Innovative sponge-based moving bed-osmotic membrane bioreactor hybrid system using a new class of draw solution for municipal wastewater treatment

© 2016 Elsevier Ltd. For the first time, an innovative concept of combining sponge-based moving bed (SMB) and an osmotic membrane bioreactor (OsMBR), known as the SMB-OsMBR hybrid system, were investigated using Triton X-114 surfactant coupled with MgCl2 salt as the draw solution. Compared to traditional activated sludge OsMBR, the SMB-OsMBR system was able to remove more nutrients due to the thick-biofilm layer on sponge carriers. Subsequently less membrane fouling was observed during the wastewater treatment process. A water flux of 11.38 L/(m2 h) and a negligible reverse salt flux were documented when deionized water served as the feed solution and a mixture of 1.5 M MgCl2 and 1.5 mM Triton X-114 was used as the draw solution. The SMB-OsMBR hybrid system indicated that a stable water flux of 10.5 L/(m2 h) and low salt accumulation were achieved in a 90-day operation. Moreover, the nutrient removal efficiency of the proposed system was close to 100%, confirming the effectiveness of simultaneous nitrification and denitrification in the biofilm layer on sponge carriers. The overall performance of the SMB-OsMBR hybrid system using MgCl2 coupled with Triton X-114 as the draw solution demonstrates its potential application in wastewater treatment

A novel osmosis membrane bioreactor-membrane distillation hybrid system for wastewater treatment and reuse

© 2016 . A novel approach was designed to simultaneously enhance nutrient removal and reduce membrane fouling for wastewater treatment using an attached growth biofilm (AGB) integrated with an osmosis membrane bioreactor (OsMBR) system for the first time. In this study, a highly charged organic compound (HEDTA3-) was employed as a novel draw solution in the AGB-OsMBR system to obtain a low reverse salt flux, maintain a healthy environment for the microorganisms. The AGB-OsMBR system achieved a stable water flux of 3.62 L/m2 h, high nutrient removal of 99% and less fouling during a 60-day operation. Furthermore, the high salinity of diluted draw solution could be effectively recovered by membrane distillation (MD) process with salt rejection of 99.7%. The diluted draw solution was re-concentrated to its initial status (56.1 mS/cm) at recovery of 9.8% after 6 h. The work demonstrated that novel multi-barrier systems could produce high quality potable water from impaired streams

Women's perspectives on termination service delivery in Vietnam: a cross-sectional survey in three provinces.

OBJECTIVE: To explore the perspectives of abortion service users regarding termination methods and abortion service delivery in Vietnam. MATERIALS AND METHODS: Structured exit interviews were conducted between August and November 2011 with women who underwent termination of pregnancy at 62 public health facilities in Hanoi, Khanh Hoa, and Ho Chi Minh City in Vietnam. All women presenting for termination during the study period were recruited to participate in the study. Following their abortion, women were asked about their perspectives on abortion service delivery and attributes of medical abortion (MA) versus manual vacuum aspiration (MVA). Multiple logistic regression was used to assess the association between current method uptake and each attribute. RESULTS: A total of 1,233 women were included in the survey: 541 (43.9%) from Hanoi, 163 (13.2%) from Khanh Hoa, and 529 (42.9%) from Ho Chi Minh: 23.1% underwent MA; 78.9% reported that women should be given a choice between MA and MVA; and 77.6% thought that abortion services were accessible. Among the 48% who responded, 30.1% thought that MA should be made available at primary/secondary health care facilities. Among women who had previously undergone both methods, women who reported that MA "feels more natural" (like a menstrual regulation/period) were more likely to choose MA for their current abortion (odds ratio 2.15, 95% confidence interval 1.26-3.69). CONCLUSION: MA uptake is significantly lower than MVA uptake. Further insights to women's perceptions of MA in Vietnam could help improve abortion service delivery in the country

Attributes and perspectives of public providers related to provision of medical abortion at public health facilities in Vietnam: a cross-sectional study in three provinces.

