Impact of solution variables on the removal of heavy metals from wastewaters by a recycled iron sorbent

2000 ◽  
Vol 42 (1-2) ◽  
pp. 347-352
Author(s):  
E.H. Smith ◽  
S. Chatterjee
Keyword(s):  
Heavy Metals ◽  
Oxalic Acid ◽  
Metal Speciation ◽  
Surface Finishing ◽  
Complexing Agents ◽  
Lead Removal ◽  
Adsorption Equilibria ◽  
Removal Of Heavy Metals ◽  
Cadmium And Lead ◽  
The Impact

Waste shot-blast fines from surface finishing processes have been demonstrated to be effective for removing heavy metals from solution by adsorption.The technology offers the potential for inexpensive recovery and reuse of a material normally discarded as a solid waste. While metal removals compare favorably with those achieved by commercial sorbents, applications issues such as the impact of background metal-complexing agents require investigation. The presence of oxalic acid, a complexing organic compound, impacted cadmium and lead adsorption in accordance with predictions from metal speciation equilibria; i.e., a small but measurable reduction in lead removal was observed, but cadmium adsorption was relatively unaffected. The effects were repeated in dynamic column experiments, with lead removals reduced by 15 to 20% in the presence of the ligand. Efforts to model adsorption equilibria in the presence of oxalic acid did not fully capture the reduced lead removal, presumably because the model does not consider the complete formation of metal-oxalic acid complexes prior to contact with the sorbent.

Heavy Metal Removal in the Presence of Colloid-Stabilizing Organic Material and Complexing Agents

1986 ◽  
Vol 18 (1) ◽  
pp. 19-29 ◽  
Author(s):  
I. Licskó ◽  
I. Takács
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Colloidal Dispersion ◽  
Laboratory Model ◽  
Complexing Agents ◽  
Stabilizing Agents ◽  
Removal Of Heavy Metals ◽  
Alkaline Conditions ◽  
The Stability

It has been established in laboratory model experiments that the removal of dissolved heavyimetals from wastewaters is rendered more difficult in the presence of colloid-stabilizing agents. This unfavourable effect can be eliminated by the addition of Mg2+ ions and the adjustment to a fairly high pH. By increasing the concentration of Mg2+ ions, the pH necessary for destroying the stability of colloidal dispersion can be lowered. These findings also apply to the combined removal of different heavy metals (Cu, Zn, Cr(III), Ni, Cd). In alkaline conditions, in the presence of ammonium salts, some heavy metals (Cu, Zn, Ni) form high stability amine complexes. A higher pH is necessary for the breakdown of these complexes and the satisfactory removal of heavy metals.

Use of citric acid for heavy metals extraction from contaminated sewage sludge for land application

2006 ◽  
Vol 54 (9) ◽  
pp. 129-135 ◽  
Author(s):  
D. del Mundo Dacera ◽  
S. Babel
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Land Application ◽  
Metal Extraction ◽  
Lead Removal ◽  
Inorganic Matter ◽  
Highly Effective ◽  
Removal Of Heavy Metals ◽  
Anaerobically Digested Sludge ◽  
Extracting Agents

Recent studies revealed that organic acids such as citric and oxalic acids seemed to be more promising as chemical extracting agents for removal of heavy metals from contaminated sludge, since they are biodegradable and can attain a higher metal extraction efficiency at mildly acidic pH compared to other extracting agents. Results of a lab-scale study on the efficiency of citric acid in the extraction of chromium (Cr), copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn) from anaerobically digested sludge, revealed that citric acid seemed to be highly effective in extracting Cr (at 100%), Cu (at 88%), Ni (at 98%) and Zn (at 100%) at pH 2.33, mostly at 5 days leaching time except for Cu and Zn, which are at 1 day and 2 h contact times respectively. Lead removal at the same pH was also high at 95% but at a longer leaching time of 11 days. At pH 3, citric acid seemed to be highly effective in extracting Pb (at 100%) at 1 day leaching time, although higher removals were also attained for Ni (70%) and Zn (80%) at only 2 h leaching time. Chemical speciation studies showed that Cr, Cu and Ni in the sludge sample seem to predominate in residual fractions, while Pb and Zn were found mostly bound to organic and inorganic matter forms, hence the potential of the sludge for land application.

scholarly journals Ultrafiltration treatment of wastewater contained heavy metals complexed with palygorskite

2020 ◽  
Vol 22 (4) ◽  
pp. 1-9
Author(s):  
Jun Ren ◽  
Tianyi Cao ◽  
Xin Yang ◽  
Ling Tao
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Ph Value ◽  
Rejection Rate ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Low Molecular Weight ◽  
Sodium Tartrate ◽  
Removal Of Heavy Metals ◽  
Ultrafiltration Process

