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A novel process configuration was designed to increase biofilm growth in tertiary moving bed biofilm reactors (MBBRs) by providing additional substrate from primary treated wastewater in a sidestream reactor under different redox conditions in order to improve micropollutant removal in MBBRs with low substrate availability. This novel recirculating...
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... experiments were performed to determine the degradation rates of 21 micropollutants (Supporting Information, SI, Table S1), as described previously ( Edefell et al., 2021), in 1 L reactors with effluent wastewater and Anox K Z-400 carriers (166 m 2 m -3 ) from the pilot plants at pH 7.9 ± 0.8 and ambient temperature (21.3 ± 1.9 °C). Triplicate reactors were used for biofilm carriers from the recirculating MBBR, while single reactors were used for carriers from the highloaded and tertiary MBBRs. ...Context 2
... MBBR pilot-scale units were operated continuously for 13 months with primary treated, secondary treated, and ozonated wastewater (Table 1), and seasonal variations in the water temperature (11-20 °C). Biomass concentrations and nitrification capacities in the MBBRs under the different operational conditions are summarized in Table 2, while the effluent concentrations are provided in Table S8. ...Context 3
... the negligible or minor decreases in COD in the main treatment train it appears as the biomass growth (Table 2) was primarily caused by the bioavailable organic matter in the sidestream treatment (S8). The elevated concentrations of particulate organic matter and nutrients in the ozonated wastewater (Table 1), were the result of high water flows during sampling. 1.5 ± 0.1 0.1 ± 0.0 0.9 ± 0.1 1.8 ± 0.3 2.3 ± 0.6 (g NH₄ + -N m -2 d -1 ) 0.7 0.04 0.8 0.8 1.1 ...Context 4
... no significant removal of micropollutants was observed in the abiotic control experiments (Table S9), abiotic transformation seems to be of minor importance for the observed removal. The low sorption affinity to biomass of the investigated micropollutants indicate that removal through sorption is limited as estimates from literature data (typically <15%, Table S10). These estimations are further supported by the negligible removal in the anaerobic experiments for the majority of the micropollutants (Table S9), as further discussed in section 3.3. ...Context 5
... in micropollutant degradation rates in the high-loaded and tertiary MBBRs (Figure 2) cannot solely be explained by the differences in biomass concentrations ( Table 2). The degradation capacity of several of the micropollutants, such as the beta blockers atenolol and metoprolol, the macrolide antibiotics clarithromycin and erythromycin, and the iodinated contrast media iohexol, iomeprol and iopromide, were higher when comparing degradation rates per unit biomass, k bio , by the biofilm in the tertiary MBBR than in the high-loaded MBBR (Table S11). ...Context 6
... Impact of additional feeding A systematic increase was seen in both biomass concentration (Table 1) and degradation rates per unit carrier surface area (Figure 3) when operating the recirculating MBBR system treating effluent wastewater while providing additional substrate to the biofilm carriers in a sidestream reactor with primary treated wastewater. ...Context 7
... recirculating MBBR also exhibited higher degradation rate constants of atenolol and metoprolol than those derived from conventional MBBR and IFAS treatment (Table 3). The biofilms in the tertiary and recirculating MBBRs exhibited similar ranges of degradation rate constants per unit of biomass, k bio , for the majority of the micropollutants, although some variations were seen between the different operating conditions (Table S11). Increased biomass concentration therefore appears to be the main cause of the increased degradation rates per unit J o u r n a l P r e -p r o o f surface area in recirculating MBBRs (Figure 3). ...Citations
... Treatment alternatives applicable to municipal wastewaters are evaluated based on conventional polluting parameters such as the chemical oxygen demand (COD) without addressing micropollutants. It is a known fact that quite an array of micropollutants are not removed during conventional municipal wastewater treatment [1][2][3][4]. As a result, since they are mixed with the water resource, the micropollutants, in further scarce concentrations, continue to pose a threat to the water ecosystem in which they are introduced. ...
