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•Membrane-based treatments and AOP combination was assessed for wastewater reclamation.•MBR and MBBR-MBR can regenerate wastewater with highest quality set in ...2018/0169/COD.•Pharmaceuticals in urban wastewater can be completely removed using MBBR-MBR + AOP.•The heterotrophic kinetics of biomass is affected by the presence of pharmaceuticals.
This research was performed to assess the production of reclaimed water from urban wastewater in membrane bioreactor – advanced oxidation process (MBR-AOP) and moving bed biofilm reactor – membrane bioreactor – advanced oxidation process (MBBR-MBR-AOP) combined treatments to study the effect of biofilm incorporation. Both combined treatments were operated at the same conditions (10 h of hydraulic retention time, 6500 mg/L of mixed liquor suspended solids and 25 mg/L of hydrogen peroxide dosage over 15 min). Additionally, the removal capacity of some pharmaceuticals (carbamazepine, ciprofloxacin and ibuprofen) and their impact on the kinetic behaviour of the biomass in both systems were evaluated. From the results, it was found a membrane-based bioreactor can achieve both wastewater secondary treatment and pre-treatment for advanced oxidation process, so both MBR-AOP and MBBR-MBR-AOP treatments have a great potential to produce high quality reclaimed water (biological oxygen demand <0.5 mgO2/L, suspended solids <1 mg/L, turbidity <1 NTU and no presence of E. coli), according to European Commission proposal 2018/0169/COD. The addition of carriers improved the biodegradation of the most persistent pharmaceuticals in the biological treatment (from 69.20 ± 1.54% to 75.14 ± 2.71% for carbamazepine and from 60.41 ± 2.16 to 63.14 ± 2.70% for ciprofloxacin). It had, as a consequence, the MBBR-MBR-AOP system showing a complete degradation of pharmaceuticals after 5 min AOP treatment compared to the MBR-AOP system. The loss of biomass in the MBR-AOP (from 5233.45 to 4451.92 mg/L) and the increase of the substrate degradation rate for organic matter in both treatments (from 37.27 to 41.42 and from 30.25 to 33.19 mgO2/(L·h) in MBR-AOP and MBBR-MBR-AOP, respectively) are some of the consequences of pharmaceuticals in urban wastewater.
•Resource recovery from urban wastewater to promote shift towards a circular economy.•Pilot and full-scale studies show MBBR as suitable system for treated wastewater reuse.•Numerous methods ...developed for nutrient recovery from WWTP’s effluents.
Over the last years, an increasing concern has emerged regarding the eco-friendly management of wastewater. Apart from the role of wastewater treatment plants (WWTPs) for wastewater and sewage sludge treatment, the increasing need of the recovery of the resources contained in wastewater, such as nutrients and water, should be highlighted. This would allow for transforming a wastewater treatment plant (WWTP) into a sustainable technological system.
The objective of this review is to propose a moving bed biofilm reactor (MBBR) as a novel technology that contributes to the circularity of the wastewater treatment sector according to the principles of circular economy. In this regard, this paper aims to consider the MBBR process as the initial step for water reuse, and nutrient removal and recovery, within the circular economy model.
An integrated interpretation of the late Paleozoic structural and geochronological record of the Iberian Massif is presented and discussed under the perspective of a Gondwana-Laurussia collision ...giving way to the Variscan orogen. Compressional and extensional structures developed during the building of the Variscan orogenic crust of Iberia are linked together into major tectonic events operating at lithosphere scale. A review of the tectonometamorphic and magmatic evolution of the Iberian Massif reveals backs and forths in the overall convergence between Gondwana and Laurussia during the amalgamation of Pangea in late Paleozoic times. Stages dominated by lithosphere compression are characterized by subduction, both oceanic and continental, development of magmatic arcs, (over- and under-) thrusting of continental lithosphere, and folding. Variscan convergence resulted in the eventual transference of a large allochthonous set of peri-Gondwanan terranes, the Iberian Allochthon, onto the Gondwana mainland. The Iberian Allochthon bears the imprint of previous interaction between Gondwana and Laurussia, including their juxtaposition after the closure of the Rheic Ocean in Lower Devonian times. Stages governed by lithosphere extension are featured by the opening of two short-lived oceanic basins that dissected previous Variscan orogenic crust, first in the Lower-Middle Devonian, following the closure of the Rheic Ocean, and then in the early Carboniferous, following the emplacement of the peri-Gondwanan allochthon. An additional, major intra-orogenic extensional event in the early-middle Carboniferous dismembered the Iberian Allochthon into individual thrust stacks separated by extensional faults and domes. Lateral tectonics played an important role through the Variscan orogenesis, especially during the creation of new tectonic blocks separated by intracontinental strike-slip shear zones in the late stages of continental convergence.
