Membrane Bioreactors

The convergence of quantum-confined graphene materials with piezoelectric surface acoustic wave(SAW) technology represents a transformative breakthrough in membrane-based water purificationsystems. This comprehensive theoretical framework introduces SAW-enhanced nitrogen-doped graphenequantum dot (N-GQD) membranes through four foundational theorems: Dynamic Charge AmplificationTheorem (DCAT), Acoustic Streaming Optimization Theory (ASOT), Selective Ion Transport Engineering(SITE), and Quantum Interference Membrane Theory (QIMT). The revolutionary DCAT demonstratestheoretical enhancement factors of 340% in ion transport through engineered pyridinic nitrogen sitesunder optimized SAW-induced electric fields (10⁶-10⁸ V/m), with corresponding activation energyreductions of 0.3-1.2 eV. The advanced ASOT framework predicts 96.8% reduction in biofouling throughcontrolled acoustic streaming with calculated fluid velocities reaching 3.5 mm/s at membrane surfaces.SITE modeling enables prediction of selectivity coefficients exceeding 2500:1 for targeted heavy metalremoval while maintaining unprecedented water permeability rates. Through integrated multi-scalecomputational modeling employing density functional theory (DFT), large-scale molecular dynamics(LSMD), computational fluid dynamics (CFD), and quantum Monte Carlo simulations, this workdemonstrates potential for 92% energy reduction compared to conventional reverse osmosis whileachieving superior contaminant removal efficiency. The theoretical framework establishes pathways forcommercial-scale implementation with projected manufacturing costs 30% below current membranetechnologies and 15-year operational lifespans.

A method was developed for rapid and accurate determination of cysteinylleukotrienes (LTC4, LTD4, LTE4), essential biomarkers of bronchial asthma, in exhaled breath condensate. The method consists of an immunoseparation procedure combined with selective and sensitive detection by LC-ESI-MS in the multiple reaction monitoring mode (MRM) and using a stable-isotope-dilution assay. The precision of the method was around 94 %. The mean accuracy was higher than 90 % for the content of cysteinylleukotrienes in the concentrate up to 250 pg ml-1. The method was tested on patients with occupational bronchial asthma and compared with healthy subjects. The differences between the two groups were significant.

Highlights-AnMBRs are an effective technology for treatment of slaughterhouse wastewater-COD removal was consistently over 95% and was independent of OLR and HRT-Organic loading limit of 3-3.5 gCOD.L-1 d-1 was imposed by active biomass inventory-Biomass inventory in the AnMBR was limited to 40 g.L-1 (TS) to manage fouling ABSTRACT Anaerobic Membrane Bioreactors (AnMBRs) enable high space loading by retaining solids selectively through microfiltration membranes. For organic industrial wastewaters, this offers an alternative to lagoons and granule based high-rate anaerobic treatment due to excellent effluent quality, high tolerance to load variations, and ability to produce a solids free effluent for the purposes of reuse. While there has been extensive work on low-strength and low solids effluent, there has been limited application in high-solids, high fats systems such as slaughterhouse wastewater, which are a key application. A 200L AnMBR pilot plant operated at 2 Australian cattle slaughterhouses consistently removed over 95% of chemical oxygen demand (COD) from the wastewater. Virtually all degradable COD was converted to biogas, 78-90% of nitrogen and 74% of phosphorus in the wastewater were released to the treated permeate as ammonia and phosphate respectively; which would enable subsequent nutrient capture. The mass loading rate limit of 3-3.5 gCOD.L-1 d-1 is imposed by the active biomass inventory, with this in turn limited to 40 g.L-1 (TS) by the need to manage membrane fouling control.

A self-forming dynamic membrane bioreactor (SFD MBR) is a cost-effective alternative to conventional MBR, in which the synthetic membrane is replaced by a “cake layer,” an accumulation of the biological suspension over a surface of inert, low-cost support originated by filtration itself. Under optimized conditions, the cake layer is easy to remove and quick to form again, resulting a “dynamic membrane.” The permeate of the SFD MBR has chemo-physical characteristics comparable to those of conventional ultrafiltration-based MBR. In this paper, two nylon meshes with pore sizes of 20 and 50 µm, respectively, were tested in a bench-scale SFD MBR in which an air mass load (AML) was periodically supplied tangentially to the filtration surface to maintain filtration effectiveness. The SFD MBR equipped with 20 µm nylon mesh coupled with 5 min of AML every 4 h showed the best performance, ensuring both a permeate with turbidity values always below 3 NTU and revealing no increases in transmembrane pressure (TMP) with manual maintenance needs. A benchmark test with the only difference of a suction break (relaxation) instead of AML was conducted under identical operating conditions for validation with an already known maintenance strategy. This latter test produced a permeate of very good quality, but it needed frequent TMP increases and consequent manual cleanings, showing that a periodic AML coupled with the use of a 20 µm mesh can be an optimal strategy for long-term operation of SFD MBR.

