The replacement of the nondescript term ‘heavy metals’ by a biologically and chemically significant classification of metal ions

1980 ◽  
Vol 1 (1) ◽  
pp. 3-26 ◽  
Author(s):  
Evert Nieboer ◽  
David H.S. Richardson
Keyword(s):  
Heavy Metals ◽  
Metal Ions

scholarly journals Ideal pH for the adsorption of metal ions Cr6+, Ni2+, Pb2+ in aqueous solution with different adsorbent materials

2021 ◽  
Vol 6 (1) ◽  
pp. 115-123
Author(s):  
Luísa P. Cruz-Lopes ◽  
Morgana Macena ◽  
Bruno Esteves ◽  
Raquel P. F. Guiné
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Walnut Shell ◽  
Lead Adsorption ◽  
Viable Solution ◽  
Chestnut Shell ◽  
Adsorption Processes ◽  
Irreversible Effects ◽  
Optimal Values ◽  
Ph Range

Abstract Industrialization increases the number of heavy metals released into the environment. Lead (Pb2+), nickel (Ni2+) and chromium (Cr6+) are among these toxic metals and cause irreversible effects on ecosystems and human health due to their bio-accumulative potential. The decontamination through adsorption processes using lignocellulosic wastes from agricultural and/or forestry processes is a viable solution. Hence, this work aimed at studying the effect of pH on the biosorption of the metal ions using four different by-product materials: walnut shell, chestnut shell, pinewood and burnt pinewood. These experiments were conducted with solutions of the three heavy metals in which the adsorbents were immersed to measure the rate of adsorption. A range of pH values from 3.0 to 7.5 was used in the experiments, and the concentrations were determined by atomic absorption. The results showed different behaviour of the biosorbent materials when applied to the different metals. The lead adsorption had an ideal pH in the range of 5.5–7.5 when the walnut shell was used as an adsorbent, corresponding to values of adsorption greater than 90%, but for the other materials, maximum adsorption occurred for a pH of 7.5. For the adsorption of chromium, the pH was very heterogeneous with all adsorbents, with optimal values of pH varying from 3.0 (for chestnut shell) to 6.5 (for walnut shell and wood). For nickel, the best pH range was around pH 5, with different values according to the lignocellulosic material used. These results indicate that the tested biosorbents have the potential to decontaminate wastewater in variable extensions and that by controlling the pH of the solution; a more efficient removal of the heavy metals can be achieved.

Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

scholarly journals Batch Sorption Experiments: Langmuir and Freundlich Isotherm Studies for the Adsorption of Textile Metal Ions onto Teff Straw (Eragrostis tef) Agricultural Waste

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mulu Berhe Desta
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Low Cost ◽  
Agricultural Waste ◽  
Equilibrium Concentration ◽  
Eragrostis Tef ◽  
Batch Adsorption ◽  
Textile Effluents

Adsorption of heavy metals (Cr, Cd, Pb, Ni, and Cu) onto Activated Teff Straw (ATS) has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the low-cost adsorbent ATS for the removal of heavy metals from textile effluents. The influence of contact time, pH, Temperature, and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly, and the optimal removal efficiency was reached within about 1 hour. Further increase in contact time did not show significant change in equilibrium concentration; that is, the adsorption phase reached equilibrium. The adsorption isotherms could be fitted well by the Langmuir model. The value in the present investigation was less than one, indicating that the adsorption of the metal ion onto ATS is favorable. After treatment with ATS the levels of heavy metals were observed to decrease by 88% (Ni), 82.9% (Cd), 81.5% (Cu), 74.5% (Cr), and 68.9% (Pb). Results indicate that the freely abundant, locally available, low-cost adsorbent, Teff straw can be treated as economically viable for the removal of metal ions from textile effluents.

scholarly journals Estimation of the Concentration of Some Heavy Metals in Groundwater in Rutba City

2021 ◽  
Vol 904 (1) ◽  
pp. 012009
Author(s):  
A W Abd Byty ◽  
M A Gharbi ◽  
A H Assaf
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Large Scale ◽  
Toxic Metal ◽  
Scale Production ◽  
Future Health ◽  
Distribution Maps ◽  
Guideline Values

Abstract Toxic metal pollutants in groundwater should be identified to prevent future health risks. In this paper, the presence of heavy metals in groundwater in the western region of Iraq was investigated. The heavy metals concentrations, including Ni2+, Co2+, Zn2+, Pb2+, Cr3+, Cd2+, As3+ and Hg2+ were explored in twenty selected aquifers near Rutba City and the results were presented as spatial distribution maps. Findings indicate that contamination with the investigated heavy metal ions possesses a serious threat to the study area’s groundwater quality when compared to WHO and IEPA guideline values. Thus, a new approach to remove or adsorb heavy metal ions can be developed for large-scale production and the safe use of these aquifers water. Results revealed that the highest concentrations in mg/L1 of 2.312 in w19, 1.098 in w2, 5.78 in w17, 0.292 in w9, 3.349 in w5, 0.32 in w13, 0.074 in w11 and 5.622 in w1 for Zn2+, Cr3+, As3+, Pb2+, Ni2+, Co2+, Cd2+ and Hg2+ were recorded, respectively.

