Optimization of Chlorella pyrenoidosa Removal by Low Frequency Ultrasonic Irradiation Using Response Surface Design

2011 ◽  
Vol 295-297 ◽  
pp. 1860-1865 ◽  
Author(s):  
Zhi Zhang ◽  
Chao Liu ◽  
Gong Duan Fan ◽  
Jing Luo ◽  
Yan Dong Wang
Keyword(s):  
Response Surface ◽  
Irradiation Time ◽  
Removal Rate ◽  
Low Frequency ◽  
Chlorella Pyrenoidosa ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Control Parameters ◽  
Single Factor ◽  
Surface Design

The control parameters of the removal of Chlorella pyrenoidosa, which was irradiated by low frequency ultrasonic, is optimized by using single factor experiments and response surface methodology (RSM). First of all, the approximate ranges of the ultrasonic frequency, the ultrasonic power and the irradiation time were estimated with single factor experiments for the further experiments. And then the optimized values of the three control parameters were determined, which were analyzed by using central composite design (CCD) and RSM. The results showed that the removal rate of chlorophyll-a could reach to 64.1% after the irradiation for 6.34min by using ultrasonic of 77.7 kHz and 250W. Ultrasonic technology can remove Chlorella pyrenoidosa cells in water quickly and effectively, so as to achieve the purpose of water purification.

Electrochemical oxidative degradation of indigo wastewater based on chlorine-containing system

2020 ◽  
Vol 49 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Wei Zhang ◽  
Weiwei Lv ◽  
Xiaoyan Li ◽  
Jiming Yao
Keyword(s):  
Chemical Oxygen Demand ◽  
Response Surface ◽  
Electrochemical Oxidation ◽  
Surface Analysis ◽  
Removal Rate ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Single Factor ◽  
Dyeing Wastewater ◽  
Content Type

Purpose In this study, the oxidative degradation performance of indigo wastewater based on electrochemical systems was explored. The decolourization degrees, removal rate of chemical oxygen demand and biochemical oxygen demand of the indigo wastewater after degradation were evaluated and optimized treatment conditions being obtained. Design/methodology/approach The single factor method was first used to select the electrolyte system and electrode materials. Then the response surface analysis based on Box–Behnken Design was chosen to determine the influence of four independent variables such as FeCl3 concentration, NaCl concentration, decolourization time and voltage on the degradation efficiency. Findings On the basis of single factor experiment, the electrode material of stainless steel was selected in the double cell, and the indigo wastewater was electrolyzed with FeCl3 and NaCl electrolytes. The process conditions of electrochemical degradation of indigo wastewater were optimized by response surface analysis: the concentration of FeCl3 and NaCl was of 16 and 9 g/L, respectively, with a decolourization time of 50 min, voltage of 10 V and decolourization percentage of 98.94. The maximum removal rate of chemical oxygen demand reached 75.46 per cent. The highest ratio of B/C was 3.77, which was considered to be more biodegradable. Research limitations/implications Dyeing wastewater is bringing out more and more pollution problems to the environment. However, there are some shortcomings in traditional technologies such as adsorption and filtration. As a kind of efficient and clean water treatment technology, electrochemical oxidation has been applied to the treatments of various types of wastewater. The decolourization and degradation of indigo wastewater is taken as an example to provide reference for the treatment of wastewater in actual plants. Practical implications The developed method provided a simple and practical solution for efficiently degrading indigo wastewater. Originality/value The method for the electrochemical oxidation technology was novel and could find numerous applications in the degradation of printing and dyeing wastewater.

scholarly journals Sonocatalytic degradation of methyl orange in aqueous solution using Fe-doped TiO2 nanoparticles under mechanical agitation

2018 ◽  
Vol 16 (1) ◽  
pp. 1283-1296 ◽  
Author(s):  
Shoujian Song ◽  
Changchun Hao ◽  
Xianggang Zhang ◽  
Qing Zhang ◽  
Runguang Sun
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Response Surface ◽  
Ultrasonic Irradiation ◽  
Ph Value ◽  
Irradiation Time ◽  
Ultrasonic Frequency ◽  
Mechanical Agitation ◽  
Initial Concentration ◽  
Degradation Of Methyl Orange

AbstractIn the present study, the Fe-doped TiO2 modified nanoparticles was successfully synthesized by the combination of the sol-gel method and heat treatment, and the degradation of methyl orange was tested by the combination method of ultrasonic radiation and mechanical agitation. The effects of different factors on the degradation of methyl orange (MO) solution were studied, such as ultrasonic irradiation time, the ultrasonic frequency, the added amount of catalyst, the initial pH value, the initial concentration of methyl orange, and revolutions per minute. The optimal experimental conditions for sonocatalytic degradation of the MO obtained were: ultrasonic irradiation time = 60 min, pH value = 3.0 and revolutions per minute = 500 rpm. By means of response surface analysis, the best fitting conditions were as follows: ultrasonic frequency = 36.02 kHz, added amount of catalyst = 490.50 mg/L, the initial concentration of methyl orange = 9.22 mg/L, and the optimum condition was close to the experimental data by response surface method. Under optimal conditions, the sonocatalytic degradation of MO was 99%. The degradation of MO showed that the combination of Fe-doped modified TiO2 nanoparticles, mechanical agitation and ultrasonic irradiation was discovered that can degrade methyl orange effectively in aqueous solution.

