Towards low energy-carbon footprint: Current versus potential P recovery paths in domestic wastewater treatment plants.

With the unprecedented exhaustion of natural phosphorus (P) resource and the high eutrophication potential of the associated-P discharge, P recovery from the domestic wastewater is a promising way and has been putting on agenda of wastewater industry. To address the concern of P resource recovery in an environmentally sustainable way is indispensable especially in the carbon neutrality-oriented wastewater treatment plants (WWTPs). Therefore, this review aims to offer a critical view and a holistic analysis of different P removal/recovery process in current WWTPs and more P reclaim options with the focus on the energy consumption and greenhouse gas (GHG) emission. Unlike P mostly flowing out in the planned/semi-planned P removal/recovery process in current WWTPs, P could be maximumly sequestered via the A-2B- centered process, direct reuse of P-bearing permeate from anaerobic membrane bioreactor, nano-adsorption combined with anaerobic membrane and electrochemical P recovery process. The A-2B- centered process, in which the anaerobic fixed bed reactor was designated for COD capture for energy efficiency while P was enriched and recovered with further P crystallization treating, exhibited the lowest specific energy consumption and GHG emission on the basis of P mass recovered. P resource management in WWTPs tends to incorporate issues related to environmental protection, energy efficiency, GHG emission and socio-economic benefits. This review offers a holistic view with regard to the paradigm shift from "simple P removal" to "P reuse/recovery" and offers in-depth insights into the possible directions towards the P-recovery in the "water-energy-resource-GHG nexus" plant.

DNAH14 variants are associated with neurodevelopmental disorders.

Neurodevelopmental disorders (NDD) are complex and multifaceted diseases involving genetic and environmental sciences. Rapid developments in sequencing techniques have made it possible to identify new disease-causing genes. Our study aimed to identify novel genes associated with NDDs. Trio whole-exome sequencing was performed to evaluate potential NDD variants. We identified three unrelated patients with compound heterozygous DNAH14 variants. The detailed clinical information and genetic results of the recruited patients were obtained and systematically reviewed. Three compound heterozygous DNAH14 variants were identified as follows: c.6100C > T(p.Arg2034Ter) and c.5167A > G(p.Arg1723Gly), c.12640_12641delAA(p.Lys4214Valfs*7) and c.4811T > A(p.Leu1604Gln), andc.7615C > A(p.Pro2539Thr) and c.11578G > A(p.Gly3860Ser), including one nonsense, one frameshift, and four missense variants, which were not existent or with low minor allele frequencies based on the gnomAD database. The missense variants were assumed to be damaging or probably damaging by using multiple bioinformatics tools. Four of these variants were located in the AAA+ ATPase domain, while two were located in the C-terminal domain. Most affected amino acids were highly conserved in various species. A spectrum of neurological and developmental phenotypes was observed, including seizures, global developmental delay, microcephaly, and hypotonia. Thus, our findings indicate that variants of DNAH14 could lead to previously unrecognized NDDs.

Circular RNA Sequencing Reveals Serum Exosome Circular RNA Panel for High-Grade Astrocytoma Diagnosis.

BACKGROUND: Although major advances have been made in the histopathological diagnosis of high-grade astrocytoma (HGA), methods for effective and noninvasive diagnosis remain largely unknown. Exosomes can cross the blood-brain barrier and are readily accessible in human biofluids, making them promising biomarkers for HGA. Circular RNAs (circRNAs) have potential as tumor biomarkers owing to their stability, conservation, and tissue specificity. However, the landscape and characteristics of exosome circRNAs in HGA remain to be studied. METHODS: CircRNA deep sequencing and bioinformatics approaches were used to generate a circRNA profiling database and analyze the features of HGA cell circRNAs and HGA cell-derived exosome circRNAs. Exosome circRNA expression in the serum and tissues of healthy individuals and patients with HGA was detected using reverse transcription-quantitative PCR. Additionally, the receiver operating characteristic curve and overall survival curves were analyzed. RESULTS: By investigating the characteristics of HGA cell-derived exosome circRNAs and HGA cell circRNAs, we observed that exosomes were more likely to enrich short-exon and suppressor circRNAs than HGA cells. Moreover, a serum exosome circRNA panel including hsa_circ_0075828, hsa_circ_0003828, and hsa_circ_0002976 could be used to screen for HGA, whereas a good prognosis panel comprised high concentrations of hsa_circ_0005019, hsa_circ_0000880, hsa_circ_0051680, and hsa_circ_0006365. CONCLUSIONS: This study revealed a comprehensive circRNA landscape in HGA exosomes and cells. The serum exosome circexosome circRNA panel and tissue circRNAs are potentially useful for HGA liquid biopsy and prognosis monitoring. Exosome circRNAs as novel targets should facilitate further biomarker discovery and aid in HGA diagnosis and therapy monitoring.