AbstractPalygorskite was applied in complexation-ultrafiltration treatment of heavy metals in wastewater under different pH and ionic strength. The results indicated that the rejection of heavy metals increased significantly with pH value, and decreased slightly with an increase of ionic strength of Na+ and Cl–. A certain concentration of NaCl significantly reduced the rejection rate of Cu2+. The rejection of Cu2+, Zn2+ and Cd2+ could reach over 86.8%, 93.6% and 93.7% at pH of 7 and 0.1 mol/L NaCl. The rejection of heavy metals was severely affected by low molecular weight competing complexing agents and the effect of sodium tartrate was greater than triethanolamine. In the presence of sodium tartrate, the rejection of Cu2+, Zn2+ and Cd2+ could arrive over 81.4%, 57.6% and 60.5% at pH of 7 in 20 min. Palygorskite was offered a potential complexing agent for the removal of heavy metals in wastewater at the complexation-ultrafiltration process.

Heavy Metals Speciation of Size-fractionated Sediments Collected from Combined Sewer System Using Sequential Extraction Method

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
K. Kojima ◽  
I. Kasuga ◽  
F. Kurisu ◽  
H. Furumai
Keyword(s):  
Heavy Metals ◽  
Sequential Extraction ◽  
Extraction Method ◽  
Metal Speciation ◽  
High Mobility ◽  
Aquatic Organisms ◽  
Total Content ◽  
Combined Sewer ◽  
Sequential Extraction Method ◽  
The Impact

Sediments deposited in sewer pipes have been concerned as one of the main pollution loads from combined sewer overflow (CSO). Since the toxicity, mobility and bioavailability of heavy metals depend on their speciation, it is necessary to consider not only their amounts but also their speciation to evaluate the adverse effects on aquatic organisms in receiving waters. Sequential extraction method was applied to the size-fractionated sediments to evaluate heavy metal speciation. Although the speciation of Cr, Ni, Cu, Zn and Pb differed among sampling points as well as their contents, the content of easily exchangeable fraction was strongly correlated with total content for all the metals except for Cu. The result of heavy metals speciation revealed that Ni, Zn and Pb in combined sewer sediments could have high mobility potential. The result of size-fractionated sediments indicated that the contents and mobility potential of the heavy metals were larger as particle size was finer. Thus, it is important to control fine sediments in combined sewer to reduce the impact of CSO pollution.

Removal of heavy metals from fly ash and the impact on its quality

2002 ◽  
Vol 77 (3) ◽  
pp. 389-395 ◽  
Author(s):  
Henk W Nugteren ◽  
Maria Janssen-Jurkovícová ◽  
Brian Scarlett
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Removal Of Heavy Metals ◽  
The Impact

scholarly journals Comportamiento del hierro, cromo, cadmio y plomo total en las aguas superficiales del río Manzanares, Venezuela, durante los periodos de sequía y lluvia en el año 1994

2016 ◽  
Author(s):  
William James Senior ◽  
Ivan León Luna ◽  
Gregorio Martínez ◽  
Arístide Márquez ◽  
Ivis Fermín
Keyword(s):  
Heavy Metals ◽  
Anthropogenic Activities ◽  
Total Iron ◽  
Mixing Process ◽  
Geochemical Process ◽  
Removal Of Heavy Metals ◽  
Removal Processes ◽  
Cadmium And Lead ◽  
Del Rio ◽  
Iron Chromium

Results are presented for total iron, chromium, cadmium, and lead concentrations measured in the surface water of the Manzanares river (Venezuela), during two typical weather periods of the region (May and November) of 1994. The existence of removal processes in the early stages of the mixing process of freshwater and seawater is evident from their spatial distributions. It is suggested that this removal of heavy metals is associated with the geochemical process of flocculation and the formation of oxihydroxides, rather than with the dilution process. Input of heavy metals to the ecosystem was observed at low salinities that are likely associated to the process of desorption and are due to anthropogenic activities.

scholarly journals The impact of the nutritional supplement “ERAMIN” on the heavy metal content in meat and offals

2019 ◽  
Vol 95 (2) ◽  
pp. 199-202
Author(s):  
V. M. Poznyakovskiy ◽  
Sergey L. Tikhonov ◽  
N. V. Tikhonova
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Content ◽  
Nickel Content ◽  
Nutritional Supplement ◽  
Longissimus Dorsi ◽  
Control Group ◽  
Slaughter Cattle ◽  
Cadmium And Lead ◽  
The Impact