The self-forming dynamic membrane bioreactor (SFD MBR) is an evolution of the conventional ultrafiltrationbased MBR where filtration occurs through a cake layer (dynamic membrane, DM) supported by a filtration net. The effluent quality levels that may be achieved through this technology are comparable to those of conventional MBR and suitable for effluent reuse, as shown in previous research. In addition, SFD MBR are more sustainable, both in terms of investment costs (filtration net materials are cheaper than UF membranes), and operation. Indeed, the typical operating pressure of these systems is below 100 mbar, thus compatible with gravity-driven operation. Nevertheless, as all membrane-based processes, also SFD MBR require periodic maintenance cleaning of the supports holding the filtering layers, in order to ensure high and constant effluent quality and steady operation. In this paper, different strategies for continuous or temporized cyclic DM maintenance aimed at limiting the frequency of on-site manual cleaning interventions are compared. In particular, five tests were performed at the bench scale adopting the same process conditions except for the type of DM maintenance strategy. Continuous fine-bubble air scouring of the membrane surface was compared with two intermittent cyclic procedures based on backwash with permeate (with and without simultaneous air scouring) and mass air load supply (with two cycles of different durations), respectively. The results have confirmed the overall high performance of this technology under all the tested conditions, with COD removal efficiencies always exceeding 86 %, effluent turbidity values normally well below 5 NTU (and often much lower), complete nitrification and partial nitrogen removal. Furthermore, the comparison among the different DM maintenance strategies has shown that the mass air load supply is the most efficient approach towards sustainable operation. In particular, shorter mass air load cycles provided the best performance in limiting the manual cleaning needs, which under this condition were as low as once every 3 weeks. The key finding of this study is the demonstration of cyclic air mass load as an effective preventive cleaning strategy allowing good performance of a bench-scale SFD MBR, strongly reducing the manual maintenance requirements. More experiments are required to confirm these results in larger scale installations.

This article presents a literature review on developments of membrane reactors for biological waste gas treatment as well as examples of applications to different compounds. The use of membranes combines selective separation of compounds from a waste gas stream followed by biological removal. Gas transport phenomena and different types of membranes used in biological waste gas treatment are discussed. So far, membrane-based biological waste gas treatment has only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, membrane bioreactor technology can be useful in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with conventional methods for biological waste gas treatment.

This study first illustrates the IEMB potential for the simultaneous removal of nitrate, perchlorate and bromate from drinking water. The removal of each of these pollutants to concentrations below the recommended levels for drinking water was successfully achieved. The initial development of the IEMB concept for the case of ionic mercury removal is then presented and discussed. For this purpose, appropriate cation exchange membranes were selected, and a suitable mixed microbial culture, capable of converting ionic mercury into elemental mercury, was obtained.

The review paper deals with the use of silver nanoparticles (AgNPs) in water treatment and recycling systems and the presence of AgNPs in wastewater systems. In the water industry, AgNPs can be used in the water treatment process as new filter materials (layers applied to the membranes of various compositions) or as a gentle alternative to the existing drinking water disinfection (solar disinfection in combination with titanium). On the other hand, AgNPs also can be a certain risk to the ecosystem if they are released from such surface-treated materials or preparations into wastewater. The AgNPs, present in the wastewater, then penetrate to the wastewater treatment plants, where they can affect the treatment process itself, especially the sensitive biological nitrification process. Silver ions with antibacterial properties are effectively removed by wastewater treatment plants and no significant negative effect on the treatment process by higher concentrations of silver has been rep...

The review paper deals with the use of silver nanoparticles (AgNPs) in water treatment and recycling systems and the presence of AgNPs in wastewater systems. In the water industry, AgNPs can be used in the water treatment process as new filter materials (layers applied to the membranes of various compositions) or as a gentle alternative to the existing drinking water disinfection (solar disinfection in combination with titanium). On the other hand, AgNPs also can be a certain risk to the ecosystem if they are released from such surface-treated materials or preparations into wastewater. The AgNPs, present in the wastewater, then penetrate to the wastewater treatment plants, where they can affect the treatment process itself, especially the sensitive biological nitrification process. Silver ions with antibacterial properties are effectively removed by wastewater treatment plants and no significant negative effect on the treatment process by higher concentrations of silver has been rep...