scholarly journals Gradient Cleaning Method of Potato Based on Multi-Step Operation of Dry-Cleaning and Wet Cleaning

Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1139
Author(s):  
Hongguang Yang ◽  
Jianchun Yan ◽  
Hai Wei ◽  
Huichang Wu ◽  
Shenying Wang ◽  
...  
Keyword(s):  
Removal Rate ◽  
Crushed Stone ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Potato Tubers ◽  
Dry Cleaning ◽  
Impurity Removal ◽  
Cleaning Method ◽  
Damage Rate ◽  
Moving Speed

In view of the poor effectiveness of existing potato cleaning methods in China and reflecting the findings of a research analysis of basic sizes and types of impurities on potato tubers, a gradient cleaning method for potato based on a multi-step dry-cleaning and wet cleaning operation was proposed. The method mainly consists of dry-cleaning and wet cleaning. The dry-cleaning stage, which combines vibration and brushing, could effectively remove impurities such as residual rhizomes, peeled potato skin, and large pieces of soil and crushed stone from the surface of potato tubers. The wet cleaning stage adopts the gradient cleaning method of pre-cleaning, rough cleaning and fine cleaning, which could further remove soil and crushed stone attached to the surface and hidden in the sprout eyes of potato tubers. The optimal parameter combination for the gradient cleaning method was determined as follows. The potato feeding amount was 3 t/h, the speed of the rubber chain rod mechanism was 25 r/min, the speed of the first and third brush roller was 40 r/min, the speed of the second and fourth brush roller was 56 r/min, the moving speed of the immersion mechanism conveying net chain was 0.04 m/s, the speed of the brush roller in the high pressure spray and brush roller combination mechanism was 40 r/min, the ultrasonic power was 1200 W, the ultrasonic frequency was 33 kHz, the bubble intensity was 300 L/min, and the moving speed of the conveying net chain in the ultrasonic and bubble combination mechanism was 0.05 m/s. Taking the impurity removal rate and damage rate of potato tuber as the test indexes, a potato cleaning performance test was carried out under the optimal parameters combination. The results showed that the average impurity removal rate and damage rate of potato tubers were 99.05% and 2.48%, respectively. Additionally, the operational performance fully met the requirements for potato cleaning. This study provides a new method for potato cleaning in China and can also provide a reference for cleaning other root and tuber crops.

Algal Control by Low-Frequency, Low-Power Ultrasonic in Eutrophic Water Bodies

2012 ◽  
Vol 433-440 ◽  
pp. 811-816
Author(s):  
Deng Ling Jiang ◽  
Guo Wei Ni ◽  
Yu Min Zhang ◽  
You Po Su
Keyword(s):  
Low Power ◽  
Ultrasonic Irradiation ◽  
Irradiation Time ◽  
Algal Growth ◽  
Low Frequency ◽  
Water Bodies ◽  
Ultrasonic Power ◽  
Water Ecosystem ◽  
Power Ultrasonic ◽  
Algal Control

Ultrasonic cavitations can control algal growth. Considering water ecosystem protection and characteristics of ultrasonic technology, low frequency and low power ultrasonic was especially suitable to control algal growth in water bodies. Effects of low-frequency and low-power ultrasonic irradiation on natural blend algal growth were investigated. The algae spices were collected from a fresh water body. It mainly consists of Cyanophyta, Bacillariophyta and Chlorophyta. The results showed that ultrasonic irradiation with frequency of 60KHz, power of 0.24W/cm2 and irradiation time of 1min, inhibited algal growth significantly. Inhibition of ultrasonic irradiation on algal growth enhanced with ultrasonic power increased. Inhibition did not increase again When ultrasonic power exceeds 0.24W/cm2. The effect of algal control was sustainable by ultrasonic irradiation with interval period of 2-4 days.

Extraction of Chondroitin Sulfate from Tilapia Byproducts with Ultrasonic-Microwave Synergistic

2013 ◽  
Vol 726-731 ◽  
pp. 4381-4385 ◽  
Author(s):  
Chang Yu Cheng ◽  
Wei Wen Duan ◽  
Zhen Hua Duan ◽  
Yang Hai ◽  
Xin Gui Lei ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Chondroitin Sulfate ◽  
Response Surface ◽  
Microwave Power ◽  
Oreochromis Niloticus ◽  
Optimum Process ◽  
Ultrasonic Power ◽  
Single Factor ◽  
Optimum Conditions ◽  
Extraction And Separation

