scholarly journals The Estimation of Acidic Behavior of Wood by Treatment with Aqueous Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Güneş Uçar ◽  
Mualla Balaban Uçar
Keyword(s):  
Aqueous Solution ◽  
Wood Species ◽  
Ph Value ◽  
Phosphate Solution ◽  
Weak Acids ◽  
New Approach ◽  
Conjugate Acid ◽  
Phosphate Solutions

As a new approach, the acidity that wood exhibits under moderate conditions is assayed by stimulated dissociation of weak wood acids in lightly basic secondary phosphate solutions. To assure a sufficient dissociation of hardly soluble weak acids in the solution, the amount of wood suspended in solutions should be small but vary depending on the degree of acidity of wood species. However, the difficulties are associated with the titration of very dilute acids limiting the precision of the measurement. If the disintegrated wood is suspended in a secondary phosphate solution, the weak woods acids form the conjugate acid from secondary phosphate resulting in a pH fall of the solution. The decrease in the pH value in phosphate solution, which depends on the wood acidity, can be evaluated to estimate the acidity arising from wood under moderate conditions.

A New Approach to Fluorescent Chemosensor of Cu2+ Ion

2014 ◽  
Vol 513-517 ◽  
pp. 65-69
Author(s):  
Xiao Jun Hu ◽  
Xin Yan Hu ◽  
Zhi Zhang
Keyword(s):  
Aqueous Solution ◽  
Electron Transfer ◽  
Self Assembly ◽  
Ph Value ◽  
Sodium Dodecyl ◽  
Fluorescence Emission ◽  
Fluorescent Chemosensor ◽  
Dynamic Quenching ◽  
Transfer Effects ◽  
New Approach

According to the principle of dynamic quenching a new ON-OFF fluorescent chemosensor for Cu2+ions was designed, this chemosensor was composed of p-tert-butylthiacalix [arene (TCA),sodium dodecyl sulfate (SDS) and perylene through the form of self-assembly in aqueous solution. Addition of Cu2+ions could result in a quenching of the fluorescence emission of perylene inside micelles, which due to intramicellar complex-fluorophore electron-transfer or energy-transfer effects induced by the complexation of TCA with the Cu2+ions.The experimental results indicated that: Under the condition of TCA/perylene was 800/1, SDS concentration was 150mmol/L and pH value above 9, according to the fluorescence quenching ,within a certain range of the concentration of Cu2+ion can be linearly determined.

scholarly journals Hydrogeochemical Characterization as a Tool to Recognize “Masked Geothermal Waters” in Bahía Concepción, Mexico

Resources ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 23
Author(s):  
Pablo Hernández-Morales ◽  
Jobst Wurl ◽  
Carlos Green-Ruiz ◽  
Diego Morata
Keyword(s):  
Spatial Distribution ◽  
Thermal Water ◽  
Elevated Temperatures ◽  
Ph Value ◽  
Spring Water ◽  
Geothermal Resources ◽  
Geothermal Waters ◽  
New Approach ◽  
Deep Reservoir ◽  
Hydrogeochemical Characterization

Geo-thermalism has been widely recognized on the Baja California Peninsula, especially during the last decade. The current research, carried out on Bahia Concepcion, evidences the existence of geothermal springs, which get recharged mainly by groundwater and seawater. The groundwater can be characterized as Na+-Cl− and Na+-HCO3− type, with a pH value close to neutrality. The slightly more acidic thermal sites presented temperatures between 32 °C and 59 °C at the surface. Based on the relationships of the Cl− and Br−, as well as the B/Cl−, and Br−/Cl− ratios, seawater was recognized as the main source of salinity. The spatial distribution is explained directly through marine intrusion, or via sprays and aerosols within the rainwater. Seawater ratios in thermal springs varied from 62% to 83%, corresponding mainly to shallow inflow, but seawater inputs into the deep thermal reservoir were also recognized. Temperatures in the geothermal deep reservoir were inferred from 114 to 209 °C, calculated through the SiO2 and Na+-K+ geothermometers. In addition to previously reported thermal sites at Bahía Concepción, and based on their elevated temperatures, two new sites were identified. Another five springs do not fulfill the commonly used definition, based on differential temperature, but show the typical hydrogeochemical signature of thermal water. A new approach to identify this low-temperature geothermal-influenced spring water by its hydrogeochemical composition is presented, for which the term “Masked Geothermal Waters” (MGW) is introduced. Our findings increase the area of the geothermal anomaly and, therefore, the potential of geothermal resources. The approach proposed in this research will also be useful to identify more MGW in other coastal areas.

