Photocatalytic ozonation for degradation of 2-sec-butyl-4,6-dinitrophenol (DNBP) using titanium dioxide: effect of operational parameters and wastewater treatment

2013 ◽  
Vol 40 (2) ◽  
pp. 711-722 ◽  
Author(s):  
T. Mousanejad ◽  
M. Khosravi ◽  
S. M. Tabatabaii ◽  
A. R. Khataee ◽  
K. Zare
Keyword(s):  
Titanium Dioxide ◽  
Wastewater Treatment ◽  
Operational Parameters ◽  
Photocatalytic Ozonation

scholarly journals Photocatalytic ozonation in an immersion rotary body reactor for the removal of micro-pollutants from the effluent of wastewater treatment plants

2021 ◽  
Author(s):  
Simon Mehling ◽  
Tobias Schnabel ◽  
Jörg Londong
Keyword(s):  
Titanium Dioxide ◽  
Wastewater Treatment ◽  
Reaction Rate ◽  
Energetic Efficiency ◽  
Maximum Reaction Rate ◽  
Photocatalytic Ozonation ◽  
Maximum Reaction ◽  
Irradiation Power ◽  
Real Wastewater ◽  
Micro Pollutants

Abstract Carrier-bound titanium dioxide catalysts were used in a photocatalytic ozonation reactor for the degradation of micro-pollutants in real wastewater. A photocatalytic immersion rotary body reactor with 36 cm disk diameter was used, which was irradiated using UV-A LEDs. The rotating disks were covered with catalysts based on stainless steel grids coated with titanium dioxide. The dosing of ozone was carried out through the liquid phase via an external enrichment and a supply system transverse to the flow direction. The influence of irradiation power and ozone dose on the degradation rate for photocatalytic ozonation was investigated. In addition, the performance of the individual processes photocatalysis and ozonation were studied. The degradation kinetics of the parent compounds were determined by LC-MS/MS. First-order kinetics were determined for photocatalysis and photocatalytic ozonation. A maximum reaction rate of the reactor was determined, which could be achieved by both photocatalysis and photocatalytic ozonation. At a dosage of 0.4 mg /mg DOC, the maximum reaction rate could be achieved using 75% of the irradiation power used for sole photocatalysis, allowing increases in the energetic efficiency of photocatalytic wastewater treatment processes. The process of photocatalytic ozonation is suitable to remove a wide spectrum of micro-pollutants from wastewater. HIGHLIGHT within the work, reaction rates for the degradation of micropollutants in real wastewater matrix are presented. due to the number of investigated pollutants as well as the practical investigation conditions, a more precise evaluation of the use of photocatalysis and photocatalytic ozonation for wastewater treatment is possible.

Технологические аспекты обезвоживания осадков промышленно-дождевых сточных вод автотранспортных предприятий

2019 ◽  
pp. 25-30
Author(s):  
G. Variushina
Keyword(s):  
Wastewater Treatment ◽  
Moisture Content ◽  
Vacuum Filter ◽  
Operational Parameters ◽  
Technological Parameters ◽  
Wastewater Treatment Process ◽  
Motor Transport ◽  
Cationic Flocculant ◽  
Residual Sludge ◽  
Treatment Facilities