End-to-end artificial intelligence platform for the management of large vessel occlusions: A preliminary study.

OBJECTIVES: In this study, we developed a deep learning pipeline that detects large vessel occlusion (LVO) and predicts functional outcome based on computed tomography angiography (CTA) images to improve the management of the LVO patients. METHODS: A series identifier picked out 8650 LVO-protocoled studies from 2015 to 2019 at Rhode Island Hospital with an identified thin axial series that served as the data pool. Data were annotated into 2 classes: 1021 LVOs and 7629 normal. The Inception-V1 I3D architecture was applied for LVO detection. For outcome prediction, 323 patients undergoing thrombectomy were selected. A 3D convolution neural network (CNN) was used for outcome prediction (30-day mRS) with CTA volumes and embedded pre-treatment variables as inputs. RESULT: For LVO-detection model, CTAs from 8,650 patients (median age 68 years, interquartile range (IQR): 58-81; 3934 females) were analyzed. The cross-validated AUC for LVO vs. not was 0.74 (95% CI: 0.72-0.75). For the mRS classification model, CTAs from 323 patients (median age 75 years, IQR: 63-84; 164 females) were analyzed. The algorithm achieved a test AUC of 0.82 (95% CI: 0.79-0.84), sensitivity of 89%, and specificity 66%. The two models were then integrated with hospital infrastructure where CTA was collected in real-time and processed by the model. If LVO was detected, interventionists were notified and provided with predicted clinical outcome information. CONCLUSION: 3D CNNs based on CTA were effective in selecting LVO and predicting LVO mechanical thrombectomy short-term prognosis. End-to-end AI platform allows users to receive immediate prognosis prediction and facilitates clinical workflow.

Dual-Functional Graphene Oxide-Based Photothermal Materials with Aligned Channels and Oleophobicity for Efficient Solar Steam Generation.

Desalination by solar steam generation (SSG) has emerged as one of the most efficient approaches to address the issue of global water shortage. In this work, novel graphene oxide (GO)-based solar steam generators (GO-SSGs) with aligned channels were prepared by directional freezing and simple carbonization of a hydrogel composed of GO and poly(vinyl alcohol) (PVA). Benefitting from their excellent light absorption (light absorption efficiency exceeds 94%), better thermal insulation (thermal conductivity, 0.259 W/(m K)), and suitable porous structure, which facilitates rapid water transportation, the GO-SSGs show superior SSG performance with a high solar energy conversion efficiency of up to 92% achieved under an irradiation of 1.0 kW/m2. Interestingly, uniquely aligned channels endow them with good salt-rejection performance; the solar energy conversion efficiency of GO-SSGs in 20 wt % NaCl, KCl, and MgCl2 brine can reach more than 85%. To improve their antifouling performance, a chemically hydrophilic and oleophobic modification was conducted, making it possible to run SSG even in oily wastewater; for instance, a solar energy conversion efficiency of 84% was obtained in an aqueous solution containing 10 wt % n-hexadecane. Compared with the existing photothermal materials, these materials show advantages of simple manufacture, high SSG efficiency, superior salt tolerance, and antifouling performance, which make them promising candidates as a kind of new high-performance photothermal materials for desalination even in oily wastewater, thus further expanding the scope of their practical SSG application.

Degradation of Polyamide Nanofiltration Membranes by Bromine: Changes of Physiochemical Properties and Filtration Performance.

