scholarly journals An Investigation on Effectiveness of Grafted Potato Starch as an Adsorbent for Hard Water Treatment

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Desderia Mgombezi ◽  
Maheswara Rao Vegi
Keyword(s):  
Water Treatment ◽  
Potato Starch ◽  
Correlation Coefficients ◽  
High Hardness ◽  
Hard Water ◽  
Order Kinetic ◽  
Isothermal Model ◽  
Order Kinetic Model ◽  
Living Organisms ◽  
Hardness Removal

Water is essential for the life of all living organisms. But water with very high hardness (Ca2+ and Mg2+) is harmful to health. In addition, hard water clogs the pipes in the industries. This study was conducted to investigate the effectiveness of grafted potato starch as an adsorbent for hard water treatment. Four samples of well water from Nzuguni, Ng’hong’hona, Kisasa, and Swaswa of Dodoma municipal were analyzed by the EDTA titrimetric method. The results showed the highest hardness of 547 mg/L in the water sample of Ng’hong’hona from which hardness was removed. The maximum percentage removal of 74.50% was achieved at 80 minutes of optimum contact time. The optimum adsorbent dose is 3.5 g at which 80.7% of removal was achieved. The optimum temperature was 80°C at which 75.8% of removal achieved. An increase in pH increased the percentage of removal up to a pH of 12 with 71.1%. The data obtained showed that the adsorption process fitted Langmuir type II isothermal model and pseudo-second-order kinetic model with correlation coefficients of 0.9994 and 0.9940, respectively. Grafted potato starch has shown higher efficiency in hardness removal, and hence, this adsorbent is highly recommended for the treatment of hard water.

scholarly journals Adsorption removal of Cr(VI) by isomeric FeOOH

2019 ◽  
Vol 80 (2) ◽  
pp. 300-307
Author(s):  
Di Zhang ◽  
Jiaxin Liu ◽  
Shibei Zhu ◽  
Huixin Xiong ◽  
Yiqun Xu
Keyword(s):  
Active Sites ◽  
Correlation Coefficients ◽  
Order Kinetic ◽  
Isothermal Adsorption ◽  
Adsorption Mechanisms ◽  
Ph Values ◽  
Adsorption Removal ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Theoretical Evidence

Abstract The aim of this work is to study the performances of isomeric α-, β-, and γ-FeOOH (goethite, akaganéite and lepidocrocite, including five samples named as Gth1 and Gth2, Aka1 and Aka2, and Lep, respectively) for removing hexavalent chromium (Cr(VI)) from aqueous solutions. The adsorption mechanisms were explored by kinetic and isothermal experiments. Adsorption efficiencies under the different pH values, anions, and the levels of adsorbate and adsorbent were also measured. Results showed that the Cr(VI) adsorption by isomeric FeOOH could be best described by pseudo-second-order kinetic model. The processes of Cr(VI) isothermal adsorption could be greatly fitted by the Langmuir and Freundlich equations with the high correlation coefficients of R2 (>0.92). Also, there were the optimum pH values of 3.0–8.0 for FeOOH to adsorb Cr(VI), and their adsorption capacities were tightly related with the active sites of adsorbents. Cr(VI) adsorptions by these adsorbents were easily influenced by H2PO4–, and then SO42–, while there were little effects by Cl–, CO32– and NO3–. These obtained results could provide a potentially theoretical evidence for isomeric FeOOH materials applied in the engineering treatment of the polluted chromate-rich waters.

Fast Removal of Pb2+ from Aqueous Solution by Water Insoluble Konjac Glucomannan

2009 ◽  
Vol 610-613 ◽  
pp. 65-68 ◽  
Author(s):  
Xue Gang Luo ◽  
Feng Liu ◽  
Xiao Yan Lin
Keyword(s):  
Aqueous Solution ◽  
Correlation Coefficients ◽  
Konjac Glucomannan ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Equilibrium Process ◽  
Fast Removal

Konjac glucomannan (KGM) was converted into water insoluble konjac glucomannan (WIKGM) by treating with NaOH through completely deacetylated reaction. Adsorption study was carried out for the adsorption of Pb2+ from aqueous solution using water insoluble konjac glucomannan. The influences of pH, contact time, temperature and initial Pb2+ concentration on the absorbent were studied. Results of kinetic data showed that the Pb2+ adsorption rate was fast and good correlation coefficients were obtained for the pseudo second-order kinetic model. The equilibrium process was described well by the Langmuir isotherm model with maximum adsorption capacity of 9.18 mg/g on WIKGM at 25°C.