Water contamination with various micropollutants is a serious environmental concern since this group of chemicals cannot always be removed efficiently with advanced treatment methods. Therefore, alternative chemical-and energy-intensive oxidation processes have been proposed for the removal of refractory and/or toxic chemicals. However, similar treatment performances might result in different environmental impacts. Environmental impacts can be determined by adopting a life cycle assessment methodology. In this context, lab-scale experimental data related to 100% iprodione (a hydantoin fungicide/nematicide selected as the model micropollutant at a concentration of 2 mg/L) removal from simulated tertiary treated urban wastewater (dissolved organic carbon content = 10 mg/L) with UV-C-activated persulfate treatment were studied in terms of environmental impacts generated during photochemical treatment through the application of a life cycle assessment procedure. Standard guidelines were followed in this procedure. Iprodione removal was achieved at varying persulfate concentrations and UV-C doses; however, an "optimum" treatment condition (0.03 mM persulfate, 0.5 W/L UV-C) was experimentally established for kinetically acceptable, 100% iprodione removal in distilled water and adopted to treat iprodione in simulated tertiary treated wastewater (total dissolved organic carbon of iprodione + tertiary wastewater = 11.2 mg/L). The study findings indicated that energy input was the major contributor to all the environmental impact categories, namely global warming, abiotic depletion (fossil and elements), acidification, eutrophication, freshwater aquatic ecotoxicity, human toxicity, ozone depletion, photochemical ozone creation, and terrestrial ecotoxicity potentials. According to the life cycle assessment results, a concentration of 21.42 mg/L persulfate and an electrical energy input of 1.787 kWh/m 3 (Wh/L) UV-C light yielded the lowest undesired environmental impacts among the examined photochemical treatment conditions.
... The rate and magnitude of the 14 CO 2 formation from ibuprofen and diclofenac were higher in the experiments with the Kivik GAC (high oxygen) versus the Svedala GAC (low oxygen), indicating that the availability of oxygen in GAC filters could promote the degradation of organic micropollutants (Fig. 4). Higher degradation rates have also been reported for ibuprofen and diclofenac under aerobic compared with anoxic conditions in activated sludge processes [24,67] and moving bed biofilm reactors [68]. Other factors, such as type of bitumen-based GAC (Aquasorb 5000 or Aquasorb 6100), EBCT, and influent DOC, also vary between the filters (Fig. 1), potentially affecting the microbial composition and the degradation of the studied pollutants. ...
... Further, the differences in EBCT resulted in large differences in actual operation time between the filters after a certain number of BV (Fig. 4). Nonetheless, free oxygen has been shown to be a prerequisite for degradation of ibuprofen and diclofenac in other biological wastewater treatment processes [24,67,68], and in contact with GAC [16]. Thus, low oxygen concentration could be one, but not necessarily the only, limiting factor for the degradation of organic micropollutants. ...
The capacity for organic micropollutant removal in granular activated carbon (GAC) filters for wastewater treatment changes over time. These changes are in general attributed to changes in adsorption, but may in some cases also be affected by biological degradation. Knowledge on the degradation of organic micropollutants, however, is scarce. In this work, the degradation of micropollutants in several full-scale GAC and sand filters was investigated through incubation experiments over a period of three years, using 14C-labeled organic micropollutants with different susceptibilities to biological degradation (ibuprofen, diclofenac, and carbamazepine), with parallel 16S rRNA gene sequencing. The results showed that the degradation of diclofenac and ibuprofen in GAC filters increased with increasing numbers of bed volumes when free oxygen was available in the filter, while variations over filter depth were limited. Despite relatively large differences in bacterial composition between filters, a degradation of diclofenac was consistently observed for the GAC filters that had been operated with high influent oxygen concentration (DO >8 mg/L). The results of this comprehensive experimental work provide an increased understanding of the interactions between microbial composition, filter material, and oxygen availability in the biological degradation of organic micropollutants in GAC filters.
... The control tests were only performed once since no major changes were observed. The difference between batches II and III allows us to infer the influence of metabolic and cometabolic processes in the compound biotransformation (Edefell et al., 2021). Table 3 presents the wastewater characterization as well as the volume used per batch. ...
... Most of the studies were carried out under aerobic conditions with CAS or MBR, yet there are currently other technologies (e.g., MBBR, AGS), that operate with different redox conditions. For example, MBBR exhibited high removals of micropollutants, mostly at high-loaded reactors (Edefell et al., 2021), while Margot et al. (2016) have pointed out that AGS achieved higher removals of 40%, 15%, 75%, and 20% for compounds like benzotriazole, diclofenac, gabapentin, and metoprolol, correspondingly. However, Burzio et al. (2022) observed that AGS was less effective in biotransforming some micropollutants compared to CAS. ...
