scholarly journals Effective removal of chemical oxygen demand and phosphates from aqueous medium using entrapped activated carbon in alginate

2018 ◽  
Vol 3 (5) ◽  
pp. 227-236
Author(s):  
Soha A Abd El-Gawad ◽  
Hossam M Abd ElAziz

The aim of this study is to decrease different wastewater contaminants using entrapped activated carbon in alginate polymer (AG-AC) by adsorption. Different phosphate concentrations were prepared in the laboratory. The effect of the operating parameter was studied by external factors (e.g., contact time, pH, concentrations, adsorbent dose, and stirring rate). The results were analyzed according to the Freundlich and Langmuir adsorption isotherm. The adsorption data are more appropriate by the Freundlich isotherm. Efficient removal percentages for COD (500 mg\L) at pH 3 using dose 30g of the adsorbent for 60min with a fixed stirring rate at 100rpm were about (79%). Efficient removal percentages for phosphates (5mg\L) at pH 4 using dose 30g of the adsorbent for 45min with a fixed stirring rate at 100rpm were about (89%). The best-operating conditions have been determined to increase phosphate removal efficiency.

2001 ◽  
Vol 44 (4) ◽  
pp. 247-253 ◽  
Author(s):  
P. Torres ◽  
E. Foresti

The results obtained from the operation of a treatment system composed of an anaerobic (up-flow sludge blanket - UASB) reactor followed by an aerobic (sequencing batch - SBR) reactor treating domestic sewage are presented and discussed. The pilot plant was monitored during 6 months, aiming to obtain performance data on organic matter, nitrogen and phosphate removal under different operating conditions. The UASB reactor was operated at a constant hydraulic detention time (θ) of 6 h while the SBR performance was monitored in four different duration cycles (24, 12, 6 and 4 h) corresponding to aeration times (AT) of 22, 10, 4 and 2 h, respectively. COD and TSS overall removal efficiencies (Eo) up to 91% and 84%, respectively, were achieved independently on the aeration time applied to the SBR. In respect to nitrification and phosphate removal, AT was found to be a determinating operating parameter. TKN removal of approximately 90% was achieved for AT equal to or higher than 10 h; complete nitrification occurred for AT higher than 4 h; significant phosphate removal (72%) occurred only at the AT of 2 h. It was not possible to achieve simultaneous efficient removal of nitrogen and phosphate, under the operating conditions imposed on the treatment system.


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


2010 ◽  
Vol 450 ◽  
pp. 445-448
Author(s):  
Zheng Wang ◽  
Zhao Qian Jing ◽  
Yu Kong ◽  
Wei Shen

The aim of this study was the assessment of reduction of chemical oxygen demand (COD) from micro-polluted water using activated carbon-attapulgite composite adsorbent prepared using activated carbon and natural attapulgite through compounding, granulation and calcination. The complete study was done in batch mode to investigate the effect of operating parameters. Adsorption of COD was found to be dependent on contact time, pH, temperature and initial COD concentration. Adsorption equilibrium attained within 80 minutes time. The optimum pH range for adsorption of organics was found to be 8. The sorption of organics decreased with rise of temperature because adsorption process was exothermic. The studied adsorption data fitted well to Langmuir adsorption model with the correlation coefficient 0.9947. The activated carbon-attapulgite composite adsorbent in this study shows very good promise for practical applicability on removal of COD from micro-polluted water.


RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6452-6459 ◽  
Author(s):  
Guangzhi Xin ◽  
Min Wang ◽  
Lin Chen ◽  
Yuzhou Zhang ◽  
Meicheng Wang ◽  
...  

A novel adsorbent zeolite/N-doped porous activated carbon (ZAC) was prepared by the synthesis of zeolite and mesoporous carbon to remove ammonia nitrogen (NH4+–N) and chemical oxygen demand (COD) from aqueous solution.


1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.


2007 ◽  
Vol 9 (4) ◽  
pp. 107-110 ◽  
Author(s):  
Bożena Seredyńska-Sobecka ◽  
Maria Tomaszewska

The influence of ozonation on the activated carbon adsorption of phenol and humic acid To study the influence of ozonation on the activated carbon adsorption, a model solution containing approximately 8 mg/dm3 of humic acid and approximately 1 mg/dm3 of phenol has been ozonated, and then adsorption kintetics and adsorption isotherm experiments have been performed. The applied ozone doses ranged from 1 to 3 mg O3/dm3, and a contact time was 1 min. In the adsorption experiments, the commercial activated carbon CWZ-30 (Gryfskand Sp. z o.o., Hajnówka, Poland) has been used. Phenol adsorption under equilibrium conditions was determined by the Freundlich isotherm equation, and the modified Freudlich isotherm equation has been employed for the determination of humic acid equilibrium adsorption. The applied oxidation conditions resulted in color, chemical oxygen demand (COD), total organic carbon (TOC) and UV254 absorbance removal, by 4 - 13%, 3 - 6%, 3 - 7%, respectively. After ozonation, phenol concentration decreased by 6 - 23%. These changes in the model solution did not affect the humic acid adsorption, however, they deteriorated phenol adsorption.