Приводятся сведения об условиях формирования, объемах, химическом составе и свойствах осадков очистных сооружений производственных сточных вод автотранспортных предприятий. Даны примеры технологических решений по обезвоживанию образующихся в процессе очистки шламов. Рассмотрены технологические аспекты процесса интенсификации механического обезвоживания уплотненных осадков с использованием высокомолекулярных полиэлектролитов. Представлены данные лабораторных экспериментов по выбору типа флокулянта, его дозы, технологических параметров процесса, а также результаты определения влажности обезвоженных осадков, полученные на модели барабанного вакуум-фильтра. Приведены примеры эффективных обезвоживающих аппаратов отечественного производства и их технические характеристики, рекомендации и критерии их выбора, а также факторы, оказывающие влияние на эксплуатационные параметры обезвоживающего оборудования. Установлено, что наилучшая обезвоживающая способность барабанных вакуум-фильтров (остаточная влажность шламов от 66 до 83) может быть достигнута при применении катионного флокулянта ВПК-402 для осадков различных производственных цехов автотранспортного предприятия.Information on the conditions of generation, volumes, chemical composition and properties of sludge generated at the industrial wastewater treatment facilities of motor transport enterprises is provided. Examples of process engineering solutions for dewatering sludge generated during the wastewater treatment process are given. The technological aspects of enhancing mechanical dewatering of thickened sludge using high-molecular polyelectrolytes are considered. The data of laboratory experiments on choosing the type of flocculant, its dose, technological parameters of the process, as well as the results of determining the moisture content of dewatered sludge obtained in a model of a drum vacuum filter are presented. Examples of effective domestically produced dewatering apparatus and their technical characteristics, recommendations and criteria for their selection, as well as factors influencing the operational parameters of the dewatering equipment are given. It is found that the highest dewatering capacity of drum vacuum filters (residual sludge moisture content from 66 to 83) can be achieved by using VPK-402 cationic flocculant for processing sludge generated at the workshop premises of a motor transport enterprise.

Performance evaluation of different wastewater treatment technologies operating in a developing country

2011 ◽  
Vol 1 (1) ◽  
pp. 37-56 ◽  
Author(s):  
Sílvia C. Oliveira ◽  
Marcos von Sperling
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Septic Tank ◽  
Operational Parameters ◽  
Technical Literature ◽  
Effluent Quality ◽  
Loading Rates ◽  
Treatment Processes ◽  
Treatment Technologies ◽  
Uasb Reactors

This article analyses the performance of 166 wastewater treatment plants operating in Brazil, comprising six different treatment processes: septic tank + anaerobic filter, facultative pond, anaerobic pond + facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The study evaluates and compares the observed effluent quality and the removal efficiencies in terms of BOD, COD, TSS, TN, TP and FC with typical values reported in the technical literature. In view of the large performance variability observed, the existence of a relationship between design/operational parameters and treatment performance was investigated. From the results obtained, no consistent relationship between loading rates and effluent quality was found. The influence of loading rates differed from plant to plant, and the effluent quality was dictated by several combined factors related to design and operation.

scholarly journals Niche Differentiation among Three Closely RelatedCompetibacteraceaeClades at a Full-Scale Activated Sludge Wastewater Treatment Plant and Putative Linkages to Process Performance

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Veronica R. Brand ◽  
Laurel D. Crosby ◽  
Craig S. Criddle
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Niche Differentiation ◽  
Full Scale ◽  
Pure Oxygen ◽  
Operational Parameters ◽  
Metabolic Potential ◽  
Operational Conditions

ABSTRACTMultiple clades within a microbial taxon often coexist within natural and engineered environments. Because closely related clades have similar metabolic potential, it is unclear how diversity is sustained and what factors drive niche differentiation. In this study, we retrieved three near-complete Competibacter lineage genomes from activated sludge metagenomes at a full-scale pure oxygen activated sludge wastewater treatment plant. The three genomes represent unique taxa within theCompetibacteraceae. A comparison of the genomes revealed differences in capacity for exopolysaccharide (EPS) biosynthesis, glucose fermentation to lactate, and motility. Using quantitative PCR (qPCR), we monitored these clades over a 2-year period. The clade possessing genes for motility and lacking genes for EPS biosynthesis (CPB_P15) was dominant during periods of suspended solids in the effluent. Further analysis of operational parameters indicate that the dominance of the CPB_P15 clade is associated with low-return activated sludge recycle rates and low wasting rates, conditions that maintain relatively high levels of biomass within the system.IMPORTANCEMembers of the Competibacter lineage are relevant in biotechnology as glycogen-accumulating organisms (GAOs). Here, we document the presence of threeCompetibacteraceaeclades in a full-scale activated sludge wastewater treatment plant and their linkage to specific operational conditions. We find evidence for niche differentiation among the three clades with temporal variability in clade dominance that correlates with operational changes at the treatment plant. Specifically, we observe episodic dominance of a likely motile clade during periods of elevated effluent turbidity, as well as episodic dominance of closely related nonmotile clades that likely enhance floc formation during periods of low effluent turbidity.

