Refine Search

New Search

Results: 27

(searched for: doi:10.1155/2017/6254683)
Save to Scifeed
Page of 1
Articles per Page
by
Show export options
  Select all
Xiangdong Li, Yanwen Guo, Yuhan Xie, Yue Sun
Published: 22 November 2022
Journal: Rsc Advances
Rsc Advances, Volume 12, pp 34006-34019; https://doi.org/10.1039/d2ra05343h

Abstract:
An activated sludge lysis ash/chitosan composite adsorbent was synthesised using an in situ coprecipitation method, making lysis ash for fluoride removal from wastewater has an outstanding overall cost advantage.
M Syaifuddin, A Y Bagastyo
Published: 1 October 2022
Abstract:
Tomato ketchup industrial sector is associated with various environmental problems including high concentration wastewater containing organic pollutant and suspended solid. While the industry always considers from an economic point of view, electrocoagulation can be the best alternative of treat wastewater which has the advantage easy in operation, minimum space requirements, low volumes of sludge produced, and can be used in high concentration wastewater. This paper investigated the effect of pH and current electricity on performance of removal of COD and TSS in tomato ketchup wastewater treatment. The research was conducted in continuous flow using cylindrical reactor with rod aluminum anode dan helical stainless-steel cathode, while the pH and current variations were 6, 7, 8 and 30 A, 35 A, and 40 A respectively. Based on analyzed data, aluminum has an effectiveness in COD and TSS removal. On the other hand, pH and current has a significant role on the process of removing COD and TSS. The best removal of COD and TSS was under the 35 A and pH 8 condition with 81,86 % (103.24 gCOD) and 82.61% (6.48 gTSS).
Peng Cui,
Published: 13 June 2022
Journal: Jom
Jom, Volume 74, pp 3111-3118; https://doi.org/10.1007/s11837-022-05359-0

The publisher has not yet granted permission to display this abstract.
, Himanshu Bhushan Sahu
Published: 4 May 2022
Petroleum Science and Technology pp 1-14; https://doi.org/10.1080/10916466.2022.2071447

Abstract:
Shale is a coal mine waste belongs to sedimentary type of rocks. These wastes are generated in tons per year from various mine sectors. In this study shale samples collected from Samleshwari open cast mine were used as an adsorbent for defluoridation of mine waste water. The two types of shale samples, that is, old shale sample (OSS) and new shale sample (NSS) were collected from Samleshwari open cast mine located in IB valley coalfields of MCL mine, Odisha. The fluoride removal efficiency of the samples were increased by using heat activation (100 °C, 500 °C, and 800 °C) and chemical activation using different chemicals (KOH, NaOH, K2CO3, H2SO4, and ZnCl2). The effect of different parameters were also taken in to consideration during the batch adsorption process. The pH of the resulting water decreased slightly but maintained in between 4.5 and 7.5 confirms it’s applicability for drinking purpose. Maximum fluoride Removal obtained using OSS 800 and OSS KOH (heat) were 85.01% and 92.23%, respectively, at initial concentration of 3 ppm, contact time 60 min, dose 10 mg and pH 4.9. The process followed Freundlich isotherm and data were well fitted to pseudo second order kinetics upon analysis with adsorption capacity 42.66 mg/gm and 45.16 mg/gm for OSS 800 and OSS KOH (heat), respectively.
, Abraha Gebrekidan Asgedom, , , Zenebe Hailu Gebremikael, Kassa Amare Mesfin
Advances in Materials Science and Engineering, Volume 2022, pp 1-12; https://doi.org/10.1155/2022/4038444

Abstract:
This study was aimed to investigate the efficiency of locally available low-cost and eco-friendly activated agricultural biosorbents produced from corncob and sorghum husk for the removal of fluoride from aqueous solution using batch adsorption. The activated biosorbents were characterized using SEM, XRD and FTIR spectroscopy. Effects of particle size (0.063–1.0 mm), contact time (15–120 min), pH (2–12), dose (2–10 g), and initial concentration (0.5–5.0 mg/L) were investigated. The morphology analysis revealed that biosorbents showed the presence of a high binding capacity for fluoride adsorption. The maximum adsorption was attained; size of the adsorbent 0.063 mm, pH 7, contact time 60 min, and 6 g dose of the biosorbents. Moreover, the adsorption kinetics followed the pseudo-second-order model and the adsorption isotherms fitted well to the Langmuir model. Furthermore, a field study was conducted using real water sample collected from Semema, Tigray, Ethiopia, and maximum fluoride removal was observed to be 79.44% and 77.05% for the activated carbons of Corncob and Sorghum husk at optimum conditions. Therefore, this experimental finding indicated that activated carbon of Corncob and Sorghum husk can be used as efficient, cheap, and eco-friendly biosorbents for the removal of fluoride from drinking water at community level.
Soumya Ghosh, Alhadji Malloum, Chinenye Adaobi Igwegbe, , , , Amina Othmani, Ömür Gökkuş, Nabisab Mujawar Mubarak
Published: 5 December 2021
Journal of Molecular Liquids, Volume 346; https://doi.org/10.1016/j.molliq.2021.118257

