scholarly journals Organobentonites as multifunctional adsorbents of organic and inorganic water pollutants

2014 ◽  
Vol 79 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Natаsa Jovic-Jovicic ◽  
Aleksandra Milutinovic-Nikolic ◽  
Marija Zunic ◽  
Zorica Mojovic ◽  
Predrag Bankovic ◽  
...  

The aim of this study was to find a low cost, easy to synthesize and efficient adsorbent for the simultaneous adsorption of both organic and inorganic pollutants (including textile dyes, toxic metals etc.). The starting material, domestic bentonite clay from Bogovina was modified with amounts of hexadecyltrimethylammonium cations corresponding to 0.5 and 1.0 times of the value of the cation exchange capacity value. The organobentonites were tested as adsorbents in a three-dye-containing solution, a three-component solution of Pb2+, Cd2+ and Ni2+ and a hexa- component solution containing all investigated dyes and toxic metal cations. The used adsorbents showed the highest affinity toward Acid Yellow 99 and Ni2+ ions. Dye adsorption was enhanced in the presence of toxic metal cations, while the adsorption of all toxic cations from the hexa-component solution was lower than from the three-component solution containing only toxic cations. The synthesized hexadecyltrimethylammonium bentonite could be regarded as an efficient multifunctional adsorbent for the investigated type of water pollutants.

2021 ◽  
Author(s):  
Pan Liu ◽  
Yongjun Liu ◽  
Aining Zhang ◽  
Zhe Liu ◽  
Xingshe Liu ◽  
...  

Abstract Background Natural zeolite, abundant hierarchically porous structure aluminosilicate mineral, have high affinity to ammonium in solution. A considerable amount of literature has been published on the removal of ammonium in waters by zeolite, but mainly focused on the low-content and even trace ammonium. Few literatures were reported about the natural zeolite as adsorbent to remove high-level of ammonium in coal chemical wastewater. Therefore, adsorption mechanism of high-concentration ammonium in aqueous solution using Chinese natural zeolite was disclosed by the strategy of experimental optimization combining with Molecular Dynamics simulation. ResultsThe natural zeolite presented unique adsorption performances for high- ammonium distinguish from that of low ammonium, which were characterized as exhibiting faster adsorption rate, greater loading capacity and apparent desorption. The hybrid physical-chemical adsorption as the mechanism was induced from the adsorption kinetics and isotherm study in 4000 mg-N/L solution. Besides to the electrostatic attraction between the framework and guest ammonium exchanged by metal cations in the zeolite framework, the existence of the chemical bonding and hydrogen bonding forces was supported experimentally from the ion exchange capacity (IEC) investigation by the great disequilibrium between the total exchanged metal cations and ammonium. Moreover, the above were confirmed theoretically by the calculated results in the perspective of bonding strength in MD simulation. Considering comprehensively, we concluded physisorption dominated the initial adsorption stage as multilayer adsorption and chemisorption governed the subsequent adsorption process as monolayer form. Besides, the putative explanation for the desorption-occurrence was given that most ammonium concentrated in the channel openings physically, and transferred into the bulk solution preferentially through the mesopores and macropores. Conclusions Overall, we have demonstrated that the Chinese natural zeolite had the potential to capture high-concentration ammonium in wastewater remediation effectively. Considering with several research thinking comprehensively, this investigation enriched the adsorption mechanism research, and provided a novel insight for designing a workable approach for rapidly alleviating subsequent water decontamination processes using low-cost abundant minerals.


Author(s):  
Seroor Atalah Khaleefa Alia ◽  
Dr. Mohammed Ibrahimb ◽  
Hussein Ali Hussein

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.


2020 ◽  
pp. 1-22
Author(s):  
Edwin A. Ofudje ◽  
Ezekiel F. Sodiya ◽  
Francis H. Ibadin ◽  
Abimbola A. Ogundiran ◽  
Samson O. Alayande ◽  
...  