Moving bed biofilm reactor to treat wastewater Leyva-Díaz, J. C.; Martín-Pascual, J.; Poyatos, J. M.
International journal of environmental science and technology (Tehran),
04/2017, Letnik:
14, Številka:
4
Journal Article
Recenzirano
This review carries out a comparative study of advanced technologies to design, upgrade and rehabilitate wastewater treatment plants. The study analyzed the relevant researches in the last years ...about the moving bed biofilm reactor process with only attached biomass and with hybrid biomass, which combined attached and suspended growth; both could be coupled with a secondary settling tank or microfiltration/ultrafiltration membrane as a separation system. The physical process of membrane separation improved the organic matter and NH
4
+
-N removal efficiencies compared with the settling tank. In particular, the pure moving bed biofilm reactor–membrane bioreactor showed average chemical oxygen demand, biochemical oxygen demand on the fifth day and total nitrogen removal efficiencies of 88.32, 90.84 and 60.17%, respectively, and the hybrid moving bed biofilm reactor–membrane bioreactor had mean chemical oxygen demand, biochemical oxygen demand on the fifth day and total nitrogen reduction percentages of 91.18, 97.34 and 68.71%, respectively. Moreover, the hybrid moving bed biofilm reactor–membrane bioreactor showed the best efficiency regarding organic matter removal for low hydraulic retention times, so this system would enable the rehabilitation of activated sludge plants and membrane bioreactors that did not comply with legislation regarding organic matter removal. As the pure moving bed biofilm reactor–membrane bioreactor performed better than the hybrid moving bed biofilm reactor–membrane bioreactor concerning the total nitrogen removal under low hydraulic retention times, this system could be used to adapt wastewater treatment plants whose effluent was flowed into sensitive zones where total nitrogen concentration was restricted. This technology has been reliably used to upgrade overloaded existing conventional activated sludge plants, to treat wastewater coming from textile, petrochemical, pharmaceutical, paper mill or hospital effluents, to treat wastewater containing recalcitrant compounds efficiently, and to treat wastewater with high salinity and/or low and high temperatures.
AbstractEmerging contaminants are a global concern, as Directive 2013/39/UE shows. Given the possible consequences that may lead to the presence of these compounds in water resources, different ...proposals are being evaluated to avoid their discharge into the environment. This study focuses on the use of a biological and physicochemical combined treatment formed by a membrane bioreactor with an H2O2/UltraViolet (UV) advanced oxidation process coupled subsequently to degrade contaminants of emerging concern in real urban wastewater. The membrane bioreactor operated at 16 h of hydraulic retention time and 4,250 mg/L of mixed liquor suspended solids. Different hydrogen peroxide dosages (25, 50, and 100 mg/L) were tested in the photoreactor at 20°C and the natural pH of the wastewater. Different initial concentrations of a mix of pharmaceuticals (carbamazepine, ciprofloxacin, and ibuprofen) were tested. Removal efficiencies obtained in the biological stage ranged from 66.23%–96.18%, 90.63%–100%, and 90.04%–96.48%, respectively. However, complete removal was achieved after the physicochemical stage when the concentrations of contaminants in the mix were similar to current concentration levels in urban wastewater.