Outflows from secondary stages of conventional mechanical-biological wastewater treatment plants (WWTPs) still contain significant concentrations of faecal pollution indicators suggesting the potential presence of pathogenic organisms. The decrease in the concentration of somatic coliphages and bacterial indicators of faecal pollution during the technological stages (coagulation, sand filtration, membrane ultrafiltration, sorption on granular activated carbon, disinfection, accumulation) of a semi-operational plant designed for multi-stage tertiary treatment or rather recycling of treated wastewater was monitored and discussed. During the tertiary treatment, faecal bacteria indicators were better removed than somatic coliphages, hence the inclusion of somatic indicators among faecal pollution indicators in water quality control for reuse is entirely appropriate. Subsequent tertiary treatment, including disinfection, is essential for safe reuse of treated water.

Lawrence K. Wang, Jiaping Paul Chen, Yung-Tse Hung, Nazih K. Shammas (2010), Membrane and Desalination Technologies, Humana Totowa, NJ, USA, 716 pages, ISBN 978-1-58829-940-6 ,  https://doi.org/10.1007/978-1-59745-278-6    .....    ABSTRACT:  This book includes the following chapters:  (1) Membrane Technology: Past, Present and Future;  (2) Preparation of Polymeric Membranes; (3) Advanced Membrane Fouling Characterization in Full-Scale Reverse Osmosis Processes;  (4) Membrane Filtration Regulations and Determination of Log Removal Value;  (5) Treatment of Industrial Effluents, Municipal Wastes, and Potable Water by Membrane Bioreactors; (6) Treatment of Food Industry Foods and Wastes by Membrane Filtration; (7) Membrane Separation: Basics and Applications; (8) Membrane Systems Planning and Design; (9) Adsorption Desalination: A Novel Method;  (10) Membrane Processes for Reclamation of Municipal Wastewater; (11) Potable Water Biotechnology, Membrane Filtration and Biofiltration; (12) Desalination of Seawater by Thermal Distillation and Electrodialysis Technologies; (13) Desalination of Seawater by Reverse Osmosis;  (14) Membrane Technologies for Point-of-Use and Point-of-Entry Applications; (15) Membrane Technologies for Oil–Water Separation; and (16) Gas-Sparged Ultrafiltration: Recent Trends, Applications and Future Challenges.

This study presents an original method for in situ characterisation of the structure and organization of a microbial deposit accumulated on a membrane surface during filtration operations. The strategy is based on coupling macroscopic measurements (filtration results) and local observations at the microscopic level. This approach has been performed thanks to the use of self-fluorescent microorganisms (modified microorganisms) and the design of a specific filtration cell allowing a direct microscopic visualisation of the deposit to be performed without any treatment which could damage or modify the structure. Indeed the use of living fluorescent cells has allowed a non-destructive, in situ and in vivo, study of the deposits. As an example of application, the influence of microorganism size and morphology on the filtration performances and the deposit characteristics were examined in the case of dead-end microfiltration of model suspensions (yeasts and bacteria) obtained under controlled conditions. For these compact deposits the upper part of the deposits, corresponding to a 30 m thickness slice, could be precisely analysed at the microscopic level and for yeasts/bacteria mixed deposit, the local microorganisms organization in the slice could be analysed. For pure yeasts deposit, the porosity obtained by image analysis, 12%, was in agreement with the calculated value by Carman-Kozeny equation using permeate flow measurements.

صنایع نساجی و رنگرزی یکی از صنایع مهم و پایه در هر کشوری است. رنگ‌های راکتیو محلول در آب به‌دلیل درخشندگی زیاد، مصرف انرژی کم و روش‌های کاربردی ساده، یکی از مهم‌ترین گروه رنگ‌های مورد استفاده در فرایند رنگرزی در صنعت نساجی هستند. پساب حاوی رنگ‌هایی مانند NB21 برای اکوسیستم و سلامت عمومی خطرناک است و لازم است قبل از ورود پساب به اکوسیستم، رنگ‌های موجود در آن با روشی حذف شوند. فرایند فتوکاتالیستی یکی از فرایندهای اکسیداسیون پیشرفته است که توانایی آن برای حذف انواع ترکیبات سمی و سخت تجزیه‌پذیر اثبات شده است. در این پژوهش نانوذرات اکسید روی از محلول خالص‌سازی شده حاصل از پسماند کارخانه ذوب روی بافق به‌دست آمد. نانوذره به‌دست آمده توسط دستگاه‌های مختلفی بررسی و آنالیز شد. تشکیل، خلوص و خواص نوری نانوذرات اکسید روی توسط طیف‌سنج مادون قرمز بررسی شد. در نهایت این نانوساختارها به‌منظور بررسی خواص فتوکاتالیستی آنها، حذف رنگ راکتیو NB21 و بررسی سه پارامتر غلظت رنگ، pH و میزان نانوذره بر رنگ‌بری آن، تحت پرتو UV، به‌کار برده شدند. نتایج الگوهای پراش پرتو ایکس، نشان‌دهنده ساختار ورتزیت و شش وجهی ...

