Adsorption of Fluorine from Aqueous Solution by Chitosan Magnetic Microspheres of Loading Lanthanum

2013 ◽  
Vol 634-638 ◽  
pp. 367-374 ◽  
Author(s):  
Jin Song Wang ◽  
Feng Rong Fang ◽  
Heng Yue ◽  
Qing Wei Guo ◽  
Zhen Cheng Xu
Keyword(s):  
Reaction Time ◽  
Removal Rate ◽  
Fluoride Concentration ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Magnetic Microspheres ◽  
Optimum Operating ◽  
Operating Parameters ◽  
Sorption Data ◽  
Effects Of Ph

The adsorption of fluoride by chitosan magnetic microspheres of loading lanthanum metal (CTS-La) was investigated in this study. The chitosan magnetic materials were prepared by organically-linking technique. The effects of pH, the reaction time, the initial concentration, dosage and temperature on the removal rate were studied to determine to the optimum operating parameters. The experimental results show that CTS-La is a black particle shape material with magnetism. The magnetic microspheres have high adsorption ability for fluoride, and the maximum removal of F- was 98.4% under the operating parameters of the initial fluoride concentration 10mg/L, pH=2-3,the reaction time 60minutes, dosage 0.1g, temperature 318K. . The equilibrium sorption data are fitted reasonably well in Langmuir and Freundlich isotherm model, and the correlation coefficients (R2) were Langmuir’s correlation and 0.9997 respectively.

scholarly journals Kinetic Sorption Studies of Heavy Metal Contamination on Indian Expansive Soil

2009 ◽  
Vol 6 (4) ◽  
pp. 1125-1132 ◽  
Author(s):  
M. K. Gupta ◽  
A. K. Singh ◽  
R. K. Srivastava
Keyword(s):  
Heavy Metal Contamination ◽  
Expansive Soil ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Sorption Data ◽  
Freundlich Model ◽  
Metallic Cadmium ◽  
Pseudo Second Order ◽  
Alluvial Clay

Sorption of metallic cadmium from the pH adjusted aqueous solutions at varying initial concentrations onto an alluvial (clay) soil through batch sorption experiments was studied. The pH of the initial concentrations ranging between 50 mg/L to 250 mg/L was varied from 3.0 to 8.0. The sorption experiments were carried out for different durations and up to 16 hours. The cadmium continued to sorb till the last experimental pH=8. The experimental sorption data fitted very well with both Langmuir and Freundlich isotherm models and Freundlich model gave higher correlation coefficients. The pseudo-second order kinetics model was most agreeable with the experimental sorption data, whereas the pseudo-first order model was found to be insufficient.

scholarly journals Effect of H2O2Oxidation/Alkaline Hydrolysis on Waste Activated Sludge Disintegration and Dewaterability

2018 ◽  
Vol 65 ◽  
pp. 05021 ◽  
Author(s):  
Gan Chin Heng ◽  
Mohamed Hasnain Isa ◽  
Ming Han Lim
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Activated Sludge ◽  
Alkaline Hydrolysis ◽  
Optimum Operating ◽  
Waste Activated Sludge ◽  
Operating Parameters ◽  
Peroxide Oxidation ◽  
Operating Variables ◽  
H2o2 Oxidation

In the present study, the effect of hydrogen peroxide oxidation/alkaline hydrolysis was investigated on waste activated sludge (WAS), to enhance its disintegration and dewaterability. The effects of three operating parameters viz., pH, H2O2dose and reaction time, on the degree of WAS disintegration and dewaterability were assessed using response surface methodology. The optimum operating variables to achieve VSS removal 20%, CST reduction 20%, sCOD 6100 mg/L and EPS 455 mg/L were: pH 10.5, 1300 g H2O2/kg TS and 40 min reaction time. Results showed that WAS can be efficiently disintegrated and dewatered by H2O2 oxidation/alkaline hydrolysis for subsequent biological digestion.

