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The research presented in this manuscript concerns the evaluation of the effectiveness of microstrainers, which are designed to reduce the amount of plankton in treated surface water. The efficiency of microstrainer filtration analysis is very important for the proper course of the water-treatment process not only in the Water-Treatment Plant (WTP)...
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... However, the removal of dissolved toxins using MF and UF is due to the adsorption of the cyanotoxins onto the membrane surface, which significantly decreases with time as the absorption sites become occupied. Enhancing the membrane filtration processes has also recently been realized via advanced operating procedures (Czyżewska and Piontek, 2019;. ...
... One of the solutions is the application of microstrainer filtration as a preliminary stage in drinking water treatment. The effectiveness of removal of phytoplankton, including cyanobacteria, may be more than 90% [15][16][17]. ...
A seasonal plethora of cyanobacteria in the plankton community can have severe implications, not only for water ecosystems but also for the availability of treated water. The catchment of the Obrzyca River (a source of drinking water) is seasonally exposed to harmful cyanobacterial bloom. Previous studies (2008–2012; 2019) revealed that the most polluted water of the Obrzyca River was Uście, close to the outlet of Rudno Lake (at the sampling point). Therefore, the effect on this lake was specifically examined in this study. Sampling was performed from May to September at that site and from July to September 2020 at Rudno Lake. The conducted analysis revealed a massive growth of Aphanizomenon gracile, especially in Rudno Lake. The results showed not only the distinct impact of cyanobacterial bloom on phytoplankton biodiversity but also the presence of microcystins and other cyanopeptides in both sampling points. The maximal total concentration of microcystins (dmMC-RR, MC-RR, dmMC-LR, MC-LR, MC-LY, MC-YR) equaled 57.3 μg/L and the presence of cyanopeptides (aeruginosin, anabaenopeptin) was originally determined in Rudno Lake, August 2021. The presence of these toxins was highlighted in our results for the first time. The same samples from the lake were the most toxic in biotoxicological investigations using the planarian Dugesia tigrina. The performed bioassays proved that D. tigrina is a sensitive bioindicator for cyanotoxins. The physical and chemical indicators of water quality, i.e., color, temperature, total suspended solids, and total nitrogen and phosphorus, showed a significant correlation among each other and towards cyanobacterial abundance and microcystin concentrations.
... For example, manually dredging or removing algae can be labour and resource intensive. Moreover, ultrasonic methods (Feng et al., 2022), filtration (Czyżewska and Piontek, 2019), and adsorption methods are also known to be more expensive when compared to other methods and could also result in secondary pollution problems. Air floatation methods need large quantities of flocculants, which again costs more (Jeong et al., 2021). ...
... The most classic ways of fighting are physical. These include filtration of water from cyanobacteria [5]. An interesting option is the use of biological filters such as wetlands, which lead to a decrease in biogenic elements in the water, which prevent cyanobacteria from multiplying [6]. ...
Currently, a lot of attention is being paid to the fight against water blooming. This paper presents a theoretical basis for combating cyanobacteria using laser radiation. The obtained models show that it is possible to carry out effective control of cyanobacteria in reservoirs even of a very large area. Controlling cyano-bacteria is achieved by irradiating them with a laser installation located on the basis of USV. It can determine the trajectory of movement along the reservoir and destroy cyanobacteria in the most promising areas of the fight. The analysis of cyanobacteria concentrations and reservoir characteristics is carried out by aerial photography using an UAV, which is an integral part of the complex. The use of laser radiation makes it possible to exclude the use of chemicals to combat algae and thereby eliminate the environmental pollution factor. The paper presents the parameters necessary for calculating the parameters of the UAV flight, as well as a method for finding a way for an USV. It also presents the concept of mapping places with the most intensive rate of reproduction of cyanobacteria. Calculations demonstrate the potential for the destruction of cyanobacteria on an area of 155.52 m2 using a 7110 W laser installation with a wavelength of 650 nm.KeywordsRemote controlLaser exposureUAVMultispectral analysisCalculation of the UAV trajectory
... Filtration methods generally include sand filtration and membrane filtration, which can remove algal cells intact without breaking the cells [21]. Sand filtration is usually used after coagulation and sedimentation or air flotation processes and is suitable for raw water with low concentrations of suspended matter and algae cells; raw water with high algae cell concentrations may clog or infiltrate the filter bed. ...
