural biosorbents (microbial cells or their products) arise as promising environmentally friendly alternatives. In this study, the binding efficiency of the polysaccharide secreted by Enterobacter A47, FucoPol, towards lead (Pb2+), cobalt (Co2+), copper (Cu2+) and zinc (Zn2+) cations was demonstrated. FucoPol revealed a higher performance for the biosorption of Pb2+, with a maximum overall metal removal of 93.9 ± 5.3% and a specific metal uptake of 41.1 ± 2.3 mg/gEPS, from a Pb2+ solution with an initial concentration of 10 mg/L, by a 5 g/L FucoPol solution. The overall metal removal decreased considerably (≤31.3 ± 1.6%) for higher Pb2+ concentrations (48 and 100 mg/L) probably due to the saturation of FucoPol’s binding sites. Pb2+ removal was also less efficient (66.0 ± 8.2%) when a higher FucoPol concentration (10 g/L) was tested. Pb2+ removal efficiency of FucoPol was maximized at pH 4.3, however, it was affected by lower pH values (2.5–3.3). Moreover, the FucoPol’s sorption performance was unaffected (overall metal removal: 91.6–93.9%) in the temperature range of 5–40 °C. These findings demonstrate FucoPol’s great potential for utilization as a biodegradable and safe biosorbent for treating waters and wastewaters contaminated with Pb2+.

scholarly journals Exploiting the Potential in Water Cleanup from Metals and Nutrients of Desmodesmus sp. and Ampelodesmos mauritanicus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1461
Author(s):  
Roberto Braglia ◽  
Lorenza Rugnini ◽  
Sara Malizia ◽  
Francesco Scuderi ◽  
Enrico Luigi Redi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Cost Effective ◽  
Single Species ◽  
Nitrogen And Phosphorus ◽  
Removal Rates ◽  
Sequential Approach ◽  
Removal Capacity ◽  
Green Microalga

Increasing levels of freshwater contaminants, mainly due to anthropogenic activities, have resulted in a great deal of interest in finding new eco-friendly, cost-effective and efficient methods for remediating polluted waters. The aim of this work was to assess the feasibility of using a green microalga Desmodesmus sp., a cyanobacterium Nostoc sp. and a hemicryptophyte Ampelodesmos mauritanicus to bioremediate a water polluted with an excess of nutrients (nitrogen and phosphorus) and heavy metals (copper and nickel). We immediately determined that Nostoc sp. was sensitive to metal toxicity, and thus Desmodesmus sp. was chosen for sequential tests with A. mauritanicus. First, A. mauritanicus plants were grown in the ‘polluted’ culture medium for seven days and were, then, substituted by Desmodesmus sp. for a further seven days (14 days in total). Heavy metals were shown to negatively affect both the growth rates and nutrient removal capacity. The sequential approach resulted in high metal removal rates in the single metal solutions up to 74% for Cu and 85% for Ni, while, in the bi-metal solutions, the removal rates were lower and showed a bias for Cu uptake. Single species controls showed better outcomes; however, further studies are necessary to investigate the behavior of new species.

CHEMODYNAMICS OF TRACE POLLUTANTS DURING SNOWMELT ON ROOF AND STREET SURFACES

1994 ◽  
Vol 30 (1) ◽  
pp. 73-85 ◽  
Author(s):  
J. Daub ◽  
J. Förster ◽  
R. Herrmann ◽  
A. Robien ◽  
T. Striebel
Keyword(s):  
Heavy Metals ◽  
Suspended Solids ◽  
Chemical Properties ◽  
Snowmelt Runoff ◽  
Meltwater Runoff ◽  
Rainwater Runoff ◽  
High Concentrations ◽  
Physical And Chemical ◽  
Specific Metal ◽  
And Chemical Properties

