scholarly journals Synthetic Iowaite Can Effectively Remove Inorganic Arsenic from Marine Extract

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3052
Author(s):  
Jing Ji ◽  
Wenwen Huang ◽  
Lingchong Wang ◽  
Lu Chen ◽  
Yuanqing Wei ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Inorganic Arsenic ◽  
Order Kinetic ◽  
Marine Products ◽  
Organic Arsenic ◽  
Inclusion Morphology ◽  
Standard Solution ◽  
Marine Food ◽  
Adsorption Rates ◽  
Removal Of Arsenic

For the removal of arsenic from marine products, iowaite was prepared and investigated to determine the optimal adsorption process of arsenic. Different chemical forms of arsenic (As(III), As(V)) with varying concentrations (0.15, 1.5, 5, 10, 15, and 20 mg/L) under various conditions including pH (3, 5, 7, 9, 11) and contact time (1, 2, 5, 10, 15, 30, 60, 120, 180 min) were exposed to iowaite. Adsorption isotherms and metal ions kinetic modeling onto the adsorbent were determined based on Langmuir, Freundlich, first- and second-order kinetic models. The adsorption onto iowaite varied depending on the conditions. The adsorption rates of standard solution, As(III) and As(V) exceeded 95% under proper conditions, while high complexity was noted with marine samples. As(III) and As(V) from Mactra veneriformis extraction all decreased when exposed to iowaite. The inclusion morphology and interconversion of organic arsenic limit adsorption. Iowaite can be efficiently used for inorganic arsenic removal from wastewater and different marine food products, which maybe other adsorbent or further performance of iowaite needs to be investigated for organic arsenic.

scholarly journals The sorption of inorganic arsenic on modified sepiolite: Effect of hydrated iron(III)-oxide

2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Arsenic Removal ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Deionized Water ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.

scholarly journals Zeolite-Rich Composite Materials for Environmental Remediation: Arsenic Removal from Water

2020 ◽  
Vol 10 (19) ◽  
pp. 6939
Author(s):  
Bruno de Gennaro ◽  
Paolo Aprea ◽  
Barbara Liguori ◽  
Barbara Galzerano ◽  
Antonio Peluso ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Arsenic Removal ◽  
Fixed Bed ◽  
Exchange Capacity ◽  
Order Kinetic ◽  
Natural Zeolites ◽  
Dynamic Conditions ◽  
Good Ability ◽  
Adsorption Rates ◽  
Surface Modified

Natural zeolites are used as adsorbents in purification processes due to their cation-exchange ability and molecular sieve properties. Surface modified natural zeolites (SMNZs), produced by attaching cationic organic surfactants to the external surface, can simultaneously act as ionic exchangers and organic molecule adsorbents. In this paper, SMNZs were produced and investigated as adsorbents for As(V) removal from wastewater: two natural zeolites, clinoptilolite and phillipsite, were modified using HDTMA-Br and HDTMA-Cl as surfactants. The obtained samples were then characterized under static and dynamic conditions. Results showed that As(V) removal follows a pseudo-second order kinetic, with fast adsorption rates: every sample reached 100 % removal in 2 h, while equilibrium data showed a Langmuir-like behavior, with a greater anion uptake by the HDTMA-Br modified SMNZs due to the formation of a compact and complete micellar structure. Finally, fixed-bed tests were performed to characterize the samples under dynamic conditions assessing the effect of severe operating parameters on the dynamic exchange capacity, selectivity and efficiency of the process. The obtained results demonstrate a good ability of the tested materials to adsorb As(V) from wastewater, confirming the effectiveness of the proposed surface modification technique in expanding the possibility of using natural zeolites in these processes.

Specifically Designed Amine Functional Group Doped Sludge Biochar for Inorganic and Organic Arsenic Removal

2020 ◽  
Author(s):  
Chih-Kuei Chen ◽  
Nhat-Thien Nguyen ◽  
Thuy-Trang Le ◽  
Cong-Chinh Duong ◽  
Thi-Thanh Duong
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Arsenic Removal ◽  
Physical Adsorption ◽  
Inorganic Arsenic ◽  
Chemical Adsorption ◽  
Arsenic Adsorption ◽  
Organic Arsenic ◽  
Adsorption Energies