... In Table 2, the biomass efficiency (k bio ) of pharmaceuticals' removal in different MBBR studies including the FF or non-FF regimes are compared [11,16,40,59]. Generally, the k bio showed, that the different kinds of MBBRs were mostly compound-dependent. ...
... For instance, the k bio of 288 h FF cycle time in this study was relatively high for eprosartan, gabapentin, mycophenolic acid, tramadol, valsartan and venlafaxine (Table 2). For other previous FF MBBRs (Table 2), a polishing FF MBBR (72 h cycle time) showed the highest k bio for atenolol, ciprofloxacin and propranolol [59], and a recirculating MBBR operated in between aerobic (famine) and anaerobic (feast) mode (6 h cycle time) exhibited the high k bio only for benzotriazole and losartan [16]. On the other hand, the pure polishing MBBR (only feeding effluent wastewater) and a third staged MBBR (similar to polishing reactor) showed the highest k bio on citalopram, diclofenac, ibuprofen, metoprolol, sotalol, carbamazepine, phenazone and 4 contrast media [11,40]. ...
... However similar effects were also reported in previous studies [11,19]. The wastewater parameters, reactor and operation conditions except the FF cycle time might have a significant impact on the removal of pharmaceuticals, which explained the different performance of previous FF and non-FF reactors (Table 2) [11,16,40,59]. ...
Feast-famine (FF) regimes improved the removal of recalcitrant pharmaceuticals in moving bed biofilm reactors (MBBRs), but the optimal FF cycle remained unresolved. The effects of FF cycle time on the removal of bulk substrates (organic carbon and nitrogen) and trace pharmaceuticals by MBBR are systematically evaluated in this study. The feast to famine ratio was fixed to 1:2 to keep the same loading rate, but the time for the FF cycles varied from 18 h to 288 h. The MBBR adapted to the longest FF cycle time (288 h equaling 48 × HRT) resulted in significantly higher degradation rates (up to +183%) for 12 out of 28 pharmaceuticals than a continuously fed (non-FF) reactor. However, other FF cycle times (18, 36, 72 and 144 h) only showed a significant up-regulation for 2–3 pharmaceuticals compared to the non-FF reactor. Enantioselective degradation of metoprolol and propranolol occurred in the second phase of a two phase degradation, which was different for the longer FF cycle time. N-oxidation and N-demethylation pathways of tramadol and venlafaxine differed across the FF cycle time suggestin the FF cycle time varied the predominant transformation pathways of pharmaceuticals. The abundance of bacteria in the biofilms varied considerably between different FF cycle times, which possibly caused the biofilm to remove more recalcitrant bulk organic C and pharmaceuticals under long cycle times.
... The system has been proved to be effective in the removal of more than 20 pharmaceutical compounds compared with the conventional activated sludge system (CAS) [20]. For this reason, modification of MBBR for treatment of wastewater containing pharmaceuticals has been continuously studied [21][22], but the complete removal was not always achieved [23][24]. Also, the disadvantages of MBBR needs to be considered for successful operation, which include the oxygen conditions, long start-up time, and the effects from other toxic pollutants [1,21,25]. ...
... For this reason, modification of MBBR for treatment of wastewater containing pharmaceuticals has been continuously studied [21][22], but the complete removal was not always achieved [23][24]. Also, the disadvantages of MBBR needs to be considered for successful operation, which include the oxygen conditions, long start-up time, and the effects from other toxic pollutants [1,21,25]. Thus, bio-augmentation of specific microbes that can grow and tolerate those conditions in the reactor could be a way to obtain higher removal efficiencies of pharmaceuticals in wastewater by MBBR [26]. However, bioaugmentation with pure cultures for wastewater treatment is challenging as the cultures may not be dominating the environment, so the application is moving toward the use of microbial communities [20]. ...
... The removal process was mainly caused by the biomass of biofilms growing on the carriers during the start-up of the reactor. To achieve higher efficiency, other environmental conditions should be optimized for biofilm formation, e.g., longer HRT [1], additional substrates [21], and redox conditions [22]. Apart from the reactor operation, the limitations of this study should also be addressed in future research including the measurement of water quality parameters along with diclofenac removal, the presence of other pollutants that interfere with the removal, and the characteristics of sludge and microorganisms that play a role in the adsorption and biodegradation of diclofenac. ...