In order to investigate the concentration levels and chemodynamic behaviour of organic micropollutants and heavy metals in snowmelt runoff from urban sealed surfaces, meltwater was sampled from one street :and four different roof catchments. Apart from peak concentrations of suspended solids during short intense street runoff from rain, concentrations of suspended solids in snowmelt runoff are two to fivefold higher than in rain runoff. However, the specific metal concentrations in suspended solids of snowmelt (except Zn) are lower than in suspended solids of rainwater runoff. This partly compensates the higher concentration of suspended solids. There are no distinct differences in concentrations of heavy metals between rain and meltwater runoff willi the exception of dissolved Cd; its concentrations are increased when high concentrations of macro ions are present. We explain high concentrations of PAH with a molecular weight of 202 or less in snowmelt with longer equilibration times available during melting than during rain runoff. An enhancement of solubility by DOC seems to be likely. The physical and chemical properties of various roof surfaces greatly influence the temporal variation of PAH concentrations during snowmelt runoff.

COMPARATIVE STUDY USING RAW AND TREATED CASSAVA AND LEMON RESIDUES IN THE REMOVAL OF NICKEL (II)

Agrociencia ◽  
2021 ◽  
Vol 55 (2) ◽  
pp. 145-158
Author(s):  
Candelaria Tejada Tovar ◽  
Diofanor Acevedo ◽  
Angel Villabona Ortíz ◽  
Nórida Pájaro Gómez ◽  
María Otero
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Citrus Limon ◽  
Manihot Esculenta Crantz ◽  
High Concentrations ◽  
High Level

Increasing pollution of water bodies by heavy metals from different anthropogenic activities, mainly of industrial nature, generates a high level of danger due to accumulation. Within a given time, heavy metals reach high concentrations in living organisms, especially those around sites of discharge. The objective of this research was to evaluate the adsorption capacity of dried lemon (Citrus limon) and cassava (Manihot esculenta Crantz) peels, raw or treated with citric acid, to remove Ni (II) in synthetic aqueous solution with 100 mg L-1 of metal. To assess adaptation and characterize these bio-adsorbents, biomasses were washed with distilled water. They were dried at 90 °C for 24 h and then ground in a mill. The modification of the cassava and lemon peels was carried out with 0.6 M citric acid; followed by adsorption and kinetic tests that were carried out in a discontinuous system. The biomaterials were characterized by chemical, elemental and Fourier transform infrared spectroscopy (FTIR) analysis. We found that both biomasses are composed mostly of carbon and cellulose. The FTIR showed the presence of carboxyl, amino, carbonyl and hydroxyl functional groups, which intervene in the adsorption process. Lemon and cassava peels showed 95.8% adsorption capacity of Ni (II) ions, and 75.69% removal of the contaminants. The best adsorbent particle sizes were 0.5 mm for lemon, and 1 mm for cassava peel, the two biomasses at pH 6. The best fit of the experimental data was Freundlich’s model and the pseudo-second-order model best described adsorption kinetics in the Ni (II) removal process. Treatment of the biomasses with citric acid did not render a significant improvement in metal removal. The best conditions for an efficient adsorption process were achieved using a specific particle size for lemon, 0.5 mm, and 1 mm for cassava residues.

scholarly journals Heavy metals concentration in soils from parks and green areas in Belgrade

2009 ◽  
Vol 74 (6) ◽  
pp. 697-706 ◽  
Author(s):  
Mirjana Marjanovic ◽  
Marija Vukcevic ◽  
Dusan Antonovic ◽  
Suzana Dimitrijevic ◽  
Djordje Jovanovic ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Urban Soils ◽  
Anthropogenic Activities ◽  
The Past ◽  
Ph Values ◽  
Green Areas ◽  
The City ◽  
Very High ◽  
Pb Concentration

