Decomposition of 1,4-dioxane by photo-Fenton oxidation coupled with activated sludge in a polyester manufacturing process

2009 ◽  
Vol 59 (5) ◽  
pp. 1003-1009 ◽  
Author(s):  
M. H. So ◽  
J. S. Han ◽  
T. H. Han ◽  
J. W. Seo ◽  
C. G. Kim
Keyword(s):  
Activated Sludge ◽  
Pilot Scale ◽  
Cyclic Ether ◽  
Fenton Oxidation ◽  
International Agency ◽  
Optimal Conditions ◽  
High Concentrations ◽  
Uv C ◽  
Scale Reactor ◽  
By Products

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H2O2 and 1,400 ppm FeSO4 were maintained along with 10 UV-C lamps (240 μW/cm2) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.

scholarly journals Desalination of Produced Water by Membrane Distillation: Effect of the Feed Components and of a Pre-treatment by Fenton Oxidation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Francesco Ricceri ◽  
Mattia Giagnorio ◽  
Giulio Farinelli ◽  
Giulia Blandini ◽  
Marco Minella ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Produced Water ◽  
Membrane Distillation ◽  
Fenton Oxidation ◽  
Produced Waters ◽  
Pre Treatment ◽  
High Concentrations ◽  
Membrane Wetting ◽  
By Products

Abstract The treatment of produced waters (by-products of oil and gas extraction) with the innovative process of membrane distillation is challenging, because these highly saline streams contain high concentrations of organic compounds and hydrocarbons that cause membrane wetting and impairment of performance. To design the most compact treatment scheme and with the aim of obtaining an easier management of produced water for reuse purposes, Fenton oxidation is here investigated as a feed pre-treatment that may produce an effluent easily handled by membrane distillation. In high-recovery membrane distillation tests, we systematically investigate the detrimental effects of individual contaminants in a synthetic produced water mimicking the composition of a real sample. The recovery rate depends strongly on the initial salinity, which eventually causes scaling and pore blocking. Surfactants are found to be mainly responsible for membrane wetting, but volatile and hydrophobic organics also spoil the quality of the product water. A Fenton oxidation pre-treatment is thus performed to degrade the target organics, with the aim of enhancing the effectiveness of the following membrane distillation and to improve the quality of the final product. The combined oxidation-membrane distillation scheme has both advantages and limitations, which need to be carefully evaluated and further investigated.

Pilot scale study of sequencing batch reactor (SBR) retrofit with integrated fixed film activated sludge (IFAS): nitrogen removal and design consideration

2018 ◽  
Vol 4 (4) ◽  
pp. 569-581 ◽  
Author(s):  
Renzun Zhao ◽  
Hong Zhao ◽  
Rich Dimassimo ◽  
Guoren Xu
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Pilot Scale ◽  
Design Consideration ◽  
Fixed Film ◽  
Seeding Effect ◽  
Pilot Scale Reactor ◽  
Scale Reactor

IFAS process was coupled with SBR operation in a pilot-scale reactor to verify the feasibility and to evaluate the performance of IFAS-SBR. Significant nitrification improvement in the IFAS-SBR system was observed, which is attributed to both the introduction of attached-growth biomass on media carriers and the “seeding effect” by biofilm sloughing.

scholarly journals Cytostatic Drug 6-Mercaptopurine Degradation on Pilot Scale Reactors by Advanced Oxidation Processes: UV-C/H2O2 and UV-C/TiO2/H2O2 Kinetics

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 567
Author(s):  
Luis A. González-Burciaga ◽  
Juan C. García-Prieto ◽  
Manuel García-Roig ◽  
Ismael Lares-Asef ◽  
Cynthia M. Núñez-Núñez ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Pilot Scale ◽  
Cytostatic Drug ◽  
Contaminant Degradation ◽  
Ph Values ◽  
Initial Ph ◽  
Acidic Conditions ◽  
Kinetic Calculations ◽  
Uv C ◽  
By Products

