The Elimination of Mineral Micropollutants

1982 ◽  
Vol 14 (12) ◽  
pp. 87-105 ◽  
Author(s):  
B Regnier ◽  
C Goblet ◽  
J Genot ◽  
W J Masschelein
Keyword(s):  
Heavy Metals ◽  
Contact Time ◽  
Ph Value ◽  
Elimination Rate ◽  
Cation Exchange Resin ◽  
Specific Effect ◽  
Waste Waters ◽  
Variable Elimination ◽  
Heavy Metal Salts ◽  
Treatment Facilities

Mineral micropollutants in waste waters and drinking water are essentially composed of heavy metal salts. Their elimination, when present in trace quantities, is discussed in this paper. The techniques, which water treatment facilities can use, necessitate preclarification in open basins (efficiency varying between 20 and 90%), elimination by filtration, with efficiencies depending largely on preoxidation but particularly on coagulation-precipitation and related techniques. Our investigations, as well as certain literature data, demonstrate the predominating importance of contact between water and sludges in decanters-clarificators. Thus, Jar tests often yield only a poorly representative result of the elimination of heavy metals by coagulation-flocculation-decantation. As to the use of aluminium sulphate, for example, the elimination rates mentioned relating to the elimination rate or % removal in laboratory experiments, in pilot tests with sludge beds and in treatment plants respectively are as follows: Fe: 100, 95, 100; Mn: 4, 38, 97; Cu: 91, 83, 85; Cr: 29, 8, 83; Cd: 21, 29, 96; Ni: 0, 20, 50; Co: 0, 16, 51; Pb; -, 52, 61. It should be noted that treatment in plants is much more elaborate (oxidation by chlorine dioxide, application of activated silica and a one hour contact time with the sludge bed) than in pilot experiments (15 minutes contact time and a sludge bed without activated carbon). The oxidation state of metals plays an important role in techniques for their elimination by the usual methods such as coagulation-flocculation-decantation as well as in coprecipitation phenomena of Fe and Mn for example. The method of alkaline precipitation, in which the pH value needed is obtained by addition of lime, results in elimination rates over 80% and generally far over 90%. This method uses at the same time direct precipitation and coprecipitation in a calcium carbonate/magnesium oxide matrix. Ion exchange gives highly variable elimination results according to the ion present and its concentration. In practice, strong cation exchange resin are generally applied. In treatment plants, adsorption on carbon allows an overall yield of 50-100% removal of the metal concerned, provided that preoxidation and sufficient contact times are allowed. The experimental distinction of the specific effect due to adsorption is difficult, but according to our studies, adsorption occurs to a small extent only in the majority of cases. 30-50% of the remaining traces are eliminated by infiltration of purified waters underground, where a levelling of concentrations also occurs. In addition to the investigations presented, studies still being carried out demonstrate a sufficient stabilization of heavy metals immobilized with lime in order to allow them to be dumped in the environment without risk. This method seems confirmed as a method of choice in treatment of waste waters loaded with heavy metals.

scholarly journals Investigation of Heavy Metal (Lead) Removal from Aqueous Solution by Using Advanced Oxidation Process (Fenton)

2019 ◽  
pp. 1-7
Author(s):  
Fahimeh Moghadam ◽  
Asma Ghasemi Pourafshar
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Contact Time ◽  
Advanced Oxidation Process ◽  
Aqueous Media ◽  
Elimination Rate ◽  
Lead Removal ◽  
Chronic Complications ◽  
Food And Beverage ◽  
Lead Metal