h i g h l i g h t s • CLEA-Lac was recycled by a MF membrane without a significant loss of activity. • There was a clear synergistic effect between the CLEA-Lac and the MF membrane. • HBR achieved more than 90% eliminations of the three selected pharmaceuticals. • HBR could be used as an innovative bioprocess to eliminate micropollutants.

In this study, the removal of bisphenol A (BPA) by laccase in a continuous enzymatic membrane reactor (EMR) was investigated. The effects of key parameters, namely, type of laccase, pH, and enzyme activity, were initially evaluated. Once optimal conditions were determined, the continuous removal of the pollutant in an EMR was assessed in synthetic and real biologically treated wastewaters. The reactor configuration consisted of a stirred tank reactor coupled to a ceramic membrane, which prevented the sorption of the pollutant and allowed the recovery and recycling of laccase. Nearly complete removal of BPA was attained under both operation regimes with removal yields above 94.5 %. In experiments with real wastewater, the removal of BPA remained high while the presence of colloids and certain ions and the formation of precipitates on the membrane potentially affected enzyme stability and made necessary the periodic addition of laccase. Polymerization and degradation were observed as probable mechanisms of BPA transformation by laccase.

Enzymatic treatments based on oxidative enzymes, such as peroxidases, laccases and tyrosinases, have been proposed as an alternative to conventional methods to remove a broad range of contaminants present in wastewater. The aim of this study is to discuss existing technologies for the removal of pollutants based on the use of oxidative enzymes, including a discussion on the most important factors affecting the efficiency of the proposed systems. Factors involved in the catalytic cycle of the enzyme (biocatalyst, substrates and mediators), the addition of certain components to the reaction medium (additives, surfactants or solvents) as well as operational parameters (temperature, pH or agitation) will be discussed. Finally, two types of reactors: onestage and two-stage enzymatic membrane reactors, especially designed for the treatment of micropollutants present in secondary effluents, will be described in detail. ARTICLE HISTORY

The aim of this thesis is to study and compare effect of each certain water quality indicator to water treatment energy consumption. Also, determination of kinds of equipment which are the most exposed of those parameters change. This thesis describes the basic technological processes of water treatment. For research there were considered various Russian water treatment equipment. The graphical dependences of water quality indicators changes and energy consumption were constructed. The results of this study can be used for energy audits at various pulp and paper mills' water treatment installations and in other industries ones such as energy sector for example.

The aim of this thesis is to study and compare effect of each certain water quality indicator to water treatment energy consumption. Also, determination of kinds of equipment which are the most exposed of those parameters change. This thesis describes the basic technological processes of water treatment. For research there were considered various Russian water treatment equipment. The graphical dependences of water quality indicators changes and energy consumption were constructed. The results of this study can be used for energy audits at various pulp and paper mills' water treatment installations and in other industries ones such as energy sector for example.

Vysoká škola báňská-Technická univerzita Ostrava, Fakulta bezpečnostního inženýrství, Katedra bezpečnostního managementu. Disertační práce se zabývá problematikou mísení znečištění v povrchových vodách z bodového zdroje od místa úniku/vypouštění až k místu, kde je koncentrace polutantu spojitá v celém příčném úseku toku. Experimentálně byl na různých typech toků v České republice ověřen rozsah mísící zóny pomocí vhodné metody a následně porovnán s výpočtovými postupy autorů, kteří se touto problematikou zabývali. Pomocí Českého imisního testu byla predikována oblast překračování norem environmentální kvality a oblast možného chronického a akutního účinku na vodní organismy vlivem modelových případů úniku závadné látky do toku. Hlavním výstupem práce je metodický postup pro vymezování mísící zóny v podmínkách ČR. Zjištěné poznatky a výstupy práce jsou využitelné pro zlepšení havarijního managementu.

