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1

Optimizing the MBBR System and Integrating Nanoparticles to Improve Wastewater Treatment Efficiency

Eid Ahmed, El-sayed Abd-Elaziz, Ayoub Mohamed, El-Morsy Ahmed

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 2

218--229

EN

Wastewater treatment faces a growing challenge in removing nutrients and organic matter. This study aimed to evaluate the effectiveness of the moving bed biofilm reactor (MBBR) system in removing nutrients and organic from municipal wastewater. The impact of different carrier filling ratios and hydraulic retention times (HRT) on the removal efficiency was systematically investigated. Moreover, the addition of nanoparticle additives to enhance system performance was evaluated. The optimal conditions for the MBBR system were 30–45% filling ratios and a 10-hour HRT, resulting in maximum removal efficiencies for biological oxygen demand (BOD5), chemical oxygen demand (COD) and ammonia (NH4 + -N) with a percentage of 85.23%, 81.69%, and 54.45% respectively. Furthermore, adding nanoparticles improved the BOD5 and COD removal efficiencies by 6.6% and 8.0% respectively, compared to the MBBR system without nanoparticles.

2

Performance of Compact Bio-Contact Oxidation Reactors for Municipal Wastewater Treatment Under Different Hydraulic Retention Time

Awad Ameera Mohamad, Ibrahim Husham T., Al-Aboodi Ali H.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 12

304--318

EN

This study employed a laboratory-scale continuous upflow bio-contact oxidation reactor to treat 50 L/day of municipal wastewater in Al Rumaitha City, located north of Al Muthanaa Province in Iraq. The reactor configuration consisted of two anoxic-aerobic reactors nested inside each other, with a 1:3 volume ratio of anoxic to aerobic zones. Both the anoxic and aerobic reactors were loaded with K1 bio-media, filling them to 50% capacity for fixing and preserving the biomass. The reactors were operated in a mode that achieved full nitrification-denitrification without any sludge return, relying solely on internal recycling from the aerobic to the anoxic reactor. After biofilm formation on the carriers, three distinct hydraulic retention times (HRTs) were investigated – ranging from 24 to 12 hours – to evaluate their impact on removing biological nutrients from municipal sewage. In this operational approach, the preferred internal recycle ratio and gas/water ratio for effective nitrogen removal were a complete feed rate recycle of 100% and a ratio of 1:5, respectively. The experiment results highlighted that a 24-hour hydraulic retention time was most suitable for the simultaneous removal of organic carbon (COD) and nutrients. During this period, average removal efficiencies were found to be 93.51% for COD, 94.50% for ammonium (NH4+), 60.98% for total nitrogen (TN), and 67.57% for total phosphorus (TP). Furthermore, the aerobic bio-contact oxidation reactors maintained an average dissolved oxygen (DO) concentration of 4.89 mg/L. In contrast, the anoxic bio- contact oxidation reactors exhibited a lower average DO concentration of 0.38 mg/L.

3

Krystalizacja struwitu i hydroksyapatytu w procesie usuwania związków biogennych na złożu filtracyjnym

Wąsik E., Bugajski P., Chmielowski K., Nowak A., Mazur R.

Przemysł Chemiczny

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2017

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T. 96, nr 8

1739--1743

PL

Przeprowadzono badania, mające na celu określenie, jakie zjawiska wpływają na usuwanie azotu amonowego i fosforanów podczas filtracji ścieków przez złoże w warunkach zmiennego hydraulicznego czasu zatrzymania HRT. Stwierdzono, że podstawą usuwania tych związków w złożu z naturalnym wypełnieniem (wyprażoną opoką) nie była biofiltracja, lecz procesy chemiczne. Zaobserwowano tworzenie się kryształów struwitu oraz hydroksyapatytu zarówno na powierzchni, jak i wewnątrz filtru, co było przyczyną bardzo wysokiej efektywności usuwania jonów N-NH4+ oraz PO43- i bakterii grupy coli. Badania mikroskopowe próbek osadu powstałego na powierzchni złoża, czyli w miejscu, gdzie dopływały ścieki, oraz wewnątrz filtru potwierdziły powstawanie kryształów fosforanu amonowo-magnezowego oraz apatytu.

EN

The N-NH4+ and PO43- ions and coli bacteria-contg. preliminary purified sewage was filtered through CaO beds (for up to 192 h) and studied for formation of struvite and hydroxyapatite crystals to det. the removal degree of the contaminations. The N-NH4+ ions were removed in 96.8%, the PO43-ions in 99.8% and coli bacteria in 100%.