Author(s):  
T. G. Ambaye ◽  
M. Vaccari ◽  
E. D. van Hullebusch ◽  
A. Amrane ◽  
S. Rtimi

AbstractCurrently, due to the rapid growth of urbanization and industrialization in developing countries, a large volume of wastewater is produced from industries that contain chemicals generating high environmental risks affecting human health and the economy if not treated properly. Consequently, the development of a sustainable low-cost wastewater treatment approach has attracted more attention of policymakers and scientists. The present review highlights the recent applications of biochar in removing organic and inorganic pollutants present in industrial effluents. The recent modes of preparation, physicochemical properties and adsorption mechanisms of biochar in removing organic and inorganic industrial pollutants are also reviewed comprehensively. Biochar showed high adsorption of industrial dyes up to 80%. It also discusses the recent application and mechanism of biochar-supported photocatalytic materials for the degradation of organic contaminants in wastewater. We reviewed also the possible optimizations (such as the pyrolysis temperature, solution pH) allowing the increase of the adsorption capabilities of biochar leading to organic contaminants removal. Besides, increasing the pyrolysis temperature of the biochar was seen to lead to an increase in its surface area, while it decreases their amount of oxygen-containing functional groups, consequently leading to a decrease in the adsorption of metal (loid) ions present in the medium. Finally, the review suggests that more research should be carried out to optimize the main parameters involved in biochar production and its regeneration methods. Future efforts should be also carried out towards process engineering to improve its adsorption capacity to increase the economic benefits of its implementation.


2022 ◽  
Vol 1048 ◽  
pp. 459-467
Author(s):  
Sadamanti Sireesha ◽  
Utkarsh Upadhyay ◽  
Inkollu Sreedhar ◽  
K.L. Anitha

Heavy metal contamination has been one of the primary environmental concerns for many years in most developing countries. As the industries continue to search for low-cost and efficient adsorbents to treat their effluents contaminated with these toxic metal ions, biomass-based adsorbents have gained much attention. This work exploits such ten different biomass-based adsorbents (namely, Karanja de-oiled cake, Neem de-oiled cake, Neem leaves, Moringa Leaves, Bagasse, Mango Kernel, Wheat Bran, Eucalyptus, Fly ash, and Corn cob) for adsorption of copper ions in particular. Further, selected adsorbents (namely Karanja de-oiled cake, Neem de-oiled cake, Bagasse, Wheat Bran and Mango Kernel) were taken to the next stage and modified to biochar and tested again for copper removal. Among the biomass-based adsorbents, the highest adsorption capacity was observed for Neem de-oiled cake (equal to 9.6 mg/g). While for biochar-based adsorbents, Bagasse showed the highest adsorption capacity for copper (equivalent to 13.0 mg/g).


2020 ◽  
Vol 32 (5) ◽  
pp. 1121-1127
Author(s):  
Mahesh Kumar Gupta ◽  
P.K. Tandon ◽  
Neelam Shukla ◽  
Harendra Singh ◽  
Shalini Srivastava

Acid activated carbon obtained from cheap, non-toxic and locally available banana peel was used as a low cost and efficient adsorbent for the removal of dyes methyl orange and rhodamine-B from the aqueous solution. Changes in the resulting material before and after activation and after treatment were studied by different techniques, such as SEM-EDX, XRD, FTIR measurements. Effects of duration of treatment, amount of banana peel activated carbon, pH, and initial methyl orange and rhodamine-B concentration, on the removal of dye were studied to get optimum conditions for maximum dye removal. Removal efficiency of the activated ash remains almost constant in a wide range of pH from 2.5 to 5.6. In 75 min at room temperature removal of 98.5 % methyl orange (anionic) and 99.0 % rhodamine-B (cationic) dyes with 0.1 g and 0.125 g, respectively was obtained from the contaminated water having 10 ppm dye concentration.


2015 ◽  
Vol 5 (2) ◽  
pp. 33-38
Author(s):  
Quang Thai Le ◽  
Minh Tuan Pham ◽  
Nguyen Quynh Trinh ◽  
Khac Tuan Vu ◽  
Hong Ha Nguyen ◽  
...  

Ion exchange is one of the most popular techniques for recovery and purification of uranium from sulfuric acid leaching solution, especially for recovery of uranium from a low uranium containing solutions. Resins commonly used are strong base or weak base anion resins with amine functional group. The anionic form of resins may be NO3-, Cl- , SO­42- or OH-. The selection of  a resin depends on the uranium total exchange capacity, selectivity and the cost. The previous studies often use Amberlite IRA-420 for concentration and purification of uranium solution from Pa Lua sandstone ores. This is a good and suitable resin but high price. To diversify the resins and reduce the costs, instead of IRA-420, the authors tested two commercial resins Indion GS300 (India) and Purolite A400 (UK) in the processing of uranium solution from sandstone ores. The results showed that the uranium total exchange capacity of  these resins is only about 80 - 85% over  Amberlite IRA-420, but these resins should be able to be used instead of Amberlite IRA-420 due to their low cost and availability in Vietnam.


