scholarly journals REMOVAL OF A CHEMICAL DYE FROM WASTEWATER USING LOW COST AGRO-BASED ADSORBENTS: CONTINUOUS ADSORBERS

2019 ◽  
Vol 11 (2) ◽  
pp. 229-245
Author(s):  
Hatem Asal Gzar ◽  
Noor Qassim Sabri

Natural materials that are readily available in large amounts in nature and easily accessible may be used as low cost additives. The aim of this study is to measure the susceptibility of these locally available materials, conocarpus plant, to improve the quality of wastewater discharged from textile industry. In addition to conocarpus- without chemically treated, conocarpus- chemically treated, carbonized conocarpus and activated carbon were used as adsorbents in order to make a comparison, and to test which one of the four types give the best efficiency for removing dye. The ability of adsorbents to adsorb dye was studied using continuous system; studied parameters were effect of flow rate, bed depth, and initial concentration. The experimental results showed that maximum removal efficiency of conocarpus - without chemically treated was found to be 90% after 75 min at flow rate 20 l/h, pH value 3 , bed depth 5cm and initial concentration 40 mg/l. The maximum removal efficiency for conocarpus- chemically treated was up to 83.75% after 15 min at flow rate 10 l/h, pH value 3, bed depth 10 cm and initial dye concentration 40 mg/l. The maximum removal efficiency for carbonized conocarpus was up to 99.67% after 15 min at flow rate 10 l/h, pH value 3, bed depth 10 cm and initial dye concentration 40 mg/l. For activated carbon the maximum removal efficiency was found to be 99.75% after 15 min at flow rate 10 l/h, pH value 3, bed depth 10cm and initial dye concentration 40 mg/l.

2019 ◽  
Vol 11 (2) ◽  
pp. 246-255 ◽  
Author(s):  
Hatem Asal Gzar ◽  
Noor Qassim Sabri

Natural materials that are readily available in large amounts in nature and easily accessible may be used as low cost additives. The aim of this study is to measure the susceptibility of these locally available materials, conocarpus plant, to improve the quality of wastewater discharged from textile industry.  In addition to conocarpus plant, carbonized conocarpus and activated carbon were used as adsorbents in order to make a comparison, and to test which one of the three types give the best efficiency for removing dye. The ability of adsorbents to adsorb dye was studied using batch system; studied parameters were effect of pH, dose of adsorbents, time, and agitation speed. The experimental results showed that the maximum removal efficiency of conocarpus was found to be 87.5% at 50 rpm mixing speed, pH value 3 , mixing time 120 min and the dose of adsorbent was 0.25 g.  The maximum removal efficiency for carbonized conocarpus was up to 98.7% at 150 rpm mixing speed, pH value 3 , mixing time was equal to 7 hours and the dose of sorbent was 1.25 g. For activated carbon the maximum removal efficiency was found to be 99% at mixing speed of 200 rpm, pH value 3 or 11, mixing time was equal to 7 hours and the dose of the sorbent was 1.25 g. The above removal efficiencies were obtained at temperature 20 °C.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao Li Ma ◽  
Guang Tao Fei ◽  
Shao Hui Xu

Abstract In this study, polyaniline (PANI) is prepared by means of chemical oxidization polymerization and directly loaded on the modified fiber ball (m-FB) to obtain macroscale polyaniline/modified fiber ball (PANI/m-FB) composite, and then its removal ability of Cr(VI) is investigated. The effects of different parameters such as contact time, pH value and initial concentration on Cr(VI) removal efficiency are discussed. The experimental results illustrate that the favorable pH value is 5.0 and the maximum removal capacity is measured to be 293.13 mg g−1. Besides, PANI/m-FB composites can be regenerated and reused after being treated with strong acid. The kinetic study indicates that the adsorption procedure is mainly controlled by chemical adsorption. More importantly, the macroscale of composites can avoid secondary pollution efficiently. Benefiting from the low cost, easy preparation in large scale, environmentally friendly, excellent recycling performance as well as high removal ability, PANI/m-FB composites exhibit a potential possibility to remove Cr(VI) from industrial waste water. Graphic Abstract The polyaniline (PANI) was coated on modified fiber ball (m-FB) to remove Cr(VI) in waste water, and this kind of PANI/m-FB composites can avoid secondary pollution efficiently due to its macrostructure. Furthermore, the removal capacity can reach to 291.13 mg/g and can be multiple reused.


2013 ◽  
Vol 781-784 ◽  
pp. 1637-1645 ◽  
Author(s):  
Ting Jun Ma ◽  
Yi Qing Xu

The degradation effectiveness and reaction kinetics of representative organophosphorus (OP) pesticide in a packed-bed plasma reactor have been studied. Important parameters, including peak voltage, pulse frequency, gas-flow rate, initial concentration, diameter of catalyst particles, and thickness of catalyst bed which influences the removal efficiency, were investigated. Experimental results indicated that rogor removal efficiency as high as 80% can be achieved at 35 kV with the gas flow rate of 800 mL/min and initial concentration of 11.2 mg/m3.The removal efficiency increased with the increase of pulsed high voltage, and pulse frequency, the decrease of the diameter of catalyst particles and the thickness of catalyst bed. Finally, a model was established to predict the degradation of the rogor, which generally can simulate the experimental measurements to some degree.