The publisher has not yet granted permission to display this abstract.
Published: 24 November 2021
by MDPI
Journal: Molecules
Abstract:
Using small-scale batch tests, various researchers investigated the adsorptive removal of fluoride using low-cost clay minerals, such as Bentonite. In this study, Column adsorption studies were used to investigate the removal of fluoride from aqueous solution using acid-treated Bentonite (ATB). The effects of initial fluoride concentration, flow rates, and bed depth on fluoride removal efficiency (R) and adsorption capability (qe) in continuous settings were investigated, and the optimal operating condition was determined using central composite design (CCD). The model’s suitability was determined by examining the relationship between experimental and expected response values. The analysis of variance was used to determine the importance of independent variables and their interactions. The optimal values were determined as the initial concentration of 5.51 mg/L, volumetric flow rate of 17.2 mL/min and adsorbent packed-bed depth of 8.88 cm, with % removal of 100, adsorptive capacity of 2.46 mg/g and desirability of 1.0. This output reveals that an acid activation of Bentonite has made the adsorbent successful for field application.
, Himanshu Bhushan Sahu
International Journal of Environmental Analytical Chemistry pp 1-12; https://doi.org/10.1080/03067319.2021.1934832

Abstract:
The increase in hazardous substances in drinking water is an eye-catching problem of modern world. Where the urban life style is setting new goals, the environment safety of living beings is in poor hands. Almost each and every living thing depends on water for basic survival, but the pollution makes it difficult for health and growth. Fluoride is an ion present in nature and also essential for our body. It helps to strengthen the bone and teeth. But the rapid industrialisation increases the amount of fluoride in natural sources, this increased level tends to decline the health of human, water animals, and plants. So our focus should be to remove the excess fluoride, make water drinkable as per the quality standards for a better future. Various techniques are discussed like coagulation, ion-exchange, membrane separation, adsorption, and electrocoagulation for fluoride removal with advantages and disadvantages. An analysis was performed keeping various criteria for the removal of fluoride ion from water. Adsorption was found to be most suitable compared to others.
, Arun Kumar, Beteley Tekola, Beshah Mogessie, Esayas Alemayehu
Published: 10 June 2021
Water Science and Technology, Volume 84, pp 2661-2674; https://doi.org/10.2166/wst.2021.220

Abstract:
The feasibility of fluoride adsorption from aqueous solutions using naturally available bentonite clay in both modified and unmodified forms is investigated in this report. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy analysis was applied to describe the structure and nature of modified and unmodified bentonite clay. The physicochemical characteristics of the adsorbent were also investigated for moisture content, pH, apparent density, specific surface area, cation exchange capacity and its point-of-zero charge. SEM images reveal particles are dispersed homogeneously and are irregular in shape. XRD and EDX analyses reveal that the bentonite is composed of seven materials: calcite, silica, alumina, hematite, bornite and green cinnabar, and chloride which are considered as impurities. Raw bentonite clays have shown very low fluoride removal efficiency (47.19%). Modification of the clay surface with HCl and aluminum oxide, on the other hand, increased fluoride removal efficiency to 79.77% and 94.38%, respectively. At 5 mg/L initial fluoride concentration, 10 cm bed depth packed dose of adsorbent, and 180 min breakthrough time, a 2.88 mg/g of fluoride removal capacity was observed. As a result, aluminum oxide modified bentonite clay was chosen for further investigation and the results are not presented here.
Awash Almebo, Hunachew Beyene Mangasha, , , , Belay Negassa, Adane Erimias Mangasha, Alem Eskeziya Ayinalem, Mekonnen Birhanie Aregu
Published: 1 January 2021
Environmental Health Insights, Volume 15; https://doi.org/10.1177/11786302211052384

