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Synergistic control of the risks posed by emerging antimicrobials and antibiotic resistance genes (ARGs) is crucial for ensuring ecological safety. Although electrogenic respiration can enhance the biodegradation of several antimicrobials and reduce ARGs accumulation, the association mechanisms of antimicrobial biodegradation (trimethoprim, TMP) with the fate of the antimicrobial resistome remain unclear. Here, the biotransformation pathway of TMP, microbial associations, and functional gene profiles (e.g., degradation, antimicrobial resistance, and electron transfer) were analyzed. The results showed that the microbial electrogenic respiration significantly enhanced the biodegradation of TMP, especially with a cosubstrate sodium acetate supply. Electroactive bacteria enriched in the electrode biofilm positively correlated with potential TMP degraders dominated in the planktonic communities. These cross-niche microbial associations may contribute to the accelerated catabolism of TMP and extracellular electron transfer. Importantly, the evolution and dissemination of overall ARGs and mobile genetic elements (MGEs) were significantly weakened due to the enhanced cometabolic biodegradation of TMP. This study provides a promising strategy for the synergistic control of the water ecological risks of antimicrobials and their resistome, while also highlighting new insights into the association of antimicrobial biodegradation with the evolution of the resistome in an electrically integrated biological process.

GRAPHICAL ABSTRACT ABSTRACT Immobilization has been reported to be an efficient approach for bacteria-based self-healing concrete to maintain the high-efficiency mineral-forming capacity of incorporated bacteria over a period of time. [...]

The selective oxidation of ammonia nitrogen (NH4+-N) to dinitrogen (N2) by persulfates (PS)-based advanced oxidation processes (SR-AOPs) without the input of light or electrons is desired, but presents enormous challenges. In this study, S-doped carbon nanotubes (SCNTs) were prepared via a high-temperature sintering process and used to activate PS for NH4+-N oxidation in the presence of magnesium oxide (MgO). Compared with pristine carbon nanotubes (CNTs), SCNTs improved the N2selectivity of NH4+-N oxidation by SR-AOPs, which was attributed to the lower impedance of SCNTs than that of CNTs, enhancing the direct electron transfer pathway of NH4+-N oxidation. In the SCNTs/PS/MgO process, the non-radical pathway dominated the oxidation of NH4+-N. When SCNTs/PS/MgO process treated polluted lake water, 84.0 % of NH4-N removal and 85.8 % selectivity towards N2were achieved at initial pH of 6, initial NH4+-N concentration of 30 mg N/L, SCNTs dosage of 8 g/L, the mass ratios of SCNTs to PS of 1: 1, and reaction time of 60 min, highlighting its potential for practical applications.

In this work, we systematically investigated the performance and degradation mechanism of quinoline using a persulfate (PS) or sulfite (S(Ⅳ)) assisted WO3/CuFe2O4/Cu (10WCC) photocatalysis. The experimental results showed the degradation efficiency of quinoline were the best in the PS-photocatalysis system with the catalyst dosage of 3 g/L, the PS dosage of 4 mmol/L and pH of 7, and that were the best in the S(Ⅳ)-photocatalysis system with the catalyst dosage of 2 g/L, the S(Ⅳ) dosage of 5 mmol/L and pH of 7. In addition, the S(Ⅳ)-photocatalysis system (77.2%, 1.43 h−1) had lower degradation efficiency than the PS-photocatalysis system (100%, 11.04 h−1) under visible light irradiation. The main active species in the 10WCC/VIS/PS system were h+and ·OH, while in the 10WCC/VIS/S(Ⅳ) system they were h+, ·O2-and SO4·-. This was likely because the electrons of 10WCC could not be captured by S(Ⅳ), and more electrons were captured by O2to form ·O2-. Some h+oxidized S(Ⅳ), resulting in a small amount of ·OH. Thus, ·O2-and SO4·-played key roles in presence of S(Ⅳ). Moreover, h+was most important in both systems, indicating photocatalytic degradation dominated quinoline removal reaction. This study provides some reference for SO4·-coordinated photocatalysis technology.

Sulfaquinoxaline (SQX) is a vital sulfonamide antibiotic for the treatment of livestock infections. Although its degradation has become a research focus in the last few years, its biodegradation process and biometabolic mechanisms were rarely studied. In this research, microbial electrolytic cells (MECs) were used to remove SQX using sodium acetate as a co-substrate. The findings indicated that the maximum removal rate of SQX for a 5-day period in co-substrate reached 94.2%, and SQX exhibited a lower resistance (45.64 Ω) and had a larger double-layer area than a single substrate (95.03 Ω). LCMS/MS analysis suggested that SQX could eventually degrade to 17 byproducts through hydrolysis, hydroxylation, N rearrangement and sulfur reduction. Density flooding theory (DFT) calculations showed that sodium acetate addition weakened the N-C bond and facilitated hydroxylation. Meanwhile, the fluorescence composition of fDOM shifted from protein-like to humic acid-like with co-substrate supplementation. Microbial community analysis showed that Actinobacteria, Proteobacteria, Bacteroidotaand Chloroflexiwere highly correlated with SQX removal. Analysis of the metabolic pathways showed that key enzymes such as NAT, CAT, DHP and NAD+were involved in the degradation of SQX. Biotoxicity tests indicated that weak electrical stimulation was beneficial in reducing biotoxicity. These results provide theoretical basis and new insights into the bioelectrochemical degradation of SQX.