Acetylation of Pomelo Peel for the Production of Oil Materials

2014 ◽  
Vol 955-959 ◽  
pp. 2534-2538
Author(s):  
Jun Chen Zou ◽  
Xiao Yan Liu ◽  
Wen Bo Chai ◽  
Xin Ying Zhang ◽  
Yu Sen Liu
Keyword(s):  
Acetic Anhydride ◽  
Correlation Coefficients ◽  
Kinetic Studies ◽  
Sorption Kinetics ◽  
Lubricating Oil ◽  
Order Kinetic ◽  
Pomelo Peel ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Spilled Oil

Pomelo peel was esterified with acetic anhydride using 4-dimethyl-amino pyridine as a catalyst under reaction temperature of 60 °C and duration of 3 h. At 0.1 g 4-dimethyl-amino pyridine of the catalyst in 80 ml acetic anhydride, the highest sorption values of 14.95 g/g diesel and 18.39 g/g lubricating oil were achieved, which was found to be much higher than raw pomelo peel. FTIR and SEM studies produced evidence for acetylation. The sorption kinetics and reusability were studied. The kinetic studies show good correlation coefficients for a pseudo-second-order kinetic model. This work demonstrated that pomelo peel modified by acetic anhydride is an efficient and environment-friendly biosorbent for the removal of spilled oil.

scholarly journals Efecto del proceso de acidificación sobre el color de queso cottage

2017 ◽  
Vol 28 (3) ◽  
pp. 677 ◽  
Author(s):  
Ramiro Vargas-Uscategui ◽  
Anthony Arenas-Clavijo ◽  
Juan Sebastian Ramírez-Navas
Keyword(s):  
Linear Correlation ◽  
Color Change ◽  
Correlation Coefficients ◽  
Cottage Cheese ◽  
Order Kinetic ◽  
First Order ◽  
Zero Order Kinetics ◽  
Significant Difference ◽  
Order Kinetic Model ◽  
Kinetics Order

The objective of this study was to evaluate the color change of cottage cheese made with different processes of acidification (enzymatic and chemical) over time. The research was conducted at Universidad del Valle (Cali, Colombia) laboratories, between 2014 and 2015. Microbial rennet and lactic culture (CC) were used for enzymatic coagulation method (control cheese), and solutions of citric acid (CA) and phosphoric acid (PA) were used for the chemical method. The physicochemical properties were determined, and color behavior was analyzed over nine days of storage. Significant differences in acidity and moisture for the three coagulants were found. In the color plane, it was observed that the final and initial points of the coordinates a * and b * are close together; changes in color were mostly due to changes in brightness. The speed at which brightness decreased in the three cheeses matches kinetics order to zero and one. The first order kinetics displayed in higher values of linear correlation coefficients (R), AC: 0.8410 ± 0.0533; AF: 0.8390 ± 0.0847, and CC: 0.8717 ± 0.0256. The kinetics of change in color also adjusted correctly to zero and the first order kinetic model; that is, no significant difference (p <0.05) between these results. However, the speed of color change for the three cheeses had a slightly higher setting for zero order kinetics, as evidenced by the linear correlation coefficient (R) results, AC: 0.8800 ± 0.0205; AF: 0.8543 ± 0.0099, and CC: 0.7982 ± 0.0605.

scholarly journals Thermal Stability and Degradation Kinetics of Patulin in Highly Acidic Conditions: Impact of Cysteine

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 662
Author(s):  
Enjie Diao ◽  
Kun Ma ◽  
Hui Zhang ◽  
Peng Xie ◽  
Shiquan Qian ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Degradation Kinetics ◽  
Correlation Coefficients ◽  
Degradation Process ◽  
Weibull Model ◽  
Degradation Efficiency ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Acidic Conditions ◽  
Kinetics Of