The National Egyptian Agenda 2030 recently adopted the concepts of sustainable cities, mitigating and adapting to climate change. This study responded to these concepts by treating sewage to reuse it in softscaping and recycling sludge to reduce energy consumption and support heating systems by producing biogas. Of the limitations of this study, it focuses on a compound to propose a model to increase the sustainability of Egyptian cities. This study used many technologies, such as biological treatment processes, activated sludge, trickling filters, and fixed bioreactors. However, Membrane bioreactors (MBRs) have seemed to be the most suitable technology because of their low cost and footprint. Additionally, a pilot laboratory was established to simulate the sewage treatment plant. It consisted of a primary sedimentation tank followed by an MBR tank and a chlorine disinfection tank, where the sludge was fed into a cylindrical anaerobic digester. The amount of sludge collected generat...

En el presente artículo se revisan las distintas clases de contaminantes emergentes, su origen y uso, y su presencia en las cuencas españolas, tanto en aguas superficiales como subterráneas. Los microcontaminantes emergentes son compuestos de distinto origen y naturaleza que hasta ahora habían pasado inadvertidos debido a su baja concentración (en el orden de las ppb) y sobre los que no hay regulación específica. Están divididos en seis grandes grupos y muchos de ellos se comportan como disruptores endocrinos, provocando efectos negativos sobre la salud humana y el medio ambiente. Se encuentran presentes en las aguas ya que las plantas de tratamiento de aguas residuales no están diseñadas para su eliminación, por lo que están siendo vertidos. Se discuten las distintas alternativas para su eliminación-tratamiento físico-químicos, biológicos y tecnologías híbridas-, destacando dentro de los procesos físico-químicos el empleo de procesos avanzados de oxidación (AOPs) que están resultando muy prometedores.

Enzymatic treatments based on oxidative enzymes, such as peroxidases, laccases and tyrosinases, have been proposed as an alternative to conventional methods to remove a broad range of contaminants present in wastewater. The aim of this study is to discuss existing technologies for the removal of pollutants based on the use of oxidative enzymes, including a discussion on the most important factors affecting the efficiency of the proposed systems. Factors involved in the catalytic cycle of the enzyme (biocatalyst, substrates and mediators), the addition of certain components to the reaction medium (additives, surfactants or solvents) as well as operational parameters (temperature, pH or agitation) will be discussed. Finally, two types of reactors: onestage and two-stage enzymatic membrane reactors, especially designed for the treatment of micropollutants present in secondary effluents, will be described in detail. ARTICLE HISTORY

Undoubtedly, the activated sludge process is one of the most common methods of biological wastewater treatment. Among the most common problems of activated sludge process systems is bulking of sludge (bulking). More than 50% of activated sludge wastewater treatment plants worldwide constantly or occasionally face this problem. In this case, the relative density of the flocs is low. It causes inappropriate sedimentation in secondary ponds and causes problems such as reducing treatment efficiency and imposing additional costs in the treatment and disposal of excess activated sludge. The current study, which was carried out on a laboratory scale (pilot) in the refinery unit of Shahid Tondgoyan Petrochemical Company, to investigate the factors affecting the creation of bulking. Factors include process parameters such as adjusting the ratio of input feed to microorganism (F/M), microorganism concentration, supply of nitrogen and phosphorus nutrients, dissolved oxygen, temperature, pH, and the use of cationic polyelectrolyte coagulant to improve the sedimentation rate of activated sludge. The optimal parameters in the amount of sedimentation are F/M equal to 0.35, MLSS in the range of ppm 2500 to 3000 ppm, nitrogen, and phosphorus nutrients relative to the amount of pollution (COD/N/P) in the range of 100/4/1 until 100/5/1, dissolved oxygen 2 to 3 mg/L, temperature 25-35 °C, pH range 8.5 and in the dose of 4.8 mg/gr TSS/L of cationic polyelectrolyte coagulant in 180 min. In general, by adjusting the process parameters in the indicated range, the amount of SVI can be controlled in the desired range of close to 150 mg/L.

