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Adsorptive removal of metformin on specially designed algae-lignocellulosic biochar mix and techno-economic feasibility assessment
2022
De Bhowmick, Goldy | Briones, Rowena M. | Thiele-Bruhn, Sören | Sen, Ramkrishna | Sarmah, Ajit K.
Batch sorption of metformin hydrochloride (MET) onto a specially designed biochar mix consisting of both macro (MAC) and micro (MIC) algae, rice husk and pine sawdust was conducted. Pyrolysis of both MAC and MIC algae mixture was done followed by chemical activation with hydrogen-peroxide. Additionally, sorption of MET under the influence of pH was separately investigated. Batch studies of isotherms were well described by Freundlich model with high non-linearity and Freundlich exponent values ranged anywhere from 0.12 to 1.54. Heterogeneity of MET adsorption to the bonding sites was attributed to the surface functional groups of the modified biochar. Amongst the four biochars, the activated macroalgae biochar (MACAC) and microalgae biochar (MICAC) depicted favourable adsorption of MET with maximum adsorption at pH 7. Up to 76% of MET removal from the environment was obatained using the MACAC biochar. Scanning electron micrographs coupled with energy dispersive X-ray, as well as elemental analyses confirmed formation of oxygen containing surface functional groups due to activation strengthening chemisorption as the main sorption mechanism. Further, Fourier transform infra-red spectroscopy and other surface functional group analyses along with Zeta potential measurements reinforced our proposed sorption mechanism. Lowest zeta potential observed at pH 7 enhanced the electrostatic force of attraction for both the biochars. Negative zeta potential value of the biochars under different pH indicated potential of the biochars to adsorb other positively charged contaminants. From a techno-economic perspective, capital expenditure cost is not readily available, however, it is envisaged that production of pyrolyzed biochar from algal biomass could make the process economically attractive especially when the biochar could be utilised for high-end applications.
Mostrar más [+] Menos [-]Air quality during the COVID-19: PM2.5 analysis in the 50 most polluted capital cities in the world
2020
Rodríguez-Urrego, Daniella | Rodríguez-Urrego, Leonardo
On December 31, 2019, the Chinese authorities reported to the World Health Organization (WHO) the outbreak of a new strain of coronavirus that causes a serious disease in the city of Wuhan, China. This outbreak was classified as SARS-CoV2 and is the cause of the COVID-19 disease. On March 11, 2020, the WHO declares it a Pandemic and today it is considered the greatest challenge in global health that humanity has faced since World War II and it is estimated that between 40 and 60% of the population worldwide will catch the virus. This has caused enormous challenges in countries around the world in social, economic, environmental and obviously health issues. These challenges are mainly due to the effects of the established quarantines in almost all capitals and major cities around the world, from Asia, Europe to America. However, these lockdown which began worldwide from January 23, have had a significant impact on the environment and on the air quality of cities as recently reported by NASA (National Aeronautics and Space Administration) and ESA (European Space Agency), with reductions according to them of up to 30% in some of the epicenters such as the case of Wuhan. Knowing that air pollution causes approximately 29% of lung cancer deaths, 43% of COPD deaths, and 25% of ischemic heart disease deaths, it is important to know the effects of quarantines in cities regarding air quality to take measures that favor populations and urban ecosystems when the emergency ends. Therefore, this paper describes the behavior of PM₂.₅ emissions particulate matter from the 50 most polluted capital cities in the world according to the WHO, measured before-after the start of the quarantine. Likewise, the impact at the local and global level of this emissions behavior, which averaged 12% of PM₂.₅ decrease in these cities.
