scholarly journals Preparation and Electrocatalytic Performance of Bi-Modified Quartz Column Particle Electrode for Phenol Degradation

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jiguo Huang ◽  
Haitao Chen ◽  
Shuo Pang ◽  
Gang Liu ◽  
Huanyu Cui ◽  
...  
Keyword(s):  
Removal Rate ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Preparation Condition ◽  
Electrocatalytic Property ◽  
Catalyst Carrier ◽  
Electrocatalytic Performance ◽  
Triclinic Phase ◽  
2D System ◽  
Calcination Method

Bismuth oxide (Bi2O3) and its composites have good electrocatalytic performance. Quartz column is a good kind of catalyst carrier with the characteristics of high mechanical strength and good stability. A novel Bi-modified quartz column particle electrode (BQP) was prepared by the dipping-calcination method. The characterization results revealed that Bi2O3was successfully loaded on quartz column. The optimum preparation condition was calcining at 550°C for 4 h. Electrocatalytic performance was evaluated by the degradation of phenol and the results indicated that the triclinic phase of Bi2O3showed the best electrocatalytic property. Besides, when the dosage concentration of the particle electrode was 125 g/L and the electrolytic voltage was 12 V, the degradation rate of phenol (200 mg/L) reached the highest (94.25%), compared with 70.00% of that in two-dimensional (2D) system. In addition, the removal rate of chemical oxygen demand (COD) was 75.50%, compared with 53.30% of that in 2D system. The reusability and regeneration of BQP were investigated and the results were good. Mechanism of enhanced electrochemical oxidation by BQP was evaluated by the capture of hydroxyl radical.

The highest inhibition coefficient of phenol biodegradation using an acclimated mixed culture

2015 ◽  
Vol 73 (5) ◽  
pp. 1033-1040 ◽  
Author(s):  
Mojtaba Mohseni ◽  
Payman Sharifi Abdar ◽  
S. Mehdi Borghei
Keyword(s):  
Mixed Culture ◽  
Degradation Rate ◽  
Growth Parameters ◽  
Removal Rate ◽  
Substrate Inhibition ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Phenol Biodegradation ◽  
Culture Substrate

In this study a membrane biological reactor (MBR) was operated at 25 ± 1 °C and pH = 7.5 ± 0.5 to treat synthetic wastewater containing high phenol concentrations. Removal efficiencies of phenol and chemical oxygen demand (COD) were evaluated at four various hydraulic retention times (HRTs) of 24, 12, 8, and 4 hours. The removal rate of phenol (5.51 kg-Phenol kg-VSS−1 d−1), observed at HRT of 4 h, was the highest phenol degradation rate in the literature. According to COD tests, there were no significant organic matter in the effluent, and phenol was degraded completely by mixed culture. Substrate inhibition was calculated from experimental growth parameters using the Haldane, Yano, and Edward equations. The results show that the Haldane equation is fitted to the experimental data in an excellent manner. Kinetic parameters were derived by nonlinear regression with a correlation coefficient (R2) of 0.974. The values for Haldane constants μmax, Ks, and Ki were 0.3085 h−1, 416 mg L−1 and 1,886 mg L−1, respectively. The Ki value is the highest value obtained for mixed cultures degrading phenol under batch conditions.

Accelerated Phenol Removal by Amplifying the Metabolic Pathway with a Recombinant Plasmid Encoding Catechol 2, 3 Oxygenase

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2191-2194 ◽  
Author(s):  
M. Fujita ◽  
M. Ike ◽  
T. Kamiya
Keyword(s):  
Metabolic Pathway ◽  
Recombinant Plasmid ◽  
Removal Rate ◽  
Phenol Degradation ◽  
Wild Strain ◽  
Phenol Concentration ◽  
Phenol Removal

The metabolic pathway of the phenol degradation in Pseudomonasputida BH was amplified by introducing the recombinant plasmid containing catechol 2,3 oxygenase gene isolated fron the chromosome of BH. This strain could degrade phenol and grow much faster than the wild strain at the phenol concentration of 100mg/L. This strain seems to accelerate the phenol removal rate if it is applied to the treatment of wastewater containing phenol.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Aeration Tank ◽  
Remarkable Effect ◽  
Cod Removal Efficiency ◽  
Volumetric Loading

