scholarly journals Rationale for the Combined Use of Biological Processes and AOPs in Wastewater Treatment Tasks

2021 ◽  
Vol 11 (16) ◽  
pp. 7551
Author(s):  
Vladimir Shtepa ◽  
Magdalena Balintova ◽  
Yelizaveta Chernysh ◽  
Viktoriia Chubur ◽  
Stefan Demcak ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Anodic Oxidation ◽  
Structural Model ◽  
Treatment Quality ◽  
Combined Use ◽  
Treatment Facilities ◽  
Almost All ◽  
Aerobic And Anaerobic ◽  
Standard Disk

This paper aims to form a unified concept of the integrated use of different wastewater treatment methods to form a resistant biological treatment stage of technological systems under the influence of such toxic factors as antibiotics and surfactants. The processes of mechanical treatment, ozonation, UV irradiation, and electrolytic anodic oxidation were implemented in an electrotechnological wastewater treatment facility. Wastewater treatment quality was determined by the concentration of nitrogen compounds in aqueous solutions according to the method of Lurie. Biodiagnostics of the investigated activated sludge via surfactant action was carried out at polyethylene oxide concentrations of 10, 30, and 50 mg/dm3. As a result of experiments on wastewater treatment after aquaculture, an improvement in the reduction of pollutants only by the indicator “nitrate concentration” was determined: by 20% after anodic oxidation, and by 15% after photolysis. At almost all surfactant concentrations studied, the activated sludge was not completely recovered, which was expressed in a decrease in its quantity and in the inability to aggregate flakes of activated sludge. The diameter of the growth retardation of the standard disk with antibiotic (amoxiclav) by the accumulative culture of activated sludge was 17.3 ± 2 mm at a concentration of 4 mg/dm3 and 31.3 ± 3 mm at a concentration of 6 mg/dm3. In the process of studying the state of the activated sludge’s biocenosis under the influence of such toxicants, several regularities were revealed. The directions of using combined approaches of water treatment and wastewater treatment were defined. The structural model of treatment facilities using aerobic and anaerobic bioprocesses together with advanced oxidative technologies was substantiated.

Improving the hydrobiological analysis of activated sludge at the Minsk wastewater treatment facilities

2021 ◽  
pp. 26-36
Author(s):  
О.С. Дубовик ◽  
Р.М. Маркевич ◽  
Е.В. Гаврилович ◽  
И.А. Гребенчикова ◽  
В.В. Иванович
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Point System ◽  
Treatment Conditions ◽  
Filamentous Microorganisms ◽  
Different Seasons ◽  
Treatment Facilities ◽  
Favorable Conditions ◽  
Quantitative Account ◽  
Different Levels

На основании накопленного опыта эксплуатации сооружений Минской очистной станции и обзора источников информации определена схема гидробиологического анализа активного ила, приведена форма регистрации результатов проведенного анализа. Для количественного учета нитчатых микроорганизмов разработана собственная пятибалльная система. Для нитчатых микроорганизмов, выявленных в активном иле, на основании анализа литературных данных определены условия, благоприятствующие их массовому развитию. В течение длительного периода времени, включающего разные сезоны года, проведена апробация усовершенствованной методики для мониторинга состояния иловой суспензии очистных сооружений двух площадок станции: классических четырехкоридорных аэротенков-вытеснителей первой площадки и биореакторов с каскадной денитрификацией второй площадки. Определены представители нитчатых микроорганизмов, постоянно обитающие в очистных сооружениях, выявлены доминирующие виды. Проведено сопоставление результатов анализа нитчатых форм и седиментационных характеристик активного ила. Сделаны заключения об особенностях биоценоза аэротенков первой площадки и биореакторов второй площадки, идентичности по видовому составу сообществ нитчатых бактерий, влиянии состава сточных вод и условий их очистки (нагрузка на ил, наличие зон с разным уровнем аэрации) на свойства иловой суспензии. Based on the accumulated experience in operating the Minsk Wastewater Treatment Facilities and a review of information sources, a scheme for the hydrobiological analysis of activated sludge was determined, and a form for recording the results of the analysis was provided. For the quantitative account of filamentous microorganisms, an original five-point system was developed. Based on the literature data analysis, favorable conditions for the mass growth of filamentous microorganisms found in activated sludge were determined. Over a long period of time, including different seasons of the year, the improved methodology was tested for monitoring the state of the sludge suspension at two sites of the treatment facilities: traditional four-line continuous-flow aeration tanks at the first site and bioreactors with cascade denitrification at the second site. The species of filamentous microorganisms, permanently living in wastewater treatment structures, have been identified, and the dominant species have been determined. The results of the analysis of filamentous forms and sedimentation characteristics of activated sludge are compared. Conclusions were made about the features of the biocenosis in the aeration tanks at the first site and in the bioreactors at the second site; about the identity of the species composition of the filamentous bacteria communities, the effect of the wastewater composition and treatment conditions (sludge load, occurrence of zones with different levels of aeration) on the properties of the sludge suspension.

