•Mechanisms of contaminant adsorption on microplastics were identified.•Removability of contaminant-adsorbing microplastics was reviewed.•The fate and transport of contaminant-adsorbing microplastics ...were examined.•Factors influencing removal efficiency of microplastics were reviewed.
Plastic pollution has been a significant and widespread global issue, and the recent COVID-19 pandemic has been attributed to its worsening effect as plastics have been contaminated with the deadly infectious virus. Microplastics (MPs) may have played a role as a vector that carries hazardous microbes such as emerging bacterial threats (i.e. antibiotic resistant bacteria) and deadly viruses (e.g., coronavirus); this causes great concern over microplastics contaminated with emerging contaminants. Mitigation and treatment of MPs are challenging because of a range of factors including but not limited to physicochemical properties and composition of MPs and pH and salinity of the solution. Despite the heterogeneous nature of aquatic systems, research has overlooked interactions between contaminants and MPs under environmental conditions, degradation pathways of MPs with adsorbed contaminants, and, especially, the role of adsorbed contaminants in the efficiency of MP treatment through membrane filtration, in comparison with other treatment methods. This review aims to (1) analyze an assortment of factors that could influence the removal of MPs and mechanisms of contaminant adsorption on MPs, (2) identify mechanisms influencing membrane filtration of MPs, (3) examine the fate and transport of MPs with adsorbed contaminants, (4) evaluate membrane filtration of contaminant-adsorbing MPs in comparison to other treatment methods, and (5) draw conclusions and the future outlook based on a literature analysis.
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Background
Washed platelet concentrates (WPC), prepared with an automated system cell processor (ACP), have recently been approved to be manufactured and marketed in Japan. From the perspective of ...risk management, it is preferable to secure alternative technologies for ACP. Here, we conducted a study to evaluate the quality of WPC prepared using an automated membrane filtration‐based system, Lovo.
Study design and methods
Replaced PCs prepared from apheresis PCs were equally divided into control and test units, and subsequently washed using ACP and Lovo respectively. Work and operational efficiencies were evaluated by in vitro analyses, including total handling time, platelet recovery, and plasma protein removal rate. Product quality, including a set of biochemical and physiological indicators of platelets and supernatants, were assessed before and 3 days after washing.
Results
In vitro platelet recovery rates and plasma protein removal rates were >85% and >95%, respectively, in both groups. The pH values on day 0 were significantly high (6.97 vs. 6.86) due to low pCO2 in the test group, while no significant differences in glucose consumption and lactate production were observed between the two groups. The levels of hypotonic shock responses, aggregation response, platelet shape, CD62P expression, and sCD62P concentration were similar in both groups during the 3‐day storage period.
Conclusion
Platelet washing with Lovo provides platelet quality equivalent to, or better than, conventional washing with ACP. Thus, the new automated system, Lovo, can be considered as an alternative to ACP for WPC preparation.
Direct membrane filtration has shown great potential in wastewater treatment and resource recovery in terms of its superior treated water quality, efficient nutrient recovery, and sustainable ...operation, especially under some scenarios where biological treatment is not feasible. This paper aims to give a comprehensive review of the state-of-the-art of direct membrane filtration processes (including pressure-driven, osmotic-driven, thermal-driven, and electrical-driven) in treating different types of wastewater for water reclamation and resource recovery. The factors influencing membrane performance and treatment efficiency in these direct membrane filtration processes are well illustrated, in which membrane fouling was identified as the main challenge. The strategies for improving direct membrane filtration performance, such as physical and chemical cleaning techniques and pretreatment of feed water, are highlighted. Towards scaling-up and long-term operation of direct membrane filtration for effective wastewater reclamation and resource recovery, the challenges are emphasized and the prospects are discussed.
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•Direct membrane filtration (DMF) of wastewater is reviewed.•High-quality reclaimed water is produced during DMF of wastewater.•Enhanced resource recovery is achieved during DMF of wastewater.•Physical/chemical cleaning and pretreatment effectively control fouling of DMF•Economic analysis and life cycle assessments of large-scale DMF are needed.