The thermal stability and degradation kinetics of patulin (PAT, 10 μmol/L) in pH 3.5 of phosphoric-citric acid buffer solutions in the absence and presence of cysteine (CYS, 30 μmol/L) were investigated at temperatures ranging from 90 to 150 °C. The zero-, first-, and second-order models and the Weibull model were used to fit the degradation process of patulin. Both the first-order kinetic model and Weibull model better described the degradation of patulin in the presence of cysteine while it was complexed to simulate them in the absence of cysteine with various models at different temperatures based on the correlation coefficients (R2 > 0.90). At the same reaction time, cysteine and temperature significantly affected the degradation efficiency of patulin in highly acidic conditions (p < 0.01). The rate constants (kT) for patulin degradation with cysteine (0.0036–0.3200 μg/L·min) were far more than those of treatments without cysteine (0.0012–0.1614 μg/L·min), and the activation energy (Ea = 43.89 kJ/mol) was far less than that of treatment without cysteine (61.74 kJ/mol). Increasing temperature could obviously improve the degradation efficiency of patulin, regardless of the presence of cysteine. Thus, both cysteine and high temperature decreased the stability of patulin in highly acidic conditions and improved its degradation efficiency, which could be applied to guide the detoxification of patulin by cysteine in the juice processing industry.

Investigation of Modified Mangrove Bark on the Sorption of Oil in Water

2014 ◽  
Vol 567 ◽  
pp. 74-79 ◽  
Author(s):  
Asadpour Robabeh ◽  
Nasiman Sapari ◽  
Mohamed Hasnain Isa ◽  
Kalu Uka Orji
Keyword(s):  
Palmitic Acid ◽  
Adsorption Capacity ◽  
Sorption Capacity ◽  
Oil Spills ◽  
Low Cost ◽  
Correlation Coefficients ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model

Today oil spills generally cause worldwide worry due to their damaging effects on environment. Use of agricultural wastes such as raw and modified mangrove barks (RhizophoraApiculata), as an abundant and low cost adsorbent for oil-products spill cleanup in aquatic systems, has been developed to control these spills. Sorption capacity can improve by modification of adsorbent. The modification significantly increased the hydrophobicity of the adsorbent. The raw mangrove bark was modified using fatty acid (Palmitic acid) to improve its adsorption capacity. Oil sorption capacity of the modified bark was studied and compared with the raw bark. Kinetic tests were conducted with a series of contact time. The kinetic studies show good correlation coefficients for a pseudo-first-order kinetic model. A correlation between surface functional groups of the adsorbent was studied by FTIR spectrum. The results gave the maximum adsorption capacity of 2640.00 ± 2.00 mg/g for Palmitic acid treated bark (PTB). The prepared adsorbent revealed the potential to use as a low-cost adsorbent in oil-spill clean-up.

Highly Efficient Adsorption of Eriochrome Black T in Wastewater on Mesoporous Alumina Sphere

2014 ◽  
Vol 936 ◽  
pp. 834-842
Author(s):  
Heng Liu ◽  
Na Tian ◽  
Ya Yang Tian ◽  
Chu Dai ◽  
Yan Xin Wang
Keyword(s):  
Azo Dyes ◽  
Correlation Coefficients ◽  
Kinetic Studies ◽  
Mesoporous Alumina ◽  
Adsorption Behavior ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Eriochrome Black T ◽  
Order Kinetic Model

The present study presents the adsorption behavior of mesoporous alumina sphere for Eriochrome black T (EBT) azo dyes. The batch adsorption experiments were carried out to optimize various experimental parameters such as contact time and dye concentration. The maximum adsorption of EBT was achieved 312.5mg/g. The kinetic studies revealed that the adsorption process followed the pseudo-second-order kinetic model. The adsorption behavior was analyzed by Langmuir and Freundlich isotherms. The values of correlation coefficients (R) showed that the Langmuir isotherm model found to be best fit. Results of study showed that Mesoporous alumina sphere proved to be highly effective for the removal of selected azo dyes.

scholarly journals Biosorption of Pentachlorophenol from Aqueous Solutions by Aspergillus Niger Biomass

2016 ◽  
Vol 10 (3) ◽  
pp. 33-39
Author(s):  
Reza Shokoohi ◽  
◽  
Salah Azizi ◽  
Seyed Amir Ghiasian ◽  
Ali Poormohammadi ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Correlation Coefficients ◽  
Maximum Efficiency ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Order Kinetic Model ◽  
Decreasing Ph ◽  
Biomass Dosage