•Residues from olive grove to produce ceramic bricks as a new environmental-friendly.•Modifying porosity behavior of clay bricks by adding organic residues.•Using lightweight bricks can solve the ...problem of energy efficiency in construction.•New ceramic products with higher added value and lower environmental impact.
In the present study, residue from olive groves has been used for the manufacture of clay ceramic bricks as a new environmentally-friendly solution. For this purpose, waste products of olive cultivation, such as olive prunings, leaves and wood, were ground to obtain a particle size of 0–2 mm; 7.5%, 15% and 25% of olive waste was added to the clay, clay bodies were moulded in pastes with the incorporation of 7.5, 15 and 25% by volume of waste; and finally, the green bodies were fired at 850 °C. The influence of the type and ratio of waste on the physical and mechanical properties of waste clay bricks was studied and compared with clay bricks without waste following standard procedures. Ceramic samples were characterized using a series of technological tests, such as linear shrinkage, bulk density, apparent porosity, water absorption, suction, compressive strength and thermal conductivity. The best results were obtained from the samples containing 7.5% olive waste showing that these organic pore-forming wastes have the potential for producing lighter bricks that could be marketed as low density clay masonry units with adequate mechanical properties and higher thermal insulating capacity.
Bacteria are key players in biological wastewater treatments (WWTs), thus a firm knowledge of the bacterial population dynamics is crucial to understand environmental/operational factors affecting ...the efficiency and stability of the biological depuration process. Unfortunately, little is known about the microbial ecology of the advanced biological WWTs combining suspended biomass (SB) and attached biofilms (AB). This study explored in depth the bacterial community structure and population dynamics in each biomass fraction from a pilot-scale moving bed membrane bioreactor (MBMBR) treating municipal sewage, by means of temperature-gradient gel electrophoresis (TGGE) and 454-pyrosequencing. Eight experimental phases were conducted, combining different carrier filling ratios, hydraulic retention times and concentrations of mixed liquor total suspended solids. The bacterial community, dominated by Proteobacteria (20.9–53.8%) and Actinobacteria (20.6–57.6%), was very similar in both biomass fractions and able to maintain its functional stability under all the operating conditions, ensuring a successful and steady depuration process. Multivariate statistical analysis demonstrated that solids concentration, carrier filling ratio, temperature and organic matter concentration in the influent were the significant factors explaining population dynamics. Bacterial diversity increased as carrier filling ratio increased (from 20% to 35%, v/v), and solids concentration was the main factor triggering the shifts of the community structure. These findings provide new insights on the influence of operational parameters on the biology of the innovative MBMBRs.
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•Bacterial populations dynamics were analyzed in a moving bed membrane bioreactor.•Bacterial community was investigated by means of TGGE & 454-pyrosequencing.•Suspended biomass & attached biofilm showed similar diversity profiles.•Multivariate analysis linked community structure shifts to operating variables.•Solids concentration was the main factor explaining populations dynamics.
A hybrid moving bed biofilm reactor–membrane bioreactor (hybrid MBBR–MBR) system has been tested in this study at two scales to analyse the scale-up effect. Two municipal wastewater treatment plants ...were used, one at laboratory scale (hybrid MBBR–MBRL) with a reactor working volume of 24 l and one at pilot scale (hybrid MBBR–MBRP) with a reactor working volume of 358 l. Hybrid MBBR–MBRL and hybrid MBBR–MBRP showed that the hybrid MBBR–MBR systems used in this research were reliable for organic matter removal with COD removal percentages of 90.97±2.55% and 95.56±2.01% for hybrid MBBR–MBRL and hybrid MBBR–MBRP, respectively. In hybrid MBBR–MBRL, the sludge retention time was higher but the biofilm density was lower due to the wall effect, so the two effects cancelled one another out and the COD removal efficiencies were found to be similar. The study identified the most influential variables and their effects on the process. Hybrid MBBR–MBRL and hybrid MBBR–MBRP were influenced by the attached and suspended biomass and temperature, while the influent loading rate only affected hybrid MBBR–MBRP. On the whole, hybrid MBBR–MBRP showed a better performance from the point of view of the kinetics of the heterotrophic biomass, with values of YH=0.6130mgVSSmgCOD−1, μm,H=0.0146h−1, KS=9.8852mgO2L−1, and bH=0.0031h−1.