Background and Aim: Undoubtedly, controlling the maximum entry of heavy metals into the food is one of the measures which should be taken into account in order to maintain the food consumers' health and achieve the food safety. The sensitivity and importance of this issue are doubled due to the irreparable, acute and chronic complications of heavy metals which are classified according to the effects on the nervous system until the carcinogenesis in the human body. On the other hand, this issue is significantly important since these metals differently enter to crops such as tea, water, and rice and generally the food and beverage that are widely consumed. Therefore, the aim of this study is to remove heavy lead metal from aqueous solution by Fenton method. This study is an experimental study. The samples are synthesized in a collection of laboratories at the Faculty of Health, and the pH parameters, contact time and lead elimination rate and the optimal Fenton ratio are investigated. Results are analyzed using SPSS software and Charts are plotted by excel. The results showed that the best pH for removal of lead 5 and its best concentration is 30 mg/ L, and the optimal Fenton ratio is 1 to 5, as well as the best contact time for removal of lead from aqueous media for 10 minutes. The present study showed that the pH factor, contact time, Fenton concentration and lead in all four were effective in removing lead from aquatic solution.

scholarly journals Bioadsorption of Heavy Metals From Industrial Wastewater Using Some Species of Bacteria

2016 ◽  
Vol 13 (3) ◽  
pp. 435-448
Author(s):  
Baghdad Science Journal
Keyword(s):  
Heavy Metals ◽  
Contact Time ◽  
Industrial Wastewater ◽  
Lead Concentration ◽  
Ph Value ◽  
Metal Adsorption ◽  
Copper Adsorption ◽  
E Coli ◽  
Sulfate Reducing ◽  
Different Temperatures

Three isolated bacteria were examined to remove heavy metals from the industrial wastewater of the Diala State Company of Electrical Industries, Diyala-Iraq. The isolated bacteria were identified as Pseudomonas aeruginosa, Escherichia coli and Sulfate Reducing Bacteria (SRB). The three isolates were used as an adsorption factor for different concentrations of Lead and Copper (100, 150, and 200 ppm.), in order to examine the adsorption efficiency of these isolates. In addition, the effect of three factors on heavy metals adsorption were examined; temperature (25, 30, and 37 ?C), pH (3 and 4.5) and contact time (2 and 24 hrs). The results showed that the highest level of lead adsorption was obtained at 37 ?C by E. coli, P, aerugenosa and SRB with percentage of 95, 95.3 and 99.7 % respectively, whereas, E. coli, P. Aerugenosa and SRB gave a copper adsorption percentage of (40.63, 50.51 and 80.57%) respectively at 37 ?C. Moreover, E.coli showed different percentage of metal adsorption ranged from 6.4% to 95 % with lead concentration of 100 and 200 ppm at pH4.5 and for each of 2 and 24 hrs contact time, whereas, it exerts percentage of copper adsorption ranged from 3.5 % to 40.63 % at 100 and 200 ppm and pH value of 4.5 for similar contact time. P. aerugenosa was also shown to be involved in metal adsorption with percentage ranged from 1.39 % for lead concentration of 150 ppm to 97.9 % for 200ppm under pH of 3 and contact times of 2 and 24 hrs. Interestingly, SRB exhibits significant differences in metal absorption values ranged from 14.97 % for lead (100 ppm) to 99.32 % at 200 ppm with a pH value of 3 and contact times of 2 and 24 hrs and under different temperatures.

scholarly journals Washing Batch Test of Contaminated Sediment: The Case of Augusta Bay (SR, Italy)

2020 ◽  
Vol 10 (2) ◽  
pp. 473
Author(s):  
Lucia Lumia ◽  
Maria Gabriella Giustra ◽  
Gaspare Viviani ◽  
Gaetano Di Bella
Keyword(s):  
Heavy Metals ◽  
Citric Acid ◽  
Petroleum Hydrocarbons ◽  
Contact Time ◽  
Ph Value ◽  
Weight Ratio ◽  
Total Petroleum Hydrocarbons ◽  
Contaminated Sediment ◽  
Ph Values ◽  
Removal Efficiencies