Abstract:
Background: Long-term consumption of water containing an excessive amount of fluoride causes dental and skeletal fluorosis. De-fluoridation options differ in terms of scale, efficacy, long-term viability, and user acceptance. Therefore, this study aimed to identify the challenges of using fluoride-filtered water and its associated factors among households. Methods: A cross-sectional study was conducted from April to May, 2018 among 405 randomly selected households in Dugda Woreda of Ethiopia Rift Valley East Shewa Zone, Oromia Region. A structured interviewer-administered questionnaire was used to collect the data. SPSS version 20 was used to enter and analyze the collected data. Logistic regression analysis was used to identify association between dependent and independent factors and explained by odds ratio with 95%CI. Results: A total of 228 (56.3%) households were found to utilize fluoride filtered water from community water supply schemes for drinking and cooking purposes. No family history of fluorosis (AOR = 44.4, 95%CI: 18.8, 104.74), monthly income of less than 1000 ETB (AOR = 0.03, 95%CI: 0.004, 0.23), good knowledge of community fluoride filter schemes (AOR = 5.93, 95%CI: 1.30, 26.9), and not afford to pay bill of ⩾0.50 ETB [AOR = 0.4, 95%CI: 0.20, 0.91] were factors significantly associated with utilization of community-level fluoride-filtered water. Conclusion: In this study, more than half of the households used fluoride filtered water. Family monthly income, affordability, presence of family members with the history of fluoride exposure, and knowledge about community fluoride filter schemes were factors significantly associated with utilization of community-level fluoride-filtered water.
Published: 3 October 2020
International Journal of Chemical Engineering, Volume 2020, pp 1-10; https://doi.org/10.1155/2020/8820727

Abstract:
Excessive fluoride in potable groundwater is a serious health problem in rural areas of many developing countries. The presence of a small amount of fluoride in potable water is beneficial to human health, but a high amount (>1.5mg/L) has adverse effects. The present study is aimed to prepare a new cost-effective adsorbent of kaolin clay that can be used as a valuable defluoridating agent. Characterization of the prepared adsorbent was carried out using DSC, FTIR, TGA, and XRD. Also, the surface area of the adsorbent was measured by BET analysis. The clay was activated with concentrated H2SO4, and the effects of various experimental parameters such as temperature (25, 40, 50, and 60°C), pH (2, 4, 6, and 8), particle size (<0.075, 0.0750.15, and 0.150.30mm), contact time (30, 60, 90, 120, and 150min), and dose of the adsorbents (0.5, 1, 1.5, 2.0, and 2.5g) were investigated using a batch adsorption method. The specific surface area of raw and activated clay was found to be 10.598m2/g and 5.258m2/g, respectively. The optimum fluoride removal by both adsorbents was obtained at pH 4, temperature 50°C, particle size 0.075mm, and 60min. In both adsorbents, the degree of fluoride removal was increased with a decrease in the particle size of the adsorbent and increased contact time and dosage of the adsorbent. In all parameters, adsorption by activated clay was better than raw kaolin clay for retaining fluoride. The obtained data were well fitted with Freundlich and Langmuir isotherm models.
Chaiti Ray, , Arunabha Majumder, Malabika Biswas Roy
Journal of The Institution of Engineers (India): Series E, Volume 101, pp 149-160; https://doi.org/10.1007/s40034-020-00168-z

The publisher has not yet granted permission to display this abstract.
, Ankit Soni, Mohammad Jawed
Journal of The Institution of Engineers (India): Series A, Volume 101, pp 535-548; https://doi.org/10.1007/s40030-020-00448-2

The publisher has not yet granted permission to display this abstract.
Andraju Naga Babu, Devarapu Srinivasa Reddy, Govindarajan Suresh Kumar, Kunta Ravindhranath,
Published: 8 December 2019
Water Environment Research, Volume 92, pp 880-898; https://doi.org/10.1002/wer.1283

Abstract:
The present work proposes the synthesis of robust biochar from Gracilaria Rhodophyta red weeds for sequential removal of Al(III) and fluoride from wastewater. The sorption experiments have been modelled by preliminary optimization of operational parameters using 24 factorial statistical modelling. The model has estimated an optimum sequential‐synergetic removal of 44.5 mg/g of Al(III) and 2.1 mg/g of fluoride onto the biochar. FESEM, BET, XRD, EDX and FTIR established the potentiality of biochar towards synergetic‐sorption of Al(III) and fluoride. The thermodynamic analysis projected that the adsorption is physisorption in nature. The adsorption of Al(III) and fluoride follows the Langmuir and Freundlich isotherm models respectively and the kinetic analysis established the pseudo‐second‐order deposition of Al(III) and fluoride ions. The synthesised adsorbent is regenerative enough and could achieve synergetic removal of Al(III) and fluoride ions from industrial and ground water contaminated water bodies.
, T. Ya. Datsko, E. D. Politova, G. F. Volodina, A. S. Smolyanskii
Surface Engineering and Applied Electrochemistry, Volume 55, pp 455-462; https://doi.org/10.3103/s1068375519040161