In recent years, the frequent outbreaks of cyanobacterial blooms have caused severe water pollution in many rivers and lakes at home and abroad, endangering drinking water safety and human health. How to remove cyanobacteria from water bodies safely, quickly, and economically has attracted the attention of many scientists. Currently, the typical treatment methods for algae in algae-bearing water bodies are physical, biological, and chemical methods. The physical method of algae removal is for both the symptoms and the root cause, but the workload is extensive, with high input costs, and should not be used on a large scale. The biological method is low-cost, but the removal efficiency is slow and unsuitable for the treatment of sudden water bloom. The chemical method can kill algae quickly, but it is easy to cause secondary pollution. These methods are relatively independent of each other, so the choice of a practical combination of technologies is essential for algal bloom removal and eutrophication management. This paper reviews the current application status and advantages and disadvantages of algae removal technologies at home and abroad; classifies them from physical, chemical, biological, and combined methods; and provides an outlook on the future development direction of algae removal technologies.
... There are two possible approaches to address the problem of the presence of MC-LR in waters: (i) remove the cyanobacteria that produce them or (ii) directly eliminate the free toxin [1]. The conventional treatments present in a drinking water treatment plant (DWTP; e.g., coagulation, flocculation, sedimentation and filtration) allow one to implement the first of the two approaches [22][23][24][25]. However, these treatments are not able to remove the MC-LR already secreted by cyanobacteria and present in the water in dissolved form [26]. On the contrary, adsorption on AC is confirmed to be a viable solution for the removal of low molecular weight substances such as cyanotoxins in general and specifically MC-LR [27][28][29]. ...
The hepatotoxin microcystin-LR (MC-LR) represents one of the most toxic cyanotoxins for human health. Considering its harmful effect, the World Health Organization recommended a limit in drinking water (DW) of 1 µg L−1. Due to the ineffectiveness of conventional treatments present in DW treatment plants against MC-LR, advanced oxidation processes (AOPs) are gaining interest due to the high redox potential of the OH• radicals. In this work UV/H2O2 was applied to a real lake water to remove MC-LR. The kinetics of the UV/H2O2 were compared with those of UV and H2O2 showing the following result: UV/H2O2 > UV > H2O2. Within the range of H2O2 tested (0–0.9 mM), the results showed that H2O2 concentration and the removal kinetics followed an increasing quadratic relation. By increasing the initial concentration of H2O2, the consumption of oxidant also increased but, in terms of MC-LR degraded for H2O2 dosed, the removal efficiency decreased. As the initial MC-LR initial concentration increased, the removal kinetics increased up to a limit concentration (80 µg L−1) in which the presence of high amounts of the toxin slowed down the process. Operating with UV fluence lower than 950 mJ cm−2, UV alone minimized the specific energy consumption required. UV/H2O2 (0.3 mM) and UV/H2O2 (0.9 mM) were the most advantageous combination when operating with UV fluence of 950–1400 mJ cm−2 and higher than 1400 mJ cm−2, respectively.
... Reeds are known to purify waterbodies from a number of harmful substances during vegetation [1][2][3][4]. Besides, reed can be collected and dried to use it as an eco-friendly sorbent to trap heavy-metal ions [5][6][7][8][9][10][11] or mechanically capture phytoplankton [12,13] that grows rapidly in areas at ecological risk and exacerbates the negative impact that aquatic environments are exposed to. ...
Reed is able to absorb water, a quality that enables using it as a cartridge filler in eco-friendly filters to address the contamination of waterbodies. Aside from capturing harmful substances and pathogens, such filters actively absorb water. As the filtering medium becomes saturated with a fluid, its absorption capacity degrades, which is why one needs to know the saturation rates if the water purification process is to be effective. This knowledge helps find out how frequently the cartridge filler must be replaced. Absorption rates were sufficient for purification for three hours as shown by experimental laboratory tests using reeds ground to a variety of specific particle sizes without additional processing that would modify its structure physically and chemically. This indicates that cartridges have to be refilled with a new biosorbent at least twice over the daily period of bacterial activity observable from 10 am to 4 pm during daylight hours.