2020 ◽  
Vol 3 (1) ◽  
pp. 208-220
Author(s):  
Sara Jamaliniya ◽  
O. D. Basu ◽  
Saumya Suresh ◽  
Eustina Musvoto ◽  
Alexis Mackintosh

Abstract A renewable, green activated carbon made from sucrose (sugar) was compared with traditional bituminous coal-based granular activated carbon (GAC). Single and multi-component competitive adsorption of nitrate and phosphate from water was investigated. Langmuir and Freundlich isotherm models were fitted to data obtained from the nitrate and phosphate adsorption experiments. Nitrate adsorption fits closely to either Freundlich or Langmuir model for sucrose activated carbon (SAC) and GAC with a Langmuir adsorption capacity of 7.98 and 6.38 mg/g, respectively. However, phosphate adsorption on SAC and GAC demonstrated a selective fit with the Langmuir model with an adsorption capacity of 1.71 and 2.07 mg/g, respectively. Kinetic analysis demonstrated that adsorption of nitrate and phosphate follow pseudo-second-order kinetics with rate constant values of 0.061 and 0.063 g/(mg h), respectively. Competitive studies between nitrate and phosphate were demonstrated in preferential nitrate removal with GAC and preferential phosphate removal with SAC. Furthermore, nitrate and phosphate removals decreased from 75% removal to 35% removal when subject to multi-component solutions, which highlights the need for adsorption analysis in complex systems. Overall, SAC proved to be competitive with GAC in the removal of inorganic contaminants and may represent a green alternative to coal-based activated carbon.


2021 ◽  
Vol 6 (1) ◽  
pp. 1-7
Author(s):  
Eis Sri Hartati ◽  
◽  
Muhammad Hatta Dahlan ◽  
Tuti Indah Sari

Waste containing dyes causes visual pollution and increase the risk of environmental and health issue. The aim of this study was to determine the best operating conditions of jumputan liquid waste treatment using bottom ash batubara and agar wood with variations in feed flow rate (1, 2, and 3 l/min), filtration time (30, 60, 90, and 120 mins), and treatment. The results are compared with the parameters of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), and pH of clean water quality standards for jumputan industry businesses and/or activities regulated in the Governor’s of Sumatera Selatan Regulation Number 16 year 2005. The initials analysis of jumputan liquid waste before processing showed that jumputan liquid waste did not meet these quality standards, except pH and turbidity levels. In this study, jumputan liquid waste was pretreated using coal bottom ash and activated carbon, then filtered. Biodegradation of jumputan liquid waste by conventional method. The best of BOD, COD, TSS, pH, and the percentage of color rejection in the study were obtained in the treatment of jumputan liquid waste using bottom ash batubara and activated carbon at 120 minutes filtration time and a 1 l/minute feed flow rate namely BOD 5.98 mg/l, COD 15 mg/l, TSS 22.3 mg/l, pH 7.32, color 5 Pt-Co, and 0 NTU turbidity. The filtration with bottom ash coal and agar wood can removed the coloring from dyes.


2018 ◽  
Vol 7 (4) ◽  
pp. 253-258 ◽  
Author(s):  
Dorsaf Bouharat ◽  
Farida EL Yousfi ◽  
Anas Ellaghdach ◽  
Badr Dine Souhail ◽  
Nabila Slimani Alaoui

A physio-chemical characterization of olive oil mill wastewater (OMW) obtained from a continuous two-phases olive oil extraction process is presented. High organic load of OMW from Ben Karrich region has been registered. The values of chemical oxygen demand (COD) and total phenolic compounds were 84.5 g of O2/L and 3.79 g/L, respectively. In this sense, a treatment using activated carbon as adsorbent was proposed. Results have shown high removal percentages in total phenolic compounds (98%) and COD (90%). The optimal operating conditions were 4 g of activated carbon and adsorbing time equal to 5 minutes.


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