scholarly journals The Influence of Heavy Metal Ions on the Viability and Metabolic Enzyme Activity of the Marbled Crayfish Procambarus virginalis (Lyko, 2017)

2018 ◽  
Vol 70 ◽  
pp. 11-23 ◽  
Author(s):  
Oleg Marenkov ◽  
Mykola V. Prychepa ◽  
Julia Kovalchuk
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Enzyme Activity ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Physiological State ◽  
Metabolic Enzyme ◽  
Nickel Ions ◽  
The Individual ◽  
Marbled Crayfish

In the experiment with marbled crayfishProcambarusvirginalis(Lyko, 2017), chronic effects of various concentrations of heavy metal ions on the physiological state and enzyme activity were investigated. The obtained results showed that among the investigated heavy metals nickel ions influenced the weight indexes and mortality of crustaceans the most negatively. According to the results of the research, significant changes were noted in the individual biochemical parameters of marbled crayfish under the influence of manganese, lead and nickel ions. The most significant changes in the activity of lactate dehydrogenase were detected in muscle tissues affected by manganese and nickel ions. A significant decrease in the activity of succinate dehydrogenase in muscle of marbled crayfish was determined after the action of heavy metal ions. Investigation of changes in the activity of alkaline phosphatase under the influence of the ions of manganese, lead and nickel has its own characteristics, which indicates certain violations in the tissues of cell membranes. Changes in the activity of enzymes were also reflected in the overall protein content. Changes in these parameters may indicate a rapid biochemical response of crustaceans to the toxic effects of heavy metals.

Research Progress in Removing Heavy Metals from Waste Water via Bio-Sorption

2014 ◽  
Vol 587-589 ◽  
pp. 692-695
Author(s):  
Wei Sun
Keyword(s):  
Waste Water ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Water Treatment ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Waste Water Treatment ◽  
Research Progress ◽  
Traditional Methods ◽  
Sorption Method

Bio-absorption has an unparalleled advantage over other traditional methods in removing and recycling heavy metal ions from waste water. Consequently, it has a promising future. In this paper, the traditional methods and the bio-sorption method via which heavy metals are removed from waste water are compared to summarize the mechanism of bio-sorption, the types of bio-sorbent, the factors that can influence bio-sorption and the state of its application in waste water treatment .

scholarly journals A systematic study for removal of heavy metals from aqueous media using Sorghum bicolor: an efficient biosorbent

2018 ◽  
Vol 77 (10) ◽  
pp. 2355-2368 ◽  
Author(s):  
Khalida Naseem ◽  
Zahoor H. Farooqi ◽  
Muhammad Z. Ur Rehman ◽  
Muhammad A. Ur Rehman ◽  
Robina Begum ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Aqueous Media ◽  
Review Article ◽  
Isotherm Models ◽  
Adsorption Efficiency ◽  
Adsorption Isotherm Models ◽  
Removal Of Heavy Metals

Abstract This review is based on the adsorption characteristics of sorghum (Sorghum bicolor) for removal of heavy metals from aqueous media. Different parameters like pH, temperature of the medium, sorghum concentration, sorghum particle size, contact time, stirring speed and heavy metal concentration control the adsorption efficiency of sorghum biomass for heavy metal ions. Sorghum biomass showed maximum efficiency for removal of heavy metal ions in the pH range of 5 to 6. It is an agricultural waste and is regarded as the cheapest biosorbent, having high adsorption capacity for heavy metals as compared to other reported adsorbents, for the treatment of heavy metal polluted wastewater. Adsorption of heavy metal ions onto sorghum biomass follows pseudo second order kinetics. Best fitted adsorption isotherm models for removal of heavy metal ions on sorghum biomass are Langmuir and Freundlich adsorption isotherm models. Thermodynamic aspects of heavy metal ions adsorption onto sorghum biomass have also been elaborated in this review article. How adsorption efficiency of sorghum biomass can be improved by different physical and chemical treatments in future has also been elaborated. This review article will be highly useful for researchers working in the field of water treatment via biosorption processing. The quantitative demonstrated efficiency of sorghum biomass for various heavy metal ions has also been highlighted in different sections of this review article.