6-Mercaptopurine (6-MP) is a commonly used cytostatic agent, which represents a particular hazard for the environment because of its low biodegradability. In order to degrade 6-MP, four processes were applied: Photolysis (UV-C), photocatalysis (UV-C/TiO2), and their combination with H2O2, by adding 3 mM H2O2/L (UV-C/H2O2 and UV-C/TiO2/H2O2 processes). Each process was performed with variable initial pH (3.5, 7.0, and 9.5). Pilot scale reactors were used, using UV-C lamps as radiation source. Kinetic calculations for the first 20 min of reaction show that H2O2 addition is of great importance: in UV-C experiments, highest k was reached under pH 3.5, k = 0.0094 min−1, while under UV-C/H2O2, k = 0.1071 min−1 was reached under the same initial pH; similar behavior was observed for photocatalysis, as k values of 0.0335 and 0.1387 min−1 were calculated for UV-C/TiO2 and UV-C/TiO2/H2O2 processes, respectively, also under acidic conditions. Degradation percentages here reported for UV-C/H2O2 and UV-C/TiO2/H2O2 processes are above 90% for all tested pH values. Ecotoxicity analysis of samples taken at 60 min in the photolysis and photocatalysis processes, suggests that contaminant degradation by-products present higher toxicity than the original compound.

scholarly journals Bio-Electro-Fenton: a novel method for treating leachate in Da Phuoc Landfill, Vietnam

2020 ◽  
Vol 23 (1) ◽  
pp. 461-469
Author(s):  
Ho Nhut Linh ◽  
Hai Truong Nam Ho
Keyword(s):  
Proton Exchange Membrane ◽  
Advanced Oxidation Process ◽  
Operation Time ◽  
Pilot Scale ◽  
Proton Exchange ◽  
Scale Model ◽  
Anode Chamber ◽  
Optimal Conditions ◽  
Pre Treatment ◽  
High Concentrations

Introduction: Leachate is a noticeable pollution problem because it contains a considerable amount of persistent organic pollutants (POPs). If leachate isn’t treated thoroughly, its leak will negatively affect the environment. Therefore, appropriate treatment technologies are required to remove them. Bio-Electro-Fenton (BEF) is a new method using microorganisms such as electrolytes to convert chemical energy into electricity to help create H2O2 support advanced oxidation process (AOPs). The potentiality of the applicability of BEF technology as a pretreatment step for leachate from Da Phuoc landfill (operation time > 12 years), Ho Chi Minh City. Methods: The BEF pilot scale model (30 x 10 x 10 cm) is divided by a proton exchange membrane (PEM) (Nafion®112) into two chambers (anode and cathode). Cathode chamber used a graphite electrode, the anode chamber used a carbon fabric electrode. The experiments aimed to determine the optimal conditions of parameters affecting the BEF system by determining the efficiency of COD removal and BOD5/COD ratio in leachate. Results: At optimal conditions of the model including pH 3, [Fe2+] = 4g/L, current intensity = 1A, reaction time  60 minutes and airflow = 12 L/min, as a result COD was reduced by 68.2% from 4950 mgO2/L to 1574.1 mgO2/L, the ratio of BOD5/COD = 0.1. Conclusion: The study result showed that Bio-electro-Fenton process is effective for wastewater with high concentrations of pollutant and difficult to treat as leachate, suggesting that the appropriate method for pre-treatment processes support the thorough elimination of pollutants.

scholarly journals Optimization of banana crop by-products solvent extraction for the production of bioactive compounds

2021 ◽  
Author(s):  
Sara Díaz ◽  
Antonio N. Benítez ◽  
Sara Ramírez-Bolaños ◽  
Lidia Robaina ◽  
Zaida Ortega
Keyword(s):  
Antioxidant Activity ◽  
Aqueous Ethanol ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Total Phenol Content ◽  
Optimal Conditions ◽  
Satisfactory Description ◽  
Optimized Conditions ◽  
By Products ◽  
Banana Crops