Efficient treatment of dairy processing wastewater in a laboratory scale Intermittently Aerated Sequencing Batch Reactor (IASBR)

2018 ◽  
Vol 85 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Peter Leonard ◽  
Emma Tarpey ◽  
William Finnegan ◽  
Xinmin Zhan
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Wastewater Treatment Plant ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Operational Parameters ◽  
Dairy Processing

This Research Communication describes an investigation into the viability of an Intermittently Aerated Sequencing Batch Reactor (IASBR) for the treatment of dairy processing wastewater at laboratory-scale. A number of operational parameters have been varied and the effect has been monitored in order to determine optimal conditions for maximising removal efficiencies. These operational parameters include Hydraulic Retention Time (HRT), Solids Retention Time (SRT), aeration rate and cycle length. Real dairy processing wastewater and synthetic wastewater have been treated using three laboratory-scale IASBR units in a temperature controlled room. When the operational conditions were established, the units were seeded using sludge from a municipal wastewater treatment plant for the first experiment, and sludge from a dairy processing factory for the second and third experiment. In experiment three, the reactors were fed on real wastewater from the wastewater treatment plant at this dairy processing factory. These laboratory-scale systems will be used to demonstrate over time that the IASBR system is a consistent, viable option for treatment of dairy processing wastewater in this sector. In this study, the capacity of a biological system to remove both nitrogen and phosphorus within one reactor will be demonstrated. The initial operational parameters for a pilot-scale IASBR system will be derived from the results of the study.

Investigation of titanium dioxide/ tungstic acid -based photocatalyst for human excrement wastewater treatment

2018 ◽  
Vol 146 ◽  
pp. 7-14 ◽  
Author(s):  
Fei Xu ◽  
Can Wang ◽  
Kemeng Xiao ◽  
Yufeng Gao ◽  
Tong Zhou ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Wastewater Treatment ◽  
Tungstic Acid

scholarly journals Catalytic Advanced Oxidation Processes for Sulfamethoxazole Degradation

2019 ◽  
Vol 9 (13) ◽  
pp. 2652 ◽  
Author(s):  
Jéssica Martini ◽  
Carla A. Orge ◽  
Joaquim L. Faria ◽  
M. Fernando R. Pereira ◽  
O. Salomé G. P. Soares
Keyword(s):  
Carbon Nanotubes ◽  
Titanium Dioxide ◽  
Reaction Time ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Catalytic Ozonation ◽  
Ion Concentrations ◽  
Oxidation Processes ◽  
Photocatalytic Ozonation ◽  
Mineralization Degree

The degradation of sulfamethoxazole (SMX) by several advanced oxidation processes (AOPs) is carried out in the presence of different catalysts. The catalysts used consisted of carbon nanotubes (CNT), titanium dioxide (TiO2), a composite of carbon nanotubes and titanium dioxide (TiO2/CNT), and iron supported on carbon nanotubes (Fe/CNT). SMX removal was evaluated by catalytic ozonation, photocatalysis, catalytic oxidation with hydrogen peroxide, and combinations of these processes. The evolution of the SMX concentration during reaction time, the mineralization degree, the toxicity of the treated solution, and the formation of organic intermediates and ions were monitored. Ozonation catalyzed by Fe/CNT and CNT and photocatalytic ozonation in the presence of CNT presented the fastest degradation of SMX, whereas photocatalytic ozonation with CNT showed the best results in terms of organic matter removal (92% of total organic carbon (TOC) depletion). Total mineralization of the solution and almost complete reduction of toxicity was only achieved in the photocatalytic ozonation with H2O2 and Fe/CNT catalysts. The compound 3-amino-5-methylisoxazole was one of the first intermediates formed during SMX degradation. p-Benzoquinone was only formed in photocatalysis. Oxalic and oxamic acids were also detected and in most of the catalytic processes they appeared in small amounts. Ion concentrations increased with the reaction time.

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