RESUMO
Due to global demand, millions of tons of plastics have been widely consumed, resulting in the widespread entry of vast amounts of microplastic particles into the environment. The presence of microplastics (MPs) in water supplies, including bottled water, has undergone systematic review, assessing the potential impacts of MPs on humans through exposure assessment. The main challenges associated with current technologies lie in their ability to effectively treat and completely remove MPs from drinking and supply water. While the risks posed by MPs upon entering the human body have not yet been fully revealed, there is a predicted certainty of negative impacts. This review encompasses a range of current technologies, spanning from basic to advanced treatments and varying in scale. However, given the frequent detection of MPs in drinking and bottled water, it becomes imperative to implement comprehensive management strategies to address this issue effectively. Consequently, integrating current technologies with management options such as life-cycle assessment, circular economy principles, and machine learning is crucial to eliminating this pervasive problem.
Assuntos
Microplásticos , Poluentes Químicos da Água , Purificação da Água , Abastecimento de Água , Microplásticos/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Monitoramento Ambiental/métodos , Água Potável/química , Plásticos/análiseRESUMO
Herein, a sponge membrane bioreactor (Sponge-MBR) combined with ozonation process was performed to remove the antibiotics which frequently existed in the hospital wastewater. Whilst seven antibiotics i.e., norfloxacin, ciprofloxacin, ofloxacin, sulfamethoxazole, erythromycin, tetracycline and trimethoprim were widely used in medications, this integration was applied for the evaluation of treatment performance under different fluxes. As the results, whilst the antibiotics were eliminated about 45-93%, the tetracycline was completely removed (100%) using Sponge-MBR operated at the flux of 10 LMH. For enhancement of antibiotics removal, the ozonation process was introduced to treat the membrane permeate. Overall efficiencies were 97⯱â¯2% (trimethoprim), 92⯱â¯4% (norfloxacin), 90⯱â¯1% (erythromycin), 88⯱â¯4% (ofloxacin), 83⯱â¯7 (ciprofloxacin) and 66⯱â¯1% (sulfamethoxazole). These results demonstrated Sponge-MBR coupled with ozonation could be a prospective technology for the hospital wastewater treatment.
Assuntos
Antibacterianos/análise , Reatores Biológicos , Membranas Artificiais , Ozônio/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Hospitais , Modelos TeóricosRESUMO
The current study was conducted in the Cua Dai estuary, Vietnam, (1) to assess the status of persistent organic pollutants (POPs) and (2) to examine the interactive effect of season and estuary position on the concentration of the pollutants in surface water and sediment. Fifty-two water and sediment samples were taken in the dry and rainy seasons from inner- and outer-estuary positions to analyze for six POPs, including hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), heptachlor, aldrin, dieldrin, and polychlorinated biphenyl (PCBs). The averaged concentrations of the respective POPs in water samples were 0.07, 0.1, 0.01, 0.03, 0.001, and 0.2 µg L-1 and in sediment samples were 2.6, 3.1, 0.9, 0.2, 0.2, and 121 µg kg-1. Of the six POPs examined, the concentration of DDTs in sediment samples and PCBs in water samples was significantly affected by the interactive effect of the two examined factors. The concentrations of HCHs, DDTs, heptachlor, and aldrin in water samples and of HCHs in sediment samples were significantly higher in the rainy season than in the dry season. Sediment samples collected from the inner position had a significantly higher concentration of HCHs and PCBs than in the outer position. Some mechanisms possibly influenced the varying POP concentration could include (1) greater riverine discharge in the rainy season and (2) the sea dilution effect in the outer position. Therefore, the concentration of the individual examined POPs in water and sediment in the Cua Dai estuary significantly depended on either the season, estuary position, or their combination.
Assuntos
Estuários , Água Doce/química , Sedimentos Geológicos/química , Compostos Orgânicos/análise , Estações do Ano , Poluentes Químicos da Água/análise , Monitoramento Ambiental , VietnãRESUMO
Photobioreactor technology, especially bubble column configuration, employing microalgae cultivation (e.g., Chlorella sp.), is an ideal man-made environment to achieve sufficient microalgae biomass through its strictly operational control. Nutrients, typically N and P, are necessary elements in the cultivation process, which determine biomass yield and productivity. Specifically, N:P ratios have certain effects on microalgae's biomass growth. It is also attractive that microalgae can sequester CO2 by using that carbon source for photosynthesis and, subsequently, reducing CO2 emission. Therefore, this study aims to investigate the effect of N:P ratios on Chlorella sp.'s growth, and to study the dynamic of CO2 fixation in the bubble column photobioreactor. According to our results, N:P ratio of 15:1 could produce the highest biomass yield (3568⯱â¯158â¯mgâ¯L-1). The maximum algae concentration was 105â¯×â¯106â¯cells mL-1, receiving after 92â¯h. Chlorella sp. was also able to sequester CO2 at 28⯱â¯1.2%, while the specific growth rate and carbon fixation rate were observed at 0.064 h-1 and 68.9⯱â¯1.91â¯mgâ¯L-1â¯h-1, respectively. The types of carbon sources (e.g., organic and inorganic carbon) possessed potential impact on microalgae's cultivation.
Assuntos
Sequestro de Carbono , Fotobiorreatores , Biomassa , Dióxido de Carbono , Chlorella , MicroalgasRESUMO
Hospital wastewater contains huge amounts of hazardous pollutants which are being discharged daily to environment with or without treatment. Antibiotics were among the important group of pharmaceuticals considered as a potential source of health risk for human and other living creatures. Although the investigations about the existence of antibiotics in hospital wastewater have gained concern for researchers in many countries, there is only one research conducted in Hanoi-Vietnam. Hence, in this study, investigations have been done to fulfill the requirement of real situation in Vietnam by accomplishing survey for 39 health care facilities in Ho Chi Minh City. As results, seven popular antibiotics were detected to exist in all samples such as sulfamethoxazole (2.5 ± 1.9 µg/L), norfloxacin (9.6 ± 9.8 µg/L), ciprofloxacin (5.3 ± 4.8 µg/L), ofloxacin (10.9 ± 8.1 µg/L), erythromycin (1.2 ± 1.2 µg/L), tetracycline (0.1 ± 0.0 µg/L), and trimethoprim (1.0 ± 0.9 µg/L). On the other hand, survey also showed that only 64% of health care facilities using conventional activate sludge (AS) processes in wastewater treatment plants (WWTPs). As a consequence, basic environmental factors (BOD5, COD, TSS, NH4+-N, or total coliforms) were not effectively removed from the hospital wastewater due to problems relating to initial design or operational conditions. Therefore, 18% effluent samples of the surveyed WWTPs have exceeded the national standard limits (QCVN 28:2010, level B).