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.

scholarly journals ACID ORANGE 52 DYE DEGRADATION BY ELECTROCATALYTIC PLUS PHOTOCATALYTIC TECHNIQUE AND INTERMEDIATES DETECTION

2018 ◽  
Vol 61 (4-5) ◽  
pp. 111
Author(s):  
Hui Zhao ◽  
Heng Zhong ◽  
Lei Sun ◽  
Alexander V. Nevsky ◽  
Dongsheng Xia
Keyword(s):  
Dye Degradation ◽  
Removal Rate ◽  
Degradation Mechanism ◽  
Oxygen Demand ◽  
Ionization Mass ◽  
Light Spectrum ◽  
Resource Saving ◽  
Acid Orange ◽  
Visible Part ◽  
Photocatalytic Processes

The degradation efficiency of Acid Orange 52 dye in an aqueous solutions using the combination of electrocatalytic and photocatalytic processes has been studied. Electrocatalytic and photocatalytic methods in practice reckon among advanced oxidation processes (AOPs). The effect of catalyst B dosage and irradiarion time on the rate of mentioned dye degradation was studied in the photocatalytic process. It was shown, that when Acid Orange 52 simulated dye wastewater was treated by electrocatalytic technique under optimal conditions with catalyst A, the decolorization treatment effect was 95 % in visible part of light spectrum (464 nm) and 38.6 % in ultraviolet part (270 nm), respectively. When the combined electrocatalytic-photocatalytic technique was processed with catalysts A and B, the color removal rate of dye could reach 99.3% (464 nm) and 91.5% (270 nm), respectively. The large amount of products of small mole weight was formed in the course of oxidation reaction. Moreover, the obtained values of chemical oxygen demand (COD) and total organic carbon (TOC) witnessed, that the combination of electrocatalytic and photocatalytic processes could significantly improve the biodegradability of dye as a whole．It was shown, that the removal rate of COD and TOC, respectively, were 54.3% and 72.8%. The reaction intermediates were determined by electrospray ionization-mass spectrometry (ESI-MS) analysis, and as a result, the probable degradation mechanism (pathway) has been proposed. The results of the work may be useful as theoretical bases for designing effective resource-saving, technically efficient and economically sound wastewater treatment systems, containing hardly biodegradable azo dyes.Forcitation:Zhao H., Zhong H., Sun L., Xia D., Nevsky A.V. Acid Orange 52 dye degradation by electrocatalytic plus photocatalytic technique and intermediates detection. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 4-5. P. 111-118

scholarly journals Investigation of the Efficiency of Phosphorus Removal Using Anionic Resins From the Continuous Flow in the Waste Stabilization Pond Outlet: A Case Study of Kaboodrahang Wastewater Treatment Plant

2019 ◽  
Vol 6 (1) ◽  
pp. 16-20
Author(s):  
Ali Akbar Rahmani Sarmazdeh ◽  
Mostafa Leili
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Phosphorus Removal ◽  
Continuous Flow ◽  
Removal Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Cold Season ◽  
Stabilization Pond ◽  
The Mean

This research mainly aimed to investigate phosphorus removal from stabilization pond effluent by using anionic resins in the continuous flow mode of operation due to high amounts of phosphorus in the wastewater treatment plant effluent of Kaboodrahang, western Iran, as well as the violation from a prescribed effluent standard to discharge receiving the surface waters. For this purpose, the pilot was made of a plexiglass cylinder and other equipment such as pump and other accessories, as well as Purolite A-100 resin. The reactor effects on the desired study parameters were assessed in two warm and cold seasons. The results showed that the phosphorus concentrations reduced from 7-10 mg/L to 4-7 mg/L and the rate of phosphorus removal was higher in the hot season compared to the cold season. Moreover, the optimum temperature and pH were obtained 21ºC and 8.5, respectively. The mean inlet biological oxygen demand (BOD) was 150 mg/L for both warm and cold seasons, where the highest removal rate of 17% was obtained in the cold season. The mean chemical oxygen demand concentration of the pilot was 250 mg/L for both seasons, and the highest removal rate was observed in the cold season with an efficiency of 18%. Regarding the total suspended solids with the mean inlet of 230 mg/L, the highest removal efficiency was obtained 6% in the warm season.