Two experimental campaigns were conducted to optimize the applicability of the Sediment Washing treatment on the marine sediments of Augusta Bay contaminated with heavy metals and total petroleum hydrocarbons (TPH). In the first campaign were used EDTA, citric acid, and acetic acid to removal only heavy metals (Ni, Cu, Zn, Cr, and Hg) from the sediments, while in the second campaign EDTA, citric acid, and EDDS were used to removal heavy metals (Ni, Cu, Cr, and Pb) and TPH. The tests were conducted at different pH values and contact times with 1:10 solid:liquid weight ratio. In the first experimental, at pH values 4, contact time 3 h, and citric acid, high removal efficiencies (78–82%) have been obtained for Ni, Cu, Zn, and Cr metals, while, in the second experimental campaign, at pH value 4, contact time 0.5 h, and citric acid, high removal efficiencies have been achieved especially for Pb and TPH. Finally, on the basis of the results obtained, a conceptual sediment washing treatment layout was proposed and the related costs estimated.

Parameters Affecting Dye Adsorption - Using Graphene Coated Sand (GSC)

2018 ◽  
Vol 4 (02) ◽  
Author(s):  
Seroor Atalah Khaleefa Alia ◽  
Dr. Mohammed Ibrahimb ◽  
Hussein Ali Hussein
Keyword(s):  
Heavy Metals ◽  
Contact Time ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Adsorption ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Engineering Designs ◽  
Heavy Metals Ions ◽  
Coated Sand

Adsorption is most commonly applied process for the removal of pollutants such as dyes and heavy metals ions from wastewater. The present work talks about preparing graphenic material attached sand grains called graphene sand composite (GSC) by using ordinary sugar as a carbon source. Physical morphology and chemical composition of GSC was examined by using (FTIR, SEM, EDAX and XRD). Efficiency of GSC in the adsorption of organic dyes from water was investigated using reactive green dye with different parameters such as (ph, temperature, contact time and dose). Adsorption isotherm was also studied and the results showed that the maximum adsorption capacity of dye is 28.98 mg/g. This fast, low-cost process can be used to manufacture commercial filters to treat contaminated water using appropriate engineering designs.

The new technology of waste water treatment by using bioreactors with bio membranous movable bed – biochips

2020 ◽  
Vol 10 (3) ◽  
pp. 276-292
Author(s):  
Maria Y. Savostyanova ◽  
◽  
Lidia А. Norina ◽  
Arina V. Nikolaeva ◽  
◽  
...  
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Water Resources ◽  
Waste Water Treatment ◽  
Combined Treatment ◽  
Research Work ◽  
Pollution Level ◽  
Waste Waters ◽  
Treatment Facilities ◽  
Movable Bed

Retaining of water resources quality is one of the global ecological problems of the modern time. The most promising direction in solving the problem of water resources protection is the reduction of negative environmental influence of waste water from production facilities by upgrading the existing water treatment technologies. To treat utility water, technical and rain water from site facilities of Transneft system entities, the specialists developed and approved standard technological diagrams, which are used in producing treatment facilities. The standard technological diagrams provide for all necessary stages of waste water treatment ensures the reduction of pollution level to normal values. However, during operation of treatment facilities it was established, that to ensure the required quality of waste water treatment with initially high levels of pollution, the new technological solutions are necessary. The author presents the results of scientific-research work, in the context of which the best affordable technologies were identified in the area of the treatment of waste water with increased content of pollutants and non-uniform ingress pattern. On the basis of the research results the technical solutions were developed for optimization of operation of existing waste water treatment facilities by means of using combined treatment of technical and rain waters and utility waste waters and applying bioreactor with movable bed – biochips. The use of bioreactor with movable bed allows the increase in the area of active surface, which facilitates increase and retention of biomass. Biochips are completely immersed into waste waters, and biofilm is formed on the entire volume of immersion area, facilitating retention of biomass and preventing formation of sediments. Due to mixing the floating device with biofilm constantly moves along the whole area of bioreactor, and, in doing so, speeds up biochemical processes and uniformity of treatment. The advantages of a bioreactor with movable bed – its active sludge durability against increased and changing pollutant concentrations, change of waste water temperature and simplicity of application – ensured the possibility of its use for blending utility waters, technical and rain waters.