Mostrar más [+] Menos [-]Major threats of pollution and climate change to global coastal ecosystems and enhanced management for sustainability
2018
Lü, Yonglong | Yuan, Jingjing | Lu, Xiaotian | Su, Chao | Zhang, Yueqing | Wang, Chenchen | Cao, Xianghui | Li, Qifeng | Su, Jilan | Ittekkot, Venugopalan | Garbutt, Richard Angus | Bush, Simon | Fletcher, Stephen | Wagey, Tonny | Kachur, Anatolii | Sweijd, Neville
Coastal zone is of great importance in the provision of various valuable ecosystem services. However, it is also sensitive and vulnerable to environmental changes due to high human populations and interactions between the land and ocean. Major threats of pollution from over enrichment of nutrients, increasing metals and persistent organic pollutants (POPs), and climate change have led to severe ecological degradation in the coastal zone, while few studies have focused on the combined impacts of pollution and climate change on the coastal ecosystems at the global level. A global overview of nutrients, metals, POPs, and major environmental changes due to climate change and their impacts on coastal ecosystems was carried out in this study. Coasts of the Eastern Atlantic and Western Pacific were hotspots of concentrations of several pollutants, and mostly affected by warming climate. These hotspots shared the same features of large populations, heavy industry and (semi-) closed sea. Estimation of coastal ocean capital, integrated management of land-ocean interaction in the coastal zone, enhancement of integrated global observation system, and coastal ecosystem-based management can play effective roles in promoting sustainable management of coastal marine ecosystems. Enhanced management from the perspective of mitigating pollution and climate change was proposed.
Mostrar más [+] Menos [-]PM2.5 induces the distant metastasis of lung adenocarcinoma via promoting the stem cell properties of cancer cells
2022
Pan, Junyi | Xue, Yueguang | Li, Shilin | Wang, Liuxiang | Mei, Jie | Ni, Dongqi | Jiang, Jipeng | Zhang, Meng | Yi, Shaoqiong | Zhang, Rong | Ma, Yongfu | Liu, Yang | Liu, Ying
Lung cancer is the most common cancer in China and second worldwide, of which the incidence of lung adenocarcinoma is rising. As an independent factor, air pollution has drawn the attention of the public. An increasing body of studies has focused on the effect of PM₂.₅ on lung adenocarcinoma; however, the mechanism remains unclear. We collected the PM₂.₅ in two megacities, Beijing (BPM) and Shijiazhuang (SPM), located in the capital of China, and compared the different components and sources of PM₂.₅ in the two cities. Vehicle emissions are the primary sources of BPM, whereas SPM is industrial emissions. We found that chronic exposure to PM₂.₅ promotes the tumorigenesis and metastasis of lung adenocarcinoma in patient-derived xenograft (PDX) models, as well as the migration and invasion of lung adenocarcinoma cell lines. SPM has more severe effects in vivo and in vitro. The underlying mechanisms are related to the stem cell properties of cancer cells, the epithelial-mesenchymal transition (EMT) process, and the corresponding miRNAs. It is hopeful to provide a theoretical basis for improving air pollution in China, especially in the capital area, and is of the significance of long-term survival of lung cancer patients.
Mostrar más [+] Menos [-]Transfers of embodied PM2.5 emissions from and to the North China region based on a multiregional input-output model
2018
Yang, Xue | Zhang, Wenzhong | Fan, Jie | Yu, Jianhui | Zhao, Hongyan
Atmospheric PM₂.₅ pollution has become a global issue, and is increasingly being associated with social unrest. As a resource reliant local economy and heavy industry cluster, the North China region has become China's greatest emitter, and the source of much pollution spillover to outside regions. To address this issue, the current study investigates the transfers of embodied PM₂.₅ emissions to and from the North China region (which is taken to include Hebei, Henan, Shandong, and Shanxi, and is referred to here as HHSS). The study uses a top-down pollutant emission inventory and environmentally extended multi-regional input-output (EE-MRIO) model. The results indicate that the HHSS area exported a total of 660 Gg of embodied PM₂.₅ to other domestic provinces, mainly producing outflows to China's central coastal area (Jiangsu, Zhejiang, and Shanghai) and the Beijing-Tianjin region. HHSS also imported 224 Gg of embodied PM₂.₅ from other domestic regions, primarily from Inner Mongolia and the northeast. Furthermore, the transfer of embodied emissions often occurred between geographically adjacent areas to save costs; Beijing and Tianjin mainly transferred embodied pollution to Hebei and Shanxi, whilst Jiangsu, Shanghai, and Zhejiang tended to import embodied air pollutants from Shandong and Henan. At the sectoral level, the melting and pressing of metals, the production of non-metallic products, and electric and heat power production were the three dominant economic sectors for PM₂.₅ emissions, together accounting for 81% of total discharges. Capital formation played a key role in outflows (75%) in all sectors. Moreover, the virtual pollutant emissions exported to foreign countries also significantly affected HHSS′ discharges significantly, making up 340 Gg. Allocating responsibility for some proportion of HHSS′ emissions to the Beijing-Tianjin area and the central coastal provinces may be an effective approach for mitigating releases in HHSS.
