scholarly journals Chemical kinetics and particle size effects of activated carbon for free chlorine removal from drinking water

2018 ◽  
Vol 14 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Fanke Meng ◽  
Guoping Li ◽  
Binbin Zhang ◽  
Jinbin Guo
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Volume Flow Rate ◽  
Kinetic Constant ◽  
Chemical Kinetic ◽  
Free Chlorine ◽  
Order Kinetic ◽  
Potential Health ◽  
Kinetic Reaction ◽  
Chlorine Removal

Abstract Activated carbon is an economic material to grab free chlorine in drinking water to reduce potential health risks. In this research, chemical kinetic reaction of the activated carbon for free chlorine removal was studied, which exhibited the first order kinetic reaction performance. A relationship between the rate of chlorinated water flowing through the activated carbon, and the free chlorine (ClO−) concentrations before and after the reduction by activated carbon was obtained. The logarithm of the free chlorine concentration (lnC) was linearly related to the reciprocal of the volume flow rate (1/v). The slope was dependant on the kinetic constant of the activated carbon dechlorination reaction. This research is beneficial for the scientists and engineers to study the mechanism of the chemical kinetic reaction of the free chlorine removal by activated carbon and design activated carbon-loaded water purification reactors.

Microencapsulation of natural vanilla (Vanilla planifolia) extract in β-cyclodextrin by using kneading method

2017 ◽  
Vol 119 (10) ◽  
pp. 2240-2252
Author(s):  
Wunwisa Krasaekoopt ◽  
Ampapan Jongyin
Keyword(s):  
Design Methodology ◽  
Storage Stability ◽  
Kinetic Constant ◽  
Suitable Condition ◽  
Order Kinetic ◽  
Chiang Mai ◽  
Kinetic Reaction ◽  
Content Type ◽  
Positive Effects ◽  
Kneading Method

Purpose The purpose of this paper is to encapsulate vanilla extract by using inclusion complex of ß-cyclodextrin and also to investigate the qualities of the encapsulated powder in terms of vanillin content, moisture content, and stability under accelerated condition. Design/methodology/approach A randomized block and factorial 3×3 experimental designs with three replications were used for the studies of solvent extraction, microencapsulation of natural vanilla extract and stability of microencapsulated vanilla powder. Findings Ethanol concentration and ratio of vanilla to ethanol had positive effects on vanillin content. The extraction with 55 percent ethanol and the ratio of vanilla pods to ethanol as 1:4 provided the highest vanillin content of 341.23 mg/100 mL of the extract. The amount of vanilla extract and kneading time gave significant (p<0.05) effect on the microencapsulation efficiency (ME). The greatest ME found was 94.50 percent when 9 percent vanilla extract and 10 min of kneading time were used. The interaction of temperature and water activity gave significant effect on the second-order kinetic reaction of encapsulated vanilla powder (p<0.05).The most suitable condition of storage was 35°C with aw of 0.64, providing the kinetic constant (k) of 0.0024, and correlation coefficient (R2) of 0.92 with thalf-life of 4.54 weeks. Originality/value This study provides the most suitable condition for natural vanilla extraction and microencapsulation as well as storage stability for natural vanilla powder production using the third grade vanilla pods grown at Royal Project, Khun Wang Center, Chiang Mai, Thailand.

Resorcinarene Cavitand Polymers for the Remediation of Halomethanes and 1,4-Dioxane

2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Capacity ◽  
The United States ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Porous Polymer ◽  
Organic Micropollutants ◽  
Executive Summary ◽  
Regulatory Limits

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>

A Residual Chlorine Removal Method to Allow Drinking Water Monitoring by Biological Early Warning Systems

2005 ◽  
Author(s):  
Willian H. VAN DER Schalie ◽  
David E. Trader ◽  
Mark W. Widder ◽  
Tommy R. Shedd ◽  
Linda M. Brennan
Keyword(s):  
Drinking Water ◽  
Early Warning ◽  
Early Warning Systems ◽  
Water Monitoring ◽  
Residual Chlorine ◽  
Warning Systems ◽  
Removal Method ◽  
Chlorine Removal

Removal of microcystin-LR from drinking water with TiO2-coated activated carbon

2004 ◽  
Vol 4 (5-6) ◽  
pp. 21-28
Author(s):  
S.-C. Kim ◽  
D.-K. Lee
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Synergistic Effect ◽  
Fluidized Bed ◽  
Continuous Flow ◽  
High Surface ◽  
High Surface Area ◽  
Fluidized Bed Reactor ◽  
Exterior Surface ◽  
Tio2 Particles

TiO2-coated granular activated carbon was employed for the removal of toxic microcystin-LR from water. High surface area of the activated carbon provided sites for the adsorption of microcystin-LR, and the adsorbed microcystin-LR migrated continuously onto the surface of TiO2 particles which located mainly at the exterior surface in the vicinity of the entrances of the macropores of the activated carbon. The migrated microcystin-LR was finally degraded into nontoxic products and CO2 very quickly. These combined roles of the activated carbon and TiO2 showed a synergistic effect on the efficient degradation of toxic microcystin-LR. A continuous flow fluidized bed reactor with the TiO2-coated activated carbon could successfully be employed for the efficient photocatalytic of microcystin-LR.