There was performed an experimental study on the reduction of heavy metals in meat and products of slaughter cattle. For the experiment, according to the principle of analogues there were formed two groups of 15 Hereford calves each: 1 - control, 2 - experimental. Calves from the second group, in addition to the basic diet from the age of 3 months received dietary supplement "Eramin" in a dose of 50 mg/kg of body weight for 10 days every 3 months throughout the period of growing and fattening. In that the content of heavy metals in the meat of calves is established to fail to exceed the MPC. The amount of copper, iron and nickel in the control group exceeded average by 93,2 and 77,8%, respectively. The nickel content in muscle longissimus dorsi of the control group is 0,046 mg/kg, which is 5,6 times above the average. Against the background of the use of "Eramin" in the ration of calves in meat there was shown a significant (P ≤ 0,05) decrease in iron, cadmium and lead 12,0; 9,8 and 11,4%, respectively.

scholarly journals AQUATIC PLANT (HYDRILLA VERTICILLATA) ROLES IN BIOACCUMULATION OF HEAVY METALS

2020 ◽  
Vol 51 (2) ◽  
pp. 574-584
Author(s):  
Al-Zurfi & Al-Tabatabai
Keyword(s):  
Heavy Metals ◽  
Aquatic Plant ◽  
Removal Rate ◽  
Hydrilla Verticillata ◽  
Bioaccumulation Factor ◽  
Lead Removal ◽  
Removal Ratio ◽  
Cadmium And Lead

The current study was aimed to test the ability of Hydrilla verticillata plant ability to accumulated of cadmium and lead in its tissues. The plant was treated with different concentrations of cadmium (1,2,4,8) ppm and lead (0.5,5,10,20) ppm for 21 days'. The concentration of metals was measured in plant and water, Bioaccumulation factor and removal ratio were also measured during days (1,7,14,21), as well as measured biomass and length of the plant were measured at the end of the experiment. The results were shown that the highest cadmium and lead removal rate were (77, 88) % at concentration (4, 10) ppm during (21, 7) days, respectively, also the bioaccumulation factor (BCF) of the two metals were (21639 and 45467) at concentrations (4 and 0.5) ppm during the 21st day of the experiment respectively. The biomass of plant in treated aquarium with different concentrations of cadmium showed a decrease during the experimental days, while increased in biomass of plant treated aquarium with different concentrations of lead. The length rate of the plant was significantly reduced in the plant that treated with cadmium but significant increase in plant treated with lead compared to the control.

scholarly journals Adaptation of Selected Ectomycorrhizal Fungi to Increased Concentration of Cadmium and Lead

2016 ◽  
Vol 23 (3) ◽  
pp. 483-491
Author(s):  
Katarzyna Bandurska ◽  
Piotr Krupa ◽  
Agnieszka Berdowska ◽  
Magdalena Marczak
Keyword(s):  
Heavy Metals ◽  
Ectomycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Colorimetric Method ◽  
Fungal Resistance ◽  
Fruiting Bodies ◽  
Industrial Emissions ◽  
Mineral Salts ◽  
Cadmium And Lead ◽  
The Impact

Abstract Plants together with water and minerals actively take from the soil heavy metals such as cadmium and lead. The negative role of ions of these metals on plant growth and development depends not only on their concentration in the soil, but also on a number of factors that may affect the transport of minerals from the soil to the roots. The harmful effects of xenobiotics getting from the soil to the plants are limited by the organic compounds contained in the soil, soil structure and pH. Particularly noteworthy are biotic factors, such as bacteria and fungi which greatly limit the translocation of heavy metals. Stream of new scientific reports show that the symbiotic combination of fungi with plant roots so called mycorrhizae is a factor that may be important in reducing the impact of soil contamination by heavy metals. Mycorrhiza by filtering solutions of water and mineral salts stop a considerable amount of heavy metals in the internal mycelium or on its surface. It was proved that plants with properly formed mycorrhiza grow better in hard to renew lands, such as salty, sterile soils contaminated with industrial waste. Questions to which answer was sought in this study are: 1) whether mycorrhizal fungi for many years growing in the contaminated areas have managed to adapt to these adverse conditions and 2) do the same species derived from clean areas are less resistant to contamination by heavy metals? Stated problems tried to be solved based on the fruiting bodies of fungi collected from ectomycorrhizal fungi picked from the areas contaminated by industrial emissions and areas free of contamination. The interaction of cadmium and lead ions on the growth of mycelium was examined by plate method and binding of heavy metals in fruiting structures of fungi were done by colorimetric method with use of methylene blue. It has been shown that the fungal resistance, even of the same species, to high concentration of heavy metals varies depending on the origin of symbiont. Isolated fungi from contaminated areas are better adapted to high concentrations of xenobiotics. Ability to bind cadmium and lead to fruiting bodies of fungi varies.

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