The current study included the investigation of several metals and their distribution in urban soils from parks and green areas in the city of Belgrade. The soils were sampled in January and February 2008. The concentrations of Cd, Co, Cu, Pb, Mn and Zn were measured, as well as the pH values and organic matter contents. The obtained results showed that there was a significant level of contamination in some samples, especially with lead, and that it was most probably caused by anthropogenic activities, mostly from traffic. The results were compared with the National legislation and Netherlands standards. Also, the recent results were compared with the data from previous work and it was concluded that there has been a certain increase of the Pb concentration in the past three years. The level of pollution in playground soil was very high and each analyzed sample exceeded the Dutch target value for Cd, Co and Pb.

scholarly journals Phytoextraction and the economic perspective of phytomining of heavy metals

2017 ◽  
Author(s):  
Amjad Ali ◽  
Di Guo ◽  
Amanullah Mahar ◽  
Wang Ping ◽  
Fazli Wahid ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Accumulation Rate ◽  
Anthropogenic Activities ◽  
Low Cost ◽  
Developed Countries ◽  
Research Area ◽  
Economic Benefits ◽  
Global Market ◽  
Green Technology

Abstract. The world rapid growing population, expanding economics and anthropogenic activities contribute to heavy metals pollution, which are non-biodegradable, persistent and threaten the environment. The rising level of heavy metals in environment emphasizes on indigenous technologies, but conventional technologies are too expensive, laborious and result in secondary pollution. Phytoremediation/phytoextraction is a plant based technology, which is environmental friendly, economic and effective for heavy metals remediation. The global market of phytoremediation is 34–54 billion US$ and is expanding in the developed countries, providing an opportunity for this green technology. Suitability of phytoextraction depends on biomass production, accumulation rate and tolerance to target metals. Metals uptake can be enhanced by exploring effective hyperaccumulators, expanding phytomining operations and extending molecular studies on accumulation mechanism, tolerance and sensitivity of heavy metals. Hyperaccumulator plants achieve greater performance at low cost than conventional technologies for in situ metal removal. Phytomining generate revenue and provide new research area for biofortification of food and feed, biofuel and metal rich biochar production in future. This review highlights the sources of heavy metals and its effects on plants, enhancing phytoremediation process and increasing economic benefits of phytomining.

scholarly journals Unraveling the Underlying Heavy Metal Detoxification Mechanisms of Bacillus Species

2021 ◽  
Vol 9 (8) ◽  
pp. 1628
Author(s):  
Badriyah Shadid Alotaibi ◽  
Maryam Khan ◽  
Saba Shamim
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Molecular Mechanisms ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Heavy Metal Removal ◽  
Downstream Processing ◽  
Bacillus Species ◽  
Chemical Waste ◽  
Bacillus Spp

The rise of anthropogenic activities has resulted in the increasing release of various contaminants into the environment, jeopardizing fragile ecosystems in the process. Heavy metals are one of the major pollutants that contribute to the escalating problem of environmental pollution, being primarily introduced in sensitive ecological habitats through industrial effluents, wastewater, as well as sewage of various industries. Where heavy metals like zinc, copper, manganese, and nickel serve key roles in regulating different biological processes in living systems, many heavy metals can be toxic even at low concentrations, such as mercury, arsenic, cadmium, chromium, and lead, and can accumulate in intricate food chains resulting in health concerns. Over the years, many physical and chemical methods of heavy metal removal have essentially been investigated, but their disadvantages like the generation of chemical waste, complex downstream processing, and the uneconomical cost of both methods, have rendered them inefficient,. Since then, microbial bioremediation, particularly the use of bacteria, has gained attention due to the feasibility and efficiency of using them in removing heavy metals from contaminated environments. Bacteria have several methods of processing heavy metals through general resistance mechanisms, biosorption, adsorption, and efflux mechanisms. Bacillus spp. are model Gram-positive bacteria that have been studied extensively for their biosorption abilities and molecular mechanisms that enable their survival as well as their ability to remove and detoxify heavy metals. This review aims to highlight the molecular methods of Bacillus spp. in removing various heavy metals ions from contaminated environments.

