scholarly journals The Efficacy of Whole Oyster Shells for Removing Copper, Zinc, Chromium, and Cadmium Heavy Metal Ions from Stormwater

2021 ◽  
Vol 13 (8) ◽  
pp. 4184
Author(s):  
Zhiying Xu ◽  
Caterina Valeo ◽  
Angus Chu ◽  
Yao Zhao
Keyword(s):  
Surface Area ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Exposure Time ◽  
Food Waste ◽  
Positive Relationship ◽  
Copper Ions ◽  
Zinc Ions ◽  
Cadmium Ions ◽  
Initial Concentration

This research investigates the use of a common food waste product for removing four different types of metals typically found in stormwater. Whole, unprocessed oyster shells are explored for use in stormwater management infrastructure that addresses water quality concerns. The role of the shells’ surface area, exposure time, and the solution’s initial concentration on the removal efficiency were examined. Beaker scale experimental results demonstrated very good efficiency by the oyster shells for removing copper ions (80–95%), cadmium ions (50–90%), and zinc ions (30–80%) but the shells were not as effective in removing hexavalent chromium (20–60%). There was a positive relationship between initial concentration and removal efficiency for copper and zinc ions, a negative relationship for hexavalent chromium, and no relationship was found for cadmium ions. There was also a positive relationship between surface area and removal efficiency, and exposure time and removal efficiency. However, after a certain exposure time, the increase in removal efficiency was negligible and desorption was occasionally observed. A mid-scale experiment to mimic real-world conditions was conducted in which continuous inflow based on a 6-h design storm was applied to 2.7 kg of whole, unprocessed oyster shells. The shells provided an 86% and an 84% removal efficiency of cadmium and copper ions, respectively, in one day of hydraulic retention time. No removal was observed for hexavalent chromium, and zinc ion removal was only observed after initial leaching. This work has significant implications for sustainable stormwater infrastructure design using a material commonly found in municipal food waste.

Preparation of Sands Modified by Aluminous Salt and its Adsorption Capability of CD2+

2011 ◽  
Vol 130-134 ◽  
pp. 856-859
Author(s):  
Chun Sheng Ding ◽  
Yang Ping Fu ◽  
Qian Fen Zhu ◽  
Jing Fu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Influencing Factors ◽  
Removal Efficiency ◽  
Specific Surface Area ◽  
Quartz Sand ◽  
Ph Value ◽  
Alkaline Condition ◽  
Initial Concentration ◽  
Adsorption Capability

In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd2+ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m2/g which was 9.38 times of that of original sand; the removal efficiency of Cd2+ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd2+ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd2+ solution, and was enhanced with the increase of pH value, the Cd2+ removal efficiency was almost 71% with pH 9.0.

Study on the Removal of Copper Ions from Water Using Eco-Friendly Attapulgite/Chitosan Composites

2012 ◽  
Vol 499 ◽  
pp. 419-422
Author(s):  
Yong Chen ◽  
Hui Xu ◽  
Jin Bao Sun ◽  
Chang Long Zhang
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Room Temperature ◽  
Copper Ions ◽  
External Factors ◽  
Mass Ratio ◽  
Absorption Time ◽  
Adsorption Time ◽  
Initial Concentration ◽  
Adsorbent Dosage

In this work attapulgite and chitosan were employed to prepare composites as eco-friendly adsorbent. Study on the removal efficiency of the adsorbent for copper ions in aqueous solution was carried out. External factors such as the amount of attapulgite in the composites, temperature, initial concentration of copper ions, adsorption time and adsorbent dosage how to influence the removal efficiency of composites were investigated. The results showed that at room temperature, 0.37g adsorbent can reach maximum adsorption rate, which the mass ratio of attapulgite and chitosan is 1:1, the initial concentration of copper ions is 50mg / L and absorption time is 2h.

Removal of Hexavalent Chromium and Turbidity in Drinking Water by Chitosan

2012 ◽  
Vol 433-440 ◽  
pp. 793-797 ◽  
Author(s):  
Shao Xiu Li ◽  
Yu Qiang Lian ◽  
Jian Feng Mai ◽  
Jian Xiong Tan ◽  
Shu Jie Hu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Drinking Water ◽  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Metal Ion ◽  
Removal Rate ◽  
Turbidity Removal ◽  
Initial Concentration ◽  
Stirring Time ◽  
Slow Mixing