•Hybrid MBBR–MBR was reliable for COD removal (higher than 90.97±2.55%).•Hybrid MBBR presents a better kinetic behaviour and higher removal rate in pilot scale.•Variations of organic loading and temperature are two effects of the scale up.•The scale of working affects the sludge retention time and attached biomass.
Rare earth (RE) doped oxyfluoride glass ceramics possess interesting optical properties with applications in telecommunications and optoelectronics, such as solid state lasers, optical amplifiers, ...etc. These materials combine the transparency and mechanical and chemical resistance of aluminosilicate glasses with the low phonon energy and facile incorporation of RE ions in the fluoride crystals. The incorporation of RE ions in the crystalline phases enhances the laser emission intensity, a major property of these materials. Transparency is achieved when crystal size is in the nanometric scale, usually below 40 nm, which avoids light scattering. A strict control of the nucleation and crystal growth processes is therefore necessary which requires a deep knowledge of the crystallisation mechanisms. The great activity and publications in this field in the last decades merit a review providing a comparative study of the different nanoglass ceramic systems, their structural and optical characterisation and their main properties and applications. This is the objective of this review paper which includes 227 references. A general discussion on glass nucleation and crystallisation theories and more relevant crystallisation parameters and characterisation techniques are put forward in the first section of the review, focused on nanocrystallisation processes in oxyfluoride systems. In the second section, the principal RE doped glass ceramics are presented. After a general introduction about the luminescence processes, including up- and down-conversion, the behaviour of RE elements in glasses and crystals are discussed. Glass ceramic compositions have been divided as follows: glass ceramics with a glass composition following Wang and Ohwaki's oxyfluoride glass ceramic, and glass ceramics with different matrix compositions, arranged by crystalline phases. Relevant properties, mainly optical and laser, are described in each system along with the most relevant applications of these materials.
Metamorphic basements are usually considered rigid and isotropic at a large scale. However, basements contain inherited weaknesses that may potentially accommodate superimposed contraction (e.g., ...fault reactivation), and that favor fold nucleation (e.g., penetrative foliations). If these conditions are met, what could be the factors that impede the development of basement folds or their recognition? Actual basement folding is rarely documented, especially for large dimensions. Here we provide a case example, discussed from the perspective of structural analysis of surface data and sustained by geophysical data. The basement of the Spanish‐Portuguese Central System is defined by an Alpine mega‐fold (Hiendelaencina Antiform) that trends parallel to this mountain range and affects the basement and its sedimentary cover, collectively. The wavelength of this fold matches or even surpasses the thickness of the crust that hosts it (36–41 km). The Moho under this mega‐fold is displaced by an Alpine fault that accounts for incipient intraplate continental subduction. The topography of the mantle may reflect an up‐warping compatible with the mega‐fold observed on the surface. Mega‐folding is observed in the hanging wall of the Berzosa Fault, which emerges as a SE‐dipping, Variscan (Paleozoic), extensional fault reactivated as a basal decollement upon Alpine (Cenozoic) contraction. The mega‐fold was formed after well‐oriented planar anisotropies in the basement (foliation and bedding). The development of this fold was assisted by heterogeneous shearing (coeval thrusting) plus the buttressing effect of pre‐existing, near‐vertical, crustal‐scale faults (Somolinos and Somosierra), which inhibited slip‐upsection through the basal decollement (Berzosa Fault).
Key Points
The basement of the easternmost part of the Spanish‐Portuguese Central System is affected by an Alpine mega‐fold
The mega‐fold has a wavelength that matches the thickness of the crust and is soled by a thrust that displaces the Moho
Mega‐folding occurred in a context of incipient intraplate subduction ruled by Variscan structural inheritance in the basement
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