Review
Environmental Sciences
Sofia L. D'Ambrosio, John A. Harrison
Summary: This article provides a critical review of methods used to estimate the diffusive flux of CH4 from lake sediments, including incubation, benthic chambers, and modeling approaches. The limitations and advantages of each method are discussed, along with published comparisons between different methods. The article also highlights the need for the development and application of new methods to advance understanding of lake CH4 fluxes.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Mauricio Silva, Camilo Roa, Nizar Bel Haj Ali, Carrie O'Reilly, Tarek Abichou, Ian R. MacDonald
Summary: In 2004, a Gulf of Mexico oil platform was destroyed by Hurricane Ivan, leading to a continuous discharge of oil and gas. In 2019, a containment device was installed to prevent oil from entering the water column. Plumes of oil and gas bubbles were observed using acoustic survey, visual inspection, and water column collections. Atmospheric methane concentrations were elevated above baseline, and oil rising to the surface was identified as the main source of methane to the atmosphere.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Engineering, Environmental
Maria K. Bjornsdotter, Leo W. Y. Yeung, Anna Karrman, Ingrid Ericson Jogsten
Summary: The study found that Lake Vattern's PFAAs are mainly polluted by atmospheric deposition and surface water inflow. A mass balance analysis of various PFAAs revealed large inputs for certain acids, and proposed correlations between different sources. The research emphasizes the importance of volatile precursor compounds in surface water contamination.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Chemical
Yingdong Wu, Zhongqiu Liu, Fang Wang, Baokuan Li, Yong Gan
Summary: A 1/4-scale water-model experiment investigated the trajectories, velocities, and size distribution of bubbles in a continuous-casting mold. The study found that the motion range of bubbles is influenced by water/gas flow rates, bubble size affects the floating direction of bubbles, and an increase in gas flow rate leads to more bubbles without increasing mean bubble diameter.
Article
Environmental Sciences
Lingling Li, Andrea Fuchs, Sonia Herrero Ortega, Bin Xue, Peter Casper
Summary: The study on spatial distribution of CH4 in deep freshwater lakes reveals that the profundal zone has the highest CH4 content and production potential, while surface water CH4 is not closely related to the sediment production sites. Variations in sediment properties across the lake lead to restricted CH4 dynamics.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Chemistry, Physical
Leon Knuepfer, Kerstin Eckert, Sascha Heitkam
Summary: This article investigates the relationship between size distribution of facet areas and bubble size in aqueous foams. The study reveals that surface measurements tend to overestimate polydispersity and the mean equivalent diameter of the facets is 6% smaller than the bubble diameter obtained through sampling. The proposed method by Wang and Neethling offers a good approximation for reducing uncertainties in surface-based bubble size measurements.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2024)
Review
Engineering, Chemical
Nalaka Rajapakse, Masoumeh Zargar, Tushar Sen, Mehdi Khiadani
Summary: Microbubble aided clarification is widely used in many industries due to its high efficiency and compact unit size. Dissolved air flotation (DAF) is the most common method for generating microbubbles. Various physicochemical parameters of the influent can have significant impacts on the performance of DAF units. This article reviews the effects of viscosity, salinity, temperature, pH, zeta potential, surface tension, solid content, particle size, and hydraulic loading rate on air dissolution, bubble size distribution, and bubble rise velocity. The findings provide important insights for the design and operation of DAF units to improve separation efficiencies.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Agronomy
Jiayu Zhao, Mi Zhang, Wei Xiao, Lei Jia, Xiufang Zhang, Jiao Wang, Zhen Zhang, Yanhong Xie, Yini Pu, Shoudong Liu, Zhaozhong Feng, Xuhui Lee
Summary: Aquaculture ponds are important anthropogenic methane sources, with water temperature being the primary driver of methane flux and ebullition being the main transport way. Dredging may have a larger influence on emission flux than aeration.
