Proliferation Of Algae Research Articles

Experimental investigation on the mechanism of the effect of flow velocity on Cyclotella meneghiniana

To investigate the growth patterns and influencing mechanisms of algal cells in the Henan section of the Middle route of South-to-North Water Transfer project under varying flow velocities, we focused on studying the dominant diatom species in this region. Utilizing self-designed experimental devices, a flow rate range of 0 to 1.0 m s−1 was established, and the growth conditions of Cyclotella meneghiniana were recorded for each group. The findings revealed that under different flow rates, C. meneghiniana exhibited a critical flow rate threshold at 0.4 m s−1, demonstrating an overall trend characterized by ‘when the flow velocity is relatively low, an increase in flow velocity will promote the growth of C. meneghiniana. However, when the flow velocity is relatively high, an increase in flow velocity will instead inhibit the growth of C. meneghiniana.’ By combining these experimental results with theoretical analysis, we explored the underlying mechanism behind the influence of flow velocity on algal cells. Our experiments demonstrated that below the critical flow rate, increased fluid velocity enhanced nutrient absorption by promoting contact between algal cells and nutrients, thereby facilitating algal cell growth. However, as fluid shear stress intensified with higher flow velocities, it eventually caused mechanical damage to cell structures leading to a critical threshold being reached. These research outcomes provide valuable insights into understanding how water dynamics impact algae cell growth while offering technical support for controlling algae proliferation based on principles derived from water dynamics within the Henan section of South-to-North Water Transfer project.

The Rise of Algae promoted eukaryote predation in the Neoproterozoic benthos.

The proliferation of marine algae in the Neoproterozoic Era is thought to have stimulated the ecology of predatory microbial eukaryotes. To test this proposal, we introduced algal particulate matter (APM) to marine sediments underlying a modern marine oxygen minimum zone with bottom-water oxygen concentrations approximating those of the late Neoproterozoic water column. We found that under anoxia, APM significantly stimulated microbial eukaryote gene expression, particularly genes involved in anaerobic energy metabolism and phagocytosis, and increased the relative abundance of 18S rRNA from known predatory clades. We additionally confirmed that APM promoted the reproduction of benthic foraminifera under anoxia with higher-than-expected net growth efficiencies. Overall, our findings suggest that algal biomass exported to the Neoproterozoic benthos stimulated the ecology of benthic predatory protists under anoxia, thereby creating more modern food webs by enhancing the transfer of fixed carbon and energy to eukaryotes occupying higher trophic levels, including the earliest benthic metazoans.

Benthic algal community dynamics on Palmyra Atoll throughout a decade with two thermal anomalies

Coral reef algae serve many important ecological functions, from primary production to nutrient uptake and reef stabilization, but our knowledge of longer-term effects of thermal stress on algae in situ is limited. While ocean warming can facilitate proliferation of algae and potential phase shifts from coral to macroalgal-dominated states, algal responses may vary by species, genus, functional group, or type (e.g., calcareous vs. fleshy). We used 11 years of annual monitoring data (2009-2019) that spans two El Niño-associated heatwaves to examine benthic algal community dynamics on Palmyra Atoll in the central Pacific Ocean. We quantified the percent cover of algal taxa via image analysis of permanent benthic photoquadrats from two habitats on Palmyra: the deeper, wave-exposed fore reef (10 m depth) and the shallower, wave-sheltered reef terrace (5 m depth). Each habitat was characterized by distinct algal communities: predominantly calcareous taxa on the fore reef and predominantly fleshy taxa on the reef terrace. Patterns in abundance fluctuated over time and/or in response to thermal anomalies in 2009 and 2015. Fleshy algae generally increased in cover post-warming, which coincided with large declines of the calcified macroalgae, Halimeda spp. Long-term monitoring of coral reef algal communities is critical for understanding their differential responses to thermal stress and can improve projections of ecosystem functioning in the context of global change.