The threat of heavy metal pollution in water sources becomes increasingly serious. Toxic hexavalent chromium is harmful for health. Chitosan is a non-toxic and pollution-free substance, it is a cationic coagulant after protonated in diluted acid solution, it also can complex for many heavy metal ion. The study on removal of Cr (Ⅵ) and turbidity in drinking water by chitosan in this paper was performed. The results showed that the removal efficiency of Cr (Ⅵ) decreased with increasing pH, the removal rate of Cr (Ⅵ) was as high as 100% at pH4 using the chitosan concentration of 1.0g/L, but in these conditions, the turbidity was not removed. The removal efficiency of Cr (Ⅵ) bore relationship to stirring time of slow mixing step and initial concentration of Cr (Ⅵ). The best stirring time was 4 hours. To attain a good removal efficiency of Cr (Ⅵ), the dosage of chitosan must increase with the initial concentration of Cr (Ⅵ) increasing. At pH7, low chitosan dosage had good turbidity removal.

scholarly journals Removal of Hexavalent Chromium From Wastewater by Cu/Fe Bimetallic Nanoparticles

2020 ◽  
Author(s):  
Jien Ye ◽  
Yi Wang ◽  
Qiao Xu ◽  
Hanxin Wu ◽  
Jianhao Tong ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Loading Rate ◽  
Bimetallic Nanoparticles ◽  
Particle Surface ◽  
Zerovalent Iron ◽  
Order Kinetic ◽  
Initial Concentration ◽  
First Order

Abstract BackgroundNanoscale zerovalent iron (nZVI) is a promising material for removing heavy metals from wastewater. However, passivation of nZVI hinders its efficiency in water treatment. Loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Purpose of this study was to clarify the effects and mechanisms of Cu loading on the removal efficiency of Cr(VI).ResultsThe results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. It was found that Cr(VI) removal followed a pseudo-first-order kinetic model. When the Cu loading rate was 3%, the initial concentration of Cr(VI) was 100 mg/L, the observed first-order rate coefficient (kobs) was 0.016 min-1 for Cu/Fe bimetallic nanoparticles at pH of 3.5, which was twice than that of nZVI (0.008 min-1). X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(Ⅲ) and precipitated on the particle surface as hydroxylated Cr(OH)3 and CrxFe1-x(OH)3 coprecipitation.ConclusionsIn this study, it was found that the loading of Cu can significantly increase the specific surface area and the Cr(VI) remove efficiency of nZVI, and the removal efficiency decreases with increasing pH and Cr(VI) initial concentration. Therefore, Cu loading can alleviate the passivation of nZVI effectively and can be beneficial for the application of iron-based nanomaterials in remediation of wastewater.

scholarly journals Application of biochar from crop residues for the removal of lead and copper

2020 ◽  
Author(s):  
José M. De la Rosa ◽  
Águeda Sánchez-Martín ◽  
María L. Sánchez-Martín ◽  
Nikolas Hagemann ◽  
Heike Knicker ◽  
...  
Keyword(s):  
Trace Elements ◽  
Removal Efficiency ◽  
Crop Residues ◽  
Copper Ions ◽  
Batch Adsorption ◽  
Sorption Data ◽  
Initial Concentration ◽  
Maximum Sorption Capacity ◽  
Removal Capacity ◽  
Maximum Sorption

<p>Due to the chemical composition and surface properties of biochar, a C-rich porous material produced by pyrolysis of biomass, it can act as an effective tool for the remediation of soils polluted with trace elements [1, 2]. However, its capacity to sorb these contaminants in a solution varies considerably depend on pyrolysis conditions, but also on the feedstock.  Thus, the major aim of this study is to evaluate the capacity of biochars from two crop residues to sorb Pb<sup>2+</sup> and Cu<sup>2+</sup>.</p><p>For this purpose, rice husk and olive pit biochars (RHB and OPB, respectively) were produced in a continuously feed reactor (Pyreka reactor, max. temperature 500 ºC, residence time 12 min; N<sub>2</sub> atmosphere).</p><p>The efficiency of lead and copper ions (Pb²⁺, Cu<sup>2+</sup>) removal by the biochars was investigated through batch adsorption experiments. 20 mL of single-metal solutions with 0.05, 0.1, 0.5, 1, 2 and 5 mM of initial concentration of Pb<sup>2+</sup> and Cu<sup>2+</sup> were mixed with 20 mg of milled biochar during 48 h. After filtering at 0.45 µm, their concentrations were measured by ICP-OES (Varian ICP 720-ES, Varian Inc., CA, USA).</p><p>Removal efficiency of both heavy metals was over 80 % for RHB and OPB when the initial cation concentration was ≤ 0.5 mM. RHB removal capacity was 26 % for Cu<sup>2+</sup> and 35 % for Pb<sup>2+</sup> when the initial concentration of metal was 5 mM, whereas OPB removal capacity for both cations was lower than 20 %. The adsorption data fitted well to a Langmuir model for both cations for RHB as other authors found [3]. Although, the Langmuir maximum sorption capacity obtained in this work for Cu<sup>2+</sup> was similar to that obtain by Samsuri et al. (2014) [3], it was lower for Pb<sup>2+</sup>. However, sorption data for OPB better fitted to a Temkin isotherm model for Cu<sup>2+</sup> and Freundlich model for Pb<sup>2+</sup>.</p><p>The selection of the adequate biomass to produce biochars for the immobilization of trace elements, as Pb and Cu, in soils is very important, due to the huge differences in their adsorption efficiency. RHB showed a greater removal efficiency for Cu<sup>2+</sup> and Pb<sup>2</sup> than OPB.</p><p><em>References:</em></p><p>[1] Uchimiya, M., Klasson, K.T., Wartelle, L.H., Lima, I.M., 2011. Chemosphere 82, 1438-1447.</p><p>[2] Zhao, J., Shen, X.-J., Domene, X., Alcañiz, J.-M., Liao, X., Palet, C., 2019. Sci. Rep. 9, 9869.</p><p>[3] Samsuri, A.W., Sadegh-Zadeh, F., She-Bardan, B.J., 2014. Int. J. Environ. Sci. Technol. 11, 967.</p><p><strong>Acknowledgements:</strong></p><p>The former Spanish Ministry of Economy, Industry and Competitiveness (MINEICO) and AEI/FEDER are thanked for funding the project CGL2016-76498-R (BIOREMEC). P. Campos thanks the “<em>Fundación Tatiana Pérez de Guzmán el Bueno</em>” for funding her PhD.</p>