Disertační práce s názvem "Analýza využití matoliny pro separaci semen a energetické účely" je zaměřena na problematiku účelného využití matoliny (výlisků z hroznů) pro separaci semen a energetické účely. Experimentální měření byla prováděna v období 2013-2015 u vzorků matoliny odebíraných u vinohradnických subjektů ve vinařské oblasti Morava. Výsledky práce jsou rozděleny do dvou hlavních částí-separace semen révy z matolin a využití matolin pro energetické účely. Hodnocení účinnosti separačního procesu bylo prováděno nejprve experimentálně v laboratorních podmínkách pomocí sít o definované velikosti otvorů, následně byla účinnost ověřena na prototypu vibračních rovinných sít. Ze získaných výsledků vyplývá, že se v závislosti na odrůdě účinnost separace pohybovala mezi 58,35-94,12 %. Výtěžnost semen je přitom 6,00-49,71 %. Zajímavou oblast využití matolin představuje bioenergetika. Z těchto důvodů byla provedena řada kalorimetrických měření za účelem stanovení spalného tepla a výhřevnosti matoliny v původním stavu, matoliny po odseparování semen (předpoklad jejich využití pro lisování oleje) a semen samotných. Z výsledků měření vyplývá, že se výhřevnost pohybuje mezi 18,61-21,14 MJ.kg-1. Nejvyšší hodnoty výhřevnosti byly stanoveny u samotných semen a matoliny v původním stavu. Lze předpokládat, že hlavním důvodem je poměrně vysoký obsah olejnaté složky v semenech révy vinné. Soubor měření byl navíc doplněn výsledky zaměřenými na využití matoliny při výrobě pelet. Jako vstupní suroviny byly využity různé poměry vysušené matoliny v kombinaci se senem a révím. Z naměřených hodnot vyplývá, že nejvyšší výhřevnost (19,22 MJ.kg-1) mají pelety složené z 60 % matoliny, 20 % réví a 20 % sena. Jejich sypná objemová hmotnost je 630,9 kg.m-3. Z hlediska mechanické odolnosti dle normy ČSN EN 15210-2 pelety vyrobené s uvedeným poměrem surovin vyhovují. Výsledky práce jsou rozšířeny také o soubor modelových výpočtů nákladovosti, která se při definovaných podmínkách pohybuje na úrovni 3,59-3,92 Kč za 1 kilogram pelet.

Removal of micropollutants from wastewaters is crucial to ensure safe water reuse and protect natural watercourses. Although membrane bioreactors (MBRs) yield improved degradation of organic compounds, hydraulic retention times are often too short to satisfy acceptable removal rates of recalcitrant organics. Often, results regarding micropollutant removal in treatment plants are susceptible to uncontrolled feed concentrations, which are concomitant to seasonality and consumer habits. In this work, we investigate the concentration transients of four selected pesticides (carbendazim, diuron, 2,4-D and atrazine), which were constantly dosed to a MBR pilot plant treating high-strength industrial effluents (COD values). In addition to the regular MBR operation, two feasible means of extending pesticide retention in bioreactors were evaluated: (i) addition of small concentrations of powdered activated carbon (PAC) into the activated sludge and (ii) coupling of the PAC-assisted MBR and a reverse osmosis unit (RO) with recirculation of the retentate. The aim of this work is to provide reliable information on the fate of micropollutants within wastewater treatment plants using different configurations under controlled feed conditions. Results have shown that carbendazim was the only pesticide efficiently (>80%) removed during regular MBR operation, which has been attributed to the presence of electron donating groups attached to its aromatic ring structure. Improved retention of diuron by addition of PAC enhanced its long-term removal, whereas the effect of PAC addition on the removal of 2,4-D and atrazine was only temporary, thus being mainly attributed to an adsorption effect. Additionally, the function of PAC as platform for biofloc formation limited sludge production and slowed down membrane fouling, further improving the general performance of the MBR. The MBR-RO hybrid process was the most effective one in increasing the residence time of pesticides in the bioreactor, regardless of their functional groups and properties, thus facilitating a generalized removal of micropollutants.

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This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Increasing awareness of the finite resources of the planet, including its environmental quality, constitutes a powerful driver for industries and governments not only to fight the effects of pollution but to avoid it at the source. Demands are mounting to replace conventional industrial processes by less-or non-polluting ones. During this gradual shift the treatment of wastes from current human activities and as a legacy of our industrial history remains a challenge. As these treatments merge with environmentally benign industrial processes a truly sustainable economy will become a reality. Enzymes or whole-cell biocatalysts in industrial processes are linked to lower consumption of energy and chemicals and are thus "green" agents. Enzymes catalyze specific reactions under moderate conditions hence they are instrumental for the selective removal of pollutants from waste streams. Enzyme specificity also precludes undesired sidereactions, while in some cases the pollutants treated could be transformed into added-value products, as illustrated in the waste biorefinery concept. The power of such biocatalysts is demonstrated in the case of emerging organic contaminants (EOCs) such as pharmaceuticals and personal care products (PPCPs), which affect treated and untreated water and associated matrices like sludges and sediments at very low but environmentally relevant concentrations ("micropollutants") through unwanted biological effects like endocrine disruption. Oxidative enzymes like fungal laccases and peroxidases are promising biocatalysts for the transformation and re...