Production of Algae-Derived Biochar and Its Application in Pollutants Adsorption—A Mini Review

Developing algae cultivation for food, chemicals, and bio-energy generates a significant amount of algal waste/residue after utilization. Meanwhile, harmful algal blooms caused by abnormal proliferation of various algae produce a large amount of algal biomass, posing serious harm to human health, the environment and the economy. Converting algae body to biochar is a crucial method with which to take advantage of this resource. Biochar usually has a large specific surface area, developed pore structure, high cation exchange capacity and rich surface functional groups. With the advantage of stable physical/chemical properties and easy modification techniques, biochar posited as an ideal adsorption material. From the perspective of algal biomass utilization, this paper reviews the preparation and modification methods, structural characteristics, physicochemical properties and environmental implications of algal biochar. The adsorption effect and mechanisms of algal biochar on nutrients, heavy metals, and organic matter in water are introduced. In light of the current research status, the challenges faced in practical application of algae-derived biochar adsorption materials are pointed out, and a research direction for preparation and application is also developed, with a view to providing a reference for the further utilization of algae-derived biochar.

A Water Quality Prediction Model Based on Modal Decomposition and Hybrid Deep Learning Models

When the total nitrogen content in water sources exceeds the standard, it can promote the rapid proliferation of algae and other plankton, leading to eutrophication of the water body and also causing damage to the ecological environment of the water source area. Therefore, making timely and accurate predictions of water quality at the source is of vital importance. Since water quality data exhibit non-stationary characteristics, predicting them is quite challenging. This study proposes a novel hybrid deep learning model based on modal decomposition, ERSCB (EMD-RBMO-SVMD-CNN-BiGRU), to enhance the accuracy of water quality forecasting. The model first employs Empirical Mode Decomposition (EMD) technology to decompose the original water quality data. Subsequently, it quantifies the complexity of the subsequences obtained from EMD using Sample Entropy (SE) and further decomposes the most complex subsequences using Sequential Variational Mode Decomposition (SVMD). To address the matter of selecting balanced parameters in SVMD, this study introduces the Red-Billed Blue Magpie Optimization (RBMO) algorithm to optimize the hyperparameters of SVMD. On this basis, a forecasting model is constructed by integrating Convolutional Neural Networks (CNN) and Bidirectional Gated Recurrent Unit (BiGRU) networks. The experimental results show that, compared to existing water quality prediction models, the ERSCB model has an improved prediction accuracy of 4.0% and 3.1% for the KaShi River and GongNaiSi River areas, respectively.

Assessment of the Usability of the Linkage between GLORIA and Sentinel-2 Imagery for the Surveillance of Algal Blooms in Freshwater Ecosystems

Due to the recent anomalous climatic conditions, the mean summer temperature in Korea for the current year reached 25.6°C, marking the highest temperature recorded since 1973. Concurrently, the incidence of large-scale green algal blooms has escalated beyond the typical frequency in the four principal river systems. The Ministry of Environment has instituted a water quality monitoring network aimed at gathering data pertinent to water quality assessment and regulatory measures; however, the reliance on discrete point data imposes constraints on comprehending the spatial distribution and proliferation of green algae. Techniques for remote monitoring of green algae utilizing satellite imagery may serve as an alternative or complementary resource to conventional point-based water quality assessments. In the present study, we devised and critically assessed an algorithm for the remote estimation of freshwater chlorophyll-a concentrations through the analysis of Sentinel-2 satellite data. Given the challenges associated with field data collection, the GLORIA dataset was employed, and three variations of the CatBoost algorithm were developed based on different input variables, with their effectiveness concerning Sentinel-2 satellite data subjected to evaluation. Among the three algorithms, the variant that was trained utilizing variables such as band ratio and spectral shape was contrasted with 76 field measurements of surface chlorophyll-a, demonstrating a commendable accuracy with an R value of 0.79, root mean square error of 10.1 mg/m<sup>3</sup> when applied to the GLORIA dataset. The chlorophyll-a quantification algorithm predicated on Sentinel-2 satellite data, which was developed in this study, holds the potential to be utilized effectively for collaborative management and responsive measures regarding green algae by providing objective insights into the prevalence of green algae across extensive areas, temporal trends, and localized hotspots.