The potential coexistence and interaction of bromine and polyamide membranes during membrane-based water treatment prompts us to investigate the effect of bromine on membrane performance. For fully aromatic polyamide membrane NF90 exposed under a mild bromination condition (10 mg/L), bromine incorporation resulted in more negatively charged (-13 vs -25 mV) and hydrophobic (55.2 vs 58.9°) surfaces and narrower pore channels (0.3 vs 0.29 nm). The permeabilities of water and neutral solutes were reduced by 64 and 69-87%, respectively, which was attributed to the decreased effective pore radius and hydrophilicity. NaCl permeability was reduced by 90% as a synergistic result of enhanced size exclusion and charge repulsion. The further exposure (100 and 500 mg/L bromine) resulted in a more hydrophobic surface (61.7 and 65.5°) and the minor further reduction for water and solute permeabilities (1-9%). Compared with chlorine, the different incorporation efficiency and properties (e.g., atomic size, hydrophilicity) of bromine resulted in opposite trends and/or different degrees for the variation of physicochemical properties and filtration performance of membranes. The bromine incorporation, the shift and disappearance of three characteristic bands, and the increased O/N ratio and calcium content indicated the degradation pathways of N-bromination and bromination-promoted hydrolysis under mild bromination conditions (480 mg/L·h). The further ring-bromination occurred after severe bromine exposure (4800-24,000 mg/L·h). The semi-aromatic polyamide membrane NF270 underwent a similar but less significant deteriorated filtration performance compared with NF90, which requires a different explanation.

Efficient removal of refractory organics in landfill leachate concentrates by electrocoagulation in tandem with simultaneous electro-oxidation and in-situ peroxone.

Leachate concentrates, an effluent produced from nanofiltration and/or reverse osmosis, contains a high amount of salts and dissolved organics especially refractory organics. Thus, the treatment of leachate concentrates would consume high energy or a large amount of chemicals. The present study is to develop an effective treatment method by using coupled electrochemical methods with the least possible energy consumption. The leachate concentrates was pretreated by electrocoagulation (EC), with aluminum or iron electrodes as anodes, to decrease the dissolved organic content. EC with Al electrode was found to be more efficient by consuming 1.25 kWh/m3 energy to remove 70% of total organic carbon (TOC). EC effluent was further subjected to a novel simultaneous electro-oxidation and in-situ peroxone process, which used a Ti-based nickel and antimony doped tin dioxide (NATO) as anode and a carbon nanotube coated carbon-polytetrafluoroethylene (CNT-C/PTFE) as cathode for oxygen reduction reaction (ORR). Compared with a traditional EO with cathode for hydrogen evolution reaction (HER-EO), ORR-EO obtained higher efficiency and an energy consumption of 26.25 kWh/m3, which was much lower than 35.5 kWh/m3 for HER-EO. Results showed that after ORR-EO, a final TOC of 57.3 mg/L was obtained. Thus, EC in tandem with ORR-EO process has an excellent capability and economic merit in the field of treating leachate concentrates.

Effect of ultrasound irradiation combined with ozone pretreatment on the anaerobic digestion for the biosludge exposed to trace-level levofloxacin: Degradation, microbial community and ARGs analysis.

Anaerobic digestion, the principal method of stabilizing biosolids in wastewater treatment plants (WWTPs), can efficiently and largely attenuate the antibiotic resistances in biosludge. This study aims to investigate the effect of oxidative pretreatment with ultrasound irradiation combined with ozone (US/O3) on the mesophilic and thermophilic anaerobic digestion (MAD and TAD) for the biosludge bearing trace fluoroquinolones contaminants-levofloxacin (LEVO) which was widely used in recent years. During the oxidation, the trace-level LEVO was almost completely degraded. The methanogenic activity in US/O3 pretreated TAD dosed 0.1 mg/L LEVO was much higher than those in single MAD and TAD, therefore leading to a remarkable increase in biogas production. The identification of levofloxacin intermediates during chemical degradation was analyzed using LCMS technique and the reaction pathway based on them was proposed. Hydroxyl radicals provided by US/O3 contributed to oxidative ring opening of LEVO as well as degradation of other biomacromolecules in the biosludge. Besides, the quinoline resistance genes-qnrA and qnrS declined significantly by 1-2 orders of magnitude in US/O3-pretreated TAD, indicating that the active radicals produced by US/O3 oxidized and degraded LEVO and therefore inactivated the antibiotic resistant bacteria or genes in the biosolids. Meanwhile, the composition and structure of the microbial community altered and the diversity and richness of total bacterial and potential human pathogens decreased, the pattern of which was correlated with LEVO-resistant genes. Among the well-known AD-related phylum including Bacteroidetes, Firmicutes, Methanobacteria as well as Thermotogae which has been previously detected in TAD and performed organic hydrolysis and degradation, the potential LEVO-resistant bacteria were probably affiliated to Actinobacteria, Bacteroidetes, Proteobacteria, Thermotogae. This study revealed the contribution of US/O3 pretreatment to the anaerobic digestion in terms of ARGs reduction for trace-LEVO- exposed biosludge and could provide useful guidance for controlling the dissemination of ARB and ARGs in sewage sludge.