Removing heavy metals from effluents with natural and modified clay-containing sorbents

2021 ◽  
pp. 30-37
Author(s):  
А.К. Стрелков ◽  
С.В. Степанов ◽  
О.Н. Панфилова ◽  
А.В. Арбузов
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Specific Productivity ◽  
Natural Material ◽  
Main Process ◽  
Tertiary Treatment ◽  
Modified Clay ◽  
Cartridge Filter

Представлены результаты исследований сорбции ионов тяжелых металлов глиносодержащими сорбентами из сточных вод гальванического производства. Цель испытаний, проведенных на пилотной установке, – разработка технологической схемы для доочистки сточных вод от ионов тяжелых металлов и извлечения отработанного сорбента с применением намывного патронного фильтра со слоем перлита. В испытаниях использовались: термически модифицированный сорбент на основе природных материалов – модифицированная глина, а также смесевый сорбент, состоящий из монтмориллонита, торфа и доломита в соотношении 5:4:1 без термической обработки. Исследования проводились по восьми ионам тяжелых металлов в диапазоне низких концентраций, характерных для сточных вод, поступающих на доочистку после отстаивания с корректировкой рН. Основные технологические параметры доочистки: pH8; продолжительность контакта сорбента с обрабатываемыми водами 90 мин, доза сорбентов 1–1,6 г/л. Отделение отработанного сорбента от очищенной воды было предусмотрено в две ступени – отстаиванием и фильтрованием на патронном намывном фильтре. Введение коагулянта «Аква-АуратÔ-30» дозой 40 мг/л по Al2O3 позволило снизить концентрацию взвешенных веществ в осветленных сточных водах, подаваемых на намывные фильтры, до 8 мг/л для модифицированной глины и 15 мг/л для смесевого сорбента. Удельная производительность намывного слоя составила 23 м3/(ч×м2), расчетная удельная нагрузка по взвеси на поверхность фильтра составила для модифицированной глины 850 г/м2, для смесевого сорбента – 680 г/м2. Расчетная продолжительность фазы фильтрования намывного слоя при использовании предварительного реагентного отстаивания составила 4,6 и 2 ч для модифицированной глины и смесевого сорбента соответственно. Обеспечена эффективность очистки сточных вод от ионов тяжелых металлов на уровне ПДК для водных объектов рыбохозяйственного значения. The results of studies of the sorption of heavy metal ions by clay-containing sorbents from plating effluents are presented. The purpose of the tests carried out in a pilot plant was developing a process scheme for the removal of heavy metal ions from effluents and extraction of the spent sorbent in a precoat cartridge filter with a layer of perlite. The materials used in the tests were as follows: thermally modified sorbent based on natural material, i. e., modified clay, as well as mixed sorbent consisting of montmorillonite, peat and dolomite in a ratio of 5:4:1 without heat treatment. The studies were carried out on eight ions of heavy metals in the low concentration range typical for the effluent coming for tertiary treatment after sedimentation with pH adjustment. The main process parameters of tertiary treatment were: pH 8; the duration of the sorbent contact with the effluent was 90 min, the dose of sorbents was 1–1.6 g/l. The separation of the spent sorbent from the effluent was executed in two stages – sedimentation and filtration in a precoat cartridge filter. The addition of Aqua-AuratTM-30 coagulant with a dose of 40 mg/l as Al2O3provided for reducing the concentration of suspended solids in the clarified effluent supplied to the precoat filters to 8 mg/l for modified clay and 15 mg/l for the mixed sorbent. The specific productivity of the alluvial layer was 23 m3/(h‧m2), the specific load of the suspension on the filter surface was 850 g/m2for modified clay, and 680 g/m2 for mixed sorbent. The estimated duration of the filtration phase of the alluvial layer while using preliminary chemical sedimentation was 4.6 and 2 h for the modified clay and mixed sorbent, respectively. The efficiency of removing heavy metal ions from effluents was provided at the level of the maximum permissible concentration for fishery water bodies.

Development of an effervescent tablet microextraction method using NiFe2O4-based magnetic nanoparticles for preconcentration/extraction of heavy metals prior to ICP-MS analysis of seafood

2019 ◽  
Vol 34 (3) ◽  
pp. 598-606 ◽  
Author(s):  
Peipei Zhou ◽  
Rongjie Zheng ◽  
Wei Zhang ◽  
Wei Liu ◽  
Yanyan Li ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Magnetic Nanoparticles ◽  
Metal Ions ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Ms Analysis ◽  
Icp Ms ◽  
Effervescent Tablet

A novel magnetic NiFe2O4-based effervescent tablet-assisted dispersive solid-phase microextraction (MNET-DSPM) was developed for extraction of metal ions prior to ICP-MS.

Chemometrical classification of biomonitoring analytical data for heavy metals. Part II. Mosses as bioindicators

1999 ◽  
Vol 69 (3-4) ◽  
pp. 287-294 ◽  
Author(s):  
S. Tsakovski ◽  
V. Simeonov ◽  
Th. Sawidis ◽  
G. Zachariadis ◽  
J. Stratis
Keyword(s):  
Heavy Metals ◽  
Analytical Data
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