scholarly journals Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
G. P. Kofa ◽  
V. H. Gomdje ◽  
C. Telegang ◽  
S. Ndi Koungou
Keyword(s):  
Ionic Strength ◽  
Rural Areas ◽  
Cost Effective ◽  
Equilibrium Studies ◽  
Fluoride Adsorption ◽  
Jar Test ◽  
Cost Effective Method ◽  
Pseudo Second Order ◽  
Fire Wood ◽  
Clay Pots

Excessive fluoride in potable water is a serious health problem in rural areas of many developing countries. Hence, there is a need to find a simple and cost-effective method for water defluoridation in such areas. In the northern part of Cameroon, clay pots are used for cooking food and water storage. The firing of these pots consists of intensive burning using fire wood. They were tested as a potential adsorbent for removing excess fluoride from water. Experiments were carried out in a jar test at room temperature (25 ± 2°C). Effects of contact time (0–90 min), pH (4, 5, 7, 8, and 9), stirring speed (60, 90, 120, and 200 rpm), and ionic strength (0–1000 mg/L) were investigated. Results showed that equilibrium was attained in 10 min whatever the pH. Pseudo-second-order and pore diffusion models described well the adsorption process. The highest amount of fluoride adsorbed (1.6 mg/g) was obtained at pH 4-5 and the optimum stirring speed is 120 rpm. Ionic strength has a significant effect on fluoride adsorption.

scholarly journals Kinetic and equilibrium studies on fluoride removal by zirconium (IV): Impregnated groundnut shell carbon

2010 ◽  
Vol 64 (4) ◽  
pp. 295-304 ◽  
Author(s):  
G. Alagumuthu ◽  
M. Rajan
Keyword(s):  
Cost Effective ◽  
Fluoride Removal ◽  
Equilibrium Studies ◽  
Fluoride Adsorption ◽  
Adsorbent Surface ◽  
Adsorption Interaction ◽  
Equilibrium Data ◽  
Endothermic Process ◽  
Pseudo Second Order ◽  
Groundnut Shell

The carbonized ground nut shell (GNSC) was impregnated with zirconium oxy chloride, and tested to determine its capacity and kinetics for fluoride adsorption from aqueous solutions. The analysis of the isotherm equilibrium data using the Langmuir, Freundlich and Redlich-Peterson equations by linear methods showed that the data fitted better with Freundlich model than the other two. Thermodynamic studies revealed that the spontaneous nature of fluoride adsorption with increase of entropy and an endothermic process. The kinetic data obtained for fluoride adsorption on zirconium impregnated ground nut shell carbon (ZIGNSC) obeyed the pseudo-second order equation. X-ray diffraction (XRD) studies confirmed the deposition of fluoride on material and Fourier transform infrared (FTIR) studies also showed the involvement of adsorbate on the adsorbent surface in the adsorption interaction. The ZIGNSC provides a cost effective material to the defluoridation problem in the developing countries by its great potential application in the fluoride removal from water.

Adsorption isotherm studies of the simultaneous removal of turbidity and hardness by natural coagulants

2013 ◽  
Vol 8 (3-4) ◽  
pp. 495-502 ◽  
Author(s):  
C. Nirmala Rani ◽  
Rajashekar Talikoti
Keyword(s):  
Rural Areas ◽  
Hard Water ◽  
Cost Effective ◽  
Simultaneous Removal ◽  
Turbidity Removal ◽  
Jar Test ◽  
Test Study ◽  
Natural Coagulants ◽  
Strychnos Potatorum ◽  
Hardness Removal

Coagulation being a cost-effective method is best suited for water treatment in rural areas. Natural coagulants suited for the simultaneous removal of turbidity and hardness were investigated. In this study, the seeds of Strychnos Potatorum, the pads of Cactus Opuntia and mucilage extracted from the fruits of Coccinia Indica in synthetic turbid water were used to promote coagulation. The mechanism of turbidity removal by the use of natural coagulants was based on adsorption and charge neutralization. In addition, the adsorption mechanism of hardness removal in hard water conforms to both Langmuir and Freundlich adsorption models. Therefore, for hard water the natural coagulants tend to adsorb hardness and form a net like structure followed by turbidity removal by sweep flocculation. The potential of these natural coagulants were obtained by means of jar test study with initial turbidities of 192 NTU (High) and 28 NTU (Low). It was found that the natural coagulants can be more efficiently used for high turbid waters. Hardness removal efficiency was found to increase with the increase in coagulant dosage.