Fish Processing Wastewater: Emission Factors and High Load Trickling Filters Evaluation

1992 ◽  
Vol 25 (1) ◽  
pp. 1-8 ◽  
Author(s):  
P. Battistoni ◽  
G. Fava ◽  
A. Gatto
Keyword(s):  
Cross Flow ◽  
Emission Factors ◽  
High Rate ◽  
Superior Performance ◽  
Pollutant Emission ◽  
Order Kinetic ◽  
Fish Processing ◽  
Kinetic Reaction ◽  
Trickling Filters ◽  
Frozen Fish

An Italian seafood factory processing frozen fish and fresh clams was investigated. Specific water consumption (SC) and pollutant emission factors (EF) are evaluated. Results evidence high SC values, in the range 18-74 1/Kg, due to defrost and extensive washing and cleaning practised; EFs appear high although not directly comparable with data reported by other authors. Two high-rate trickling filters, cross flow (CF) and vertical flow (VF), are examined over a two years period. Results suggest a pseudo half-order kinetic reaction with a superior performance of CF plastic media. From the elaboration of the experimental data a semiempirical correlation between specific surface removal (SSR) and operative parameters is obtained.

scholarly journals Adsorption and Photocatalytic Mineralization of Bromophenol Blue Dye with TiO2 Modified with Clinoptilolite/Activated Carbon

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Emmanuel Kweinor Tetteh ◽  
Sudesh Rathilal
Keyword(s):  
Activated Carbon ◽  
Photocatalytic Degradation ◽  
Oxygen Demand ◽  
Freundlich Isotherm ◽  
Reaction Rate Constant ◽  
Coefficient Of Determination ◽  
Bromophenol Blue ◽  
Blue Dye ◽  
Order Kinetic ◽  
Co Precipitation

This study presents a hybridized photocatalyst with adsorbate as a promising nanocomposite for photoremediation of wastewater. Photocatalytic degradation of bromophenol blue (BPB) in aqueous solution under UV-irradiation of wavelength 400 nm was carried out with TiO2 doped with activated carbon (A) and clinoptilolite (Z) via the co-precipitation technique. The physiochemical properties of the nanocomposite (A–TiO2 and Z–TiO2) and TiO2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. Results of the nanocomposite (A–TiO2 and Z–TiO2) efficiency was compared to that with the TiO2, which demonstrated their adsorption and synergistic effect for the removal of chemical oxygen demand (COD) and color from the wastewater. At an optimal load of 4 g, the photocatalytic degradation activity (Z–TiO2 > A–TiO2 > TiO2) was found favorably by the second-order kinetic model. Consequently, the Langmuir adsorption isotherms favored the nanocomposites (Z–TiO2 > A–TiO2), whereas that of the TiO2 fitted very well on the Freundlich isotherm approach. Z–TiO2 evidently exhibited a high photocatalytic efficacy of decomposition over 80% of BPB (COD) at reaction rate constant (k) and coefficient of determination (R2) values of 5.63 × 10−4 min−1 and 0.989, respectively.

scholarly journals Study on Adsorption Properties of Modified Corn Cob Activated Carbon for Mercury Ion

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4483
Author(s):  
Yuyingnan Liu ◽  
Xinrui Xu ◽  
Bin Qu ◽  
Xiaofeng Liu ◽  
Weiming Yi ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Adsorption Process ◽  
Physical Adsorption ◽  
Raw Material ◽  
Order Kinetic ◽  
Mercury Ions ◽  
Corn Cob ◽  
Adsorption Time ◽  
X Ray

In this study, corn cob was used as raw material and modified methods employing KOH and KMnO4 were used to prepare activated carbon with high adsorption capacity for mercury ions. Experiments on the effects of different influencing factors on the adsorption of mercury ions were undertaken. The results showed that when modified with KOH, the optimal adsorption time was 120 min, the optimum pH was 4; when modified with KMnO4, the optimal adsorption time was 60 min, the optimal pH was 3, and the optimal amount of adsorbent and the initial concentration were both 0.40 g/L and 100 mg/L under both modified conditions. The adsorption process conforms to the pseudo-second-order kinetic model and Langmuir model. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Zeta potential characterization results showed that the adsorption process is mainly physical adsorption, surface complexation and ion exchange.

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