Anaerobic fermentation is a crucial route to realize effective waste activated sludge (WAS) resource recovery and utilization, while the overall efficiency is commonly restrained by undesirable disruptors (i.e., chemical dewatering agents). This work unveiled the unexpectedly positive effects of biodewatering tannic acid (TA) on the volatile fatty acids (VFAs) biosynthesis during WAS anaerobic fermentation. The total VFAs yield was remarkably increased by 15.6 folds with enriched acetate and butyrate in TA-occurred systems. TA was capable to disintegrate extracellular polymeric substances to promote the overall organics release. However, TA further modulated the soluble proteins structure by hydrogen bonding and hydrophobic interactions, resulting in the decrease of proteins bioavailability and consequential alteration of metabolic substrate feature. These changes reshaped the microbial community and stimulated adaptive regulatory systems in hydrolytic–acidogenic bacteria. The keystone species for carbohydrate metabolism (i.e., Solobacteriumand Erysipelotrichaceae) were preferentially enriched. Also, the typical quorum sensing (i.e., enhancing substrate transport) and two-component systems (i.e., sustaining high metabolic activity) were activated to promote the microbial networks connectivity and ecological cooperative behaviors in response to TA stress. Additionally, the metabolic functions responsible for carbohydrate hydrolysis, transmembrane transport, and intracellular metabolism as well as VFA biosynthesis showed increased relative abundance, which maintained high microbial activities for VFAs biosynthesis. This study underscored the advantages of biodewatering TA for WAS treatment in the context of resource recovery and deciphered the interactive mechanisms.

In this study, the attempt was made to enhance the degradation of the typical antibiotics, metronidazole (MNZ) by coupling three-electrode photocatalytic and microbial fuel cell systems (PMFC). The PMFC reactor was constructed, and the photocatalytic bioanode, attached with TiO2, was synthesized and characterized using SEM, EDS, XPS methods. The stability of microbial on bioanode was tested during acclimatization process. Electrochemical characteristics, including power density, CV and EIS curve, were analyzed to explore the advantage of power generation and higher electron transfer interaction in the PMFC. Compared with the traditional MFC system, the improved degradation and enhanced mineralization of MNZ were achieved, and the 1.30 and 1.24-fold increase in MNZ and TOC removal were realized, respectively. The three degradation pathways of MNZ were identified by LC-MS in the coupling PMFC, and the intermediates were more easily to further degrade and mineralize. The structure of the microbial community was demonstrated, and the functional species consisted of MNZ degradation bacteria, exoelectrogens, hydrocarbon removal bacterial, and nitrogen removal bacterial, were largely enriched in the PMFC, contributing to the improved electricity production, MNZ degradation and photoelectric effect. Moreover, the photoelectric played the selective role in the enrichment of functional microbial. The study provides a promising and environmentally approach for the treatment of containing antibiotics wastewater in the practical application.

AbstractRapid hydrolysis of waste activated sludge (WAS) can be achieved by improving activities of extracellular enzymes under proper temperature conditions. As short-chain fatty acids (SCFAs) accumulation is always consumed by methanogens under anaerobic conditions, and considering that the micro-aerobic condition can inhibit the activities of methanogens, in this study, effects of temperature (55–75°C) on thermophilic micro-aerobic fermentation of WAS were investigated. Results showed that the highest soluble chemical oxygen demand (SCOD) yield was obtained at 60°C (4,407 ± 80 mg/L, 36 h), 2.0 times higher than that obtained at 75°C (2,180 ± 40 mg/L, 36 h), the corresponding hydrolysis rate was 0.6689 d−1. The highest SCFAs yield was 2,928 ± 12 mg COD/L at 60°C and 36 h, 4.9 times higher than that obtained at 75°C (594 ± 10 mg COD/L, 36 h). The analysis of SCFAs composition showed that acetic acid (HAc) accounted for the most percentage (>40%), followed by n-valeric (n-HVa) (20–25%), and propionic acids (HPr) (10–15%). Total suspended solids removal efficiency reached 18.7% after 192-h fermentation at 60°C. These results suggested that the optimal thermophilic micro-aerobic conditions for WAS hydrolysis and SCFAs accumulation from WAS were 60°C and 36-h fermentation time.

