This paper describes the removal of algae and attached water using a froth flotation method as a function of the collector type, aeration rates, the pH of the algal suspension and temperature of operation. Dispersed air flotation was used in this study to remove Scenedesmus quadricaudo. The addition of surfactants such as cetyltrimethylammonium bromide and sodium dodecylsulfate increased the aeration rates and reduced the size of air bubbles. Only cetyltrimethylammonium bromide gave high algal removal (90%) whereas sodium dodecylsulfate gave poor algal removal (16%). However, by decreasing the pH values of the algal suspension, it was possible to increase the algal removal efficiency up to 80%. Low temperature operation had an important effect on reducing the rate of algal removal but when the temperature was 20 degrees C or higher there was little change with further temperature rises. The amount of water removed with the algal phase was reduced by using a two-stage flotation process.
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http://dx.doi.org/10.1080/09593330309385539 | DOI Listing |
Mar Environ Res
January 2025
College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
Diarrhetic shellfish toxins (DSTs) are widespread in marine environments, posing potential threats to marine ecosystems, shellfish aquaculture, and human health. Despite their prevalence, knowledge of the stability of dissolved DSTs in seawater is still limited. This study aimed to investigate the effects of bacteria, temperature, and irradiation on the stability of dissolved okadaic acid (OA) and dinophysistoxin-1 (DTX1) in seawater.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Department of Civil Engineering and Environmental Management, School of Computing, Engineering and Built Environment, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA, Scotland, UK.
The prevalence of antibiotics in wastewater poses risks to human and animal health, contributing to antimicrobial resistance. Although various antibiotic removal methods exist, microalgae-based technology presents a cost-effective and eco-friendly alternative; however, limited research on its long-term integration in semi-continuous wastewater treatment trials hinders our understanding of its potential effectiveness. This investigation explored the antibiotic removal capabilities of the microalga Auxenochlorella protothecoides in photobioreactors with synthetic wastewater under semi-continuous conditions over one month.
View Article and Find Full Text PDFSci Total Environ
January 2025
Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China. Electronic address:
Under temperature and CO level rising, the dominance of toxic cyanobacteria in primary producers is continuously increasing the risks of water safety and hindering functions of aquatic ecosystems. Thus, it is necessary to evaluate the efficiency of algal control measures under climate warming. Based on highly efficient control of cyanobacteria by protozoan reported in previous studies, this study aimed to investigate top-down effect of protozoan Paramecium on toxic Microcystis under CO-mediated climate warming.
View Article and Find Full Text PDFEnviron Pollut
January 2025
School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL. Electronic address:
Harmful algal blooms (HABs) cause severe economic and environmental impacts, including hypoxic events and the production of toxins and off-flavor compounds. Chemical treatments, such as copper sulfate pentahydrate (CuSO·5HO), are often used to mitigate the damaging effects of algal blooms. However, treatment effects are usually short-lived leading to waterbodies requiring repeated CuSO·5HO applications to control persistent algal blooms, particularly in highly eutrophic systems, such as aquaculture ponds or small agricultural impoundments.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Chemical Department, Faculty of Science, Damietta University, Damietta 34517, Egypt.
The study investigated the enhancement of stability and efficacy in the removal of bivalent nickel ions (Ni(II)) by utilizing a cerium metal-organic framework (Ce-MOF) encapsulated within a food-grade algal matrix. This composite material is integrated into a dual-layer hydrogel containing chitosan and carboxymethyl cellulose. The enhancement of structural integrity in the final product can be attributed to the cross-linking process with epichlorohydrin, leading to the development of Ce-MOF-FGA/CMC-CS hydrogel beads.
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