scholarly journals Efficient Catalytic Degradation of Phenol with Phthalocyanine-Immobilized Reduced Graphene–Bacterial Cellulose Nanocomposite

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2218
Author(s):  
Binbin Wu ◽  
Yikai Sun ◽  
Qiujin Fan ◽  
Jiahui Chen ◽  
Weizheng Fang ◽  
...  
Keyword(s):  
Organic Acids ◽  
Bacterial Cellulose ◽  
Phenol Degradation ◽  
Academic Research ◽  
Oxygen Demand ◽  
Functional Materials ◽  
Degradation Ratio ◽  
Reduced Graphene ◽  
Ft Ir ◽  
Phenol Wastewater

In this report, phthalocyanine (Pc)/reduced graphene (rG)/bacterial cellulose (BC) ternary nanocomposite, Pc-rGBC, was developed through the immobilization of Pc onto a reduced graphene–bacterial cellulose (rGBC) nanohybrid after the reduction of biosynthesized graphene oxide-bacterial cellulose (GOBC) with N2H4. Field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR) were employed to monitor all of the functionalization processes. The Pc-rGBC nanocomposite was applied for the treatment of phenol wastewater. Thanks to the synergistic effect of BC and rG, Pc-rGBC had good adsorption capacity to phenol molecules, and the equilibrium adsorption data fitted well with the Freundlich model. When H2O2 was presented as an oxidant, phenol could rapidly be catalytically decomposed by the Pc-rGBC nanocomposite; the phenol degradation ratio was more than 90% within 90 min of catalytic oxidation, and the recycling experiment showed that the Pc-rGBC nanocomposite had excellent recycling performance in the consecutive treatment of phenol wastewater. The HPLC result showed that several organic acids, such as oxalic acid, maleic acid, fumaric acid, glutaric acid, and adipic acid, were formed during the reaction. The chemical oxygen demand (COD) result indicated that the formed organic acids could be further mineralized to CO2 and H2O, and the mineralization ratio was more than 80% when the catalytic reaction time was prolonged to 4 h. This work is of vital importance, in terms of both academic research and industrial practice, to the design of Pc-based functional materials and their application in environmental purification.

scholarly journals Treatment of Wastewater for Agricultural Applications in Regions of Water Scarcity

2021 ◽  
Vol 12 (5) ◽  
pp. 6336-6360
Keyword(s):  
Removal Rate ◽  
Oxygen Demand ◽  
Bacterial Count ◽  
Agricultural Fields ◽  
Total Bacterial Count ◽  
Industrial Sectors ◽  
Agricultural Applications ◽  
Electrocoagulation Process ◽  
Water Scarce ◽  
Animal Safety

This paper analyses the latest techniques for treating wastewater to make it suitable for agricultural applications in regions where irrigation water is scarce. Micro-filtration (MF) techniques yield a significant reduction in Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), and Total Bacterial Count (TBC) of wastewater, which makes it suitable to be used for irrigational purposes. Microbial Fuel Cell (MFC) technology is a viable solution for treating wastewater discharged from many industrial sectors, such as the food processing industry, for reclaiming water for agro-applications. Such industrial water may seal soil pores if directed untreated to agricultural fields. Concerning the treatment of microbial contamination of wastewater, the removal rate of pressurized membrane bio-booster (MBR) is significantly large for coliform and metals such as lead, copper, chromium, and arsenic. Both electrocoagulation and chemical coagulation are applied in the removal of oxidable chemicals from wastewater. However, the electrocoagulation process shows a higher efficiency in terms of removing COD. Contamination of agricultural fields with heavy metals is considered an adverse impact on the human and animal safety of discharging wastewater into agro-fields. Thus, removing such contaminants should be given the utmost priority in wastewater treatment, especially from industrial discharge, before they are directed to agricultural usage. Factors that govern the sustainability of a given method in a water-scarce region are also discussed.

scholarly journals Interaction of Operational and Physicochemical Factors Leading to Gordonia amarae-Like Foaming in an Incompletely Nitrifying Activated Sludge Plant

