scholarly journals Adsorption of COD in Coking Wastewater on Nitric Acid-Modified Blue Coke Activated Carbon

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Xu Jiang ◽  
Xinzhe Lan ◽  
Yonghui Song ◽  
Xiangdong Xing

The blue coke activated carbon (BAC) modified by nitric acid at different concentrations was used as an adsorbent to remove COD from coking wastewater. Characterization of BAC was performed using N2 adsorption/desorption techniques, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and Boehm titration. The results showed the Brunner–Emmet–Teller (BET) specific surface area and iodine value of BAC became higher after modification, and the adsorption capacity of BAC for coking wastewater was effectively improved with nitric acid modification. The optimal nitric acid concentration for modification was 3 mol/L (BAC-N3), which had more acid functional group contents than unmodified. The chemical oxygen demand (COD) removal rate was to reach 77.05% when 4 g BAC-N3 was added into 50 mL coking wastewater in 120 min with a shaking speed of 100 rpm at 25°C. Langmuir model could better describe equilibrium adsorption data by BAC-N3, and the kinetic study showed that the adsorption process was best fitted by the pseudo-second-order kinetic model.

2021 ◽  
Vol 37 (4) ◽  
pp. 922-927
Author(s):  
A. Kistan ◽  
V. Kanchana ◽  
N. K. Geetha ◽  
G. Infant Sujitha

The following study explains that the adsorption efficiency of activated carbon used by Groundnut foliage and groundnut husk for the deportation of COD (Chemical Oxygen demand) from groundwater collected from in and around industrial areas of Vellore district was investigated with different activating conditions (Activating agent- KOH, ZnCl2 and H3PO4; Impregnation ratio-1:1,1:2,1:2; and activation temeperture-500-700°C. The activated carbon prepared based on optimized condition has well-developed pore structure and functional groups which is confirmed from SEM image and FTIR analysis respectively. The adsorption equilibrium was reached in 240 min with the isotherm data fitted well in both the model such as Langmuir model and Freundlich’s model indicating chemisorption’s adsorption for the activated carbon. Moreover, the adsorption process was exothermic accompanied by a decrease in irregularity. Furthermore, the adsorption kinetic study indicated that the adsorption process of the prepared sample follows the pseudo-second-order kinetic model compare to the pseudo-first -order kinetic model


2014 ◽  
Vol 1073-1076 ◽  
pp. 995-999
Author(s):  
Jin Li ◽  
Guang Hua Wang ◽  
Wen Bing Li ◽  
Zheng Zhu ◽  
Yin An Zhu

This paper reports about a pilot-scale feasibility study of Advanced Treatment of Coking Wastewater with Biological Activated Carbon technology based on the better experimental data of laboratory scale test .The self-designed of the Biological Activated Carbon Aerated tower was based on the optimal operating conditions of the results obtained from laboratory scale test.The removal efficiency to pollutants of efficient compound bacterium is estimated in biological activated carbon process through the variation of COD concentration, chromaticity, and Contrast the total ion chromatogram and UV absorbance spectrum of effluent and inflow.The results of the pilot-scale test show that BAC technology may be a suitable option for the advanced treatment of Coking Wastewater. the efficient degrading strains can reproduce on the activated carbon quickly.Concentrations of COD and chromaticity in outflow water were at a lower level (with COD about 60mg/L and chromaticity about 50 degree), the average COD removal rate greater than 50% and chromaticity removal rate greater than 70%.


2012 ◽  
Vol 65 (10) ◽  
pp. 1753-1758 ◽  
Author(s):  
Dongkai Zhou ◽  
Reti Hai ◽  
Wenxing Wang ◽  
Donglin Zhao ◽  
Shuo Wang

The aerated bioreactor is a promising technology for wastewater treatment. Activated carbon fiber (ACF) used as a biomembrane carrier in wastewater disposal has attracted much more concern recently. The high modulus polyacrylonitrile (PAN)-based ACF was successfully used as a biomembrane carrier for hard-to-biodegrade industrial organic wastewater disposal in a lab-scale aerated biomembrane reactor at room temperature. The biocompatibility test shows that the biomembrane grows quickly on the ACF filler (ACFF) surface; bacteria and microzoon can breed on the ACFF surface at high chemical oxygen demand (COD) concentration. The COD removal rate tests show that the ACFF bioreactor has high capability to remove COD.


Author(s):  
Huiling Wu ◽  
Wenjing Sun ◽  
Huangzhao Wei ◽  
Ying Zhao ◽  
Chengyu Jin ◽  
...  