Efficiency of Cerium Nitrate and Hydrogen Peroxide in Removing Ammonia and Nitrite from Aquaculture Wastewater and Its Impact on Microbial Community Dynamics

Aquaculture wastewater is rich in nutrients such as nitrogen and phosphorus. If discharged directly without treatment, it can cause eutrophication of water bodies and the proliferation of algae. This study explores the treatment of aquaculture wastewater using cerium nitrate and hydrogen peroxide. To improve the treatment efficiency of ammonia and nitrite in aquaculture wastewater, a Box–Behnken design with three factors at three levels was used to optimize the process of treating aquaculture wastewater with cerium nitrate and hydrogen peroxide. The optimal process conditions for removing ammonia and nitrite were determined to be a Ce(NO3)3 dosage of 0.18 g/L, an H2O2 reaction concentration of 1.0%, and a reaction time of 30 min. Under the optimal reaction conditions, the degradation rate of ammonia and nitrite can reach 80% or more. Finally, high-throughput sequencing technology was used to explore the impact of cerium nitrate and hydrogen peroxide treatment on microbial community structure and metabolic pathways. The results showed that, at the phylum level, the dominant positions of Actinobacteriota, Proteobacteria, and Bacteroidota were maintained throughout the entire culture period. At the genus level, the relative abundance of the hgcI_clade genus under Actinobacteriota significantly increased, becoming the main dominant genus throughout the culture period. Under the condition of adding cerium nitrate and hydrogen peroxide, the metabolic functions of the microbial community were enhanced. The addition of cerium nitrate and hydrogen peroxide increased the abundance of key nitrogen metabolism genes such as amo, hao, and nap, thereby enhancing the potential nitrification/denitrification capabilities of microorganisms. The combination of cerium nitrate and hydrogen peroxide showed positive effects in the treatment of aquaculture wastewater, providing a new strategy for the green treatment of wastewater.

Late Cretaceous ecosystem dynamics in the southern incipient Arctic Ocean: A micropaleontological and geochemical perspective

Late Cretaceous ecosystem dynamics in the southern incipient Arctic Ocean: A micropaleontological and geochemical perspective

Pollution resistance and removal efficiency of mesophytic plants of polluted water bodies

With the development of cities and economic growth, the eutrophication of urban park landscape water has become a hot topic in environmental governance and research at home and abroad. Using indoor water pollution simulation experiments, the decontamination and pollution resistance performance of six aquatic plants were studied. The research results found that all six aquatic plants can reduce the pH value of eutrophic water bodies. The pH of the Lythrum salicaria L. (Q) and Iris tectorum Maxim (Y) treatment systems was the lowest which are 7.34 and 7.48, respectively. They were significantly lower than the control group (CK). The content of nitrogen and phosphorus elements were reduced by six types of plants in the wastewater. After the completion of the experiment, the total nitrogen (TN) removal efficiency of Y was as high as 66.2%, and its content decreased from 9.49 to 3.21 mg/l. The removal rates of total phosphorus (TP) by six types of plants ranged from 59.1 to 81.3% and they were significantly higher than the CK. Among them, the removal rate of TP in wastewater by Y treatment exceeded 80%, which is superior to other plants and significantly different from CK. After the completion of the experiment, the content of chlorophyll a (chl a) in the water treated with Y was the lowest (6.6 mg/l). It was significantly lower than the other treatments (P<0.05). The contents of chl a in Y decreased by 37.1% compared to the initial level. Compared to CK, it is 54.1% lower and the content of chl a in CK showed an increasing trend with time delay. Overall analysis shows that the microsystems formed by the six plants all have a certain improvement effect on water quality, effectively inhibiting the proliferation of algae in eutrophic water bodies. Among them, planting iris has the best effect. Bangladesh J. Bot. 53(3): 757-763, 2024 (September) Special

Robust Natural Light-Absorbable and -Degradable AIE Photosensitizers for Fluorescence Labeling and Efficient Photodynamic Eradication of Algal Pollutants.

