J. Papera de Oliveira
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4 records found
1
Lake Kralingse Plas (Rotterdam, the Netherlands), with a surface area of 114 ha and an average depth of 2.3 m, regularly suffered from cyanobacterial blooms. To improve water quality and meet the requirements of the European Union Water Framework Directive (WFD), the responsible authorities, following a system analysis, applied 1064 tonnes of lanthanum-modified bentonite (LMB, commercial name Phoslock®) to the entire lake in November 2021. Water quality was monitored by the water authorities on a monthly basis. Just before the LMB application, at 3, 15, and 36 months post-LMB application, sediment phosphorus (P) release, sediment P fractionation and Lanthanum (La) fate in the sediment were estimated. Following the application, the sediment La content was significantly higher in the top 4 cm of the sediment layers compared to pre-application conditions. The “HCl-P” pool was increased after LMB application, reflecting LaPO4 formation. It was the highest P fraction, increasing from 53.7% at pre-application to 59.5% after 3 months, further increasing to 62.6% of total P after 15 months, and 66.7% after 36 months. This suggested that LMB reduced sediment P release by increasing the non-bioavailable P in the sediment. The average filterable P (FP) fluxes in the sediment cores under anoxic conditions were 6.27 (±4.4), 0.29 (±0.21), −4.65 (±3.1) and 0.27 (±0.42) mg P m−2 day−1 in cores taken before the application, 3, 15, and 36 months after the application, respectively. In addition, to address the LMB efficacy on P release at different pH levels (pH 7 and pH 10), a 256-day sediment core incubation was conducted. The release rate of P following LMB application did not differ between pH 7 and pH 10, indicating the stability of La-bound P under alkaline conditions. This finding is particularly relevant for shallow eutrophic lakes, where high pH and internal P loading may occur.
Aim The objective of this study was to perform a systematic review of the literature to observe the effects of chemical and physical eutrophication control techniques on planktonic organisms in eutrophic environments. It also aimed to evaluate bibliometric production and determine knowledge gaps.
Methods The review was carried out based on the PRISMA methodology. The articles were searched in the databases of Scopus and Web of Science. The articles were screened so that only those within our objective remained. The systematic review was carried out with a final sample of 136 articles.
Results The most frequently mentioned techniques were “Floc & Sink”, “Floc & Lock”, and algaecide application, (chemicals methods); aeration, dredging, and ultrasound (physical methods). There was an increase in the number of publications from 1974 until July 2020, especially on cyanobacteria. The identified gaps were studies on the zooplankton population and plankton community succession, and long-term experiments. All the chemical techniques remove cyanobacteria biomass or biovolume. Aeration, dredging, and ultrasound, which had conflicting results without conclusive findings. The few studies about the plankton community show positive effects on phytoplankton diversity after the “Floc & Sink” technique and an increase in richness after “Floc & Lock” and aeration. All the techniques negatively affect zooplankton, reducing biomass, survival, or abundance.
Conclusions There are many studies on the effect of eutrophication control techniques on cyanobacteria, and they provide good removal of their biomass. However, there is a large gap regarding other phytoplankton taxonomic groups and zooplankton, making it difficult to draw definitive conclusions about the overall impacts of these techniques. ...
Aim The objective of this study was to perform a systematic review of the literature to observe the effects of chemical and physical eutrophication control techniques on planktonic organisms in eutrophic environments. It also aimed to evaluate bibliometric production and determine knowledge gaps.
Methods The review was carried out based on the PRISMA methodology. The articles were searched in the databases of Scopus and Web of Science. The articles were screened so that only those within our objective remained. The systematic review was carried out with a final sample of 136 articles.
Results The most frequently mentioned techniques were “Floc & Sink”, “Floc & Lock”, and algaecide application, (chemicals methods); aeration, dredging, and ultrasound (physical methods). There was an increase in the number of publications from 1974 until July 2020, especially on cyanobacteria. The identified gaps were studies on the zooplankton population and plankton community succession, and long-term experiments. All the chemical techniques remove cyanobacteria biomass or biovolume. Aeration, dredging, and ultrasound, which had conflicting results without conclusive findings. The few studies about the plankton community show positive effects on phytoplankton diversity after the “Floc & Sink” technique and an increase in richness after “Floc & Lock” and aeration. All the techniques negatively affect zooplankton, reducing biomass, survival, or abundance.
Conclusions There are many studies on the effect of eutrophication control techniques on cyanobacteria, and they provide good removal of their biomass. However, there is a large gap regarding other phytoplankton taxonomic groups and zooplankton, making it difficult to draw definitive conclusions about the overall impacts of these techniques.
Evaluation of a modified sequential P extraction protocol
Quantification of Fe(II)-P as a separate phase in seven different freshwater sediments
Brazil is an agricultural giant that plays a crucial role in the Global Phosphorus Challenge (GPC), and whose highly weathered soils are currently dependent on phosphorus (P) fertilizers derived from phosphate rock, a dwindling and critical resource. Brazil imports > 50% of its P fertilizers and P recovery from waste is not yet explored in the country, making it vulnerable to market instabilities, phosphate rock availability, and geopolitical conflicts. To make matters worse, Brazilian research budget has been shrinking for 7 years straight, hindering scientific efforts and causing significant ‘brain drain’, further undermining the country’s capacity to tackle this critical problem. However, an opportunity comes with the new Brazilian Federal government (starting January 2023), which promises to make significant investments in science and higher education. We call for all stakeholders to seize this important moment and timely collaborate in creating multidisciplinary P-related projects, taking advantage of the soon-to-be available resources to develop knowledge, technologies, and training networks to shape a new generation of experts in P management in the tropics. We are confident that through agriculture intensification, intelligent use of resources, new legislation and governance, Brazil will stride towards sustainable food production, bringing immediate value to Brazil and the world by protecting the Amazon forest and advancing to overcome the GPC.