scholarly journals Kinetics and equilibrium studies for removal of fluoride from underground water using cryptocrystalline magnesite

2015 ◽  
Vol 5 (3) ◽  
pp. 282-292 ◽  
Author(s):  
Vhahangwele Masindi ◽  
Wilson Mugera Gitari ◽  
Tholiso Ngulube
Keyword(s):  
Rural Areas ◽  
Fluoride Concentration ◽  
Underground Water ◽  
Fluoride Removal ◽  
Equilibrium Studies ◽  
Adsorption Mechanisms ◽  
Quality Guidelines ◽  
Monolayer Adsorption ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order

In the present study, the defluoridation capabilities and adsorption mechanisms of cryptocrystalline magnesite were evaluated. All experiments were done by batch procedure. Conditions assessed include time, dosage, concentration, pH and the effects of competing ions. Optimum defluoridation conditions were observed to be 20 g/L magnesite, 2:100 solid:liquid ratio, 20 min of agitation and 60 mg/L fluoride concentration. Adsorption of fluoride by magnesite was observed to be independent of pH. Cryptocrystalline magnesite showed >99% efficiency for fluoride removal. Adsorption kinetics fitted better to a pseudo-second order than a pseudo-first order thus confirming chemisorption. Adsorption data fitted better to a Langmuir than a Freundlich adsorption isotherm thus confirming monolayer adsorption. Cryptocrystalline magnesite successfully removed excess fluoride from aqueous solution to below Department of Water Affairs and Forestry water quality guidelines. As such, this material can be used for a point source defluoridation technique in rural areas and households in South Africa and other developing countries. Based on comparison studies, cryptocrystalline magnesite proved to have high adsorption capacity for fluoride removal and can be used as a substitute for conventional treatment methods.

scholarly journals Adsorption Characteristics of Pristine and Magnetic Olive Stones Biochar with Respect to Clofazimine

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 963
Author(s):  
Marwa El-Azazy ◽  
Iman Nabil ◽  
Siham S. Hassan ◽  
Ahmed S. El-Shafie
Keyword(s):  
Cost Effective ◽  
Sem Analysis ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Adsorption Efficiency ◽  
Equilibrium Studies ◽  
Thermal Stabilities ◽  
Olive Stone ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Olive stone biochars (OSBC), both pristine and following magnetization (MAG–OSBC), were utilized as eco-friendly and cost-effective sorbents for the antituberculosis, clofazimine (CLOF). Morphologies, textures, surface functionalities, and thermal stabilities of both adsorbents were explored using SEM, EDX, TEM, BET, FT-IR, Raman, XRD and TGA analyses. SEM analysis showed meso- and macroporous surfaces. BET data showed that the MAG–OSBC possesses a larger surface area (33.82 m2/g) and pore volume. Batch adsorption studies were conducted following the experimental scenario of Box–Behnken (BB) design. The adsorption efficiency of both adsorbents was evaluated in terms of the % removal (%R) and the sorption capacity (qe, mg/g). Dependent variables (%R and qe) were maximized as a function of four factors: pH, sorbent dose (AD), the concentration of CLOF ([CLOF]), and contact time (CT). A %R of 98.10% and 98.61% could be obtained using OSBC and MAG–OSBC, respectively. Equilibrium studies indicated that both Langmuir and Freundlich models were perfectly fit for adsorption of CLOF. Maximum adsorption capacity (qmax) of 174.03 mg/g was obtained using MAG–OSBC. Adsorption kinetics could be best illustrated using the pseudo-second-order (PSO) model. The adsorption–desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 92% after the sixth cycles.