The Adsorption of Cadmium Ions on Fly Ash Based Geopolymer Particles

2018 ◽  
Vol 766 ◽  
pp. 65-70 ◽  
Author(s):  
Sujitra Onutai ◽  
Takaomi Kobayashi ◽  
Parjaree Thavorniti ◽  
Sirithan Jiemsirilers
Keyword(s):  
Fly Ash ◽  
Removal Efficiency ◽  
Contact Time ◽  
Adsorption Process ◽  
Coal Fly Ash ◽  
Bet Surface Area ◽  
Cadmium Ions ◽  
Initial Concentration ◽  
Removal Capacity ◽  
Waste Coal

Geopolymer particles from waste coal fly ash were prepared in order to investigate adsorption process of Cadmium ions. The aim of the study is to focus on factors which affect adsorption process of heavy metals on geopolymer materials. The raw fly ash was mixed with sodium hydroxide solution and sodium silicate solution. After that geopolymer was cured at 80 °C for 24 hr. The sample was ground and washed until pH=7. The obtained geopolymer particles were dried at 60 oC. The raw materials and geopolymer were characterized. The XRD results showed a highly amorphous structure in obtained geopolymer. The major components of waste coal fly ash and synthesized geopolymer were SiO2, Al2O3, Fe2O3 and CaO. The BET surface area of fly ash and geopolymer particles were 0.83 m2/g and 85.01 m2/g, respectively. The adsorption conditions (initial concentration from 10-120 mg/L, temperature at 25-45 °C, pH of cadmium ions solution from 1-5, 0.02-0.14 g. of geopolymer and contact time for 5-180 min) were studied. From removal efficiency results, synthesized geopolymer had high removal capacity for cadmium ions (Cd2+). At pH 5 of solution, the highest Cd2+ removal capacity was obtained. In addition, the removal efficiency increases with an increasing geopolymer dosage, contact time and a decreasing of Cd2+ initial concentration. Moreover, both Langmuir and Freundlich models were investigated for studying adsorption isotherm. The result showed Langmuir model is more suitable for geopolymer adsorption of cadmium ion in aqueous solution than Freundlich model.

Comparative Bio-sorption of Cadmium and Nickel Ions from Aqueous Solution onto Fibers of Date Palm using Fluidized Bed Column

2019 ◽  
Vol 70 (5) ◽  
pp. 1507-1512
Author(s):  
Baker M. Abod ◽  
Ramy Mohamed Jebir Al-Alawy ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Date Palm ◽  
Operating Conditions ◽  
Initial Concentration ◽  
Bed Height

The aim of this study is to use the dry fibers of date palm as low-cost biosorbent for the removal of Cd(II), and Ni(II) ions from aqueous solution by fluidized bed column. The effects of many operating conditions such as superficial velocity, static bed height, and initial concentration on the removal efficiency of metal ions were investigated. FTIR analyses clarified that hydroxyl, amine and carboxyl groups could be very effective for bio-sorption of these heavy metal ions. SEM images showed that dry fibers of date palm have a high porosity and that metal ions can be trapped and sorbed into pores. The results show that a bed height of 6 cm, velocity of 1.1Umf and initial concentration for each heavy metal ions of 50 mg/L are most feasible and give high removal efficiency. The fluidized bed reactor was modeled using ideal plug flow and this model was solved numerically by utilizing the MATLAB software for fitting the measured breakthrough results. The breakthrough curves for metal ions gave the order of bio-sorption capacity as follow: Cd(II)]Ni(II).