The optimum conditions for the extraction and separation of chondroitin sulfate from tilapia (Oreochromis niloticus) byproducts were studied in the paper. The chondroitin sulfate was extracted by the combination of ultrasonic and microwave. On the basis of the single factor tests, the response surface methodology was taken to study the optimum process of extraction. Results show that the best conditions for the extraction and separation of chondroitin sulfate from tilapia byproducts are: the ultrasonic power is 50W, the microwave power is 98W, the extraction time is 120s, the ratio of solid to liquid is 1:50 (g/mL), and under these conditions, the extraction rate of chondroitin sulfate is 2.513%.

scholarly journals Ecofriendly Ultrasonic Rust Removal: An Empirical Optimization Based on Response Surface Methodology

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1127
Author(s):  
Lijie Zhang ◽  
Bing He ◽  
Shengnan Wang ◽  
Guangcun Wang ◽  
Xiaoming Yuan
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Rate ◽  
Ultrasonic Cavitation ◽  
Surface Model ◽  
Ultrasonic Power ◽  
Rust Layer ◽  
Cavitation Effect ◽  
Removal Technology ◽  
Main Components

This study shows that the hard-to-remove rust layer on the guide sleeve surface of a used cylinder can be removed using a specially developed, environmentally friendly formula for cleaning rust. Furthermore, we studied the rust removal technology that is based on ultrasonic cavitation and chemical etching. The surface morphology and structural components of the rust layer were observed using an electron microscope and an X-ray powder diffractometer. These tools were used to explore the mechanism of combined rust removal. Using response surface methodology (RSM) and central composite design (CCD), with the rust removal rate as our index of evaluation, data were analyzed to establish a response surface model that can determine the effect of cleaning temperature and ultrasonic power interaction on the rate of rust removal. Results showed that the main components of the rust layer on a 45 steel guide sleeve were α-FeOOH, γ-FeOOH, and Fe3O4. The rust was unevenly distributed with a loose structure, which was easily corroded by chemical reagents and peeled off under ultrasonic cavitation. With the increase in the cleaning temperature, the chemical reaction effect was intensified, and the cleaning ability was enhanced. With the increase in ultrasonic power, the cavitation effect was aggravated, the ultrasonic agitation was enhanced, and the rust removal rate was improved. According to response surface analysis and the application scope of the rust remover, we determined that the optimal cleaning temperature is 55 °C, and that the optimal ultrasonic power is 2880 W. The descaling rate under these parameters is 0.15 g·min−1·m−2.

Defluoridation of drinking water by magnesium and aluminum electrocoagulation in continuous flow-rate: A response surface design.

2021 ◽  
pp. 1-37
Author(s):  
Ana Gabriela Sierra-Sánchez ◽  
Verónica Martínez-Miranda ◽  
Elia Alejandra Teutli-Sequeira ◽  
Ivonne Linares-Hernández ◽  
Guadalupe Vázquez-Mejía ◽  
...  
Keyword(s):  
Drinking Water ◽  
Response Surface ◽  
Flow Rate ◽  
Continuous Flow ◽  
Response Surface Design ◽  
Surface Design

scholarly journals Optimization of Ultrasonic-Assisted Extraction, Characterization, and Antioxidant Activities of Polysaccharides From Sojae Semen Praeparatum

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110206
Author(s):  
Yongshuai Jing ◽  
Ruijuan Zhang ◽  
Lan Li ◽  
Danshen Zhang ◽  
Yu Liu ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Deae Cellulose ◽  
Chemical Compositions ◽  
Hydroxyl Groups ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Assisted Extraction ◽  
Ultrasonic Time ◽  
Ultrasonic Assisted ◽  
Ultrasonic Assisted Extraction

In this study, response surface methodology (RSM) was used to optimize the ultrasonic-assisted extraction parameters of Sojae Semen Praeparatum polysaccharides (SSPP-80), the optimum conditions were determined as follows: ultrasonic frequency of 100 W, ultrasonic power of 80 Hz, ultrasonic temperature of 52℃, ultrasonic time of 23 minutes, and liquid to raw material ratio of 40 mL/g. Based on these conditions, polysaccharides extraction rate was 7.72% ± 0.26%. Then, 2 novel polysaccharides (SSPP-80‐1, SSPP-80‐2) were isolated from SSPP by DEAE-cellulose 52 chromatography. The chemical compositions, physicochemical properties, and structure of SSPPs were investigated by simultaneous thermal analyzer (TGA), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FI-IR), and high-performance liquid chromatography (HPLC). The results showed that SSPP-80 and 2 fractions were mainly composed of mannose (Man), glucose (Glc), galactose (Gal), xylose (Xyl), and arabinose (Ara). In addition, the antioxidant activities were evaluated against the DPPH and hydroxyl radical in vitro, the IC50 of SSPP-80, SSPP-80‐1 and SSPP-80‐2 against DPPH free radical were 4.407, 8.267, and 5.204 mg/mL, respectively, whereas the IC50values for removing hydroxyl groups were 5.318, 3.516, and 4.016 mg/mL, respectively. It demonstrated that SSPP-80 and 2 fractions had certain antioxidant activity. Theoretical basis for use of Sojae Semen Praeparatum polysaccharides was provided by this study.

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