Abstract Usages of hospital sludge as a biochar adsorbent for wastewater treatment plants were investigated. Microwave carbonization was used to carbonize the sludge and then chemically activated with ZnCl 2 to increase surface area and porosity. A newly designed amine functional group’s (DETA) doped sludge biochar carbon (SBC) presents effective inorganic arsenic (As(III), As 2 O 3 ) and organic arsenic (p-ASA, C 2 H 7 AsO 2 ) adsorption in water. The pore volume, pore size distribution and specific surface area were determined by performing nitrogen adsorption-desorption measurements (BET). The Fourier transform infrared (FTIR) of the SBC was recorded to study the functional groups at room temperature. The composition of SBC was further determined by X-ray photoelectron spectroscopy (XPS). In order to understand the effect of amine functional complexes on arsenic adsorption, the adsorption mechanism of As 2 O 3 and p-ASA on SBC surfaces modified with amine functional complexes was studied using density functional theory (DFT). Results showed that both physical and chemical adsorption of As 2 O 3 and p-ASA on SBC surfaces occurred. The participation of amine functional complexes greatly promoted the surface activity of SBC surface and its adsorption capacity on arsenic. The physical adsorption energies of As 2 O 3 and p-ASA on SBC surface with amine functional complexes were -38.4 and -32.8 KJ mol -1 , respectively. Other hand, the chemical adsorption energies of As 2 O 3 and p-ASA on SBC surface with amine functional complexes were -92.9 KJ mol -1 and -98.5 KJ mol -1 , respectively.

Speciation and Removal of Arsenic in column packed with chitosan

2006 ◽  
Vol 1 (4) ◽  
Author(s):  
Martha Benavente ◽  
Marcos Arévalo ◽  
Joaquín Martínez
Keyword(s):  
Arsenic Removal ◽  
Arsenic Speciation ◽  
Packed Column ◽  
Arsenic Concentration ◽  
Breakthrough Curves ◽  
Arsenic Adsorption ◽  
Major Species ◽  
Standard Solution ◽  
Ph Range ◽  
Removal Of Arsenic

The arsenic speciation and arsenic removal in chitosan packed column were studied. Arsenic removal experiments were carried out with an arsenic standard solution (1.0 mg/l) and drilled well water samples from Limon Mine Community at different pH, water flowrate, and volume of adsorbent material. The simulation of arsenic speciation was carried out at a pH range from 0 to 12, a temperature of 25ºC, a pE equal to 4, and a total arsenic concentration of 1.34 x 10-5 mol kg-1. According to speciation calculations arsenic is found mainly in oxidized form in the conditions of Limon Mine’s drilled well waters, dihydrogen arsenate ion (H2AsO4-), and hydrogen arsenate ion (HAsO42-) being the major species. The experiments showed that arsenic adsorption depends mainly on the pH as well as the activity of functional groups that compose the chitosan structure. At pH 3 and volume of adsorbent material of 337.8 cm3 an adsorption of 94% was obtained from arsenic standard solution, and the arsenic present in the Limon Community’s water was almost totally removed at pH 3 and 7. The use of the results for designing purposes demands the breakthrough curves for chitosan to be determined.

Arsenic removal by MF membrane with chemical sludge adsorption and NF membrane equipped with vibratory shear enhanced process

2003 ◽  
Vol 3 (5-6) ◽  
pp. 303-310 ◽  
Author(s):  
S.-H. Yi ◽  
S. Ahmed ◽  
Y. Watanabe ◽  
K. Watari
Keyword(s):  
Arsenic Removal ◽  
Membrane Surface ◽  
Membrane Process ◽  
Low Concentrations ◽  
Strong Shear ◽  
Low Levels ◽  
Removal Processes ◽  
Removal Of Arsenic ◽  
Concentration Polarization Layer ◽  
Chemical Sludge

Conventional arsenic removal processes have difficulty removing low concentrations of arsenic ion from water. Therefore, it is very hard to comply with stringent low levels of arsenic, such as below 10 μg/L. So, we have developed two arsenic removal processes which are able to comply with more stringent arsenic regulations. They are the MF membrane process combined with chemical sludge adsorption and NF membrane process equipped with the vibratory shear enhanced process (VSEP). In this paper, we examine the performance of these new processes for the removal of arsenic ion of a low concentration from water. We found that chemical sludge produced in the conventional rapid sand filtration plants can effectively remove As (V) ions of H2AsO4- and HAsO42- through anion exchange reaction. The removal efficiency of MF membrane process combined with chemical sludge adsorption increased to about 36%, compared to MF membrane alone. The strong shear force on the NF membrane surface produced by vibration on the VSEP causes the concentration polarization layer to thin through increased back transport velocity of particles. So, it can remove even dissolved constituents effectively. Therefore, As (V) ions such as H2AsO4- and HAsO42- can be removed. The concentration of As (V) ions decreased from 50 μg/L to below 10 μg/L and condensation factor in recirculating water increased up to 7 times by using NF membrane equipped with VSEP.