Biological odour control by diffusion into activated sludge basins

2000 ◽  
Vol 41 (6) ◽  
pp. 127-132 ◽  
Author(s):  
R. P. Bowker
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
High Strength ◽  
Air Stream ◽  
Fine Bubble ◽  
Treatment Facilities ◽  
Odour Control ◽  
Odour Emissions ◽  
Air Streams

Diffusion of odourous air into activated sludge basins is an effective and economical approach for odour control at wastewater treatment plants. Over 30 facilities in North America practice this technique. Most of these applications are for dilute or moderate strength air streams with relatively low hydrogen sulfide (H2S) levels. Unfortunately, the lack of data documenting the effectiveness of the process and concerns for blower corrosion have limited its acceptance as a method for controlling odour emissions. This paper presents a compilation and review of wastewater treatment facilities that are currently using activated sludge diffusion. Performance data are tabulated, and information on operation and maintenance of the blower/diffuser systems are summarized. New data are presented that compare the effectiveness of coarse vs. fine bubble diffusers for treatment of a high strength, high-H2S air stream from sludge holding tanks at Concord, NH. Designand performance information is presented on a dedicated odour control system installed at Phoenixville, Pennsylvania in 1996 that collects high-H2S air streams from an influent chamber and primary clarifiers and diffuses it into a mechanically-aerated activated sludge basin. A cost-effectiveness analysis is presented for a blower/diffuser system installed exclusively for odour control. Methods used to overcome initial operational problems are discussed.

scholarly journals Occurrence of fungi degrading aromatic hydrocarbons in activated sludge biocenoses

2014 ◽  
Vol 31 (1) ◽  
pp. 67-75
Author(s):  
Anna Grabińska-Łoniewska ◽  
Tomasz Słomczyński ◽  
Elżbieta Pajor ◽  
Katarzyna Kołosowska
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Aromatic Hydrocarbons ◽  
Soil Bioremediation ◽  
Exhaust Gases ◽  
Anaerobic Wastewater Treatment ◽  
Aerobic And Anaerobic ◽  
Wastewater Treatment Systems ◽  
Gases Purification

A set of 21 strains of yeast-like microorganisms isolated from biocenoses of aerobic and anaerobic wastewater treatment systems were assayed for their ability to utilize aromatic hydrocarbons as a sole C-source. Basing on the achieved results, the highly biochemically active strains for application in enhancing of wastewaters and exhaust gases purification as well as soil bioremediation were selected.

scholarly journals The present situation and trends of wastewater treatment in small settlements and rural areas of Lithuania

2019 ◽  
pp. 243-250
Author(s):  
Regimantas Dauknys
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Surface Waters ◽  
Rural Areas ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Present Situation ◽  
Treatment Facilities ◽  
Biological Filters ◽  
Activated Sludge Systems

This article presents the wastewater treatment in small settlements and rural areas ofLithuania, including descriptions of capacity and loading of wastewater treatment plants(WWTPs), types of treatment facilities, and development trends of biological treatmentfacilities. In 2000 Lithuania had 597 WWTPs with capacity up to 1000 m3/d, 95% of them arethe biological treatment plants. Today the most of these WWTPs are unloaded due to thetendency to centralise wastewater treatment in rural areas of Lithuania that were in the eightand ninth decades.In small settlements and rural areas of Lithuania the aeration facilities are predominant. In theeight and ninth decades practically only the activated sludge systems were built. The situationbegan to change in the last decade of the last century: the biological filters and soil filtrationfacilities with discharge into surface waters were applied more frequently, so the building ofaeration facilities started to decrease.

scholarly journals Different engineering designs have profoundly different impacts on the microbiome and nitrifying bacterial populations in municipal wastewater treatment bioreactors