Abstract Carboxylic acids are the main pollutant of industrial wastewater during the Advanced Oxidation Process (AOPs). In this study, we here study a resin-based spherical activated carbon (RSAC, AF5) as an adsorbent and use acetic acid as a model substrate for adsorption investigation. The pH = 3, temperature = 298 K were fixed by batch technique. The pseudo-second-order kinetic model, the intraparticle and external models are fitted well, and it was found that the adsorption of acetic acid onto AF5 was controlled by liquid film diffusion. Freundlich model indicates the adsorption process is heterogeneous multi-molecular layer adsorption on the surface. AF5 shows good regenerative ability; the recovery rate of adsorption capacity is ∼88% after 5 cycles. And COD adsorption removal rate can be maintained 100% for over 35 h in an actual AOPs effluent, and it can be eluted for 100% after 8 h by 0.8wt% NaOH. The characterizations, including XRF, XRD, TG/DSC,FTIR, SEM and N2 adsorption, show that the excellent adsorption performance is mainly due to the microporous structure and large specific surface area (1,512.88 m2/g), the adsorption mechanism mainly including pore filling effect and electrostatic attraction. After five adsorption-recycles, AF5's pore characteristic does not change significantly. This study provided a scientific basis for the wastewater standard discharge process of AOPs coupled adsorption.


2012 ◽  
Vol 581-582 ◽  
pp. 1129-1132 ◽  
Author(s):  
Guang Hua Wang ◽  
Xue Qin Liu ◽  
Wen Bing Li ◽  
Yun Zhou Lu ◽  
Ming Dong Sun

The removal efficiency of degrading flora which has been constructed is investigated in biological carbon process through the variation of COD and chromaticity. The results show that the efficient degrading strains can reproduce on the activated carbon quickly;the biological activated carbon reactor,in which degrading flora to coking waste water are inoculated,is adopted to carry out the treatment of wastewater,in such a way the COD and chromaticity in outflow water can remain at a lower level (with COD about 50mg/L and chromaticity about 50 degree). The average COD removal rate is 71% and the chromaticity removal ratio is 95%.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Emmanuel Kweinor Tetteh ◽  
Sudesh Rathilal

This study presents a hybridized photocatalyst with adsorbate as a promising nanocomposite for photoremediation of wastewater. Photocatalytic degradation of bromophenol blue (BPB) in aqueous solution under UV-irradiation of wavelength 400 nm was carried out with TiO2 doped with activated carbon (A) and clinoptilolite (Z) via the co-precipitation technique. The physiochemical properties of the nanocomposite (A–TiO2 and Z–TiO2) and TiO2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. Results of the nanocomposite (A–TiO2 and Z–TiO2) efficiency was compared to that with the TiO2, which demonstrated their adsorption and synergistic effect for the removal of chemical oxygen demand (COD) and color from the wastewater. At an optimal load of 4 g, the photocatalytic degradation activity (Z–TiO2 > A–TiO2 > TiO2) was found favorably by the second-order kinetic model. Consequently, the Langmuir adsorption isotherms favored the nanocomposites (Z–TiO2 > A–TiO2), whereas that of the TiO2 fitted very well on the Freundlich isotherm approach. Z–TiO2 evidently exhibited a high photocatalytic efficacy of decomposition over 80% of BPB (COD) at reaction rate constant (k) and coefficient of determination (R2) values of 5.63 × 10−4 min−1 and 0.989, respectively.


Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract


2013 ◽  
Vol 726-731 ◽  
pp. 2100-2106 ◽  
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Shou Rui Yuan

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.


2014 ◽  
Vol 675-677 ◽  
pp. 627-632 ◽  
Author(s):  
Qun Wei ◽  
Di Lv ◽  
Mei Hui Huang ◽  
De Shui Yu ◽  
Jian Qiang You

Aerobic denitrifying bacteria, a fast and efficient strain, is extensively adopted in the wastewater sphere, and immobilized aerobic denitrifying bacteria denitrification Technology, to some extent, solves many problems existing in the direct application of aerobic denitrifying bacteria. Concentrated sulfuric acid, nitric acid, potassium permanganate, ferric chloride etc. are used to pretreat carbon fiber respectively, and then the modified the carbon fiber is applied to fix the activated aerobic denitrifying bacteria to investigate the effects of the modification of the carbon fiber and the effects of wastewater treatment with immobilized aerobic denitrifying bacteria. The results showed that the fixed efficiency of the strain with carbon fiber pretreated by nitric acid reached 50% and when the strain fixed by the modified carbon fiber in adsorption method treated wastewater, the ammonia nitrogen removal rate reached 78% and the COD removal rate was always stabilized above 40% in three days.


2012 ◽  
Vol 518-523 ◽  
pp. 2099-2103
Author(s):  
Guang Zhou Qu ◽  
Hai Bing Ji ◽  
Ran Xiao ◽  
Dong Li Liang

The activated carbon fiber (ACF) was treated by different concentration nitric acid (HNO3) and hydrogen peroxide (H2O2) oxidization to enhance its adsorption capacity to hexavalent chromium (Cr6+) ion. The adsorption amount and adsorption kinetics of Cr6+ion on ACFs, and the surface chemical groups were investigated. The results showed that the modified ACFs with 1% HNO3and 10% H2O2had a better adsorption capacity, respectively. The adsorption amount of ACFs was affected strongly solution pH value, and decreased significantly with increasing of the pH value. The adsorption kinetics indicated that the adsorption rates of Cr6+ ion on different modified ACFs were well fitted with the pseudo-second-order kinetic model. After 1% HNO3and 10% H2O2modification, respectively, the total acidic oxygen-containing groups on ACFs surface had an increase obviously, which might be enhance the adsorption amount of Cr6+ion on ACFs.


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