The synthesis of new chiral smectic A (SA) side-chain liquid crystalline polysiloxanes (LCPs) and ionomers (LCIs) containing 4-allyloxy-benzoyl-4-(S-2-ethylhexanoyl) p-benzenediol bisate (ABB) as mesogenic units and 4-[[4-(2-propenyloxy)phenyl]azo]benzenesulfonic acid (AABS) as nonmesogenic units is presented. The chemical structures of the monomers and polymers are confirmed by FTIR spectroscopy or ¹H–NMR. Differential scanning calorimetry (DSC), optical polarizing microscopy, and X-ray diffraction measurements reveal that all the polymers PI–PIV and ionomers PV–PVI exhibit SA texture. The results seem to demonstrate that the tendency toward the SA-phase region increases with increasing sulfonic acid concentration, and the thermal stability of the SA phase is determined by the flexibility of the polymer backbones and the interactions of sulfonic acid groups. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2335–2340, 2001

To address the availability of carbon sources for denitrification, the accelerated hydrolysis of the most abundant but low-availability fraction of particulate organic matter (POM) was investigated. Mesh sieves with different pore sizes were used as primary pretreatment at the start-up-stage of the biological process to separate some POM from the liquid system. The changes in soluble carbohydrates and proteins were monitored to investigate the hydrolysis performance of the sieved POM, with waste activated sludge (WAS) as the control test. The results showed that an average of 35% POM could be entrapped before filtrate mat development. In addition, benefiting from the high polysaccharides concentration, as well as the high availability due to the relatively loose physical structure, a 23% hydrolysis efficiency of POM was obtained, in contrast to that of WAS (3.4%), with a hydrolysis constant of 0.39 h−1. The prominent performance was also attributed to the unique microbial communities having been domesticated at a lower temperature, especially the cellulose-degrading bacteria Paraclostridiumand psychrophile Psychrobacter, making up 6.94% and 2.56%, respectively. Furthermore, the potential benefits and application of improved POM hydrolysis by start-up stage recovery via mesh sieves combined with anaerobic fermentation were evaluated, including selective POM entrapment, alleviation of blockage and wear, and a reduction in aeration energy. By the proposed strategy, carbon availability for biological nutrient removal (BNR) processes is anticipated to be improved more economically than that can be achieved by primary clarifier elimination.

Applying the optimal problem, we get the optimal power supply and price. However, how to make the real power consumption close to the optimal power supply is still worth studying. This paper proposes a novel data-driven inverse proportional function-based repeated-feedback adjustment strategy to control the users’ real power consumption. With the repeated-feedback adjustment, we adjust the real-time prices according to changes in the power discrepancy between the optimal power supply and the users’ real power consumption. If and only if the power discrepancy deviates the preset range, the real power consumption in different periods will be adjusted through the change of the price, so the adjustment times is the least. Numerical results on real power market show that the novel inverse proportional function-based repeated-feedback adjustment strategy brought forward in the article achieves better effect than the linear one, that is to say, the adjustments times and standard error of the residuals are less. Meanwhile, profit and whole social welfare are more. The proposed strategy can obtain more steady and dependable consumption load close to the optimal power supply, which is conducive to the balanced supply of electric energy.

Conditioning of extra carbon sources has been widely reported to facilitate fermentation of waste activated sludge (WAS). Soy sauce residue (SSR) was a relatively untapped carbon source for sludge conditioning. This batch study aimed to evaluate the possible implementation of SSR for volatile fatty acids (VFAs) production from WAS. To upgrade the bioavailability of feedstock, three typical pretreatment methods were conducted, i.e., ammonium hydroxide (AH), sulfuric acids (SA) and thermal assisted alkaline (TA). AH pretreated test (AH-PT) outperformed due to a relatively strong structure decomposition of cellulosic materials as revealed by infrared spectroscopic analysis and crystal index. As a result, performed a high hydrolysis rate of 4449 mg COD/d, 1.12-1.23-fold higher than that in TA and SA pretreated tests (TA-PTand SA-PT), and 7.8-fold higher than that in the Control test. Meanwhile, a volatile fatty acids (VFAs) contribution of 401.2 mg COD/g SSR∙L and a maximum acidification rate of 3.59 d–1was recorded, with a high sum proportion of mall molecular acetic and propionic 82.2%, 11%–70% increase over the other three tests. Besides, speciation process characterized with functional genus differentiation was identified by microbial diversity and distribution investigation and canonical correspondence analysis (CCA). Finally, a potential market value of 0.49–0.65 Billion €/year was preliminary estimated, showing promise of resource recovery from both WAS and SSR instead of extensive disposal.