Background: This study aimed to investigate the biosorption of pentachlorophenol on Aspergillus niger biomass as a method for removal of pentachlorophenol from aqueous solutions. Methods: Modified A. niger biomass with NaOH was used to absorb the pentachlorophenol. The impacts of various experimental parameters like primary pentachlorophenol concentration, pH of the solution, contact time, and biomass dosage on the biosorption of pentachlorophenol were investigated. Results: The correlation of contact time, pH and initial concentration with the biosorption of pentachlorophenol by A. niger biomass was statistically significant (P<0.001). Pentachlorophenol removal increased with decreasing pH of the solution and the maximum efficiency was obtained at pH=3. The equilibrium adsorption capacity was increased from 4.23 to 11.65 mg/g by increasing initial pentachlorophenol concentration from 10 to 40 mg/L, while pentachlorophenol removal efficiency decreased from 87 to 55%. Both Langmuir and Freundlich isotherms efficiently described adsorption equilibrium of pentachlorophenol on A. niger biomass. Correlation coefficients for the second order kinetic model were almost equal to one. Conclusion: A. niger biomass can be used to reduce the toxicity of aqueous solutions containing pentachlorophenol in acidic pH conditions.

Effect of Zr(IV) to phosphorus ratio on U(VI) adsorption by diethylenetriamine-pentamethylene phosphate Zr(IV) hybrids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
You-qun Wang ◽  
Huan Wang ◽  
Yue Feng ◽  
Zhi-bin Zhang ◽  
Xiao-hong Cao ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Molar Ratio ◽  
Order Kinetic ◽  
Isothermal Model ◽  
Synthetic Process ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Physical And Chemical ◽  
Contact Angle Analysis

Abstract In this work, diethylenetriamine pentamethylenephosphonic acid (DTPMP) was ultilized into preparing of Zr(IV) organophosphates hybrids (Zr-DTPMP-x, x was the molar ratio of Zr(IV)/DTPMP in the synthetic process, x = 0.5, 1, 2, and 3) using a hydrothermal method. The physical and chemical properties of Zr-DTPMP-x were characterized by SEM&EDS, FT-IR, XRD, Zeta potential, XPS, TGA and contact angle analysis. Moreover, the adsorptive performances of Zr-DTPMP-x for U(VI) were investigated. The adsorption results showed that the optimum molar ratio of Zr(IV) to phosphine, pH, equilibrium time, and dosage was 0.5, 4.0, 180 min, and 10 mg, respectively. Besides, the adsorption of U(VI) was in accordance with the pseudo-second-order kinetic model and Sips isothermal model. Moreover, the adsorption capacity determined by Sips isothermal model was 181.34 mg g−1 for Zr-DTPMP-0.5. Furthermore, the adsorptive selectivity of Zr-DTPMP-0.5 for U(VI) was superior than the others. Zr-DTPMP-0.5 may be a powerful candidate for diminishing the contamination of U(VI).

scholarly journals Studies of adsorption thermodynamics and kinetics of Cr(III) and Ni(II) removal by polyacrylamide

2012 ◽  
Vol 77 (3) ◽  
pp. 393-405 ◽  
Author(s):  
Zavvar Mousavi ◽  
Abdorrahman Hosseinifar ◽  
Vahdat Jahed
Keyword(s):  
Kinetic Model ◽  
Metal Ions ◽  
Correlation Coefficients ◽  
Second Order ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data

Polyacrylamide (PAA), as an adsorbent was investigated for the removal of Ni(II) and Cr(III) metal ions from their synthesized aqueous solutions. The different variables affecting the adsorption capacity of the adsorbent such as contact time, pH of the sorption medium, metal ions concentration and temperature of the solution were investigated on a batch sorption basis. The adsorption equilibrium data fitted best with the Langmuir isotherm model. The maximum adsorption capacities found to be 84.03 and 32.67 mg g-1 of the polyacrylamide for Cr(III) and Ni(II), respectively. Three kinetic models including the pseudo-first-order, pseudo-second-order and intraparticle diffusion equations were selected to follow the adsorption process. Kinetic parameters such as rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was indicated that the adsorption of both ions onto polyacrylamide could be described by the pseudo-second-order kinetic model. Different thermodynamic parameters such as ?H?, ?S? and ?G? have also been evaluated and it has been found that the sorption was feasible, spontaneous and exothermic.

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