2019 ◽  
Vol 25 (4) ◽  
pp. 341-351
Author(s):  
Aleksandar Zdravkovic ◽  
Novica Stankovic ◽  
Nebojsa Ristic ◽  
Goran Petkovic

The aim of this study was to determine adsorptive properties of acid activated bentonite clay for the removal of Direct Red 173 (DR 173) and Reactive Red 22 (RR 22) dyes from aqueous solutions. Raw and modified clay were characterized by the following methods: Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). The efficiency of activated clay adsorption was investigated depending on process parameters: the adsorbent dose, pH, temperature, initial dye concentration, and contact time. Experimental data were analyzed by Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm as well as kinetic models of pseudo-first order, pseudo-second order and intra-particle diffusion. The process of dye adsorption was best described by Langmuir, Temkin, and Dubinin-Radushkevich isotherm (R2 > 0.97). Pseudo-second order model (R2 > 0.99) had the highest correlation with the obtained kinetic results. The positive value of ?H? indicated that adsorption of dyes by activated bentonite clay is endothermic process. The activated bentonite exhibited good regenerative ability in the 0.1 M NaOH solution. Maximum adsorption capacities of acid activated bentonite clay at 25?C for DR 173 and RR 22 dyes were 356.65 and 109.58 ?mol g-1, respectively.


2020 ◽  
Vol 24 (1) ◽  
pp. 562-579
Author(s):  
Asma Behilil ◽  
Driss Lancene ◽  
Brahim Zahraoui ◽  
Meriem Belhachemi ◽  
Houcine Benmehdi ◽  
...  

Abstract Research and scientific work continue to develop low-cost treatment processes in terms of improving water quality and environmental protection. Oxide of zinc supported in natural clay is synthesized by impregnated method. The role of this modification is to increase the adsorption capacity of a basic dye (Methylene Blue) compared with calcined and natural clays. These samples are characterized by several analytical methods, X-Ray Diffraction (XRD), Thermogravimetric Analysis/Differential Thermal Analysis (TGA/TDA) and Brunauer, Emmett and Teller (BET) theory. The results show that these clays contain three phases, Sericite 2M1, Clinochlore, quartz and the presence of a new phase for the modified clay named zincite. The measured cation exchange capacity (CEC) is 9 cmolc/kg and the BET analysis shows the increase of surface area for these clays, from 9 to 30 m2 g−1. The findings show also that the impregnated clay has a better affinity than others when the kinetics data were well fitted by the pseudo-second-order. The adsorption capacities calculated using Langmuir equation of MB onto natural, calcined and impregnated clays are 154.0, 139.6 and 158.1 mg/g, respectively. The thermodynamic data showed that the adsorption of MB on these samples were exothermic. From this study, it can be concluded that these clays are efficacious materials for cationic dye removal from wastewater.


2021 ◽  
Author(s):  
Ammal Abukari ◽  
Ziblim Abukari Imoro ◽  
Abubakari Zarouk Imoro ◽  
Abudu Ballu Duwiejuah

Conversion of agricultural wastes into eco-friendly and low cost biochar is not only a smart recycling strategy but a panacea to environmental pollution management. Agricultural wastes biochar can be an effective alternative technique for controlling contaminants due to its low cost, high-efficiency, simple to use, ecological sustainability and reliability in terms of public safety. Biochars have made substantial breakthroughs in reducing greenhouse gases emissions, reducing soil nutrient leaching, sequester atmospheric carbon into the soil, increasing agricultural productivity, and reducing bioavailability of environmental contaminants. Recent advances in the understanding of biochars warrant a proper scientific evaluation of the relationship between its properties and impact on soil properties, environmental pollutant remediation, plant growth, yield, and resistance to biotic and abiotic stresses. The main factors controlling biochar properties include the nature of feedstock, heat transfer rate, residence time and pyrolysis temperature. Biochar efficacy in pollutants management largely depends on its elemental composition, ion-exchange capacity, pore size distribution and surface area, which vary with the nature of feedstock, preparation conditions and procedures. The chapter explored the possibility of using biochar from agricultural wastes as a suitable alternative for the remediation of environmental pollutants, soil conditioning and the long-term biochar application in the environment.


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