Sorption Kinetics of Pro-Oxidant-Loaded PE Plastic Bags in Aqueous Media

2015 ◽  
Vol 1125 ◽  
pp. 240-244 ◽  
Author(s):  
Giselle Lou D. Leuterio ◽  
Bryan B. Pajarito
Keyword(s):  
Water Immersion ◽  
Aqueous Media ◽  
Sorption Kinetics ◽  
Deionized Water ◽  
Alkaline Solutions ◽  
Maximum Weight ◽  
Transparent Films ◽  
Highest Weight ◽  
Plastic Bags ◽  
Kinetics Of

Sorption studies in aqueous media of pro-oxidant-loaded polyethylene (PE) films from commercial plastic bags are conducted. A total of 6 types of plastic bags are tested at three levels of thickness and two levels of color (transparent and opaque white). PE films are immersed in deionized water, acidic, and alkaline solutions at 60 °C. Sorption curves show that once the maximum uptake is reached, the weight change of PE films started to decline. The films showing the highest weight uptake and loss are observed in opaque films in alkaline solution. Analysis of variance (ANOVA) shows that during water immersion, both maximum weight uptake and loss are affected by colorant additive, with opaque films yielding the highest weight uptake and loss. During acid immersion, transparent films have significantly higher weight uptake than opaque films. The weight uptake during acid immersion is only affected by film thickness, with the thickest films showing the lowest weight uptake. Similar to results in water immersion, thickness is found to be insignificant to weight uptake and loss of PE films during alkali immersion. Meanwhile, colorant additive is significant to both weight uptake and loss for all films immersed in different solutions.

Sorption and desorption kinetics of Np(V) on magnetite and hematite

2000 ◽  
Vol 88 (8) ◽  
Author(s):  
K. Nakata ◽  
S. Nagasaki ◽  
S. Tanaka ◽  
Y. Sakamoto ◽  
T. Tanaka ◽  
...  
Keyword(s):  
Crystalline Phase ◽  
Acidic Solution ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Chemical Form ◽  
Alkaline Solutions ◽  
Desorption Kinetics ◽  
Chemical Forms ◽  
Kinetics Of ◽  
Desorption Method

Sorption kinetics of Np(V) on magnetite and hematite were investigated, and a sequential desorption method was applied to investigate changes in the chemical form of Np sorbed according to the amount of time they were in contact with the Np solution. It was found that the sorption process consists of fast sorption and slow sorption which reaches equilibrium in 1 h. According to the desorption results, it was conjectured (i) that fast sorption is attributable to sorption on/into the surface and non-crystalline phases of iron oxides for magnetite and hematite in both acidic and alkaline solutions, (ii) that sorption on/into the crystalline phase also contributes to fast sorption for hematite in an alkaline solution, and (iii) that slow sorption represents sorption into the crystalline phase of magnetite in both acidic and alkaline solutions and that of hematite in an acidic solution. From the results of sorption and desorption kinetics, it was concluded that the equilibrium between various chemical forms of sorbed Np was achieved in about 1 week, although the amount of sorbed Np reached an equilibrium in only 1 h.

scholarly journals Mechanisms of halosulfuron methyl pesticide biosorption onto neem seeds powder

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atta ul Haq ◽  
Muhammad Saeed ◽  
Muhammad Usman ◽  
Ameer Fawad Zahoor ◽  
Muhammad Naveed Anjum ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Sorption Kinetics ◽  
Point Of Zero Charge ◽  
Neem Seed ◽  
Solution Ph ◽  
Chemical Surface ◽  
Operation Conditions ◽  
Zero Charge ◽  
Pseudo Second Order ◽  
Kinetics Of