Nano-ZrO2/TiO2 Impregnated Orange Wood Sawdust and Peach Stone Shell Adsorbents for Cr (VI) Removal

2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan
Keyword(s):  
Contact Time ◽  
Ph Value ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Wood Sawdust ◽  
Adsorption Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Equilibrium Status

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

scholarly journals Synthesis, characterization and heavy metal removal efficiency of nickel ferrite nanoparticles (NFN’s)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Waheed Ali Khoso ◽  
Noor Haleem ◽  
Muhammad Anwar Baig ◽  
Yousuf Jamal
Keyword(s):  
Heavy Metals ◽  
Nickel Ferrite ◽  
Contact Time ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Ferrite Nanoparticles ◽  
Batch Adsorption ◽  
Aqueous Environment ◽  
Human Beings ◽  
Nickel Ferrite Nanoparticles

AbstractThe heavy metals, such as Cr(VI), Pb(II) and Cd(II), in aqueous solutions are toxic even at trace levels and have caused adverse health impacts on human beings. Hence the removal of these heavy metals from the aqueous environment is important to protect biodiversity, hydrosphere ecosystems, and human beings. In this study, magnetic Nickel-Ferrite Nanoparticles (NFNs) were synthesized by co-precipitation method and characterized using X-Ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS) and Field Emission Scanning Electronic Microscopy (FE-SEM) techniques in order to confirm the crystalline structure, composition and morphology of the NFN’s, these were then used as adsorbent for the removal of Cr(VI), Pb(II) and Cd(II) from wastewater. The adsorption parameters under study were pH, dose and contact time. The values for optimum removal through batch-adsorption were investigated at different parameters (pH 3–7, dose: 10, 20, 30, 40 and 50 mg and contact time: 30, 60, 90, and 120 min). Removal efficiencies of Cr(VI), Pb(II) and Cd(II) were obtained 89%, 79% and 87% respectively under optimal conditions. It was found that the kinetics followed the pseudo second order model for the removal of heavy metals using Nickel ferrite nanoparticles.

scholarly journals Application of modified green algae Nannochloropsis sp. as adsorbent in the simultaneous adsorption of Methylene Blue and Cu(II) cations in solution

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Buhani ◽  
Tri Agus Wijayanti ◽  
Suharso ◽  
Sumadi ◽  
Muslim Ansori
Keyword(s):  
Heavy Metals ◽  
Methylene Blue ◽  
Green Algae ◽  
Contact Time ◽  
Organic Dyes ◽  
Silica Matrix ◽  
Particle Coating ◽  
Adsorption Data ◽  
Magnetite Particles ◽  
Simultaneous Sorption

AbstractBiomass of algae is a very potent adsorbent for absorbing aqueous waste containing heavy metals and organic dyes. This study purposes to confirm the ability of adsorbents from green algae Nannochloropsis sp. modified with silica (ASN) and followed by coating magnetite particles (ASN-MPs) to absorb simultaneously the mixture of Methylene Blue (ME) and Cu(II) cations in aqueous solution. Simultaneous sorption of ME and Cu(II) cations to ASN and ASN-MPs was carried out by the batch method with the interaction pH condition 7, contact time 90 min, and initial concentrations of ME and Cu(II) cations (0.1–1.0 mM). Based on adsorption data, Cu(II) cations have a greater adsorption rate and capacity (qm) compared to ME at the same contact time and initial concentration. The adsorption capacity (qm) values of the bi-component ME and Cu(II) cation mixture in ASN and ASN-MPs were 1.39 × 10− 1 and 5.32 × 10− 1 mmol g− 1, respectively, with the binary Langmuir adsorption isotherm constant for Cu(II) cations greater than ME. Modified adsorbent from algae Nannochloropsis sp. with silica matrix and magnetite particle coating is an adsorbent that has a high effectiveness in the collective sorption of ME and Cu(II) cations. Therefore, these adsorbents can be used for the adsorption of cation mixtures of heavy metals and organic dyes that are cationic in solution.

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