AbstractThe aim of this work is the optimization of phenolic compound extraction from three by-products of banana crops (rachis, discarded banana, and banana’s pseudostem pulp), as a way to valorize them through a green extraction process. The influence of the temperature and aqueous ethanol concentration (Et-OH) on extract properties (total phenol content (TPC) and antioxidant activity) was firstly analyzed. 78 ℃ and ethanol concentrations close to 50% yielded the best results for the three materials. The equations obtained by the response surface methodology gave a satisfactory description of the experimental data, allowing optimizing the extraction conditions. Under optimized conditions, time influence was then assessed, although this parameter seemed not influence results. Among the three by-products, rachis extract (60% Et-OH, 78 ℃, and 30 min) presented the highest TPC (796 mg gallic acid/100 g of dried material) and antioxidant activity (6.51 mg Trolox equivalents/g of dried material), followed by discarded banana, and pseudostem pulp. Under the optimal conditions, experiments were performed at a larger scale, allowing to determine the extraction yields (EY) and to characterize the extracts. The highest EY was obtained for the rachis (26%), but the extract with the highest activity was obtained for discarded banana (50% Et-OH, 78 ℃, and 60 min), which presented a TPC of 27.26 mg/g extract corresponding to 54.59 mg Trolox equivalents/g extract. This study contributes to the valorization of banana crops residues as a source of polyphenolic compounds with bioactive functions that can be extracted under economic extraction conditions. Graphical abstract

Fluidized bed gasification of eucalyptus chips: Axial profiles of syngas composition in a pilot scale reactor

Energy ◽  
2021 ◽  
Vol 219 ◽  
pp. 119604
Author(s):  
Francesco Parrillo ◽  
Filomena Ardolino ◽  
Gabriele Calì ◽  
Davide Marotto ◽  
Alberto Pettinau ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Pilot Scale ◽  
Pilot Scale Reactor ◽  
Scale Reactor

Screening and Characterization of a Bacterium Capable of Simultaneous Heterotrophic Nitrification and Aerobic Denitrification at High Concentrations of Ammonia-Nitrogen

2014 ◽  
Vol 665 ◽  
pp. 487-490
Author(s):  
Te Wang ◽  
Zhao Xia Liu ◽  
Mei Juan Wu ◽  
Fu Hui Kang ◽  
Qing Chen ◽  
...  
Keyword(s):  
16S Rdna ◽  
Ammonia Nitrogen ◽  
Heterotrophic Nitrification ◽  
Denitrification Rate ◽  
Aerobic Denitrification ◽  
Optimal Conditions ◽  
Carbon And Nitrogen ◽  
Mass Ratios ◽  
High Concentrations ◽  
Denitrification Process

A bacterium capable of simultaneous heterotrophic nitrification and aerobic denitrification at high concentrations of ammonia-nitrogen was screened and identified and the denitrification property was investigated in this paper. The strain was isolated from aeration tank of wastewater disposed by activated sludge and analyzed and identified by 16S rDNA. The effects of different carbon sources and carbon and nitrogen mass ratios on denitrification rate were studied. The changes of various forms of ammonia-nitrogens during the simultaneous heterotrophic nitrification and aerobic denitrification process were characterized. A strain capable of simultaneous heterotrophic nitrification and aerobic denitrification at 600 mg/L nitrogen concentration has been isolated and screened. Comparison of its 16S rDNA sequence showed 100% similarity to Bacillus licheniformis strain Lr124/6. The strain was named as Bacillus sp. A22. The optimal conditions for degradation of ammonia-nitrogen by Bacillus sp. A22 were trisodium citrate as carbon source and carbon and nitrogen mass ratios of 10. The denitrification rate was 98.2% after 96 h of culture under the optimal conditions and there was hardly any intermediates accumulation in the denitrification process. It has practical applications that the denitrification can be performed efficiently at high concentrations of ammonia-nitrogen by method of simultaneous heterotrophic nitrification and aerobic denitrification by Bacillus sp. A22 in nitrogen purification treatment of wastewater with high concentrations of ammonia-nitrogen.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

Quality improvement of biosolids by ferrate(VI) oxidation of offensive odour compounds

1996 ◽  
Vol 33 (3) ◽  
pp. 119-130 ◽  
Author(s):  
Allen C. Chao ◽  
Sergio J. de Luca ◽  
Carlos N. Idle
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Potassium Ferrate ◽  
Sulphur Compounds ◽  
Environmental Recovery ◽  
Oxidizing Power ◽  
Aldehydes And Ketones ◽  
High Concentrations ◽  
By Products