scholarly journals Adsorption of p-Arsanilic Acid on Iron (Hydr)oxides and Its Implications for Contamination in Soils

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 105
Author(s):  
Yifan Yang ◽  
Shiyong Tao ◽  
Zhichun Dong ◽  
Jing Xu ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Organic Matter Content ◽  
Feed Additives ◽  
Unit Surface Area ◽  
Potential Hazard ◽  
Order Kinetic ◽  
Positive Correlation ◽  
Arsanilic Acid ◽  
Organic Arsenic ◽  
Ph Conditions

Because of the diversification of industries in developing cities, the phenomenon of the simultaneous contamination of various kinds of pollutants is becoming common, and the environmental process of pollutants in multi-contaminated environmental mediums has attracted attention in recent years. In this study, p-arsanilic acid (ASA), a kind of organic arsenic feed additive that contains the arsenic group in a chemical structure, is used as a typical contaminant to investigate its adsorption on iron oxides and its implication for contaminated soils. The adsorption kinetics on all solids can be fitted to the pseudo-second-order kinetic model well. At the same mass dosage conditions, the adsorption amount per unit surface area on iron oxides follows the order α-FeOOH > γ-Fe2O3 > α-Fe2O3, which is significantly higher than that for actual soil, because of the lower content of iron oxides in actual soil. Lower pH conditions favor ASA adsorption, while higher pH conditions inhibit its adsorption as a result of the electrostatic repulsion and weakened hydrophobic interaction. The presence of phosphate also inhibits ASA adsorption because of the competitive effect. Correlations between the amount of ASA adsorption in actual soil and the Fe2O3 content, total phosphorus content, arsenic content, and organic matter content of actual soil are also investigated in this work, and a moderate positive correlation (R2 = 0.630), strong negative correlation (R2 = 0.734), insignificant positive correlation (R2 = 0.099), and no correlation (R2 = 0.006) are found, respectively. These findings would help evaluate the potential hazard of the usage of organic arsenic feed additives, as well as further the understanding of the geochemical processes of contaminants in complicated mediums.

Arsenic Speciation: Reduction of Arsenic(V) to Arsenic(III) by Fulvic Acid

2006 ◽  
Vol 3 (2) ◽  
pp. 137 ◽  
Author(s):  
Tsanangurayi Tongesayi ◽  
Ronald B. Smart
Keyword(s):  
Fulvic Acid ◽  
Arsenic Removal ◽  
Research Effort ◽  
Arsenic Speciation ◽  
Inorganic Arsenic ◽  
Stripping Voltammetry ◽  
Reduction Reaction ◽  
Cathodic Stripping Voltammetry ◽  
Suwannee River Fulvic Acid ◽  
Removal Technologies

Environmental Context.Most technologies for arsenic removal from water are based on the oxidation of the more toxic and more mobile arsenic(iii) to the less toxic and less mobile arsenic(v). As a result, research effort has been focussed on the oxidation of arsenic(iii) to arsenic(v). It is equally important to explore environmental factors that enhance the reduction of arsenic(v) to arsenic(iii). An understanding of the redox cycling of arsenic could result in the development of cheaper and more efficient arsenic removal technologies, especially for impoverished communities severely threatened by arsenic contamination. Abstract.The objective of this study was to investigate the reduction of inorganic arsenic(v) with Suwannee River fulvic acid (FA) in aqueous solutions where pH, [FA], [As(v)], [As(iii)], and [Fe(iii)] were independently varied. Samples of inorganic As(v) were incubated with FA in both light and dark at constant temperature. Sterilisation techniques were employed to ensure abiotic conditions. Aliquots from the incubated samples were taken at various time intervals and analysed for As(iii) using square-wave cathodic-stripping voltammetry at a hanging mercury drop electrode. The study demonstrated the following important aspects of As speciation: (1) FA can significantly reduce As(v) to As(iii); (2) reduction of As(v) to As(iii) is a function of time; (3) both dark and light conditions promote reduction of As(v) to As(iii); (4) Fe(iii) speeds up the reduction reaction; and (5) oxidation of As(iii) to As(v) is promoted at pH 2 more than at pH 6.