CircRNA: functions and properties of a novel potential biomarker for cancer.

Circular RNAs, a novel class of endogenous noncoding RNAs, are characterized by their covalently closed loop structures without a 5' cap or a 3' Poly A tail. Although the mechanisms of circular RNAs' generation and function are not fully clear, recent research has shown that circular RNAs may function as potential molecular markers for disease diagnosis and treatment and play an important role in the initiation and progression of human diseases, especially in tumours. This review summarizes some information about categories, biogenesis, functions at the molecular level, properties of circular RNAs and the possibility of circular RNAs as biomarkers in cancers.

Enhancing proton transport in polyvinylidenedifluoride membranes and reducing biofouling for improved hydrogen production in microbial electrolysis cells.

Hydrophilic porous membranes, exemplified by polyvinylidene fluoride (PVDF) membranes, have demonstrated significant potential for replacing ion exchange membranes in microbial electrolysis cells (MECs). Membrane fouling remains a major challenge in MECs, impeding proton transport and consequently limiting hydrogen production. This study aims to investigate a synergistic antifouling strategy for PVDF membrane through the incorporation of a coating composed of polydopamine (PDA), polyethyleneimine (PEI), and silver nanoparticles (AgNPs). The PDA-PEI-Ag@PVDF membrane not only effectively mitigates fouling through steric and electrostatic repulsion forces, but also amplifies ion transport by facilitating water diffusion and electromigration. The PDA-PEI-Ag@PVDF membrane exhibited a reduced membrane resistance of 1.01 mΩ m2 and PDA-PEI-Ag modifying PVDF membrane was found to be effective in enhancing the proton transportation of PVDF membrane. Therefore, the enhanced hydrogen production rate of 2.65 ± 0.02 m3/m3/d was achieved in PDA-PEI-Ag@PVDF-MECs.

Filtration performance of biofilm membrane bioreactor: Fouling control by threshold flux operation.

Membrane fouling is the major factor that restricts the furtherly widespread use of membrane bioreactor (MBR). As a new generation of MBR, biofilm membrane bioreactor (BF-MBR) demonstrates high treatment efficiency and low sludge growth rate, however the filtration performance improvement and membrane fouling control are still the challenges for its further development. This work investigated the filtration performance using resistance in series model and membrane fouling control via threshold flux for BF-MBR. At first, the flux behavior and filtration resistance under various operating conditions, including agitation speed, membrane and TMP, were explored by resistance in series model. Because of the desirable anti-fouling capacity, UP100 and UP030 had the high threshold flux (100 and 90 L m-2 h-1) and low irreversible fouling resistance (1 and 1.3 × 10-10 m-1). Higher shear stress produced by higher agitation speed could reduce membrane fouling, while greatly promote the threshold flux (138 L m-2 h-1) and membrane cleaning efficiency (96%). Moreover, increasing shear stress or selecting membrane with large pore size could decrease the fouling rate and raise the threshold flux. As for TMP, high TMP reduced the removal rate for organic and nutrient, and enhanced the irreversible fouling. Besides, the aerobic-BF-MBR (101 L m-2 h-1 and 1.3 × 10-10 m-1) with lower foulant concentration had a better filtration performance than anoxic-BF-MBR (90 L m-2 h-1 and 1.5 × 10-10 m-1). Additionally, the long-term tests with 10 cycles were conducted to evaluate the industrial application value of BF-MBR (45-58 L m-2 h-1). This work provides the technical support for sustainable filtration performance of BF-MBR.