Mostrar más [+] Menos [-]Mytilus spp. as sentinels for monitoring microplastic pollution in Norwegian coastal waters: A qualitative and quantitative study
2018
Bråte, Inger Lise N. | Hurley, Rachel | Iversen, Karine | Beyer, Jonny | Thomas, Kevin V. | Steindal, Calin C. | Green, Norman W. | Olsen, Marianne | Lusher, Amy
Microplastic (MP) contamination is ubiquitous in the environment and many species worldwide have been shown to contain MP. The ecological impact of MP pollution is still unknown, thus there is an urgent need for more knowledge. One key task is to identify species suitable as sentinels for monitoring in key eco-compartments, such as coastal waters. In Norway, mussels (Mytilus spp.) have been monitored for hazardous contaminants through OSPAR since 1981. Norway has the longest coastline in Europe and adding MP to the Norwegian Mussel Watch is therefore important in a European and global context. The present study reports MP data in mussels (332 specimens) collected from multiple sites (n = 15) spanning the whole Norwegian coastline. MPs were detected at all locations, except at one site on the west coast. Among the most surprising findings, mussels from the Barents Sea coastline in the Finnmark region, contained significantly more MPs than mussels from most of the southern part of the country, despite the latter sites being located much closer to major urban areas. Only mussels from a site located very close to Oslo, the capital, contained levels similar to those observed in the remote site in Finnmark. In total an average of 1.5 (±2.3) particles ind⁻¹ and 0.97 (±2.61) particles w.w. g⁻¹ was found. The most common MPs were <1 mm in size, and fibres accounted for 83% of particles identified, although there was inter-site variability. Thirteen different polymeric groups were identified; cellulosic being the most common and black rubbery particles being the second. This study suggests Mytilus spp. are suitable for semi-quantitative and qualitatively monitoring of MPs in coastal waters. However, some uncertainties remain including mussel size as a confounding factor that may influence ingestion, the role of depuration and other fate related processes, and this call for further research.
Mostrar más [+] Menos [-]Water quality challenges associated with industrial logging of a karst landscape: Guadalcanal, Solomon Islands
2021
Albert, Simon | Deering, Nathaniel | Tongi, Scravin | Nandy, Avik | Kisi, Allen | Sirikolo, Myknee | Maehaka, Michael | Hutley, Nicholas | Kies-Ryan, Shaun | Grinham, Alistair
Human disturbance of karst landscapes in tropical volcanic islands present a unique challenge for understanding sediment transport to the coastal zone. Here we present the first evidence of urban drinking water quality impacts from industrial logging in the Solomon Islands. Despite only 6% of the Honiara's drinking water catchment being disturbed by logging, rhodamine dye tracers demonstrated complex karst sinkholes that led to high suspended sediment concentrations being transported from neighbouring Kovi catchment into the Kongulai water supply offtake point for Honiara. This has resulted in the exceedance of practical treatment thresholds of 20 NTU 9.5% of the time, leading to water supply for the majority of Honiara's residents being unavailable for 58 days in 2019. This work highlights the cost-benefit disparity between industrial logging yielding minimal short-term economic yields in comparison to on-going broader impacts of increased coastal sediment transport while restricting water supply to a developing nation's capital.