scholarly journals Selenium in wastewater can be adsorbed by modified natural zeolite and reused in vegetable growth

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110198
Author(s):  
Xiao Zhang ◽  
Xinyuan Li ◽  
Zihao Jin ◽  
Sadam Hussain Tumrani ◽  
Xiaodong Ji
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Soil Improvement ◽  
Pollutant Removal ◽  
Maximum Adsorption Capacity ◽  
Selenium Content ◽  
Water Release ◽  
Soil Release ◽  
Release Ratio ◽  
Water Pollutant

Modified natural zeolites (MNZ) are widely used in pollutant removal, but how to address these MNZ that have adsorbed pollutants must be considered. Selenium is an essential trace element for metabolism and is also a water pollutant. Selenium is adsorbed in the water by MNZ in this study first. Then the Brassica chinensis L. was planted in the soil which contains the MNZ loaded with selenium (MNZ-Se) to explore selenium uptake. MNZ-Se release tests in water and soil were also considered. The results showed the following: (1) The maximum adsorption capacity of MNZ for selenium is 46.90 mg/g. (2) Water release experiments of MNZ-Se showed that regardless of how the pH of the aqueous solution changes, the trend of the release of selenium from MNZ-Se in aqueous solution is not affected and first decreases before stabilizing. (3) Soil release experiments of MNZ-Se showed that the selenium content in the soil increased and reached the concentration in the standard of selenium-rich soil. Addition amount and soil pH value will affect the release ratio. The release ratio of MNZ-Se in the water was higher than that in the soil. (4) With an increase in the soil MNZ-Se content, the selenium content in the soil and B. c increases. Above all, MZN can be a good medium for water pollutant removal and soil improvement.

scholarly journals Removal of Phenol from Aqueous Solution Using Internal Microelectrolysis with Fe-Cu: Optimization and Application on Real Coking Wastewater

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 720
Author(s):  
Do Tra Huong ◽  
Nguyen Van Tu ◽  
Duong Thi Tu Anh ◽  
Nguyen Anh Tien ◽  
Tran Thi Kim Ngan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Reaction Rate Constant ◽  
Phenol Concentration ◽  
Treated Wastewater ◽  
Coking Wastewater ◽  
X Ray ◽  
Chemical Plating ◽  
Internal Electrolysis ◽  
Phenol Decomposition

Fe-Cu materials were synthesized using the chemical plating method from Fe powder and CuSO4 5% solution and then characterized for surface morphology, composition and structure by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The as-synthesized Fe-Cu material was used for removal of phenol from aqueous solution by internal microelectrolysis. The internal electrolysis-induced phenol decomposition was then studied with respect to various parameters such as pH, time, Fe-Cu material weight, phenol concentration and shaking speed. The optimal phenol decomposition (92.7%) was achieved under the conditions of (1) a pH value of phenol solution of 3, (2) 12 h of shaking at the speed of 200 rpm, (3) Fe-Cu material weight of 10 g/L, (4) initial phenol concentration of 100.98 mg/L and (5) at room temperature (25 ± 0.5 °C). The degradation of phenol using Fe-Cu materials obeyed the second-order apparent kinetics equation with a reaction rate constant of k of 0.009 h−1L mg−1. The optimal process was then tested against real coking wastewater samples, resulting in treated wastewater with favorable water indicators. Current findings justify the use of Fe-Cu materials in practical internal electrolysis processes.

Adsorption Characteristics of Phenol in Aqueous Solution by Pinus massoniana Biochar

2013 ◽  
Vol 295-298 ◽  
pp. 1154-1160 ◽  
Author(s):  
Guo Zhi Deng ◽  
Xue Yuan Wang ◽  
Xian Yang Shi ◽  
Qian Qian Hong
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Pinus Massoniana ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Salt Ions ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The objective of this paper is to investigate the feasibility of phenol adsorption from aqueous solution by Pinus massoniana biochar. Adsorption conditions, including contact time, initial phenol concentration, adsorbent dosage, strength of salt ions and pH, have been investigated by batch experiments. Equilibrium can be reached in 24 h for phenol from 50 to 250 mg• L-1. The optimum pH value for this kind of biochar is 5.0. The amount of phenol adsorbed per unit decreases with the increase in adsorbent dosage. The existence of salt ions makes negligible influence on the equilibrium adsorption capacity. The experimental data is analyzed by the Freundlich and Langmuir isotherm models. Equilibrium data fits well to the Freundlich model. Adsorption kinetics models are deduced and the pseudo-second-order kinetic model provides a good correlation for the adsorbent process. The results show that the Pinus massoniana biochar can be utilized as an effective adsorption material for the removal of phenol from aqueous solution.