Transparent exopolymer particles (TEP) and their potential effect on membrane biofouling.

Transparent exopolymer particles (TEP) have been described as a class of particulate acidic polysaccharides, which are large, transparent organic particles, and commonly found in seawater, surface water, and wastewater. Due to their unique physicochemical characteristics, more and more attention has recently been given to the effects of TEP on membrane fouling. In this review, the characteristics and determination methods of TEP as well as its potential effect on membrane biofouling are discussed. It appears that the analytical methods for TEP available in the literature are still debatable, and there is room for further improvement. Nevertheless, evidence suggests that TEP might be involved in the development of membrane fouling, especially at the early stage of biofilm development on membranes.

Mechanistic insights into aggregation process of graphene oxide and bacterial cells in microbial reduction of ferrihydrite.

Microbial reduction of ferrihydrite is prevalent in natural environments and plays an important role in reductive dissolution of Fe(III) minerals. With consistent release of anthropogenic graphene oxide (GO) into water bodies, new changes in the Fe(III)-reducing microorganisms/ferrihydrite binary system demand attention. Herein, we focused on the interaction of GO and bacterial cells in view of colloidal stability and interfacial forces, and on the consequences for microbial ferrihydrite reduction. The results showed that the addition of GO decreased the bioreduction efficiency of ferrihydrite down to 1/15 of the control. Meanwhile, the GO nanosheets were found not depositing on ferrihydrite but spontaneously aggregating with Shewanella spp., the representative dissimilatory Fe(III) reduction bacterial species. Using the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory and atomic force microscopy (AFM), the aggregation process can be interpreted in three steps according to the interaction energy calculation, namely, colloidal instability, reversible aggregation and irreversible aggregation. The motility of living cells seems the reason inducing the colloidal instability between GO and bacteria. While, the aggregation remains reversible even the secondary minimum achieved at the separation distance of 8.74-9.24 nm from XDLVO. When the separation distance <5.74-6.01 nm, the adhesion work predominates and causes irreversible aggregation, validated by AFM. Additionally, the probable ecological risks raised by this aggregation behavior for the imbalance of iron biogeochemical cycle were demonstrated.

The effect of nitrification inhibitors on the aerobic biodegradation of tetracycline antibiotics in swine wastewater.

The aerobic biotreatment process for the dual goals of antibiotic removal and ammonia retainment for the field-return-based treatment of swine wastewater was optimized by adding 2-chloro-6-trichloromethylpyridine (TCMP), commonly used as a nitrogen fertilizer synergist. The results show that the dosage of 5-10 mg/L TCMP daily effectively inhibited nitrification. The COD and tetracycline antibiotics (TCs) in the absence of TCMP was removed by 91% and 76%, and became 87% and 78% with 5 mg/L TCMP and 83% and 70% with 10 mg/L TCMP, respectively. The removal efficiency of four TCs generally followed a decreasing trend of chlortetracycline (CTC) > doxycycline (DC) > tetracycline (TC) > oxytetracycline (OTC). A dosage of 5 mg/L TCMP daily inhibited ammonia nitrification effectively and only slightly affected the removal of conventional organic pollutants and TCs. The contribution of volatilization and hydrolysis to the removal of TCs was negligible. The overall removal efficiency of four TCs in removal pathway experiments was 98%, 94%, 97%, and 96% for OTC, CTC, DC, and TC, of which 69%, 41%, 56%, and 62% was contributed by absorption, and 29%, 53%, 41%, and 34% was contributed by biodegradation, respectively. This study may have significant implications for the proper management of livestock wastewater intended to be used as fertilizers, which aims to reduce the exposure risk of antibiotics and preserve its nutrient value.

Analysis on the epidemiological characteristics of varicella and breakthrough case from 2014 to 2022 in Qingyang City.