4

Effect of Hydraulic Retention Time and Filling Time on Simultaneous Biodegradation of Phenol, Resorcinol and Catechol in a Sequencing Batch Reactor

Thakur C., Mall I. D., Srivastava V. C.

Archives of Environmental Protection

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2013

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Vol. 39, no. 2

69--80

EN

In the present study, treatment of synthetic wastewater containing phenol, resorcinol and catechol was studied in a sequencing batch reactor (SBR). Parameters such as hydraulic retention time (HRT) and filling time have been optimized to increase the phenol, resorcinol, catechol and chemical oxygen demand (COD) removal efficiencies. More than 99% phenol, 95% resorcinol and 96% catechol and 89% COD removal efficiency was obtained at optimum conditions of HRT = 1.25 d and fill time = 1.5 h. The heating value of the sludge was found to be 12 MJ/kg. The sludge can be combusted to recover its energy value.

5

Moving bed technology as an alternative solution for reducing bioreactor volume

Żubrowska-Sudoł M.

Environment Protection Engineering

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2012

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Vol. 38, nr 3

15--22

EN

Impact of the amount of moving bed in the continuous flow bioreactor on the required bioreactor volume has been investigated with respect to conventional activated sludge bioreactors preceded with primary sedimentation or chemical precipitation. The investigation has been carried out for a fictitious plant of the size of 1999 people equivalent (PE). It was found that for the systems designed for removal of organic matter: the volume of the integrated fixed film activated sludge (IFAS) reactor with the 15% filling ratio is similar to the volume of the activated sludge reactor (ASR) preceded with primary settlement tanks operating at 2.0 h hydraulic retention time (HRT). The volume of the IFAS reactor with the 30% filling ratio is comparable with the volume of the ASR reactor preceded with an upstream chemical precipitation stage assumed to achieve 60% removal of organics.

6

The application of UASB reactor in meat industry wastewater treatment

Kwarciak-Kozłowska A., Bohdziewicz J., Mielczarek K., Krzywicka A.

Civil and Environmental Engineering Reports

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2011

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No. 7

119-128

EN

The meat industry is a branch of the food sector, which significantly affects the degradation of the environment. Consuming large amounts of water consequently produces significant quantities of water which are characterised by a high organic content and high concentration of suspended solids, inorganic salts and nutrients. The study attempted to determine the influence of the HRT and OLR on biogas production and the treatment of wastewater from the meat industry, and it was found that the most preferred treatment process carried out was at HRT 3d (OLR-0.55 kgCOD/m3d). The anaerobic process under HRT 3d obtained a considerable degree of the removal of organic pollutants from raw wastewater designated as COD (79%), BOD (77%) and TOC (73%). The concentrations of COD and BOD were 350 mg/dm3 and 363 mg/dm3 respectively. The value of TOC reached a level of 142 mg/dm3. Due to its poor quality, effluent from a UASB reactor cannot be discharged into natural water without additional treatment processes. The addition of reverse osmosis in the meat industry wastewater treatment is suggested.

PL

W badaniach podjęto próbę określenie wpływu czasu zatrzymania ścieków z zakładu mięsnego w reaktorze UASB na efektywność ich oczyszczania oraz na wielkość dobowej produkcji biogazu. HRT zmieniano w zakresie od 2 do 6 dób co wiązało się ze zmianą obciążenia komory ładunkiem zanieczyszczeń z 0,27 kgChZT/m3d do 0,82 kgChZT/m3d. Stwierdzono, że wraz ze skracaniem czasu zatrzymania z 6d do 2d, jakość ścieków ulega pogorszeniu, ale ilość produkowanego biogazu zwiększała się. Zaobserwowano, że wielkość współczynnika biogazu ulegała obniżeniu. Stwierdzono, że najkorzystniej prowadzić proces oczyszczania badanych ścieków przy HRT równym 3 doby z uwagi na dobre efekty oczyszczania i wysoki współczynnik produkcji biogazu wynoszący 0,45 dm3 biogazu/gChZT_us. Prowadzenie procesu fermentacji przy tak ustalonych warunkach pozwoliło na wysoki stopień usunięcia zanieczyszczeń oznaczanych, jako ChZT (79%), BZT5 (77%) i OWO (73%). Stężenie ChZT ścieków oczyszczonych wynosiło 350 mg/dm3, BZT5 463mg/dm3 a OWO 142 mg/dm3. Pomimo wysokiego stopnia usunięcia zanieczyszczeń z badanych ścieków nie ma jednak możliwości odprowadzenia ich do odbiornika naturalnego. Proponuje się, aby w kolejnych etapach badań podjąć próbę doczyszczania ścieków w procesie odwróconej osmozy co w przyszłości może pozwolić na zamknięcie obiegu wody na terenie zakładu.