Analysis of the system precipitation reactor-separation unit. Porosity of the filtration cake as a function of properties of the solid phase

1981 ◽  
Vol 46 (11) ◽  
pp. 2640-2649 ◽  
Author(s):  
Otakar Söhnel
Keyword(s):  
Linear Function ◽  
Surface Area ◽  
Granulometric Composition ◽  
Solid Phase ◽  
Separation Unit ◽  
Initial Concentration ◽  
Actual Surface ◽  
Suspension Concentration

Porosity of the filtration cake, formed at filtration of model suspensions of CaCO3, BaCrO4 and ZnO is not a function of suspension concentration as long as the solid phase forming the suspension is of the same granulometric composition. The calculated surface area of the solid phase, effective as concerns filtration at ΔP = 30 kPa, is smaller than the actual surface area determined by absorption of nitrogen. Porosity of the filtration cake formed at filtration of suspensions of Mg(OH)2, CaCO3, SrCO3 and BaCO3 prepared by precipitation is a linear function of the initial concentration of precipitated solutions since it is affected by the size and polydispersity of originating particles in dependence on concentration of precipitated solutions. The cakes formed at filtration of precipitated suspensions of CaCO3, SrCO3 and BaCO3 aged for up to 2 hours from the instant of their preparation have a constant porosity which is independent of the time of suspension aging.

scholarly journals Removal of hexavalent chromium from wastewater by Cu/Fe bimetallic nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jien Ye ◽  
Yi Wang ◽  
Qiao Xu ◽  
Hanxin Wu ◽  
Jianhao Tong ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Particle Surface ◽  
Zerovalent Iron ◽  
Order Model ◽  
X Ray ◽  
Nanoscale Zerovalent Iron

AbstractPassivation of nanoscale zerovalent iron hinders its efficiency in water treatment, and loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Synthesized bimetallic nanoparticles were characterized by transmission electron microscopy, Brunauer–Emmet–Teller isotherm, and X-ray diffraction. The results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. The removal of Cr(VI) was better fitted by pseudo-second-order model than pseudo-first-order model. Thermodynamic analysis revealed that the Cr(VI) removal was spontaneous and endothermic, and the increase of reaction temperature facilitated the process. X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(III) and precipitated on the particle surface as hydroxylated Cr(OH)3 and CrxFe1−x(OH)3 coprecipitation. Our work could be beneficial for the application of iron-based nanomaterials in remediation of wastewater.

scholarly journals A new biocompatible ternary Layered Double Hydroxide Adsorbent for ultrafast removal of anionic organic dyes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Garima Rathee ◽  
Amardeep Awasthi ◽  
Damini Sood ◽  
Ravi Tomar ◽  
Vartika Tomar ◽  
...  
Keyword(s):  
Waste Water ◽  
Methyl Orange ◽  
Surface Area ◽  
Layered Double Hydroxide ◽  
Removal Efficiency ◽  
Organic Dyes ◽  
High Surface ◽  
High Surface Area ◽  
Morphological Studies ◽  
Double Hydroxide

Abstract It would be of great significance to introduce a new biocompatible Layered Double Hydroxide (LDH) for the efficient remediation of wastewater. Herein, we designed a facile, biocompatible and environmental friendly layered double hydroxide (LDH) of NiFeTi for the very first time by the hydrothermal route. The materialization of NiFeTi LDH was confirmed by FTIR, XRD and Raman studies. BET results revealed the high surface area (106 m2/g) and the morphological studies (FESEM and TEM) portrayed the sheets-like structure of NiFeTi nanoparticles. The material so obtained was employed as an efficient adsorbent for the removal of organic dyes from synthetic waste water. The dye removal study showed >96% efficiency for the removal of methyl orange, congo red, methyl blue and orange G, which revealed the superiority of material for decontamination of waste water. The maximum removal (90%) of dyes was attained within 2 min of initiation of the adsorption process which supported the ultrafast removal efficiency. This ultrafast removal efficiency was attributed to high surface area and large concentration of -OH and CO32− groups present in NiFeTi LDH. In addition, the reusability was also performed up to three cycles with 96, 90 and 88% efficiency for methyl orange. Furthermore, the biocompatibility test on MHS cell lines were also carried which revealed the non-toxic nature of NiFeTi LDH at lower concentration (100% cell viability at 15.6 μg/ml). Overall, we offer a facile surfactant free method for the synthesis of NiFeTi LDH which is efficient for decontamination of anionic dyes from water and also non-toxic.

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