BACKGROUND: The purpose of this study was to investigate attributes of public service providers associated with the provision of medical abortion in Vietnam. METHODS: We conducted a cross-sectional study via interviewer-administered questionnaire among abortion providers from public health facilities in Hanoi, Khanh Hoa, and Ho Chi Minh City in Vietnam between August 2011 and January 2012. We recruited abortion providers at all levels of Vietnam's public health service delivery system. Participants were questioned about their medical abortion provision practices and perspectives regarding abortion methods. RESULTS: A total of 905 providers from 62 health facilities were included, comprising 525 (58.0%) from Hanoi, 122 (13.5%) from Khanh Hoa, and 258 (28.5%) from Ho Chi Minh City. The majority of providers were female (96.7%), aged ≥25 years (94%), married (84.4%), and had at least one child (89%); 68.9% of providers offered only manual vacuum aspiration and 31.1% performed both medical abortion and manual vacuum aspiration. Those performing both methods included physicians (74.5%), midwives (21.7%), and nurses (3.9%). Unadjusted analyses showed that female providers (odds ratio 0.1; 95% confidence interval 0.01-0.30) and providers in rural settings (odds ratio 0.3; 95% confidence interval 0.08-0.79) were less likely to provide medical abortion than their counterparts. Obstetricians and gynecologists were more likely to provide medical abortion than providers with nursing/midwifery training (odds ratio 22.2; 95% confidence interval 3.81-129.41). The most frequently cited advantages of medical abortion for providers were that no surgical skills are required (61.7%) and client satisfaction is better (61.0%). CONCLUSION: Provision of medical abortion in Vietnam is lower than provision of manual vacuum aspiration. While the majority of abortion providers are female midwives in Vietnam, medical abortion provision is concentrated in urban settings among physicians. Individuals providing medical abortion found that the method yields high client satisfaction

The application of microalgae in removing organic micropollutants in wastewater

© 2020, © 2020 Taylor & Francis Group, LLC. Micropollutants have become a serious environmental problem with several negative outcomes for human health and ecosystems. Many efforts have been made to remove micropollutants using a variety of physical, chemical and biological methods. By far, the most attention has been paid to microalgae-based technologies for wastewater treatment in order to obtain high-quality effluents, recover algal biomass for fertilizers, protein-rich feed, biofuel, and put them to other practical use. This paper reviews the potential of microalgae-based systems for the removal of organic micropollutants from open ponds to closed photobioreactors coupled by suspended microalgal cells, immobilized cells, or microalgae-microbial consortia. The inhibition of micropollutants on microalgae growth as well as micropollutant removal mechanisms performed by microalgae-based systems are also discussed. Other treatment methods for the removal of micropollutants are analyzed to show the advantages and limitations of microalgae-based treatment strategies, from which some possible combined systems can be suggested. Finally, some recommendations for future studies on this topic are proposed. (Figure presented.)

Applicability of an integrated moving sponge biocarrier-osmotic membrane bioreactor MD system for saline wastewater treatment using highly salt-tolerant microorganisms

© 2017 Elsevier B.V. Osmotic membrane bioreactors (OsMBRs) are a recent breakthrough technology designed to treat wastewater. Nevertheless, their application in high-salinity wastewater treatment is not widespread because of the effects of saline conditions on microbial community activity. In response, this study developed an integrated sponge biocarrier-OsMBR system using highly salt-tolerant microorganisms for treating saline wastewater. Results showed that the sponge biocarrier-OsMBR obtained an average water flux of 2 L/m2 h during a 92-day operation when 1 M MgCl2 was used as the draw solution. The efficiency in removing dissolved organic compounds from the proposed system was more than 99%, and nutrient rejection was close to 100%, indicating excellent performance in simultaneous nitrification and denitrification processes in the biofilm layer on the carriers. Moreover, salt-tolerant microorganisms in the sponge biocarrier-OsMBR system worked efficiently in salt concentrations of 2.4%. A polytetrafluoroethylene MD membrane (pores = 0.45 μm) served to regenerate the diluted draw solution in the closed-loop system and produce high-quality water. The moving sponge biocarrier-OsMBR/MD hybrid system demonstrated its potential to treat salinity wastewater treatment, with 100% nutrient removal and 99.9% conductivity rejection

Exploring high charge of phosphate as new draw solute in a forward osmosis-membrane distillation hybrid system for concentrating high-nutrient sludge

© 2016 Elsevier B.V. For the first time, a high charge of phosphate was used as the draw solute in a forward osmosis-membrane distillation (FO-MD) hybrid system for concentrating high-nutrient sludge. A high water flux (12.5 L/m2 h) and a low reverse salt flux (0.84 g/m2) were simultaneously achieved at pH 9 by using 0.1 M Na3PO4 as the draw solute and deionized water as the feed solution in the FO process. The specific reverse salt flux of 0.1 M Na3PO4 (Js/Jw = 0.07 g/L) was considerably less than that of 0.1 M NaCl (Js/Jw = 0.37 g/L) because the complexion between Na+ and HPO42- at pH 9 led to the reduction of free Na+ ions, which subsequently reduced the reverse salt diffusion substantially. Moreover, for a feed solution with an initial sludge concentration of 3500 mg/L, the sludge concentration could be concentrated to 19,800 and 22,000 mg/L in the pressure-retarded osmosis (PRO) and FO membrane orientations, respectively, after 15 h of operation. Four types of MD membranes were selected for draw solution recovery; of these, a polytetrafluoroethylene membrane with a pore size of 0.45 μm was the most effective in achieving a high water flux (10.28 L/m2 h) and high salt rejection (approximately 100%) in a diluted Na3PO4 draw solution