2011 ◽  
Vol 130-134 ◽  
pp. 856-859
Author(s):  
Chun Sheng Ding ◽  
Yang Ping Fu ◽  
Qian Fen Zhu ◽  
Jing Fu

In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd2+ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m2/g which was 9.38 times of that of original sand; the removal efficiency of Cd2+ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd2+ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd2+ solution, and was enhanced with the increase of pH value, the Cd2+ removal efficiency was almost 71% with pH 9.0.


2017 ◽  
Vol 76 (6) ◽  
pp. 1466-1473 ◽  
Author(s):  
M. H. Salmani ◽  
M. Mokhtari ◽  
Z. Raeisi ◽  
M. H. Ehrampoush ◽  
H. A. Sadeghian

Wastewater containing pharmaceutical residual components must be treated before being discharged to the environment. This study was conducted to investigate the efficiency of tungsten-carbon nanocomposite in diclofenac removal using design of experiment (DOE). The 27 batch adsorption experiments were done by choosing three effective parameters (pH, adsorbent dose, and initial concentration) at three levels. The nanocomposite was prepared by tungsten oxide and activated carbon powder in a ratio of 1 to 4 mass. The remaining concentration of diclofenac was measured by a spectrometer with adding reagents of 2, 2′-bipyridine, and ferric chloride. Analysis of variance (ANOVA) was applied to determine the main and interaction effects. The equilibrium time for removal process was determined as 30 min. It was observed that the pH had the lowest influence on the removal efficiency of diclofenac. Nanocomposite gave a high removal at low concentration of 5.0 mg/L. The maximum removal for an initial concentration of 5.0 mg/L was 88.0% at contact time of 30 min. The results of ANOVA showed that adsorbent mass was among the most effective variables. Using DOE as an efficient method revealed that tungsten-carbon nanocomposite has high efficiency in the removal of residual diclofenac from the aqueous solution.


2019 ◽  
Vol 6 (7) ◽  
pp. 190351 ◽  
Author(s):  
Shuangxi Zhou ◽  
Zhiling Du ◽  
Xiuwen Li ◽  
Yunhai Zhang ◽  
Yide He ◽  
...  

In this study, natural manganese oxides (MnO x ), an environmental material with high redox potential, were used as a promising low-cost oxidant to degrade the widely used dyestuff methylene blue (MB) in aqueous solution. Although the surface area of MnO x was only 7.17 m 2 g −1 , it performed well in the degradation of MB with a removal percentage of 85.6% at pH 4. It was found that MB was chemically degraded in a low-pH reaction system and the degradation efficiency correlated negatively with the pH value (4–8) and initial concentration of MB (10–50 mg l −1 ), but positively with the dosage of MnO x (1–5 g l −1 ). The degradation of MB fitted well with the second-order kinetics. Mathematical models were also built for the correlation of the kinetic constants with the pH value, the initial concentration of MB and the dosage of MnO x . Furthermore, several transformation products of MB were identified with HPLC-MS, which was linked with the bond energy theory to reveal that the degradation was initiated with demethylation.


2021 ◽  
Vol 900 (1) ◽  
pp. 012003
Author(s):  
M Balintova ◽  
Z Kovacova ◽  
S Demcak ◽  
Y Chernysh ◽  
N Junakova

Abstract Removal of heavy metals from the environment is important for living beings. The present work investigates the applicability of the natural and MnO2 - coated zeolite as sorbent for the removal of copper from synthetic solutions. Batch experiments were carried out to identify the influence of initial pH and concentration in the process of adsorption. A maximum removal efficiency of Cu(II) was observed in 10 mg/L for natural (95.6%) and modified (96.4%) zeolite, where the values was almost identical, but at concentration of 500 mg/L was the removal efficiency of modified zeolite three times higher. Based on the correlation factors R2, the Langmuir isotherms better describe the decontamination process than Freundlich. The optimum pH value was set at 5.0.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0,enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.


2013 ◽  
Vol 807-809 ◽  
pp. 1343-1346
Author(s):  
Yi Fan Li ◽  
Ying Liu ◽  
Hou Qi Liu ◽  
Li Li

The research used activated carbon fiber (ACF) as adsorbent to remove atrazine, a kind of herbicide. It set a series of static adsorption experiments under different solution temperature, pH value and initial concentration to get a optimum adsorption condition. The experiment shows that the optimum pH for the removal of atrazine is 7. The adsorption rate is highest at 20°C. The adsorption rate decreases while the initial concentration increases.


2010 ◽  
Vol 113-116 ◽  
pp. 87-90
Author(s):  
Qing Jie Xie

The microwave irradiation (MI) was found that it had significantly treatment efficiency for pollutants removal. It was developed to treat the alage in this paper. The granular activated carbon (GAC) was used as catalyst. The effect of the acting time, MI power, GAC amount and the initial concentration on alage removal were studied. The results showed: with the increasing of the acting time, MI power, GAC amount the alage removal rate were increased, but the effect of the initial concentration to alage removal was opposite; the optimum value of acting time, MI power and GAC amount were 5min, 450W and 3g respectively with the alage removal efficiency reached up to 100%. It also showed that with the alage removed under the MI the COD, SS were removed too. It was discovered that the oxidation process was basically in conformity with the first-order dynamic reaction(ln(C/C0)=-0.9371t+0.6744(R2=0.9472)).


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