2021 ◽  
Author(s):  
Taegyu Kim ◽  
Sebastian Behrens ◽  
Timothy LaPara
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Community Composition ◽  
Municipal Wastewater ◽  
Specific Treatment ◽  
Treatment Goals ◽  
Municipal Wastewater Treatment ◽  
Α Diversity ◽  
Treatment Facilities ◽  
System Designs

Numerous wastewater treatment processes are designed by engineers to achieve specific treatment goals. However, the impact of these different process designs on bacterial community composition is poorly understood. In this study, 24 different municipal wastewater treatment facilities (37 bioreactors) with various system designs were analyzed by sequencing of PCR-amplified 16S rRNA gene fragments. Although a core microbiome was observed in all of the bioreactors, the overall microbial community composition (analysis of molecular variance; P = 0.001) as well as a specific population of Nitrosomonas spp. ( P = 0.04) were significantly different between A/O (anaerobic/aerobic) systems and conventional activated sludge (CAS) systems. Community α-diversity (number of observed operational taxonomic units [OTUs] and Shannon diversity index) was also significantly higher in A/O systems compared to CAS systems (Wilcoxon; P < 2 × 10 −16 ). In addition, wastewater bioreactors with short mean cell residence time (< 2 days) had very low community α-diversity and fewer nitrifying bacteria compared to other system designs. Nitrospira spp. (0.71%) and Nitrotoga spp. (0.41%) were the most prominent nitrite oxidizing bacteria (NOB); because these two genera were rarely prominent community members at the same time, these populations appeared to be functionally redundant. Weak evidence (AOB:NOB ≪ 2; substantial quantities of Nitrospira spp. sublineage II) was also obtained suggesting that complete ammonia oxidation by a single organism was occurring in system designs known to impose stringent nutrient limitation. This research demonstrates that design decisions made by wastewater treatment engineers significantly impact the microbiome of wastewater treatment bioreactors. IMPORTANCE Municipal wastewater treatment facilities rely on the application of numerous “activated sludge” process designs to achieve site-specific treatment goals. A plethora of microbiome studies on municipal wastewater treatment bioreactors have been previously performed; however, the role of process design on the municipal wastewater treatment microbiome is poorly understood. In fact, wastewater treatment engineers have attempted to control the microbiome of wastewater bioreactors for decades without sufficient empirical evidence to support their design paradigms. Our research demonstrates that engineering decisions with respect to system design have a significant impact on the microbiome of wastewater treatment bioreactors.

Identity, abundance and physiology of Aquaspirillum-related filamentous bacteria in activated sludge

2006 ◽  
Vol 54 (1) ◽  
pp. 237-245 ◽  
Author(s):  
T.R. Thomsen ◽  
C. Kragelund ◽  
P.H. Nielsen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Oligonucleotide Probe ◽  
Filamentous Bacteria ◽  
Type B ◽  
Anaerobic Conditions ◽  
Almost All

Microcolony-forming bacteria closely related to the genus Aquaspirillum in the Betaproteobacteria were recently observed to be abundant in many nutrient removal wastewater treatment plants. The developed oligonucleotide probe, Aqs997, however, occasionally also targeted some filamentous bacteria in activated sludge samples when fluorescence in situ hybridization was performed. In this study, the identity, abundance, and ecophysiology of these Aqs997-positive filamentous bacteria were studied in detail. Most of the Aqs997-positive filamentous bacteria could morphologically be identified as either Eikelboom Type 1701, Type 0041/0675 or possibly Type 1851, all characterized by epiphytic growth. They were found in almost all 21 wastewater treatment plants investigated. Two morphotypes were found. Type A filaments, which seemed to be the same genotype as the microcolony-forming bacteria targeted by probe Aqs997.Type B filaments also hybridized with probe GNS941, specific for the Chloroflexi phylum, so the true identity remains unclear. Aqs997-positive filaments usually stained Gram-negative, but Gram-positive filaments were also found, stressing the difficulties in identifying bacteria from morphology and simple staining results. Studies on the ecophysiology by microautoradiography showed that Aqs997-positive filamentous bacteria did not consume acetate and glucose, while some took up butyrate, mannose, and certain amino acids. Most likely, some Aqs997-positive filamentous bacteria were able to perform full denitrification such as the Aqs997-positive microcolony-forming bacteria, and some were able to store polyhydroxyalkanoates under anaerobic conditions, potentially being glycogen accumulating organisms.

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