Studies concerning the treatment, stabilization and final disposal of biosolids, one of the by-products of wastewater treatment, in environmental recovery, have been intensified by the sanitary and environmental effects of land disposal. The careful assessment of biosolid quality shows that, when appropriately managed, the environmental risks of their uses can be minimized by chemical stabilization, and biosolids could even be used as fertilizer and soil conditioner. A research study of biosolid stabilization was performed using lime as a standard process compared to potassium ferrate (VI). The chances of leaching and solubilization of metals were tested, simulating conditions for disposal in the environment. The sanitary effectiveness in terms of pathogens (bacteria, fungi and helminth eggs) were also evaluated. Experiments were performed on the lime and ferrate(VI) treatment of compounds such as ammonia, nitrate, soluble sulphides, and total sulphates, indicators of odouriferous offensive compounds which might occasionally prevent some uses of the solids, and the results are presented in this paper. Wastewater Treatment Plants emit offensive odours generated during the sewage treatment process, as well as during the treatment and the management of biosolids. This occurs in the drying beds and the spreading of biosolids on land, due to the high concentrations of sulphur compounds, nitrogen compounds, acids and organic compounds (aldehydes and ketones). The potassium ferrate(VI) utilized in the research is a powerful oxidizing agent throughout the pH scale, with the advantage of not generating by-products which will cause toxicity or mutagenicity (DE LUCA, 1981). The ion ferrate(VI) has greater oxidizing power than permanganate, e.g., it oxidizes reduced sulfur forms to sulphate, ammonia to nitrate, hypochlorite to chlorite and chlorite to chlorate(DE LUCA et al., 1992; CHAO et al., 1992). This paper shows that, as expected, the potassium ferrate (VI) treatment replaces several chemical products utilized for odour control of sludges, mainly aggressive odours caused by ammonia and sulphides, through the formation of precipitates with iron compounds. Ferrate (VI) has often been shown to destroy soluble sulphides, transforming them into sulphate. The generation of oxygen in the decomposition of ferrate(VI) increases its oxidizing power. Ferrate(VI) applied to sludges also has the double effect of transforming ammonia into nitrates, such that this product takes the place of sulphates, acting as an electron acceptor, thus preventing the development of further odours when biosolids are utilized.

ADVANCED TREATMENT OF PAPER MILL EFFLUENTS BY A TWO-STAGE ACTIVATED SLUDGE PROCESS

1994 ◽  
Vol 30 (3) ◽  
pp. 173-181 ◽  
Author(s):  
L. Knudsen ◽  
J. A. Pedersen ◽  
J. Munck
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
Paper Mill ◽  
Pilot Scale ◽  
Activated Sludge Process ◽  
Two Stage ◽  
Paper Mills ◽  
Paper Mill Effluents ◽  
Scale Test ◽  
Oxygen Requirements

The work presented in this paper concerns the application of a two-stage aerobic activated sludge process for treatment of effluents from paper mills in Denmark. The paper describes both pilot-scale test results and fullscale experience with the process. The treatment process is characterised by a bigh-load first stage (2-4 kg COD/kg MLSSxd) followed by a low-load second stage to secure full nitrification and denitrification of remaining nitrogen compounds. The results of continuous pilot-scale tests show that it is possible to obtain a reduction of more than 85% of the incoming COD,01 and a 99% reduction of the incoming BOD5, resulting in an effluent quality of 230 mg CODsol/l and less than 10 mg BOD5/l. As indicated, practically all the biodegradable organic substances are removed by the process. The remaining fraction of soluble organics measured as COD is considered to be non-biodegradable by conventional biological treatment systems. The results produced in the pilot-scale tests are confirmed by the effluent qualities obtained in a full-scale treatment plant at another paper mill, involving an identical process concept. During the pilot-scale tests, special attention bas been paid to the removal of organic compounds, organic nitrogen as well as nutrients and nitrification. In addition, the sludge characteristics and the oxygen requirements have been considered.

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