This study aimed to determine the diclofenac removal in wastewater by sludge taken from an operating wastewater treatment facility. Laboratory experiments were conducted in two parts: batch and moving-bed biofilm reactor (MBBR) experiments. Results from batch experiments showed that 0.1–2 mg L-1 of diclofenac could be removed more than 80% within 72 h, and the removal efficiency reduced to less than 60% for higher concentrations. The increase in the removal rate from 0.00058 to 0.16527 mg L-1 h-1 was observed when the initial diclofenac concentration increased from 0.1 to 10 mg L-1, respectively. The average first-order rate constants of 24-h and 72-h degradation were calculated as 4.71 × 10-2 and 1.99 × 10-2 h-1, respectively. The removal of diclofenac by sludge was mainly from biodegradation by microorganisms in sludge, followed by the adsorption onto the sludge biomass. The addition of various metal ions in the studied range did not significantly increase the diclofenac removal; however, the addition of Ca2+, Co2+, Fe3+, Mn2+, and Zn2+ tended to increase both diclofenac removal rate and efficiency. This positive effect was reduced when the metal ion concentrations were increased up to 0.75 ppm. Lastly, results from an initial phase of continuous MBBR showed that sludge addition during the start-up also extended the diclofenac removal efficiency to one week compared with 3 days in the experiment without sludge addition. In conclusion, the findings show the capability of using activated sludge in diclofenac wastewater treatment by the traditional or alternative systems.
... In order to minimize the use of such processes, the feasibility of emerging biological technologies like biofilm-based systems for enhanced degradation of MPs in WWTPs has been recently explored [12][13][14]. One notable example is moving bed biofilm reactors (MBBRs) that have been shown as a promising option for enhanced biodegradation and elimination of recalcitrant MPs (e.g., Diclofenac) in comparison to CAS systems [14][15][16][17]. ...
... As demonstrated in previous studies, composition and structure of biofilm communities and thus the rate of MPs biodegradation can be greatly influenced by several factors including MBBR configurations (i. e., serially-connected MBBRs) [15,[19][20][21], feeding strategies like feast-famine regimes [17,22], biofilm thickness [18] and organic loading rate [17,[23][24][25][26]. Organic loading rate has been shown in several studies to be positively correlated with removal of some groups of MPs, but the extent of the correlation between such operating conditions and MPs biodegradation has been found to be compound-specific [17,25]. The COD/N ratio of influent wastewater is another important aspect that can significantly affect the dynamics of microbial composition in MBBRs by inducing fully heterotrophic (i.e., high COD/N ratio), co-existing of heterotrophic/autotrophic (i.e., medium COD/N ratio) and autotrophic (i.e., low COD/N ratio) conditions in the system. ...
... where C 0 is the initial concentration of the spiked MPs, t the time and k is the kinetic rate constant of the MPs in each respective batch experiment derived as the outcome of the simulations. The obtained k values were normalized to the biomass concentration as well as to the specific surface area of carriers to achieve k bio and k surf , respectively as recently proposed by Edefell et al [15]. Such normalizations allow us to make a better comparison between the kinetic rate of the MPs in each phase of the experiment. ...
We investigated the transformation of four pharmaceuticals (Diclofenac, Naproxen, Ibuprofen and Carbamazepine) in a moving bed biofilm reactor subjected to different COD/N ratios in four experimental phases. The shift from medium to high range COD/N ratio (i.e., 5:1 to 100:1) intensified the competition between heterotrophs and nitrifying communities, leading to a transition from co-existence of heterotrophic and autotrophic conditions with high COD removal and nitrification rate in phase I to dominant heterotrophic conditions in phase II. At lower range COD/N ratios (i.e., 1:2 and 1:8) in phase III and IV, autotrophic conditions prevailed, resulting in increased nitrification rates and high abundance of amoA gene in the biofilm. Such shifts in the operating condition were accompanied by notable changes in the biofilm concentrations, composition and abundance of microbial populations as well as biodiversity in the biofilms, which collectively affected the degradation rates of the pharmaceuticals. We observed higher kinetic rates per unit of biofilm concentration under autotrophic conditions compared to heterotrophic conditions for all compounds except Naproxen, indicating the importance of nitrification in the transformation of such compounds. The results also revealed a positive relationship between biodiversity and biomass-normalized kinetic rates of most compounds.