Investigation on the Electrochemical Delignification of Pulp with Syringaldehyde

2013 ◽  
Vol 711 ◽  
pp. 257-261
Author(s):  
Ya Jie Zhong ◽  
Fan Gong Kong ◽  
Shou Juan Wang ◽  
Lei Xu ◽  
Wen Bo Wang
Keyword(s):  
Reaction Time ◽  
Electrolyte Solution ◽  
Sodium Sulfate ◽  
Kraft Pulp ◽  
Ph Value ◽  
Electrochemical Treatment ◽  
Kappa Number ◽  
Optimum Operating ◽  
Operating Parameters ◽  
Natural Mediator

The low molecular syringaldehyde was found to be a preferred natural mediator for pulp delignification in the electrochemically mediated delignification system (EMD-system). Electrochemical treatment of poplar kraft pulp with syringaldehyde results in the reduction of kappa number of about 28%, but the loss of viscosity is only 6.6%. During the process of electrochemically mediated delignification , the delignification efficiency is dependent on the voltage, the dosage of syringaldehyde , reaction temperature , pH value, reaction time and the composition of electrolyte solution. The optimum operating parameters of electrochemical delignification with syringaldehyde are obtained as follows: syringaldehyde 1mmol/l, voltage 1.8v, temperature 45°C, reaction time 4.5h, the pH-value in the range from 4.0 to 5.0, sodium sulfate 0.05mol/l.

Optimization Device for Grinding Media Performance Parameters

2011 ◽  
Author(s):  
Andrew M. Phan ◽  
Michael P. Summers ◽  
John P. Parmigiani
Keyword(s):  
Surface Temperature ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Optimum Operating ◽  
Operating Parameters ◽  
Performance Parameters ◽  
Total Material ◽  
Grinding Media ◽  
Casting Industry

The investment casting industry relies heavily on the use of grinding media during manufacturing. Typically, grinding media, when used in this application, have very short effective lifetimes. Determining the optimum life of grinding media is a key cost-containment and manufacturing-efficiency issue. However, current methods for determining optimum life as well as evaluating new grinding media products and optimum operating parameters are highly subjective and often is a matter of operator opinion. This subjectivity can lead to the premature retirement or overuse of grinding media, increasing cost and decreasing efficiency. A means of objectively and efficiently evaluating grinding media for optimum life and operating conditions, as well as evaluating new grinding-media products is needed. The approach taken in this work is to create a relatively low-cost test apparatus that uses grinding equipment, media, and specimens typically seen in the casting industry and measures key parameters. Also, the apparatus produces the fundamental motions and application forces typical of human operators. The resulting apparatus simultaneously moves a specimen in three orthogonal directions while applying a user-defined grinding force. Applied force, electric power input, grinding-motor rotational speed, test-specimen surface temperature and material removal are recorded. All operations of the device are autonomously performed through LabVIEW. The apparatus was constructed using standard commercial products for less than $15,000. Data comparing applied load versus material removal rate, surface temperature, and total material removed can be collected for different materials and grinding media. The device has been used to grind inconel specimens subjected to 10 to 70 pounds (45–312 N) of contact force corresponding to material removal rates of 0.26 to 5.26 grams/s at temperature changes of 90 to 210 degrees Fahrenheit (32.2–98.9 degrees Celsius). This data was used to determine a correlation between changes in performance parameters and a drop in material removal rate, total material removed, and belt life. No significant difference was found between the material removal rate of saw-cut and flame-cut Inconel specimens, dispelling a commonly held belief. Knowing key parameters that identify the effective lifetime of grinding media is significant to the casting industry. Methods described in this paper can be used to optimize grinding media life and determine optimum operating parameters.

Disposal of 3.5-dinitro-benzoicacid Wastewater by Semi-Coke/Ozone Combined Technology

2014 ◽  
Vol 997 ◽  
pp. 732-735
Author(s):  
Nan Nan Dang ◽  
Hui Wu Cai ◽  
Jin Meng Zhu
Keyword(s):  
Reaction Time ◽  
Benzoic Acid ◽  
Removal Rate ◽  
Catalytic Ozonation ◽  
Flow Temperature ◽  
Initial Concentration ◽  
Maximum Value ◽  
Effects Of Ph ◽  
Cod Removal Rate ◽  
Better Than

The effects of pH, initial concentration, ozone flow, temperature and semi-coke dosage on 3.5-dinitro-benzoic acid wastewater in the process of carbocoal catalytic ozonation are investigated. The results show that: the removal rate of COD increases with the rise of ozone flow and reaction time in a certain range; temperature has little effect on the removal rate of COD; the removal rate of COD achieve the maximum value when the pH is about 12; the COD removal rate of carbocoal catalytic ozonation is obviously better than single ozonation.