Current water pollution caused by the excessive proliferation of harmful algae urges green methods that can efficiently utilize natural light to treat algal pollution. Herein, a series of aggregation-induced emission (AIE) photosensitizers that can efficiently harness sunshine were synthesized for the environmentally friendly and biocompatible treatment of algal pollution. By tuning the number of thiophene units and the electron conjugation degree, the photosensitizers' absorptions were broadened to cover the whole visible light range. The positive charges guided photosensitizers to aggregate on algal cell surfaces, resulting in a turn-on fluorescence signal and robust reactive oxygen species generation under sunshine, thereby achieving fluorescence labeling and photodynamic eradication of algae. The eradication outcomes demonstrated that the AIE photosensitizers significantly outperformed the commercial algaecide ALG. At 20 ppm photosensitizers, 90.4% and 94.2% killing rates were achieved for C. reinhardtii and C. vulgaris, respectively, 2.8- and 3.6-fold higher than those from the same concentration of ALG. Excellent performances in inhibiting algae growth were also verified with efficiency superior to that of ALG. Importantly, the photosensitizers can self-degrade into biocompatible fragments under irradiation to avoid secondary pollution. The developed photosensitizers that possess sunshine convertibility and degradability provide an efficient tool for algal treatment, showing broad research and application prospects.

Lacustrine groundwater discharge-derived carbon and nitrogen to regulate biogeochemical processes as revealed by stable isotope signals in a large shallow eutrophic lake

Lacustrine groundwater discharge-derived carbon and nitrogen to regulate biogeochemical processes as revealed by stable isotope signals in a large shallow eutrophic lake

Primary productivity recovery and shallow-water oxygenation during the Sturtian deglaciation in South China

Primary productivity recovery and shallow-water oxygenation during the Sturtian deglaciation in South China

Large nitrogen cycle perturbations during the Early Triassic hyperthermal

Large nitrogen cycle perturbations during the Early Triassic hyperthermal

The Use of Electrochemical Cells to Generate Nanobubbles As Innovative Agents for Alleviating Eutrophication in Aquatic Environments

Eutrophication, characterized by the excessive accumulation of nutrients, notably nitrogen and phosphorus, in aquatic environments, represents a growing concern in contemporary environmental science. Specifically, eutrophication is intricately associated with the proliferation of algae, giving rise to the development of dense populations known as algal blooms. Harmful Algal Blooms (HABs), primarily composed of cyanobacteria and green algae, pose a threat to aquatic ecosystems by diminishing water clarity, depleting oxygen levels, and, in certain instances, generating detrimental toxins. The global incidence of HABs is increasing, and their frequency is anticipated to further rise due to the impacts of climate change.Conventional methods of water management often encounter significant challenges in effectively addressing and mitigating occurrences of algae blooms. HAB present a multifaceted challenge, influenced by nutrient pollution, climate factors, and diverse algal species. The intricate interactions among these elements contribute to the complexity of the issue. Additionally, the varying responses of algae to environmental conditions and the potential toxicity of certain species further complicate mitigation efforts. To address this challenge effectively, a nuanced understanding of these interconnected factors is essential. Implementing targeted strategies for sustainable water management is crucial for mitigating the impact of algae blooms on aquatic ecosystems and human health.Nanobubble technology represents a revolutionary approach to gas exchange, generating ultrafine bubbles with distinctive properties. These bubbles, with diameters smaller than 1000 nm, are non-buoyant, negatively charged, and exhibit remarkable longevity. These attributes allow them to spontaneously form at the interface between solid surfaces and aqueous solutions. Moreover, their small size enhances mass transport at the electrode-electrolyte interface, impacting reaction rates and catalytic activity. These electrochemical properties position nanobubbles as promising candidates for applications in electrosynthesis, energy storage, and water treatment, with ongoing research aiming to further understand their intricate interplay in diverse electrochemical processes. Nanobubbles play a pivotal role in improving water quality by reducing surface tension, preventing the escape of gas molecules into the atmosphere. This action effectively enhances the concentration of dissolved oxygen in bodies of water. By mitigating the adverse effects of HABs, nanobubbles emerge as a transformative technology with the potential to revolutionize water management strategies.Our research entails a thorough investigation into the formation mechanisms and diverse applications of nanobubbles. The work presented here specialized focuses on nanobubble generation using electrochemical cells. We aim to present how nanobubbles are generated using customized and portable electrochemical cells and the unique properties of these generated nanobubbles. Preliminary results will also be presented to compare the nanobubbles generated using electrochemical cells to the nanobubbles generated using conventional approaches currently employed in the industry. By delving into the details of nanobubble formation, we seek to understand their effectiveness at addressing the challenges associated with eutrophication and HABs in aquatic environments. This comparative analysis will shed light on the advantages and limitations of generating nanobubbles using electrochemical cells in the context of restoration of bodies of water, offering valuable insights for future applications and guiding decisions in environmental management practices.