AbstractThe current investigation was designed to remove halosulfuron methyl from aqueous media by means of neem seed powder (NSP) in batch modes. Characterizations of NSP were carried out by using EDX, SEM, FTIR, point of zero charge and surface analysis. Optimum operation conditions were scrutinized by studying the influence of different factors like solution pH, dose of NSP, contact time, initial halosulfuron methyl concentration and temperature. Result indicates the dependency of the removal of halosulfuron methyl on solution pH and maximal removal (54%) was achieved in acidic medium (i.e. pH 3.0). To identify the chemical surface of NSP, point of zero charge of NSP was determined and was found to be 6.5 which imply that the surface of NSP is positively charged below pH 6.6 and favored the anionic sorption. Kinetics of halosulfuron methyl were demonstrated well by pseudo second order due to highest R2 (0.99) owing to the nearness between experimental and calculated sorption capacities. Isotherm results imply that Langmuir was found to the principal model to explain the removal of halosulfuron methyl and maximum monolayer sorption capacity was determined to be 200 mg g−1. Thermodynamic parameters like ΔH°, ΔG° and ΔS° were calculated from van’t Hoff plot and were found negative which suggest that removal of halosulfuron methyl is exothermic and spontaneous at low temperature. These outcomes insinuate that neem seed power may be a valuable, inexpensive and ecofriendly biosorbent for the removal of pesticides.

Modeling of sorption kinetics of U(VI) micro-quantities nanostructured materials with anatase mesoporous structures

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Veniamin Zheleznov ◽  
Aleksey Golikov ◽  
Tatiana Sokolnitskaya ◽  
Sergey Ivannikov
Keyword(s):  
Nanostructured Materials ◽  
Sorption Kinetics ◽  
Uranyl Ion ◽  
Competitive Sorption ◽  
Hydroxyl Groups ◽  
Complex Ions ◽  
The Stability ◽  
Kinetics Of ◽  
Mesoporous Structures ◽  
Ionic Forms

Abstract The sorption kinetics of uranyl ions micro-quantities from fluoride solutions by nanostructured materials with anatase mesoporous structures has been studied. Using the model of competitive sorption of ions and positively charged complexes of uranyl ion on deprotonated hydroxyl groups of an anatase, kinetic curves of changes in the ratio of ionic forms of uranium in solution were calculated. Modeling was carried out under the assumption of a two-stage mechanism of uranium complex ions sorption. The modeling considered the influence of the uranyl ion carbonate complexes formation. The shift in equilibrium among ionic forms of uranyl correlates with the stability of the complexes in solution.

Study of kinetics of reaction of lignin model compounds with propylene oxide

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Krishna K. Pandey ◽  
Tapani Vuorinen
Keyword(s):  
Chemical Reaction ◽  
Propylene Oxide ◽  
Aqueous Media ◽  
Reaction Products ◽  
Model Compounds ◽  
Rapid Reduction ◽  
Visible Absorption ◽  
Lignin Model Compounds ◽  
Lignin Model ◽  
Kinetics Of

Abstract The etherification of phenolic groups has been found to inhibit photodegradation in wood and lignin rich pulps. The precise understanding of kinetics of chemical reaction between lignins or their model compounds and the etherifying agent is the first step for developing a viable modification procedure. In this study, we have investigated the reaction of lignin model compounds (namely, phenol and guaiacol) with propylene oxide in aqueous media. The kinetics of etherification reaction was studied under varying pH conditions in the temperature range 30–60°C. The etherified reaction products were characterized by gas chromatogram-mass spectrum (GC-MS). The extent of etherification of phenols and the rate of chemical reaction was followed by UV-Visible absorption spectroscopy. The reaction between lignin model compounds and propylene oxide was indicated by a rapid reduction in the absorbance accompanied by the development of a new band corresponding to etherified products. The reaction kinetics was investigated at pH ∼12 under the condition of excess concentration of propylene oxide. The reaction followed first order kinetics and rate constants increased linearly with an increase in the temperature and concentration of propylene oxide. The MS fragment data of reaction product support the proposed reaction scheme. The activation energy of the reaction of propylene oxide with phenol and guaiacol, calculated with the Arrhenius equation, was 56.2 kJ mol-1 and 45.4 kJ mol-1, respectively.

Effect of the Conditions of the Synthesis of Calcium Silicates on the Kinetics of Microbiological Treatment of Aqueous Media

2021 ◽  
Vol 66 (8) ◽  
pp. 1135-1140
Author(s):  
S. B. Yarusova ◽  
S. N. Somova ◽  
U. V. Kharchenko ◽  
P. S. Gordienko ◽  
I. A. Beleneva
Keyword(s):  
Aqueous Media ◽  
Calcium Silicates ◽  
Kinetics Of ◽  
Microbiological Treatment
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