Paper of the Year Award

2004 ◽  
Vol 31 (1) ◽  
pp. 122-122
Keyword(s):  
Cost Effectiveness ◽  
Rural Areas ◽  
Cost Effective ◽  
Target Population ◽  
Individual Counseling ◽  
Cost Information ◽  
Community Activities ◽  
Community Volunteer ◽  
Cost Effective Method ◽  
The Cost

The Community Trial of Breast Cancer Screening Promotion assessed the effectiveness and cost-effectiveness of mammography promotion by community volunteer groups in rural areas using three different intervention approaches: individual counseling, community activities, and a combined intervention including both. Societal costs of the interventions were calculated and used in conjunction with measures of effectiveness to calculate cost-effectiveness in terms of cost per additional mammogram and cost per year of life saved. Methods of collecting and using cost information to assess the cost-effectiveness of community interventions are described. The Community Activities intervention was found to be the most cost-effective, at approximately $2,000 for each additional regular mammography user in the community. The cost per year of life saved associated with mammography promotion was approximately $56,000 per year of life saved. Exploratory analyses suggest that the most cost-effective method of promoting mammography use may vary with the target population.

scholarly journals Effect of iron treatment and equilibrium pH on the kinetics of removal of some substituted phenols from synthetic wastewater onto Nostoc sp. biomass

2020 ◽  
Vol 81 (10) ◽  
pp. 2140-2151
Author(s):  
Namrata Gururani ◽  
Devesh Bhatt ◽  
Anjana Srivastava ◽  
Prakash Chandra Srivastava
Keyword(s):  
Cost Effective ◽  
Synthetic Wastewater ◽  
Complexation Reaction ◽  
Substituted Phenols ◽  
Cost Effective Method ◽  
Iron Treatment ◽  
Phenolic Group ◽  
Pseudo Second Order ◽  
The Fourier Transform ◽  
Kinetics Of

Abstract Substituted phenols, such as 4-Nitrophenol (4-NP) and 2,4-Dichlorophenol (2,4-DCP), that are present in industrial wastewaters are considered as priority pollutants due to their toxic effects. Their removal by biosorption presents an eco-friendly, cost-effective method. The kinetics of removal of 4-NP and 2,4-DCP by untreated Nostoc sp. (UNB) and Fe-treated Nostoc sp. biomass (FNB) were studied at three different pH (4.0, 7.0 and 9.0). The highest sorption of both phenols (2.28 mg 4-NP and 1.51 mg 2,4-DCP g−1) coupled with the lowest cumulative percentage desorption was recorded with FNB at pH 7.0. The sorption of both phenols by UNB and FNB was best accounted for by pseudo-second-order kinetics. Compared to UNB, FNB had significantly higher equilibrium sorption capacities for both phenols at all the three pH values and also higher sorption rate constants of 4-NP at pH 4 and 9 and of 2,4-DCP at pH 4 and 7. The Fourier transform infrared spectroscopy (FTIR) analysis showed that –OH and COO− groups of UNB interacted with Fe+3. The sorption of 4-NP and 2,4-DCP on UNB was likely through H-bonding/structural cation bridging with the phenolic group, while their sorption onto FNB appeared to be a complexation reaction with very low reversibility.

scholarly journals Magnetic Cellulose-Chitosan Nanocomposite for Simultaneous Removal of Emerging Contaminants: Adsorption Kinetics and Equilibrium Studies

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 190
Author(s):  
Phodiso Prudence Mashile ◽  
Philiswa Nosizo Nomngongo
Keyword(s):  
Emerging Contaminants ◽  
Cost Effective ◽  
Water Systems ◽  
Coefficient Of Determination ◽  
Simultaneous Removal ◽  
Equilibrium Studies ◽  
Aquatic Life ◽  
Pseudo Second Order ◽  
Β Blockers ◽  
Adsorption Desorption