... Massive cyanobacterial blooms are the result of eutrophication of the water environment. At the same time, they create problems not only during water treatment by clogging filters, disinfection byproducts, taste, odor, etc. [29], but toxic cyanobacterial blooms also have a negative impact on human health. Therefore, monitoring cyanobacterial biomass in surface waters and especially drinking water sources is crucial in quality control systems [9]. ...
Harmful cyanobacteria and their cyanotoxins may contaminate drinking water resources and their effective control remains challenging. The present study reports on cyanobacterial blooms and associated cyanotoxins in the Obrzyca River, a source of drinking water in Poland. The river was examined from July to October 2019 and concentrations of microcystins, anatoxin-a, and cylindrospermopsin were monitored. The toxicity of water samples was also tested using an ecotoxicological assay. All studied cyanotoxins were detected with microcystins revealing the highest levels. Maximal microcystin concentrations (3.97 μg/L) were determined in September at Uście point, exceeding the provisional guideline. Extracts from Uście point, where the dominant species were Dolichospermum flos-aquae (August), Microcystis aeruginosa (September), and Planktothrix agardhii (October), were toxic for Dugesia tigrina Girard. Microcystin concentrations (MC-LR and MC-RR) were positively correlated with cyanobacteria biovolume. Analysis of the chemical indicators of water quality has shown relationships between them and microcystins as well as cyanobacteria abundance.
... If difficulties in achieving the required quality of wastewater arise, it is necessary to timely eliminate the consequences of biogenic pollution in order to prevent critical conditions in the ecological balance of water bodies. The development of eutrophication can be overcome by a fairly reliable and effective way of dealing with excess phytoplankton, based on the hydromechanical principle of filtering water resources [10,11]. The devices of simple construction used in this case provide a directed effect on the epicenter of cyanobacterial reproduction, which helps to localize areas of increased biogenic pollution, preventing them from spreading. ...
Intensive water consumption from surface sources leads to debit imbalance and high level of pollution, especially for wastewater discharges, including urban wastewater treatment facilities. Dissolved harmful and organic substances enter a large number of water bodies, which leads to harsh conditions for the survival of the rivers flora and fauna. A demonstrative indicator of environmental troubles is the intensive development of blue-green algae, which are a nutrient medium for cyanobacteria. Their productivity can be limited by hydromechanical capture. It is proposed to use a small-sized mobile vessel with a filter unit using replaceable cartridges and a pump. As a filter material, it is recommended to use crushed reeds. This technical solution allows the environmentally safe disposal of biomass, saturated with phytoplankton and heavy metal ions that are effectively absorbed. An equation of the distribution of concentrations of blue-green algae over the distance measured from the water surface is provided. The calculated data obtained from the proposed dependence allow us to determine the required level of immersion of the suction probes. The optimal time period in days for the operation of filtering units during summer season was revealed.
The removal of harmful cyanobacteria has recently become an important target in water management strategies. Various methods have been developed to eliminate these microorganisms including: (1) biological methods, especially with floating treatment wetlands and riparian vegetation; (2) physical methods with aeration, mechanical circulation, and hypolimnetic oxygenation; (3) chemical methods with coagulation and flocculation processes; (4) barley straw. We propose that the in situ mechanical-based micro-sieving process provides an opportunity for this to succeed in practice. The appropriate, selective technical parameters and techniques can result in successful water quality improvement, which is essential to meet Water Framework Directive goals and especially for public health. Additionally, micro-sieving used for removing Gloeotrichia can contribute to a significant reduction in internal phosphorus loads, a necessary step in lake restoration. The theoretically probable mean cell-bound P-content transferred with G. echinulata colonies (during strong blooms) can be as high as 48 mg L−1, and this potential P-load is usually deposited on lake bottoms. The removal of cyanobacterium can result in significant limitations of internal P-sources. The method presented above could be a promising, practical, easy-to-use, and cost-effective method for managing and limiting cyanobacterial blooms.