We analyze the epidemiological characteristics of varicella and breakthrough cases in Qing Yang City, Gansu Province, and provide a basis for the formulation of varicella prevention and control policies. Varicella and breakthrough cases, public health emergency events in Qing Yang City during 2014-2022 were obtained from the China Disease Prevention and Control information System, and the immunization history of the cases were collected from the Gansu Provincial Immunization Planning Information System, descriptive epidemiological analysis of the obtained information was then performed. A total of 6961 cases of varicella were reported in Qing Yang City from 2014 to 2022, yielding an annual incidence of 36.99 cases per 100 000 population. The incidence increased from 19.74/100,000 in 2014 to 35.97/100,000 in 2022; the incidence peaks were observed from May to July and from November to January of the next year. The reported incidence is higher in males (37.70/100,000) than in females (31.54/100,000), and the main age groups were 4 ~ 6 years old (241.98/100,000), 7 ~ 9 years old (142.39/100,000), 10 ~ 14 years old (101.99/100,000). There were 1975 breakthrough cases, accounting for 28.4% of the total reported cases; the majority of patients were students, children in nursery care and scattered children; a total of 10 outbreaks of varicella were reported in primary schools (40.0%), secondary schools (30.0%), kindergartens (20.0%) and high schools (10.0%). The incidence of varicella showed an increasing trend, children and students are high-risk population. It is suggested that varicella vaccine should be included into the immunization program, and the vaccination rate of two-dose of varicella vaccine should be increased for age-eligible children, and varicella surveillance should be strengthened.

Head and neck tumor segmentation convolutional neural network robust to missing PET/CT modalities using channel dropout.

Objective. Radiation therapy for head and neck (H&N) cancer relies on accurate segmentation of the primary tumor. A robust, accurate, and automated gross tumor volume segmentation method is warranted for H&N cancer therapeutic management. The purpose of this study is to develop a novel deep learning segmentation model for H&N cancer based on independent and combined CT and FDG-PET modalities.Approach. In this study, we developed a robust deep learning-based model leveraging information from both CT and PET. We implemented a 3D U-Net architecture with 5 levels of encoding and decoding, computing model loss through deep supervision. We used a channel dropout technique to emulate different combinations of input modalities. This technique prevents potential performance issues when only one modality is available, increasing model robustness. We implemented ensemble modeling by combining two types of convolutions with differing receptive fields, conventional and dilated, to improve capture of both fine details and global information.Main Results. Our proposed methods yielded promising results, with a Dice similarity coefficient (DSC) of 0.802 when deployed on combined CT and PET, DSC of 0.610 when deployed on CT, and DSC of 0.750 when deployed on PET.Significance. Application of a channel dropout method allowed for a single model to achieve high performance when deployed on either single modality images (CT or PET) or combined modality images (CT and PET). The presented segmentation techniques are clinically relevant to applications where images from a certain modality might not always be available.

The role of probiotic intervention in regulating gut microbiota, short-chain fatty acids and depression-like behavior in lead-exposed rats.

OBJECTIVES: The aim of this study was to observe the depression-like behavior changes of rats exposed to lead with or without probiotic intervention, and to investigate changes in the gut microbiota and fecal short-chain fatty acids (SCFAs) levels after lead exposure, and the possible functions of probiotics in this process. MATERIAL AND METHODS: Adult male Sprague Dawley rats were exposed to a 300 mg/l lead acetate solution for 24 weeks, with or without probiotic (freeze-dried powder containing Lactobacillus and Bifidobacterium: 6 billion live bacteria/2 g) intervention in weeks 17-24. The sucrose preference test (SPT), the forced swim test (FST), and the tail suspension test (TST) were preformed to study the depression- like behaviors of these rats. The alteration of rat gut microbiota induced by lead exposure was analyzed by 16S rRNA sequencing, and the levels of fecal SCFAs were detected using gas chromatography. RESULTS: Neurobehavioral tests showed that lead exposure induced depression-like behavior in rats, including reduced sucrose preference in the SPT, and increased immobility times in the FST and the TST. Sequencing and gas chromatography showed that lead exposure changed the structure and the phylogenetic diversity of the gut microbiota, as well as significantly altered the levels of SCFAs. Moreover, the depression-like behaviors, and the changes in both gut microbiota and SCFAs, could be mitigated by probiotic intervention. CONCLUSIONS: Lead exposure not only changes the structure and diversity of the gut microbiome but also affects metabolic function. Probiotic intervention may be a novel initiative for the prevention and treatment of neurological damage following lead exposure. Int J Occup Med Environ Health. 2022;35(1):95-106.