Phthalate degradation by glow discharge plasma enhanced with pyrite in aqueous solution

2016 ◽  
Vol 74 (6) ◽  
pp. 1365-1375 ◽  
Author(s):  
Chensi Shen ◽  
Shaoshuai Wu ◽  
Hui Chen ◽  
Sadia Rashid ◽  
Yuezhong Wen
Keyword(s):  
Aqueous Solution ◽  
Energy Efficiency ◽  
Glow Discharge ◽  
Discharge Plasma ◽  
Ph Value ◽  
Glow Discharge Plasma ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Polymeric Compound ◽  
X Ray

In order to prevent health risk from potential exposures to phthalates, a glow discharge plasma (GDP) process was applied for phthalate degradation in aqueous solution. The results revealed that the phthalate derivatives 4-hydroxyphthalic acid, 4-methylphthalic acid and 4-tert-butylphthalic anhydride could be degraded efficiently in GDP process (498 V, 0.2 A) with high removal efficiencies of over 99% in 60 minutes. Additionally, pyrite as a promising heterogeneous iron source in the Fenton reaction was found to be favorable for GDP process. The phthalate degradation reaction could be significantly enhanced by the continuous formation of •OH and the inhibition of the quenching reaction in the pyrite Fenton system due to the constant dissolution of Fe(II) from pyrite surface. Meanwhile, the initial pH value showed little impact on the degradation of phthalates and the energy efficiency of GDP system for phthalate degradation ranged between 0.280 × 10−9 and 1.210 × 10−9 mol/J, which is similar to the GDP system with phenol, bisphenol A and methyl tert-butyl ether as the substrates. Further, the X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy analyses indicated that the pyrite was relatively stable in GDP system and there was no obvious polymeric compound formed on the catalyst surface. Overall, this GDP process offers high removal efficiency, simple technology, considerable energy efficiency and the applicability to salt-containing phthalate wastewater.

High Cr(VI) Adsorption Performance of Coal-Based Activated Carbon in Aqueous Solution

2013 ◽  
Vol 798-799 ◽  
pp. 1123-1127
Author(s):  
Hua Lei Zhou ◽  
Qiong Qiong Zhu ◽  
Dong Hua Huang
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Pore Structure ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Koh Activation ◽  
Transmission Electron ◽  
Mesoporous Adsorbent ◽  
Initial Ph

The activated carbon with high surface area was prepared by KOH activation from anthracite and used as adsorbent for removal of Cr (VI) from aqueous solution. The pore structure and surface properties were characterized by N2 adsorption at 77K, transmission electron microscope (TEM) and Fourier transform infrared spectroscopy ( FTIR). Effect of pH and isotherms at different temperature were investigated. Results show that the prepared carbon is a microporous-and mesoporous-adsorbent with developed pore structure and abundant surface oxygen-containing groups. PH value of the solution plays key function on the adsorption. The chemical adsorption dominates the adsorption process. The activated carbon exhibits much higher Cr adsorption capacity than the commercial activated carbon at initial pH of ~3. The equilibrium adsorption data are fitted by both Freundlich model and Langmuir model well.

Synthesis and Characterization of CdSe Nanoparticles with Cadmium Precursor Variation in Colloidal Synthesis

2014 ◽  
Vol 976 ◽  
pp. 52-58 ◽  
Author(s):  
Janeth Sarmiento Arellano ◽  
Enrique Rosendo ◽  
Román Romano ◽  
Gabriela Nieto ◽  
Tomás Díaz ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Sodium Tripolyphosphate ◽  
Compositional Analysis ◽  
Cadmium Acetate ◽  
Cdse Nanoparticles ◽  
Molar Concentration ◽  
Colloidal Synthesis ◽  
Cadmium Nitrate ◽  
X Ray