Physical and Chemical Characteristics of Meats of the Indonesian Indigenous Crossbred Chickens Fed Fermented Mixture of Papaya (Carica papaya L.) Leaf and Seed Meal

2020 ◽  
Keyword(s):  
Crude Protein ◽  
Control Diet ◽  
Dietary Treatment ◽  
Seed Meal ◽  
Chemical Characteristics ◽  
Breast Meat ◽  
Ph Values ◽  
Physical And Chemical Characteristics ◽  
Dietary Treatments ◽  
Physical And Chemical

The objective of this present study was to investigate the effect of feeding fermented mixture of papaya leaf and seed meal (FERM) on the physical and chemical characteristics of meats of the Indonesian indigenous crossbred chicken (IICC). The study was carried out with 300 day-old IICC. The chicks were randomly distributed to five treatment groups, i.e., CONT (control diet based on corn-soybean- diet), FERMA (diet containing 1% FERM), FERMB (2.5% FERM), FERMC (5% FERM) and FERMD (7.5% FERM). Each treatment group consisted of 6 replicates with 10 IICC in each. At week 8, one chick from each replicate was randomly taken and slaughtered. After being de-feathered and eviscerated, samples from breast and thigh meats were obtained. Results showed that the increased levels of FERM was followed by the increased (P<0.05) pH values, moisture and crude protein content of breast meats of the IICC. Dietary incorporation of FERM especially at the level of 2.5% increased (P<0.05) the content of fat in the breast meat of IICC, while further increased levels of FERM did not alter (P>0.05) the fat content of the IICC breast meat. Dietary treatment did not have any effect (P>0.05) on the lightness (L*) values of breast meat of the IICC. The redness (a*) values were higher (P<0.05) in FERMD breast meat than other. FERM diet resulted in lower (P<0.05) yellowness (b*) values in the IICC breast meat. The pH values and moisture content of thigh meat increased (P<0.05) with the increased level of FERM. The WHC decreased (P<0.05) with the elevated levels of FERM in the diets. There was an increase (P<0.05) in crude protein concentration in FERMA as compared to the other meats. Crude fat and ash concentrations in thigh meat were affected (P<0.05) by the treatments. Dietary treatments had no impact (P>0.05) on L* values of thigh meats. Feeding FERM at 7.5% from diets increased (P<0.05) and decreased (P<0.05) the redness and yellowness of meats. In conclusion, dietary inclusion of FERM especially at the level of 7.5% from diets improved the physical and chemical characteristics of the IICC meats.

Mercury Removal from Wastewater by Steamed Hoof Powder

1999 ◽  
Vol 40 (7) ◽  
pp. 109-116 ◽  
Author(s):  
M. H. Ansari ◽  
A. M. Deshkar ◽  
P. S. Kelkar ◽  
D. M. Dharmadhikari ◽  
M. Z. Hasan ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Light Metal ◽  
Mercury Removal ◽  
High Adsorption ◽  
Surface Sites ◽  
Ph Values ◽  
High Adsorption Capacity

Steamed Hoof Powder (SHP), size &lt; 53μ, was observed to have high adsorption capacity for Hg(II) with &gt;95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good settling properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na+, K+, Ca2+ and Mg2+ up to concentrations of 500 mg/L and heavy metals like Cu2+, Zn2+, Cd2+, Co2+, Pb2+, Ni2+, Mn2+, Cr3+, Cr6+, Fe2+ and Fe3+ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

Modification of Collagen for Biomedical Applications: A Review of Physical and Chemical Methods

2016 ◽  
Vol 20 (17) ◽  
pp. 1797-1812 ◽  
Author(s):  
Xiaoyue Yu ◽  
Cuie Tang ◽  
Shanbai Xiong ◽  
Qijuan Yuan ◽  
Zhipeng Gu ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Chemical Methods ◽  
Physical And Chemical
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