Abstract:
A new sorbent (Al-D) for the removal of fluoride ions is prepared by modifying diatomite with aluminum ions. The sorbent is studied using X-ray diffraction, thermogravimetry, X-ray photoelectron spectroscopy, and adsorption structure analysis; its ability to remove fluoride ions from model aqueous solutions is measured under static conditions. The diatomite, which is modified by heterogeneous hydrolysis of an aluminum salt in the presence of diatomite suspension, has a higher specific surface area and a greater sorption pore volume and exhibits excellent characteristics in fluoride adsorption. Fluoride sorption isotherms measured under equilibrium conditions are modeled using the Langmuir, Freundlich, Langmuir−Freundlich, Brunauer−Emmett−Teller, and two-step Langmuir equations. The model parameters are calculated. The two-step Langmuir model gives the best fit to the experimental isotherms (R2 = 0.9836). Fluoride adsorption on the sorbent Al-D occurs via ion exchange: surface OH groups are replaced with fluoride ions from solution to form aluminum fluoride complexes at the sorbent surface.
, El-Sayed M. Abdelrehim, Mohamed El-Sayed Elba, Sara M. H. Abdel Kawy
Published: 27 April 2019
Environmental Monitoring and Assessment, Volume 191; https://doi.org/10.1007/s10661-019-7465-5

Abstract:
Defluoridation process using raw marine organisms and synthetic organic adsorbents was accurately studied. The marine adsorbents (algae, bivalves, sea star, brittle star, and coral reef) were collected from the Egyptian Mediterranean Sea and Red Sea. The organic adsorbent of 2-amino-3-cyano-4(4-nitrophenyl)-6-phenylpyridine was synthesized. The influence of pH, shaking time, effect of temperature and adsorbent’s weight was studied. A complete fluoride removal by marine adsorbents was gained within 15–20 min. Fluoride removal procedure was evaluated by some adsorption isotherm models of linear two-parameter ((Freundlich, Tempkin, Langmuir, Flory–Huggins, Dubinin–Radushkevich, Non-ideal competitive adsorption (NICA), Brunauer–Emmett–Teller (BET), and Generalized)), nonlinear two-parameter (Langmuir and Freundlich), and nonlinear three-parameter (Redlich–Peterson, Khan, Generalized, and Toth). The most appropriate models were evaluated by error functions and statistical tests like coefficient (R2) and chi-square (χ2). Additionally, the kinetic and thermodynamic variables were calculated at variable temperatures. The results indicated that the pseudo-second-order model fitted better than the pseudo-first-order one. The negative ΔG° values confirmed that the adsorption process was favorable and spontaneous. Interestingly, this study indicated the great removal capacity of the raw organisms.
Published: 1 January 2019
Open Material Sciences, Volume 5, pp 24-33; https://doi.org/10.1515/oms-2019-0005

Abstract:
Metal oxide ceramic is getting more attention in current times due to their unique pore structures, hydrophilic surfaces, high chemical, thermal and mechanical stabilities which offer avenues for application in water treatment. This paper presents the results of an experimental study on the effects of different ratios of clay, grog, sawdust and bone char on efficiency of ceramic composite water filters. Filter of different designs were developed from clay (50, 60, 70, 75 and 80) |%|, sawdust (15, 25, and 35) |%|, grog (5 and 15) |%| bone char and 5|%| ratios by volume and sintered at temperature of 900°C for 6 hours. The Phase and functional group identification of sintered filter investigated with x-ray diffraction and infrared spectroscopy revealed the presence of mixed phase and hydroxyl functional group on the surface of sintered filter. Field emission scanning electron microscopy (FESEM) revealed the porous nature of the microstructures of the sintered filter elements. The superior ceramic water filter design (C900-50-15-35) with total porosity 35.89±0.04|%|, flow rate 2.05±0.41|%| and the percent E coli, nitrite and fluoride removal efficiency: 99.6±0.40 |%|, 81.17±0.22|%| and 96.4±0.42|%| were obtained from this work. Porosity evaluated by BET study for C900-50-15-35 demonstrated an average pore size and surface area of 5 |nm | and 7.30|m2/g|, respectively.
Page of 1
Articles per Page
by
Show export options
  Select all
Back to Top Top