The aim of this study is a summary of problems dealing with microbial pollution of flowing surface waters in the Czech Republic. Limits of counts of indicator microorganisms in current legislation and technical standards are presented, together with characteristics of the mostly used indicators of faecal pollution and methods of their detection. The paper is intended for workers, engaged in the evaluation of microbiological results and the water quality.

Klíčová slova: COVID 19-SARS-CoV-2-odpadní voda-povrchová voda-kontaminaceepidemiologický přístup k odpadním vodám-nástroj včasného varování-biomarker SOUHRN Příspěvek přináší aktuální přehledné informace o virech a koronavirech včetně SARS-CoV-2, možnostech kontaminace povrchových a odpadních vod tímto virem, způsobu jeho stanovení ve vodách metodou RT-qPCR a využití monitoringu přítomnosti viru v odpadních vodách jako biomarkeru pro sledování jeho výskytu v populaci a jako nástroje včasného varování před případným nástupem nové vlny choroby.

The purpose of this review work is to give an overview of the research reported on bioprocesses for the treatment of domestic or industrial wastewaters (WW) containing pharmaceuticals. Conventional WW treatment technologies are not efficient enough to completely remove all pharmaceuticals from water. Indeed, these compounds are becoming an actual public health problem, because they are more and more present in underground and even in potable waters. Different types of bioprocesses are described in this work: from classical activated sludge systems, which allow the depletion of pharmaceuticals by bio-degradation and adsorption, to enzymatic reactions, which are more focused on the treatment of WW containing a relatively high content of pharmaceuticals and less organic carbon pollution than classical WW. Different aspects concerning the advantages of membrane bioreactors for pharmaceuticals removal are discussed, as well as the more recent studies on enzymatic membrane reactors to the depletion of these recalcitrant compounds.

A filtration devise was developed to assess compressibility of fouling layers in membrane bioreactors. The system consists of a flat sheet membrane with air scouring operated at constant transmembrane pressure to assess the influence of pressure on resistance of fouling layers. By fitting a mathematical model, three model parameters were obtained; a back transport parameter describing the kinetics of fouling layer formation, a specific fouling layer resistance, and a compressibility parameter. This stands out from other on-site filterability tests as model parameters to simulate filtration performance are obtained together with a characterization of compressibility. Tests on membrane bioreactor sludge showed high reproducibility. The methodology's ability to assess compressibility was tested by filtrations of sludges from membrane bioreactors and conventional activated sludge wastewater treatment plants from three different sites. These proved that membrane bioreactor sludge sho...

Anaerobic membrane bioreactors (An-MBRs) are a proven technology in wastewater treatment. However, the operation of anaerobic membrane bioreactors (An-MBRs) is inevitably plagued by membrane fouling due to the action of foulants that hinders its effectiveness. Among the foulants, extracellular polymeric substances (EPS) had been identified as the major contributor towards membrane fouling, which suggest that controlling EPS production is crucial towards membrane fouling reduction. Polysaccharide and protein are the two recognized major components of EPS. This explains why in this research, polysaccharide and protein concentrations were used to measure the presence of EPS in the bioreactors. Microbe activator was added into the anaerobic membrane bioreactor (An-MBR) under different dilution factors to assess their efficiencies in promoting the performance of An-MBRs in terms of EPS and membrane fouling control. The An-MBR that was added with 1/500 dilution of microbe activator showed the highest chemical oxygen demand removal efficiency which is 79.47% ± 2.76%, while the other 3 An-MBRs with 1/125 dilution, 1/1,000 dilution and without added with microbe activator had removal efficiencies of 55.09% ± 4.25%, 56.42% ± 3.36% and 53.49% ± 4.09%, respectively. The bioreactors added with microbe activator with the dilution of 1/500 also achieved the highest EPS removal efficiency mainly in terms of polysaccharides. Also, it had the lowest membrane fouling rate during membrane filtration among the An-MBRs. It is speculated that the introduction of suitable doses of microbe activator would contribute a suitable amount of light metal cations into the bioreactor. Right concentration of light metal cations could enhance microbial activities which may help to control EPS productions. For other dilution factors, the performance of An-MBR was not enhanced. This may be due to the excessive or too little concentration of microbe activator would not improve the performance of An-MBR.

This article presents a literature review on developments of membrane reactors for biological waste gas treatment as well as examples of applications to different compounds. The use of membranes combines selective separation of compounds from a waste gas stream followed by biological removal. Gas transport phenomena and different types of membranes used in biological waste gas treatment are discussed. So far, membrane-based biological waste gas treatment has only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, membrane bioreactor technology can be useful in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with conventional methods for biological waste gas treatment.