... The iodinated contrast media IOM and IOP were transformed under anaerobic conditions in biofilm reactors (Zhang et al., 2019), in water/soil batch experiments (Schulz et al., 2008), and by abiotic corrinoid mediated reaction (El-Athman et al., 2019a;El-Athman et al., 2019b). Enhanced biotransformation under aerobic conditions in tertiary moving-bed biofilm reactors has been reported for IOP, IOM, MTP, GAB, and VAL (Edefell et al., 2021). ...
... Therefore, how to use the Mn 2+ in wastewater to improve nutrient removal is an important challenge. MBBR, as one of the alternative to conventional activated sludge, has showed better biological removal for pollutants in wastewater (Edefell et al., 2021). BioMnOx is formed in-situ by microbial catalytic oxidation of Mn 2+ , and it has good oxidation and adsorption properties (Chen et al., 2022). ...
Effect of β-cyclodextrin (β-CD) on simultaneous removal of NH4+-N, NO3--N, COD, and phosphorus (P) in biogenic manganese oxides (BioMnOx) driven moving bed biofilm reactor (MBBR) was investigated. 58.64% and 86.32%, 79.65% and 98.39%, 62.45% and 97.30%, and 24.80% and 95.90% of TN and COD were removed in phases I-IV, indicating that simultaneous nitrification and denitrification (SND) efficiencies were 75.44%, 83.91%, 72.71%, and 35.83%, respectively. Composition and fluorescence spectral characteristics of extracellular polymeric substance (EPS) were evaluated including the removal kinetics of TN and COD. Metabolic activity of Mn2+, decolorization performance of BioMnOx, and reactive oxygen species (ROS) characteristics were determined in biofilm. Furthermore, intermediate Mn3+ and BioMnOx concentration were analyzed. Finally, the removal process of nitrogen (N) and P was proposed based on characterizations of elemental characterization, electrochemistry, and microbial community. This study provides new insights into the N and P removal mediated by BioMnOx and β-CD.
... According to the authors, the biodegradation of TMP occurred due to co-metabolism, fortuitous metabolism, and mixed substrate utilization. Edefell et al. (2021) mentioned that TMP and SMX were biodegraded under all redox conditions. Carneiro et al. (2020) studied the fate of SMX and TMP in a hydrolytic/acidogenic reactor and reported almost total biotransformation of SMX while TMP was biotransformed by 70%. ...
An integrated lab-scale wastewater treatment system consisting of an anaerobic Moving Bed Biofilm Reactor (AnMBBR) and an aerobic Membrane Bioreactor (AeMBR) in series was used to study the removal and fate of pharmaceuticals during wastewater treatment. Continuous-flow experiments were conducted applying different temperatures to the AnMBBR (Phase A: 35 °C; Phase B: 20 °C), while batch experiments were performed for calculating sorption and biotransformation kinetics. The total removal of major pollutants and target pharmaceuticals was not affected by the temperature of the AnMBBR. In Phase A, the average removal of dissolved chemical oxygen demand (COD), biological oxygen demand (BOD), and ammonium nitrogen (NH4-N) was 86%, 91% and 96% while in Phase B, 91%, 96% and 96%, respectively. Removal efficiencies ranging between 65% and 100% were observed for metronidazole (MTZ), trimethoprim (TMP), sulfamethoxazole (SMX), and valsartan (VAL), while slight (<30%) or no removal was observed for carbamazepine (CBZ) and diclofenac (DCF), respectively. Application of a mass balance model showed that the predominant mechanism for the removal of pharmaceuticals was biotransformation, while the role of sorption was of minor importance. The AeMBR was critical for VAL, SMX and TMP biodegradation; the elimination of MTZ was strongly enhanced by the AnMBBR. In both bioreactors, Bacteroidetes was the dominant phylum in both bioreactors over time. In the AnMBBR, Cloacibacterium and Bacteroides had a higher abundance in the biocarriers compared to the suspended biomass.
... Besides adsorptive treatment, phosphorus and OMP can be removed simultaneously within MBBR (moving bed bioreactors) systems by controlling redox conditions and feeding regime. However, the reported removal rates for OMP are below 80 % [19,51,53]. Otherwise, algae treatment is another eco-friendly treatment technology described in the literature, but implementation is linked to high land use, enough solar irritation, and average moderate temperatures throughout the year, which restricts it's application in countries like Austria [32]. ...
