A study on the degradation of direct pink by the low-frequency ultrasonic irradiation

2010 ◽  
Vol 62 (4) ◽  
pp. 829-836 ◽  
Author(s):  
Huaili Zheng ◽  
Guocheng Zhu ◽  
Qiang He ◽  
Peng Hu ◽  
Shijun Jiao ◽  
...  

The ultrasonic degradation of direct pink was investigated in this study. Parameters affecting ultrasonic degradation degree such as ultrasonic power, pH, bubbling gas and the presence of inorganic salts, were examined. The results showed that the addition of inorganic salts (NaCl, CuSO4) facilitated the degradation of direct pink while the addition of K2CO3 inhibited it. The degradation degree was enhanced significantly in the presence of saturated gases as listed here in decreasing order of effectiveness: argon > air > oxygen > nitrogen. The degradation degree of direct pink was largely influenced by pH value and boosted by acidic condition. The optimum degree could be achieved when pH value was 3.0 or when the sound power was 150 W. However, the degradability decreased notably in alkaline condition. Also, ultrasound/H2O2 technology was used, and the results showed that ultrasound/H2O2 has a better effect on the degradation than ultrasound alone or with H2O2 oxidation. After 120 minutes, the degradation degree could reach 78.0% under the optimum conditions, when the ultrasonic power was 150 W, 50 μL H2O2, CuSO4 and argon atmosphere being added and the initial pH value of the model dye was 3.0.

2011 ◽  
Vol 236-238 ◽  
pp. 253-257
Author(s):  
Xian Zhen Zhang ◽  
De Si Sun ◽  
Hai Lin

The strain Jgj-1 was isolated from Gaoan bauxite ore. The relations of desilication of the strain Jgj-1 and the pH of solution, temperature, shaking speed, incubation time, particle size were investigated. The results shows the optimum conditions of bioleaching are as following: at 28°C, initial pH value is 7.2, particle size 0.056mm, 200rpm shaking speed, incubation 5-7 days.


2018 ◽  
Vol 7 (3.36) ◽  
pp. 170
Author(s):  
Umar M. Ibrahim ◽  
Saeed I. Ahmed ◽  
Babagana Gutti ◽  
Idris M. Muhammad ◽  
Usman D. Hamza ◽  
...  

The combination of Irish potato waste (IPW) and poultry waste (PW) can form a synergy resulting into an effective substrate for a better biogas production due to some materials they contain. In this work, optimization and kinetic study of biogas production from anaerobic digestion of IPW and PW was investigated. Response surface methodology (RSM) was applied to optimize conditions such as initial pH, solids concentrations and waste ratios. The anaerobic digestion of the two wastes was carried out in the mesophilic condition and Box-Behnken design (BBD) was used to develop and analyze a predictive model which describes the biogas yield. The results revealed that there is a good fit between the experimental and the predicted biogas yield as revealed by the coefficient of determination (R2) value of 97.93%. Optimization using quadratic RSM predicts biogas yield of 19.75% at the optimal conditions of initial pH value 7.28, solids concentration (w/v) 9.85% and waste ratio (IPW:PW) 45:55%. The reaction was observed to have followed a first order kinetics having R2 and relative squared error (RSE) values of 90.61 and 9.63% respectively. Kinetic parameters, such as rate constant and half-life of the biogas yield were evaluated at optimum conditions to be 0.0392 day-1 and 17.68 days respectively. The optimum conditions and kinetic parameters generated from this research can be used to design real bio-digesters, monitor substrate concentrations, simulate biochemical processes and predict performance of bio-digesters using IPW and PW as substrate.  


2012 ◽  
Vol 178-181 ◽  
pp. 557-561
Author(s):  
Jun Sheng Hu ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Xue Dong Ren

In diaphragm cell, by using the porous graphite as anode, ACF as the cathode, acid scarlet 3R as simulated wastewater, the experiment researched into the effect of current density, electrolyte concentration, aeration rate and the initial pH value on the color removal of wastewater. The results show that the decolourization efficiency increased gradually when the applied current density increases, but the trend will slow down when current density exceeds a certain value. The decolourization efficiency is proved to be first increases then decreases with increased electrolyte concentration and aeration rate, both excessively high and low electrolyte concentration are unfavorable to the removal of wastewater, however the aeration effect is smaller. The effect on decolorization is greater in acid condition than in alkaline condition. As the diaphragm, electrolyzer resistance increase, its average decolourization efficiency is lower than without diaphragm cell, and the decolourization efficiency of cathode area is significantly higher than the anode area.


2014 ◽  
Vol 1073-1076 ◽  
pp. 336-339
Author(s):  
Tian Qi Li ◽  
Hui Wang ◽  
Ya Qi Zhu ◽  
Zhao Yong Bian

Response surface methodology was applied to investigate the optimum degradation conditions of paracetamol using Ag/BiVO4 photocatalysts under the visible light irradiation. Experimental results show that the optimum degradation conditions were: catalyst dosage quantity was 80 mg, Ag-catalyst loading was 5%, and the initial pH value of the solution was 6, respectively. Under this condition, the degradation efficiency of paracetamol was 77.9% within 5 h under the visible light irradiation.