Arsenic Removal from Wastewater Using Adsorptive Mediums

2011 ◽  
Vol 189-193 ◽  
pp. 404-409
Author(s):  
Fu Quan Peng ◽  
Zhen Cheng Xu ◽  
Jian Hong Huang ◽  
Qing Wei Guo ◽  
Feng Nie
Keyword(s):  
Arsenic Removal ◽  
Removal Rate ◽  
National Standards ◽  
Ferrous Oxide ◽  
Anion Resin ◽  
Quartz Sands ◽  
Long Time ◽  
Removal Of Arsenic ◽  
Adsorptive Properties

Different adsorptive mediums and adsorbents’ compounds were chosen to remove arsenic from Yangzonghai Lake wastewater. Results showed that Ca(OH)2, attapulgite, bentonite, LDHs these adsorptive mediums had adsorptive capacities of less than 2.5 mg/g of As removal and it took long time for sediment before monitoring; adsorbents compounds’ results showed Fe2O3 and quartz sands had best removal rate and quartz sands had little removal of arsenic. Both strong anion resin and hydrated ferrous oxide-loaded on polystyrene diethanolamine resin(designated as PDR-HFO) can decrease As concentration to less than 0.01 mg/L reaching national standards for arsenic; anions such as SO42- can not be removed when strong anion resin was regenerated causing its loss of exchange ions; PDR-HFO exhibited excellent adsorptive properties and recyclability.

Preparation of Fe-SBC from Urban Sludge for Organic and Inorganic Arsenic Removal

2019 ◽  
Vol 19 (5) ◽  
pp. 2658-2663 ◽  
Author(s):  
Min-Fa Lin ◽  
Nhat-Thien Nguyen ◽  
Chang-Tang Chang ◽  
Po-Han Chen
Keyword(s):  
Arsenic Removal ◽  
Inorganic Arsenic

scholarly journals Arsenic speciation in food chains from mid-Atlantic hydrothermal vents

2012 ◽  
Vol 9 (2) ◽  
pp. 130 ◽  
Author(s):  
Vivien F. Taylor ◽  
Brian P. Jackson ◽  
Matthew R. Siegfried ◽  
Jana Navratilova ◽  
Kevin A. Francesconi ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Arsenic Speciation ◽  
Inorganic Arsenic ◽  
Food Sources ◽  
Arsenic Compounds ◽  
Marine Animals ◽  
Δ13c And Δ15n ◽  
Organic Arsenic

Environmental contextArsenic occurs in marine organisms at high levels and in many chemical forms. A common explanation of this phenomenon is that algae play the central role in accumulating arsenic by producing arsenic-containing sugars that are then converted into simpler organic arsenic compounds found in fish and other marine animals. We show that animals in deep-sea vent ecosystems, which are uninhabited by algae, contain the same organic arsenic compounds as do pelagic animals, indicating that algae are not the only source of these compounds. AbstractArsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge hydrothermal vents. The shrimp species, Rimicaris exoculata, the vent chimney-dwelling mussel, Bathymodiolus azoricus, Branchipolynoe seepensis, a commensal worm of B. azoricus and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (δ13C and δ15N) signature between species, suggesting different sources of As uptake. Arsenic speciation showed arsenobetaine to be the dominant species in R. exoculata, whereas in B. azoricus and B. seepensis arsenosugars were most abundant, although arsenobetaine, dimethylarsinate and inorganic arsenic were also observed, along with several unidentified species. Scrape samples from outside the vent chimneys covered with microbial mat, which is a presumed food source for many vent organisms, contained high levels of total As, but organic species were not detectable. The formation of arsenosugars in pelagic environments is typically attributed to marine algae, and the pathway to arsenobetaine is still unknown. The occurrence of arsenosugars and arsenobetaine in these deep sea organisms, where primary production is chemolithoautotrophic and stable isotope analyses indicate food sources are of vent origin, suggests that organic arsenicals can occur in a foodweb without algae or other photosynthetic life.

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