Mostrar más [+] Menos [-]Aquatic contaminants in Solomon Islands and Vanuatu: Evidence from passive samplers and Microtox toxicity assessment
2021
Smith, A.J. | Barber, Yehonatan | Davis, S. | Jones, C. | Kotra, K.K. | Losada, S. | Lyons, B.P. | Mataki, M. | Potter, K.D. | Devlin, M.J.
Water Quality issues in many Pacific countries are rising, with the increase in coastal populations and associated urban runoff but management requires contamination issues in the aquatic environment to be identified and prioritised. In Vanuatu and Solomon Islands there are few laboratories and resources to assess for the presence or impact of complex chemical contaminants. The extent and impact of chemical contamination of the marine and coastal environment is poorly described.Passive chemical samplers were used to measure a range of aquatic pollutants around the capital cities, Honiara (Solomon Islands) and Port Vila (Vanuatu). We detected a range of chemicals indicative of agricultural and industrial contamination and a few sites had concerning concentrations of specific hydrocarbons and pesticides. The rapid ecotoxicology test, Microtox, indicated toxic impacts in rivers, coastal sites and urban drains This work provides new data on chemical contamination and possible impacts of that contamination for both countries. The techniques could be applied widely across the region to generate critical data for environmental management, guide monitoring efforts and measure the impact of policy or land-use changes.
Mostrar más [+] Menos [-]Occurrence and abundance of meso and microplastics in sediment, surface waters, and marine biota from the South Pacific region
2020
Bakir, Adil | Desender, Marieke | Wilkinson, Tim | Van Hoytema, Nanne | Amos, Ruth | Airahui, Sammy | Graham, Jennifer | Maes, Thomas
Data on the occurrence and abundance of meso and microplastics for the South Pacific are limited and there is urgent need to fill this knowledge gap. The main aim of the study was to apply a rapid screening method, based on the fluorescence tagging of polymers using Nile red, to determine the concentration of meso and microplastics in biota, sediment and surface waters near the capital cities of Vanuatu and Solomon Islands. A spatial investigation was carried out for sediment, biota and water as well as a temporal assessment for sediment for two consecutive years (2017 and 2018). Accumulation zones for microplastics were identified supported by previous hydrodynamic models. Microplastics were detected for all environmental compartments investigated indicating their widespread presence for Vanuatu and Solomons Islands. This method was in alignment with previous recommendations that the Nile red method is a promising approach for the largescale mapping of microplastics in a monitoring context.
Mostrar más [+] Menos [-]Advances in Membrane Bioreactor: High Performance and Antifouling Configurations
2022
Siagian, Utjok Welo Risma | Khoiruddin, Khoiruddin | Ting, Yen Peng | Boopathy, Ramaraj | Wenten, I Gede
PURPOSE OF REVIEW: This paper reviews recent advances in a membrane bioreactor (MBR) and focuses on the features and performance of MBR configurations. Special attention is given to MBR configurations developed for improving pollutant removal and fouling control. RECENT FINDINGS: The first development discussed in this review is related to pollutant removal. Modified MBR configuration can enhance pollutant removals, such as those observed in baffled, osmotic, aerobic granular sludge, and electric field-assisted MBR. In addition, fouling is still the major problem in MBR applications. Fouling affects membrane performance stability as well as operational and capital costs. Several new MBR configurations have been developed to address fouling issues. By using dynamic membrane and free-moving particles, these new configurations make MBR operation more stable with fewer cleaning operations. In addition, lower cleaning frequency will decrease operational expenditure and capital investment. Due to their unique features, newly developed MBR configurations are proved to display high pollutant removal in wastewater treatment. Meanwhile, MBR with dynamic membranes and moving particles can decrease membrane fouling due to mechanically induced shear with lower energy consumption than shear by conventional aeration.
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