2012 ◽  
Vol 78 (23) ◽  
pp. 8165-8175 ◽  
Author(s):  
Pitiporn Asvapathanagul ◽  
Zhonghua Huang ◽  
Phillip B. Gedalanga ◽  
Amber Baylor ◽  
Betty H. Olson
Keyword(s):  
Steady State ◽  
Removal Rate ◽  
Statistical Significance ◽  
Oxygen Demand ◽  
Ammonium Ion ◽  
Content Type ◽  
Mixed Liquor ◽  
Physicochemical Changes ◽  
Cell Concentrations ◽  
Gordonia Amarae

ABSTRACTThe overgrowth ofGordonia amarae-like bacteria in the mixed liquor of an incompletely nitrifying water reclamation plant was inversely correlated with temperature (r= −0.78;P< 0.005) and positively correlated with the solids retention time (SRT) obtained a week prior to sampling (r= 0.67;P< 0.005). Drops followed by spikes in the food-to-mass ratio (0.18 to 0.52) and biochemical oxygen demand concentrations in primary effluent (94 to 298 mg liter−1) occurred at the initiation ofG. amarae-like bacterial growth. The total bacterial concentration did not increase as concentrations ofG. amarae-like cells increased, but total bacterial cell concentrations fluctuated in a manner similar to that ofG. amarae-like bacteria in the pseudo-steady state. The ammonium ion removal rate (percent) was inversely related toG. amarae-like cell concentrations during accelerated growth and washout phases. The dissolved oxygen concentration decreased as theG. amarae-like cell concentration decreased. The concentrations ofG. amarae-like cells peaked (2.47 × 109cells liter−1) approximately 1.5 months prior to foaming. Foaming occurred during the late pseudo-steady-state phase, when temperature declines reversed. These findings suggested that temperature changes triggered operational and physicochemical changes favorable to the growth ofG. amarae-like bacteria. Fine-scale quantitative PCR (qPCR) monitoring at weekly intervals allowed a better understanding of the factors affecting this organism and indicated that frequent sampling was required to obtain statistical significance with factors changing as the concentrations of this organism increased. Furthermore, the early identification ofG. amarae-like cells when they are confined to mixed liquor (107cells liter−1) allows management strategies to prevent foaming.

Assessment of the Effects of Ornamental Wetland Polyculture Combinations on Urban Sewage Treatment

2021 ◽  
Author(s):  
Min Wang ◽  
Yujue Zhou ◽  
Lin Xiang ◽  
Xiaoyang Ke ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Municipal Wastewater ◽  
Plant Biomass ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wetland Plant ◽  
Urban Sewage ◽  
Thalia Dealbata ◽  
Cyperus Alternifolius

Abstract Previous studies have shown that wetland plants can treat wastewater in a cost-effective and sustainable way, however, the studies on the performance of ornamental wetland plant diversity in treating urban sewage were scarce. Therefore, this study was conducted to assess and select wetland polyculture combination that was effective in urban sewage treatment in subtropical areas. We formed five combinations out of six ornamental wetland plant species including Thalia dealbata, Cyperus alternifolius, Iris pseudacorus, Lythrum sastlicaria, Nymphaea tetragona, and Zantedeschia aethiopica. The growth state and removal effects of each plant combination were systematically measured and assessed. The results indicated all the combinations exhibited remarkable total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH­4+-N), and chemical oxygen demand chromium (CODcr) removal rate of 70.75%-77.67%, 63.86%-73.71%, 69.73%-76.85%, and 57.28%-75.69%, respectively. Additionally, pH was reduced to 7.54-8.00 in the sewage. The purification effect reached the best during 30-36th day. The comprehensive assessment showed the mixture of Thalia dealbata + Cyperus alternifolius, closely followed by Thalia dealbata + Cyperus alternifolius+ Lythrum sastlicaria, was highly effective at extracting various pollutants, and both of them could be used as favorable combinations to convert eutrophication and purify municipal wastewater. Linear regression showed that TP, TP, NH­4+-N, and CODcr. were significantly related to plant biomass, indicating that plant biomass essential indicator for screening purification plants. Our study highlighted the importance of plant diversity in biological wastewater treatment, however the competition between plants was suggested to take into consideration in future studies.

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