Simultaneous Adsorption of Trichloroethylene and Cadmium on Attapulgite in the Groundwater

2012 ◽  
Vol 610-613 ◽  
pp. 3202-3205
Author(s):  
Hai Ying Gao ◽  
Xiao Qian Li ◽  
Hui Jie Yan ◽  
Xiao Wei Wang
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Adsorption Rate ◽  
Adsorption Time ◽  
Freundlich Adsorption Isotherm ◽  
Effects Of Ph ◽  
Combined Contamination

The adsorption of trichloroethylene (TCE) and Cd2+ combined contamination in the groundwater by attapulgite were studied, and the effects of pH, dosage of attapulgite and adsorption time on adsorption were investigated, equilibrium of the adsorptions processes were further conducted. Results showed that the adsorption rate of TCE affected little by the pH; TCE adsorption equilibrium reached after 3d, the removal rate was 71.34%; when attapulgite dosage was 0.03g, the adsorption rate was up to more than 51.08%. Freundlich isotherm was best fitted the adsorption process of TCE. Compound contamination of TCE and Cd2+ decreased the removal rate of TCE; but was in line with Freundlich adsorption isotherm.

Evaluating photo-degradation of COD and TOC in petroleum refinery wastewater by using TiO2/ZnO photo-catalyst

2016 ◽  
Vol 74 (6) ◽  
pp. 1312-1325 ◽  
Author(s):  
Dheeaa al deen Atallah Aljuboury ◽  
Puganeshwary Palaniandy ◽  
Hamidi Bin Abdul Aziz ◽  
Shaik Feroz ◽  
Salem S. Abu Amr
Keyword(s):  
Reaction Time ◽  
Treatment Time ◽  
Removal Rate ◽  
Air Flow ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Removal Rates ◽  
Operational Conditions ◽  
Photo Catalyst

The aim of this study is to investigate the performance of combined solar photo-catalyst of titanium oxide/zinc oxide (TiO2/ZnO) with aeration processes to treat petroleum wastewater. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, ZnO dosage, air flow, pH, and reaction time to identify the optimum operating conditions. Quadratic models for chemical oxygen demand (COD) and total organic carbon (TOC) removals prove to be significant with low probabilities (<0.0001). The obtained optimum conditions included a reaction time of 170 min, TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), and pH 6.8 COD and TOC removal rates of 99% and 74%, respectively. The TOC and COD removal rates correspond well with the predicted models. The maximum removal rate for TOC and COD was 99.3% and 76%, respectively at optimum operational conditions of TiO2 dosage (0.5 g/L), ZnO dosage (0.54 g/L), air flow (4.3 L/min), reaction time (170 min) and pH (6.8). The new treatment process achieved higher degradation efficiencies for TOC and COD and reduced the treatment time comparing with other related processes.

scholarly journals Preparation and Characterization of High-Efficiency Magnetic Heavy Metal Capture Flocculants

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah
Keyword(s):  
Heavy Metal ◽  
Reaction Time ◽  
High Efficiency ◽  
Removal Rate ◽  
Low Cost ◽  
Monomer Concentration ◽  
Synthesis Process ◽  
Response Surface Optimization ◽  
Metal Capture ◽  
Total Monomer Concentration

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.

scholarly journals Enzymatic Transesterification of Waste Frying Oil from Local Restaurants in East Colombia Using a Combined Lipase System

2020 ◽  
Vol 10 (10) ◽  
pp. 3566
Author(s):  
Mary Angélica Ferreira Vela ◽  
Juan C. Acevedo-Páez ◽  
Nestor Urbina-Suárez ◽  
Yeily Adriana Rangel Basto ◽  
Ángel Darío González-Delgado
Keyword(s):  
Reaction Time ◽  
Methyl Esters ◽  
Enzyme Concentration ◽  
Operating Conditions ◽  
Frying Oil ◽  
Biodiesel Production ◽  
Optimum Operating ◽  
Waste Frying Oil ◽  
Production Chain ◽  
Enzymatic Transesterification

The search for innovation and biotechnological strategies in the biodiesel production chain have become a topic of interest for scientific community owing the importance of renewable energy sources. This work aimed to implement an enzymatic transesterification process to obtain biodiesel from waste frying oil (WFO). The transesterification was performed by varying reaction times (8 h, 12 h and 16 h), enzyme concentrations of lipase XX 25 split (14%, 16% and 18%), pH of reaction media (6, 7 and 8) and reaction temperature (35, 38 and 40 °C) with a fixed alcohol–oil molar ratio of 3:1. The optimum operating conditions were selected to quantify the amount of fatty acid methyl esters (FAMEs) generated. The highest biodiesel production was reached with an enzyme concentration of 14%, reaction time of 8 h, pH of 7 and temperature of 38 °C. It was estimated a FAMEs production of 42.86% for the selected experiment; however, best physicochemical characteristics of biodiesel were achieved with an enzyme concentration of 16% and reaction time of 8 h. Results suggested that enzymatic transesterification process was favorable because the amount of methyl esters obtained was similar to the content of fatty acids in the WFO.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

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