The presence of pharmaceuticals in water systems threatens both terrestrial and aquatic life across the globe. Some of such contaminants are β-blockers and anticonvulsants, which have been constantly detected in different water systems. Various methodologies have been introduced for the removal of these emerging pollutants from different waters. Among them, adsorption using nanomaterials has proved to be an efficient and cost-effective process for the removal of pharmaceuticals from contaminated water. In this this study, a firsthand/time approach applying a recyclable magnetic cellulose-chitosan nanocomposite for effective simultaneous removal of two β-blockers (atenolol (ATN)) and propranolol (PRP) and an anticonvulsant (carbamazepine (CBZ)) is reported. A detailed characterization of the eco-friendly, biocompatible cellulose-chitosan nanocomposite with magnetic properties was performed at various rates of synthesis using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. A N2c adsorption-desorption test showed that the prepared nanocomposite is mesoporous, with a BET area of 112 m2 g−1. The BET isotherms results showed that the magnetic cellulose-chitosan nanocomposite has a pore size of 24.1 nm. The adsorption equilibrium of PRP and CBZ fitted with the Langmuir isotherm was consistent with the highest coefficient of determination (R2 = 0.9945) and (R2 = 0.9942), respectively, while the Sips model provided a better fit for ATN, with a coefficient of determination R2 = 0.9956. The adsorption rate was accompanied by a pseudo-second-order kinetics. Moreover, the swelling test showed that up to 100 percent swelling of the magnetic cellulose-chitosan nanocomposite was achieved.

Bentonite-Copolymer Composite for Removing Basic Fuchsin

2017 ◽  
Vol 726 ◽  
pp. 345-349 ◽  
Author(s):  
Yu Feng He ◽  
Hong Li ◽  
Zhen Hua Zhang ◽  
Ting Jun Lu ◽  
Rong Min Wang
Keyword(s):  
Freundlich Isotherm ◽  
Cost Effective ◽  
Molecular Formula ◽  
Order Kinetic ◽  
Basic Fuchsin ◽  
Cost Effective Method ◽  
Pseudo Second Order ◽  
Polymer Adsorbent ◽  
In Situ Copolymerization

Basic Fuchsin (BF) is a toxic triphenylmethane dye with molecular formula C20H20ClN3, which is easy to caused serious public health problems. There is a need to develop a cost effective method for its removal from the wastewater containing BF. Here, a novel composite polymer adsorbent, poly (maleic anhydride - acrylic acid - vinyl acetate)/Na-bentonite composite cross-linked with N,N'-methylenebisacrylamide was prepared by in situ copolymerization. The polymer adsorbent (NaB-PMAVM) was characterized and applied to remove BF. It was found that the removal of BF reached to 95.96%. The adsorption isotherms and kinetics were best-fit with the Freundlich isotherm model and the pseudo-second-order kinetic, respectively.

Telemedicine for eye care

2005 ◽  
Vol 11 (8) ◽  
pp. 391-396 ◽  
Author(s):  
Rosa Ana Tang ◽  
Marlene Morales ◽  
Giselle Ricur ◽  
Jade S Schiffman
Keyword(s):  
Rural Areas ◽  
Low Vision ◽  
Anterior Segment ◽  
Cost Effective ◽  
Specialty Care ◽  
Great Promise ◽  
Hybrid Techniques ◽  
Cost Effective Method ◽  
Store And Forward ◽  
Improving Patient Care

summary Tele-ophthalmology has been employed mainly for patients in under-served rural areas in need of specialty care, but other applications such as telementoring have also been used. In certain populations, cost containment is a significant issue and telemedicine is a solution. Tele-ophthalmology can be performed in realtime, by store-and-forward mode, or by hybrid techniques. After appropriate modification, a range of peripherals may be used for tele-ophthalmology, including the direct ophthalmoscope, indirect ophthalmoscope, slit lamp or retinal camera. Tele-ophthalmology applications include: detecting, screening and diagnosing diabetic retinopathy; anterior segment imaging; glaucoma screening; low vision consultation; telementoring. Tele-ophthalmology shows great promise for improving patient care and increasing access to specialty care not available in under-served areas. In developing countries tele-ophthalmology may be a cost-effective method by which richer countries can assist them.

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