Microplastic (MP) pollution in the aquatic environment is widespread, with a significant fraction of these particles originating from municipal wastewater treatment plant (WWTP) effluents. Whereas ...membrane filtration processes are touted as an effective MP removal strategy, the rejection of irregularly-shaped plastic particles, similar to those found in WWTPs, is poorly understood. Here, we characterize the filtration of irregularly-shaped MP particles (∼10 μm) through Durapore® microfiltration membranes (0.45 and 5 μm pore sizes). These particles were produced via ball-milling/sieving processes from a fluorescent polyethylene feedstock, enabling particle concentrations to be quantified using a standard fluorometric plate reader. Permeate samples from the 0.45 μm membrane exhibited low fluorescent intensities relative to feed samples, implying minimal MP transmission. Conversely, appreciable MP transmission through the 5 μm membrane was noted, with sizable MPs (∼2–7 μm) found in the permeate. This transmission was exacerbated at higher fluxes which emphasizes how operating conditions can govern MP retention. Post-filtration analyses demonstrated that particle capture occurred largely at the feed-membrane interface, where greater MP intrusion into the membrane was seen at the larger pore size. These results reaffirm the importance of choosing an appropriate membrane/membrane pore size and operating conditions to maximize MP retention in WWTPs.
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•Irregular fluorescent microplastics (∼10 μm) were created by ball-milling/sieving.•Little evidence of particle transmission was seen through a 0.45 μm membrane.•Microplastics approaching 5 μm could transmit through a 5 μm membrane's pores.•Higher permeate fluxes induced greater transmission of microplastics.•Microplastics intruded deeper into the pore structure of the 5 μm membrane.
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•An electro-responsive membrane was prepared through carbon-based material.•The negative potential on membrane achieved significant membrane fouling mitigation during filtration.•The ...electroregulated backwash process eliminated the irreversible membrane fouling at a rate of 99.1%.•The electrostatic and fluid forces were ruled during the whole filtration-backwash process.
Membrane-based separation process has been proven to be a powerful strategy for low-energy-consumption and high-efficiency water purification. However, the practical application is still subjected to serious membrane fouling. In this study, an impressive approach to alleviate membrane fouling is proposed using an electro-conductive oxygenated carbon nanotube/polypyrrole (OCNT/PPy) membrane combining electrically-regulated electrostatic and fluid forces. Benefiting from the negative potential (−1.18 V vs. SCE) applied on the membrane, the electric polarization effects significantly enhance the repulsive electrostatic force on contaminant. The transmembrane pressure increases at an ignorable rate during the filtration process. Meanwhile, for accumulated irreversible membrane fouling after multi-cycle filtrations, the positive potential (+1.19 V vs. SCE) exerted on OCNT/PPy membrane can decrease the fluid resistances of backwash flow. As a result, the electrically-regulated hydraulic backwash achieves a thorough recovery rate of permeance at 99.1 %. The numerical analysis of the antifouling mechanism reveals that the mitigation of irreversible membrane fouling is mainly attributed to rapid formation of a loose cake layer under electrical assistance. Moreover, the computational fluid dynamics verifies that the reduction of water-channel resistance enhances the elimination of foulants in membrane pores. This work motivates a new thought for membrane fouling control through electroregulation of electrostatic and fluid forces at the membrane-water interface.
Infant formulas (IFs), the sole adequate substitute to human milk, undergo several thermal treatments during production that can damage milk proteins and promote the formation of Maillard reaction ...products, modifying nutritional and sensory properties. The aim of this study was to determine the impact of a minimally processing route based on membrane filtration associated with different levels of heat treatment, on the odor, taste, texture and color attributes of IFs, then to compare with those of commercial milks. Three experimental IFs (produced with membrane filtration associated with low – T-, medium – T+, or high thermal treatments – T+++) were evaluated. Triangular tests conducted with a panel of 50 adults highlighted clear disparities between all the IFs. The same panel applied the Check-All-That-Apply method to evaluate the IFs: the range of variability between T- and T+++ was similar to that between the 2 commercial IFs, and the sensory characteristics of the experimental IFs were not far from the commercial brands for flavor and texture attributes. Analysis performed on the citation frequencies for each descriptor differentiated T-/T+ from T+++, but all the experimental IFs were described with positive sensory characteristics, unlike one commercial IF. Volatile organic compounds (VOCs) content of IFs with low and high thermal treatments were analyzed. Forty VOCs were identified by gas chromatography-mass spectrometry. T- contained a higher quantity of VOCs than T+++, except for benzaldehyde (Maillard reaction product), and aldehydes (oxidation-related products) were the most represented compounds. In conclusion, the processing was associated with sensory differences among IFs, but no marked difference in flavors was found according to CATA and physicochemical analysis. Additionally, no unpleasant sensory descriptors were noted. This shows that the minimally processed route leads to IFs that could fit well within the market from a sensory point of view.