The role of nitrification inhibitors on the removal of antibiotics in livestock wastewater by aerobic biodegradation.

An optimized aerobic-based treatment method that effectively removes antibiotics and retains ammonia is urgently needed for the field-return-based management of livestock wastewater. Allylthiourea (ATU, used for BOD determination), and 2-chloro-6-trichloromethylpyridine (TCMP) and 3,4-dimethylpyrazole phosphate (DMPP) (commonly used as nitrogen fertilizer synergists) were separately added to sequencing batch reactors (SBRs), in order to investigate their effect on nitrification inhibition and pollutant removal for livestock wastewater treatment. The laboratory test shows that the daily addition of 43.8 mg/L ATU or 17.5 mg/L TCMP to SBRs effectively inhibited nitrification. Nitrification inhibition by DMPP seemed fluctuated and insufficient even various dosing strategies were attempted. The removal efficiency of antibiotics was reduced from 95% to 85% with the addition of ATU, while not significantly influenced by TCMP and DMPP. The COD removal efficiency was reduced by only 6%-10% with the addition of three inhibitors. The pilot study shows that nitrification inhibition efficiency reached 89% with the daily addition of 11.5 mg/L TCMP. The total removal efficiency of antibiotics remained over 93%. The laboratory and pilot studies consistently demonstrate that TCMP played a satisfactory nitrification inhibition role and had a negligible effect on antibiotic removal. The current work provides a novel insight for the proper field-return-based management of livestock wastewater, which achieves the dual goals of reducing the risk of antibiotic exposure and preserving its nutrient value as fertilizers.

Enhanced refractory organics removal by •OH and 1O2 generated in an electro-oxidation system with cathodic Fenton-like reaction.

Recently, carbon nanotubes coated carbon black and polytetrafluoroethylene (CNTs-C/PTFE) gas diffusion electrode was used as an air-cathode in an electro-oxidation (EO) system for effectively generating hydrogen peroxide (H2O2) through a 2-electron oxygen reduction reaction (ORR). This ORR-EO system not only lowered applied voltage and conserved energy, but the synergistic peroxone (O3/H2O2) reaction could increase hydroxyl radicals (•OH) generation for organics elimination. However, a significant proportion of H2O2 was left in the effluent of ORR-EO, which was a loss of resources and energy. In this study, a Fenton-like reaction for in-situ H2O2 decomposition to generate active oxidation species was inserted by introducing MnO2 into the cathodic catalyst layer, and the sole MnO2/CNTs-C/PTFE air-cathode could accomplish 90% of phenol degradation. When MnO2/CNTs-C/PTFE air-cathode combined with Ti/NATO anode in an ORR-EO system, all anodic oxidation, Fenton-like reaction, and peroxone took place to successfully generate •OH and singlet oxygen (1O2). Over 95% of TOC in phenol and landfill leachate bio-effluent was effectively eliminated, with 20% energy savings compared to the ORR-EO with CNTs-C/PTFE air cathode.

The Limitations in Current Studies of Organic Fouling and Future Prospects.

Microfiltration and ultrafiltration for water/wastewater treatment have gained global attention due to their high separation efficiency, while membrane fouling still remains one of their bottlenecks. In such a situation, many researchers attempt to obtain a deep understanding of fouling mechanisms and to develop effective fouling controls. Therefore, this article intends to trigger discussions on the appropriate choice of foulant surrogates and the application of mathematic models to analyze fouling mechanisms in these filtration processes. It has been found that the commonly used foulant surrogate (sodium alginate) cannot ideally represent the organic foulants in practical feed water to explore the fouling mechanisms. More surrogate foulants or extracellular polymeric substance (EPS) extracted from practical source water may be more suitable for use in the studies of membrane fouling problems. On the other hand, the support vector machine (SVM) which focuses on the general trends of filtration data may work as a more powerful simulation tool than traditional empirical models to predict complex filtration behaviors. Careful selection of foulant surrogate substances and the application of accurate mathematical modeling for fouling mechanisms would provide deep insights into the fouling problems.