2012 ◽  
Vol 518-523 ◽  
pp. 2213-2217 ◽  
Author(s):  
Jiang Yue Tan

In this paper, ultrasonic cavitation degradation was applied to treat the wastewater containing nitroaromatic compound. The factors influence to treatment effect such as the ultrasonic power and frequency, the wastewater initial pH value, were investigated by experiment. The experimental results showed that air-blasting in ultrasonic cavitation treatment could effectively improve treatment effect. The wastewater(COD:2650 mg•L-1,BOD5:240 mg•L-1,p-nitroaniline:490 mg•L-1,nitrobenzene:100 mg•L-1)was treated by ultrasonic cavitation degradation, the removal rate of p-nitroaniline,nitrobenzene and COD could be reached 91.3%,90.6% and 83.9% respectively after 3h. Biodegradability of the wastewater (B/C ratio ) can be increased to 0.4 , which satisfied the requirement for the subsequent biochemical processes.


2013 ◽  
Vol 773 ◽  
pp. 923-926 ◽  
Author(s):  
Yong Guang Bi ◽  
Min Xia Huang

aniline solution for the study, the effects of ultrasonic time, reaction factors such as temperature, ultrasonic power, and the pH of its ultrasonic degradation rate. Experimental results show that: as time increases, the ultrasonic degradation rate of aniline also rise, When the ultrasound the irradiation time 80min, aniline degradation rate reached 89.3%, 90min when the degradation rate of 92.1%, the degradation rate of aniline with decreases with the rise of the temperature of the solution, more than 40°C the degradation rate decreased significantly. Aniline degradation rate increased with the initial solution pH value increases, indicating that the alkaline conditions are favorable for degradation of aniline solution. Relative to the traditional method, the method is fast, simple, degradation rate, etc..


2011 ◽  
Vol 71-78 ◽  
pp. 3071-3074
Author(s):  
Jun Sheng Hu ◽  
Yue Li ◽  
Zhuo Wang

Based on a static experiment, this study researched the electrochemical oxidation process of simulated dye wastewater containing Acid Scarlet 3R in the two-dimensional electrolysing cell. This experiment investigated the effect of such various factors as current density, initial concentration, supporting electrolyte concentration, and the initial pH value on the color removal. The results of the experiment clearly indicated that the rate of color removal increased when the current density was increasing gradually; it decreased when the initial concentration was increasing; it originally increased and then decreased when concentration of electrolytes was increasing; alkaline condition was not conducive to the removal of color, and the effect of decolorization was better under an acid condition than under an alkaline condition. The optimum condition of disposing of dye wastewater is when the current density is 7Am/cm², electrolyte concentration is 0.04mol/L, pH=2.5, under the condition of which the color removal rate could be 96.06%.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1645 ◽  
Author(s):  
Jianhua Xiong ◽  
Yinna Liang ◽  
Hao Cheng ◽  
Shuocheng Guo ◽  
Chunlin Jiao ◽  
...  

Intimate coupling of photocatalysis and biodegradation (ICPB) has shown promise in removing unwanted organic compounds from water. In this study, bagasse cellulose titanium dioxide composite carrier (SBC-TiO2) was prepared by low-temperature foaming methods. The optimum preparation conditions, material characterization and photocatalytic performance of the composite carrier were then explored. By conducting a single factor test, we found that bagasse cellulose with a mass fraction of 4%, a polyvinyl alcohol solution (PVA) with a mass fraction of 5% and 20 g of a pore-forming agent were optimum conditions for the composite carrier. Under these conditions, good wet density, porosity, water absorption and retention could be realized. Scanning electron microscopy (SEM) results showed that the composite carrier exhibited good biologic adhesion. X-ray spectroscopy (EDS) results confirmed the successful incorporation of nano-TiO2 dioxide into the composite carrier. When the mass concentration of methylene blue (MB) was 10 mg L−1 at 200 mL, 2 g of the composite carrier was added and the initial pH value of the reaction was maintained at 6, the catalytic effect was best under these conditions and the degradation rate reached 78.91% after 6 h. The method of preparing the composite carrier can aid in the degradation of hard-to-degrade organic compounds via ICPB. These results provide a solid platform for technical research and development in the field of wastewater treatment.


2013 ◽  
Vol 791-793 ◽  
pp. 116-119 ◽  
Author(s):  
Peng Ren ◽  
Wei Hua Lin

Lipase is a kind of important hydrolase. It was widely used in the fields of food, leather, detergent and pharmaceutical. The production of lipase from Arthrobacter sp. SD5 was studied in the present paper. The medium composition and culture condition were optimized in order to improve lipase production. The results showed the best optimum conditions were on the following: culture temperature (40°C); initial pH value (8.0); liquid volume (20%); carbon source (olive oil, 2.5%); nitrogen source (peptone, 1.0%); biosurfactant (Tween-80, 0.2%).


Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 931
Author(s):  
Xuefeng Wei ◽  
Laiyuan Zeng ◽  
Weiwei Lu ◽  
Juan Miao ◽  
Ruichang Zhang ◽  
...  

A polypyrrole-modified bimetallic electrode composed of Pd-Ag on a Ti substrate (Pd-Ag/PPY/Ti) was successfully prepared via a chemical deposition method, and was applied to the electrocatalytic hydrodechlorination of 4-chlorophenol (4-CP) in aqueous solution. The electrode was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Various influences on the dechlorination efficiency of 4-chlorophenol, including applied current, initial pH value, and temperature, were studied. The dechlorination efficiency of 4-CP reached 94% within 120 min under the optimum conditions, i.e., a dechlorination current of 6 mA, an initial pH of 2.30, and a temperature of 303 K. The apparent activation energy of the dechlorination of 4-CP by the Pd-Ag/PPY/Ti electrode was calculated to be 49.6 kJ/mol. The equivalent conversion rate constant kPd was 0.63 L.gPd−1·min−1, which was higher than the findings presented in comparable literature. Thus, a highly effective bimetallic electrode with promising application prospects and low Pd loading was fabricated.


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