Landfill leachate treatment in Brazil – An overview Costa, Alyne Moraes; Alfaia, Raquel Greice de Souza Marotta; Campos, Juacyara Carbonelli
Journal of environmental management,
02/2019, Volume:
232
Journal Article
Peer reviewed
The management of municipal solid waste (MSW) presents an ever increasing and more complex challenge in global terms. The disposal of MSW in landfills generates leachate, a liquid highly polluting to ...the aquatic environment. This review describes the state-of-the-art approaches to treatments applied to leachate in Brazil, highlighting the new technologies and alternatives that are still in the research phase, and compares the leachate treatment technologies applied around the world with the current scenario in Brazil. In Brazilian landfills, along with other technologies, the biological process is commonly applied, since this is a simple and economical approach and often it is the only technique used in small municipalities. The sanitary landfills in large Brazilian cities located in the states of São Paulo and Rio de Janeiro, invest in or outsource landfill activities, where apply advanced treatment technologies, such as membrane filtration. The use of membrane filtration technology in these cases reveals similarities with leachate treatments applied in the developed countries of North America and Europe. Brazilian researchers have highlighted the need to use efficient and economically viable technologies for the treatment of leachate in Brazilian landfills. However, the current scenario of MSW management in Brazil shows deficiencies related to the monitoring of sanitary landfills and limited information is available on the performance of leachate treatment systems.
•Brazil is a representative developing country of Latin America.•Leachate treatment technologies used in Brazilian landfills were reviewed.•The leachate treatment used around the world were discussed.•New alternatives on leachate treatment technologies in Brazil were evidenced.•Biological processes and membranes filtration stand out in leachate treatment.
•Advances on the characterization and treatment of landfill leachate are reviewed.•The state-of-the-art innovations of spectroscopic techniques are highlighted.•Advanced oxidation techniques are ...promising in landfill leachate treatment.•Limitations/challenges of current characterization/treatment approaches are discussed.•Perspectives on the development of characterizing/treating approaches are envisaged.
Landfill leachate is a complicated organic wastewater generated in the sanitary landfilling process. Landfill leachate must be appropriately disposed to avoid ecotoxicity and environmental damage. An in depth understanding of the physiochemical characteristics and environmental behaviors of landfill leachate is essential for its effective treatment. In this study, recent advances on the properties of landfill leachate, its characterization methods and treatment techniques are critically reviewed. Specifically, the up-to-date spectroscopic techniques for landfill leachate characterization and advanced oxidation treatment techniques are highlighted. Moreover, the drawbacks and challenges of current techniques for landfill leachate characterization and treatment are discussed, along with the future perspectives in the development of characterization and treatment approaches for landfill leachate.
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Antibiotic pollution is mainly caused by aquaculture wastewater and pharmaceuticals, which are frequently used by humans. Due to limited treatment efficiency or improper selection of treatment ...methods, these antibiotic residues may be very harmful in human drinking water and aquatic environments. The EAOPs coupling membrane technology (EAOPs-membrane) can play their own advantages, which can significantly improve the degradation efficiency and alleviate membrane pollution (electrochemical manners). In this context, this review mainly collecting researches and information on EAOPs-membrane treatment of antibiotic pollution published between 2012 and 2020. Discussed the different combinations of these two technologies, the mechanism of them in the system to improve the processing efficiency, prolong the working time, and stabilize the system structure. Mainly due to the synergistic effect of electrochemical behavior such as electric repulsion and in-situ oxidation, the membrane fouling in the system is alleviated. In this review it was summarized that the selection of different membrane electrode materials and their modifications. The paper also elaborates the existing challenges facing the EAOPs-membrane methods for antibiotic pollution treatment, and their prospects.
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•Antibiotics are an emerging pollutant threatening the ecological environment.•In-situ cleaning occurs in EAOPs-membrane systems.•Material modification is a way to improve performance.•High mineralization rates of antibiotics are achieved via EAOPs-membrane methods.•The EAOPs-membrane is an effective method for treatment of antibiotic.
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