Aerobic co-composting degradation of highly PCDD/F-contaminated field soil. A study of bacterial community

© 2018 Elsevier B.V. This study investigated bacterial communities during aerobic food waste co-composting degradation of highly PCDD/F-contaminated field soil. The total initial toxic equivalent quantity (TEQ) of the soil was 16,004 ng-TEQ kg −1 dry weight. After 42-day composting and bioactivity-enhanced monitored natural attenuation (MNA), the final compost product's TEQ reduced to 1916 ng-TEQ kg −1 dry weight (approximately 75% degradation) with a degradation rate of 136.33 ng-TEQ kg −1 day −1 . Variations in bacterial communities and PCDD/F degraders were identified by next-generation sequencing (NGS). Thermophilic conditions of the co-composting process resulted in fewer observed bacteria and PCDD/F concentrations. Numerous organic compound degraders were identified by NGS, supporting the conclusion that PCDD/Fs were degraded during food waste co-composting. Bacterial communities of the composting process were defined by four phyla (Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes). At the genus level, Bacillus (Firmicutes) emerged as the most dominant phylotype. Further studies on specific roles of these bacterial strains are needed, especially for the thermophiles which contributed to the high degradation rate of the co-co-composting treatment's first 14 days

Structural Disorder Provides Increased Adaptability for Vesicle Trafficking Pathways

Vesicle trafficking systems play essential roles in the communication between the organelles of eukaryotic cells and also between cells and their environment. Endocytosis and the late secretory route are mediated by clathrin-coated vesicles, while the COat Protein I and II (COPI and COPII) routes stand for the bidirectional traffic between the ER and the Golgi apparatus. Despite similar fundamental organizations, the molecular machinery, functions, and evolutionary characteristics of the three systems are very different. In this work, we compiled the basic functional protein groups of the three main routes for human and yeast and analyzed them from the structural disorder perspective. We found similar overall disorder content in yeast and human proteins, confirming the well-conserved nature of these systems. Most functional groups contain highly disordered proteins, supporting the general importance of structural disorder in these routes, although some of them seem to heavily rely on disorder, while others do not. Interestingly, the clathrin system is significantly more disordered (,23%) than the other two, COPI (,9%) and COPII (,8%). We show that this structural phenomenon enhances the inherent plasticity and increased evolutionary adaptability of the clathrin system, which distinguishes it from the other two routes. Since multi-functionality (moonlighting) is indicative of both plasticity and adaptability, we studied its prevalence in vesicle trafficking proteins and correlated it with structural disorder. Clathrin adaptors have the highest capability for moonlighting while also comprising the most highly disordered members. The ability to acquire tissue specific functions was also used to approach adaptability: clathrin route genes have the most tissue specific exons encoding for protein segments enriched in structural disorder and interaction sites. Overall, our results confirm the general importance of structural disorder in vesicle trafficking and suggest major roles for this structural property in shaping the differences of evolutionary adaptability in the three routes

Removing ammonium from water using modified corncob-biochar

© 2016 Elsevier B.V. Ammonium pollution in groundwater and surface water is of major concern in many parts of the world due to the danger it poses to the environment and people's health. This study focuses on the development of a low cost adsorbent, specifically a modified biochar prepared from corncob. Evaluated here is the efficiency of this new material for removing ammonium from synthetic water (ammonium concentration from 10 to 100 mg/L). The characteristics of the modified biochar were determined by Brunauer-Emmett-Teller (BET) test, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). It was found that ammonium adsorption on modified biochar strongly depended on pH. Adsorption kinetics of NH4+-N using modified biochar followed the pseudo-second order kinetic model. Both Langmuir and Sips adsorption isotherm models could simulate well the adsorption behavior of ammonium on modificated biochar. The highest adsorption capacity of 22.6 mg NH4+-N/g modified biochar was obtained when the biochar was modified by soaking it in HNO3 6 M and NaOH 0.3 M for 8 h and 24 h, respectively. The high adsorption capacity of the modified biochar suggested that it is a promising adsorbent for NH4+-N remediation from water