Import 11/07/2012Tato bakalářská práce se zabývá možnostmi kompostování s využitím kalů z ČOV. V první části práce jsou popsány vlastnosti čistírenských kalů z hlediska stabilizace a hygienizace kalu jako produktu při čištění odpadních vod. Další část práce shrnuje možnosti využití těchto kalů, způsoby a vývoj nakládání s čistírenskými kaly v České republice a ve světě. Následuje hodnocení obsahu živin přítomných v kalech a dále se práce zaměřuje na technologii využití kalů kompostováním, kde jsou popsány podmínky a průběh správného kompostovacího procesu, jednotlivé kompostovací technologie a možnosti následného využití kompostů s obsahem čistírenských kalů.This thesis deals with the possibilities of using sludge from wastewater treatment plants on composting. The first part describes the properties of sewage sludge in terms of stabilization and hygienization of sludge as a product of waste water treatment. Next part of this thesis summarizes the use of sludge and describes methods...

A membrane bioreactor (MBR) system based on a dead-end immersed hollow fiber membrane and filamentous fungus Aspergillus oryzae were used for treatment of baker’s yeast wastewater. The fungus was adapted to the wastewater in the bioreactor for two weeks before starting the continuous process. Average organic loading rate of 4.2 kg COD/m3.d was entered the bioreactor. MBR system was able to reduce the COD and BOD5 of the wastewater from 5000 and 1400 mg/L to 488 and 70 mg/L, respectively, over a period of 45 days, while the turbidity of the wastewater reduced from 134-282 NTU to less than 2.5 NTU in the permeate stream. Critical flux and a suitable operating flux were determined as 6.7 and 5 L/m2 h, respectively. The obtained results confirm that the MBR system was able to efficiently reduce the turbidity and suspended solid of the wastewater by 99.4% and 98.3%, respectively, resulting in a clear effluent.

This article presents a literature review on developments of membrane reactors for biological waste gas treatment as well as examples of applications to different compounds. The use of membranes combines selective separation of compounds from a waste gas stream followed by biological removal. Gas transport phenomena and different types of membranes used in biological waste gas treatment are discussed. So far, membrane-based biological waste gas treatment has only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, membrane bioreactor technology can be useful in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with conventional methods for biological waste gas treatment.

This study first illustrates the IEMB potential for the simultaneous removal of nitrate, perchlorate and bromate from drinking water. The removal of each of these pollutants to concentrations below the recommended levels for drinking water was successfully achieved. The initial development of the IEMB concept for the case of ionic mercury removal is then presented and discussed. For this purpose, appropriate cation exchange membranes were selected, and a suitable mixed microbial culture, capable of converting ionic mercury into elemental mercury, was obtained.

This article presents a literature review on developments of membrane reactors for biological waste gas treatment as well as examples of applications to different compounds. The use of membranes combines selective separation of compounds from a waste gas stream followed by biological removal. Gas transport phenomena and different types of membranes used in biological waste gas treatment are discussed. So far, membrane-based biological waste gas treatment has only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, membrane bioreactor technology can be useful in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with conventional methods for biological waste gas treatment.

Laccase (EC 1.10.3.2) and tyrosinases (EC 1.14.18.1) are ubiquitous enzymes present in nature as they are known to originate from bacteria, fungi, plants, etc. Both laccase and tyrosinase are copper-containing phenoloxidases requiring readily available O2 without auxiliary cofactor for their catalytic transformation of numerous phenolic substrates. In the present study, laccase and tyrosinase have been insolubilized as combined crosslinked enzyme aggregates (combi-CLEA) using chitosan, a renewable and biodegradable polymer, as crosslinker. The combi-CLEA, with specific activity of 12.3 U/g for laccase and 167.4 U/g for tyrosinase, exhibited high enzymatic activity at pH5-8 and temperature at 5-30°C, significant resistance to denaturation and no diffusional restriction to its active site based upon the Michaelis-Menten kinetic parameters. Subsequently, the combi-CLEA was applied to the transformation of acetaminophen as a model phenolic compound in samples of real wastewaters in orde...

The aim of this article is to introduce partial sections of the research projects TA02020128 and TA02021032 (Technology Agency of the Czech Republic). These parts of the projects pay attention to the issue of quality of sludge and other wastes produced in wastewater treatment plants (WWTP) using activated sludge process, anaerobic processes (including septics) and extensive (natural) wastewater treatment plants (with horizontal subsurface flow reed-beds), which also include mechanical pre-treatment.