A comparative study of the synthesis of cadmium selenide (CdSe) nanoparticles (NPs) using different cadmium precursors such as, cadmium nitrate (Cd (NO3)2·4H2O), cadmium acetate ((CH3COO)2Cd·2H2O) and cadmium chloride (CdCl2·2.5H2O) is presented in this work. The method used to obtain the CdSe NPs was the colloidal synthesis at low temperature and atmospheric pressure. The Cd2+ ions were obtained in aqueous solution at room temperature, the surfactant used in the process was an aqueous solution of sodium hydroxide (NaOH), penta-sodium tripolyphosphate and H2O named commonly extran, which not only helps to stabilize the NPs, but also allows adjusting the pH of the solution. Se2- ions were obtained with sodium borohydride (NaBH4) as reductant at 75 oC. The by-products from the reaction were eliminated through a cleaning process with hydrochloric acid (HCl). Molar concentration of Cd:Se was varied from 3:1 to 1:3 and the pH value was varied between 8 and 11. The obtained samples were characterized by X-ray diffraction (XRD), it was seen that the obtained NPs present cubic centered face structure. The crystallite size from the powder was calculated using the Debye-Scherrer equation and was found between 3.3 nm and 5.6 nm, the variation in size depends on the molar concentration of cadmium and selenium. Morphological study was done using scanning electron microscopy (SEM) and compositional analysis was done by energy dispersive x-ray analysis (EDAX).

scholarly journals Reverse vesicles as a new system for studying enzymes in organic solvents

1992 ◽  
Vol 285 (2) ◽  
pp. 373-376 ◽  
Author(s):  
A Sánchez-Ferrer ◽  
F García-Carmona
Keyword(s):  
Aqueous Solution ◽  
Organic Solvents ◽  
Reverse Micelles ◽  
Active Form ◽  
Ionic Surfactant ◽  
New Approach ◽  
Optically Transparent ◽  
Reverse Vesicles ◽  
Dodecyl Ether ◽  
New System

A new approach to the study of enzyme activity in organic solvents has been developed by using optically transparent reverse vesicles. Polyphenol oxidase was incorporated in an active form into the above ternary system formed by the non-ionic surfactant tetra(ethylene glycol) dodecyl ether/n-dodecane/water. The enzyme in this microenvironment, surprisingly, showed an apparent positive co-operativity which has never before been described either in aqueous solution or in reverse micelles. In addition, the Vmax. expressed was similar to that in water and twice that displayed in reverse micelles.

scholarly journals Adsorption of aquatic Cd2+ using a combination of bacteria and modified carbon fiber

2017 ◽  
Vol 36 (3-4) ◽  
pp. 857-871 ◽  
Author(s):  
Chao Xue ◽  
Peishi Qi ◽  
Yunzhi Liu
Keyword(s):  
Aqueous Solution ◽  
Composite Material ◽  
Carbon Fiber ◽  
Active Sites ◽  
Ph Value ◽  
Removal Rate ◽  
Sorption Process ◽  
Acid Sites ◽  
Heterogeneous Distribution ◽  
Carbon Fiber Material

Batch experiments were conducted to investigate the capacity and mechanisms for adsorbing Cd2+ from aqueous solutions by the composite material. The composite material was manufactured with Plesiomonas shigelloides strain H5 and modified polyacrylonitrile-based carbon fiber. Experimental results showed that the surface areas of modified polyacrylonitrile-based carbon fiber increased by 58.54% and pore width increased by 40.19% compared with unmodified polyacrylonitrile-based carbon fiber. Boehm’s titration results show the surface acid sites of composite material were increased by 712% compared with unmodified polyacrylonitrile-based carbon fiber. The field emission scanning electron microscope results show P. shigelloides H5 can be grown on the surface of modified polyacrylonitrile-based carbon fiber closely. The equilibrium removal rate and sorption quantity of composite material were 71.56% and 7.126 mg g−1, respectively. With the pH value of aqueous solution increased, the removal rate of Cd2+ ions was also increased, but the change of temperature and ionic strength had no significant effect on the removal rate. Furthermore, the results showed the whole sorption process was a good fit to Lagergren pseudo-second-order model and Freundlich isotherms model. Therefore, the results infer that there was a heterogeneous distribution of active sites, and then the sorption process was chemical adsorption and multilayer adsorption. In a word, microbial composite carbon fiber material can adsorb Cd2+ ions from aqueous solution effectively, which might be helpful in wastewater treatment in the future.

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