Abstract
Eutrophication is a global concern that has severely deteriorated aquatic ecosystems. This phenomenon has impacted the freshwater bodies (such as lakes and rivers) across the world due to the nutrients (mainly N and P) arising from point and non-point pollution sources. Nutrient enrichment induces cyanobacteria formation, hypoxia, and release of bloom toxins, causing their accumulation in aquatic organisms and humans. Preventing the use of chemicals (such as fertilizers) at the source can avoid nutrient release in the run-off streams, thus controlling non-point pollution. While point source pollutants can be effectively controlled at the sewage treatment plants. Although freshwater eutrophication managements have been widely discussed, a systematic eutrophication characterization of lakes and rivers worldwide, with their effective, economically feasible, eco-friendly, and beneficial bio-treatments is still scarce. Hence, in this review, a complete eutrophication-based characterization of lakes and rivers all over the world is provided. Different cost-effective and efficient bio-remediations to control point and non-point pollution are discussed, additionally with a comparative account for the selection of a suitable microbe and remediation approach. A combined point and non-point pollution management can eradicate eutrophication.
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•Eutrophication is an arising phenomenon in the freshwater ecosystems.•Non-point (diffuse) sources are the main cause of eutrophication.•Light, nutrients, water flow rate, and temperature influence bloom production.•A sequenced controlling strategy is required to alleviate diffuse sources.•Microalgae has dual benefits of wastewater treatment and biofuel production.