AGRICULTURAL AND FOREST METEOROLOGY
(2021)
Article
Environmental Sciences
Lei Zhang, Qianjiahua Liao, Rui Gao, Ran Luo, Cheng Liu, Jicheng Zhong, Zhaode Wang
Summary: The study found that eutrophication plays an important role in shaping the spatial distribution of diffusive CH4 fluxes in lakes, with parameters related to eutrophication having a significant positive relationship with CH4 emissions. Distance to shore and water depth are inversely correlated with CH4 emissions and modify the effects of eutrophication.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Chemistry, Physical
Shan Xue, Yihan Zhang, Taha Marhaba, Wen Zhang
Summary: This study investigates the aeration kinetics and dissolution behavior of oxygen nanobubbles (NBs) and their dependence on bubble size. The results show that larger NBs have higher oxygen mass transfer rates and equilibrium dissolution levels. The dissolution kinetics of oxygen NBs are influenced by the initial bubble size, with smaller bubbles dissolving faster and larger bubbles leading to higher equilibrium dissolution levels. Additionally, oxygen NBs determine the dissolved oxygen levels in water.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Environmental Sciences
Ye Zheng, Yu Sun, Zhihong Zhang, Chao Han, Zhaode Wang, Cheng Liu, Fan Ke, Lei Zhang, Qiushi Shen
Summary: In order to understand the distribution of nutrients, such as phosphorus (P), in eutrophic sediments, this study used the colorimetric diffusive gradients in thin films (DGT) methodology to analyze the labile P in the sediment-water interface of Lake Nansi. The results showed that the labile P concentrations in the sediment profiles of Lake Nansi exhibited significant spatial variations, with excessive P pollution increasing the concentrations. Furthermore, there was a strong positive correlation between labile P and iron, and labile P showed a strong upward mobility from the sediment to the overlying water. These results provide important information for the eutrophication processes in Lake Nansi.
Article
Engineering, Chemical
Rasoul Panjipour, Mohammad Karamoozian, Boris Albijanic
Summary: This paper discusses the relationships between bubble size distributions, gas holdups, interfacial area of bubbles and flotation kinetics by changing four factors: air velocity, solid percentage, frother dosage, and particle size. The results demonstrate that the solid percentage particularly affects gas holdups, which are directly proportional to the interfacial areas of bubbles. The knowledge about bubble size distributions and gas holdups are required to explain the flotation kinetics at different flotation conditions.
MINERALS ENGINEERING
(2021)
Article
Environmental Sciences
Nikolay G. Granin, Vladimir V. Kozlov, Marc De Batist, Igor B. Mizandrontsev, Vyacheslav G. Ivanov, Valery N. Sinyukovich, Mikhail N. Granin, Vadim V. Blinov
Summary: The construction of a dam for the Irkutsk hydroelectric power plant caused the water level in Lake Baikal to increase, leading to a migration of the gas hydrate stability zone in the sediment of the lake. The transition process involved the formation of new gas hydrates, a decrease in methane transfer, and a decrease in methane concentrations in the water. In the future, Lake Baikal may return to a stationary state with higher methane concentrations, which could have adverse effects on the ecosystem.
ENVIRONMENTAL EARTH SCIENCES
(2023)
Article
Environmental Sciences
Yuqing Miao, Henan Meng, Wenlei Luo, Biao Li, Hao Luo, Qi Deng, Youru Yao, Yinggui Shi, Qinglong L. Wu
Summary: This study quantifies the spatial and seasonal variability of diffusive greenhouse gas (GHG) emissions from Lake Fuxian in southwestern China. The results show significant variations in GHG emissions, highlighting the importance of increasing temporal resolution in GHG flux measurements. Water temperature and oxygen concentrations were found to regulate seasonal variability in emissions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Microbiology
A. Yu. Kallistova, D. D. Koval, V. V. Kadnikov, S. V. Toshchakov, S. K. Yusupov, A. O. Izotova, E. N. Vinogradova, I. Zekker, N. V. Pimenov
Summary: Eutrophication of lakes leads to increased methane emission, especially in littoral areas where the oxygen levels vary. The microbial communities in littoral areas, as well as the microorganisms involved in the methane cycle, are not well-studied. This study investigated methanogenesis and methane oxidation in a littoral site of Lake Senezh, Russia, using a combination of analytical, microbiological, and molecular techniques. The results revealed a diverse community of aerobic, facultative anaerobic, and anaerobic microorganisms capable of performing all reactions of the N, S, and CH4 cycles. Methane formation occurred through various pathways, and methane oxidation was predominantly carried out by type I methanotrophs, with type II nitrate- and nitrite-dependent methanotrophs also present. The study suggests that all potential methane formation in the littoral site of the lake could be simultaneously oxidized.