Harmful Algal Blooms on the Portuguese coast: Cross-checking events with remote sensing ocean colour data for coastal management

Harmful Algal Blooms on the Portuguese coast: Cross-checking events with remote sensing ocean colour data for coastal management

Carbon sequestration in coastal sediments via in situ capping with steel slag

Carbon sequestration in coastal sediments via in situ capping with steel slag

Synergy of lacustrine groundwater discharge and algal biomass on CH4 and CO2 pathways and emissions in a large shallow eutrophic lake

Synergy of lacustrine groundwater discharge and algal biomass on CH4 and CO2 pathways and emissions in a large shallow eutrophic lake

Spatial distribution of settlement of Diadema antillarum around Saba, Dutch Caribbean.

The mass mortality event of the herbivorous sea urchin Diadema antillarum in 1983-1984 has been a major contributor to the diminished resilience of coral reefs throughout the Caribbean. The reduction in grazing pressure resulted in algae proliferation, which inhibited coral recruitment after disturbances such as disease, hurricanes, pollution and climatic change induced marine heat waves. Natural recovery of D. antillarum after the 1983-1984 die-off has been slow. However, the few locations with recovered populations exhibit signs of improvement in coral reef health, prompting interest in D. antillarum restoration. Current restoration strategies include translocation of wild individuals, the restocking of juveniles that are either cultured from gametes or collected as settlers and head-started in a nursery, and assisted natural recovery by providing suitable settlement substrate. Both the collection of wild settlers and assisted natural recovery necessitate an understanding of the local, spatiotemporal trends in settlement. In this study, which was carried out on the Dutch Caribbean Island of Saba, artificial turf settlement collectors were deployed at nine locations around the island and monitored from June 2019 till July 2020 (13 months). The primary objective was to identify trends in larval settlement in space and time, to be able to optimize restoration efforts. Additionally, the small size of Saba allowed us to deploy settlement collectors around the island and compare D. antillarum settlement between windward and leeward sides. Our study showed that on Saba, D. antillarum settlement peaked in June and July, following similar seasonal trends observed around other islands in the Northeastern Caribbean. By far the most settlement occurred at the leeward side of the island, suggesting that hydrodynamic forces entrained D. antillarum larvae in the lee of Saba and/or calmer waters facilitated settlement. Limited settlement occurred on the more exposed windward locations. The identified high settlement locations are candidates for settler collection and restoration attempts. Continued monitoring of D. antillarum settlement, especially in light of the 2022 D. antillarum die-off, holds significance as it can provide insights into the potential of natural recovery.

Elimination of Chlorella using peracetic acid activated by dielectric barrier discharge plasma: Mechanism and cell deactivation process

Elimination of Chlorella using peracetic acid activated by dielectric barrier discharge plasma: Mechanism and cell deactivation process

A STUDY ON DETERMINATION OF TOTAL PHENOLIC AND PROTEIN AMOUNTS OF WASTE GREEN ALGAE OF MAMASIN DAM LAKE (AKSARAY-TURKEY)

The excessive proliferation of green algae in aquatic ecosystems threatens aquatic life, leading to oxygen depletion and water pollution. This study investigates two common green algae species, Ulva sp. and Cladophora sp., with potential in terms of protein and phenolic compounds. Cladophora sp. and Ulva sp. extracts were analyzed for total phenolic content using the Folin-Ciocalteau method. Despite lower phenolic content compared to specific plant species, both algae species exhibit various phenolic compounds. GC-MS analysis indicates the presence of major compounds such as limonene in Cladophora sp. and Tetradec-1-ene in Ulva sp., suggesting potential applications in the pharmaceutical and cosmetic industries. Despite modest protein amounts, the study emphasizes that algae, aligned with the increasing interest in plant-based nutrition, are a promising source for plant-based protein production. Ulva sp. and Cladophora sp. algae demonstrate potential as alternative protein sources and reservoirs of bioactive phenolic compounds from waste sources. This study pioneers further research in the food, pharmaceutical, and cosmetic industries to contribute to sustainable water resource utilization.