scholarly journals Dynamics of phytoplankton and water quality with control of cyanobacterial bloom in Lake Xuanwu,Nanjing

2010 ◽  
Vol 22 (1) ◽  
pp. 44-48 ◽  
Author(s):  
MEI Zhuohua ◽  
◽  
ZHANG Zhehai ◽  
ZHAO Chunxia ◽  
XU Min ◽  
...  
Keyword(s):  
Water Quality ◽  
Cyanobacterial Bloom ◽  
Lake Xuanwu

scholarly journals A modelling approach to simulate Chlorophyta and Cyanobacteria biomasses based on historical data of a Brazilian urban reservoir

2021 ◽  
Vol 16 (5) ◽  
pp. 1
Author(s):  
Carolina Cerqueira Barbosa ◽  
Lenora Nunes Ludolf Gomes ◽  
Ricardo Tezini Minoti
Keyword(s):  
Water Quality ◽  
Green Algae ◽  
Historical Data ◽  
Cyanobacterial Bloom ◽  
Bottom Layer ◽  
Blue Green Algae ◽  
Water Quality Deterioration ◽  
Good Agreement ◽  
Modelling Approach ◽  
Phytoplankton Group

A process-based model was used to simulate a hindcast based on the worst historical water quality condition of a tropical urban reservoir. Paranoá Lake is located in Brasília-DF, Brazil, and went through intense eutrophication in the 70s and 90s, with an important cyanobacterial bloom event in 1978. The parameters of phytoplankton were calibrated, focusing on the group of Chlorophyta (green algae) and Cyanobacteria (blue-green algae) at four depths (1, 10, 15 and 20m). The results indicated that the model was able to reproduce the Cyanobacteria biomass in comparison with the observations (RMSE=22-29.10-3 mgC L-1). On the other hand, the simulated Chlorophyta biomass showed good agreement with the observed data only in the bottom layer (RMSE=29. 10-3 mgC L-1 at 20m). In the hindcast simulation, the model was able to predict a significant increase in cyanobacterial biomass facing a water quality deterioration. In the meantime, the simulated Chlorophyta biomass decreased, which may indicate the phytoplankton group succession in response to the environmental conditions.

scholarly journals Measurement of Cyanobacterial Bloom Magnitude using Satellite Remote Sensing

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sachidananda Mishra ◽  
Richard P. Stumpf ◽  
Blake A. Schaeffer ◽  
P. Jeremy Werdell ◽  
Keith A. Loftin ◽  
...  
Keyword(s):  
Water Quality ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Water Quality Management ◽  
Cyanobacterial Bloom ◽  
Environmental Water ◽  
Public Health Issue ◽  
Management Decision ◽  
Sensor Calibration ◽  
Remotely Sensed Data

AbstractCyanobacterial harmful algal blooms (cyanoHABs) are a serious environmental, water quality and public health issue worldwide because of their ability to form dense biomass and produce toxins. Models and algorithms have been developed to detect and quantify cyanoHABs biomass using remotely sensed data but not for quantifying bloom magnitude, information that would guide water quality management decisions. We propose a method to quantify seasonal and annual cyanoHAB magnitude in lakes and reservoirs. The magnitude is the spatiotemporal mean of weekly or biweekly maximum cyanobacteria biomass for the season or year. CyanoHAB biomass is quantified using a standard reflectance spectral shape-based algorithm that uses data from Medium Resolution Imaging Spectrometer (MERIS). We demonstrate the method to quantify annual and seasonal cyanoHAB magnitude in Florida and Ohio (USA) respectively during 2003–2011 and rank the lakes based on median magnitude over the study period. The new method can be applied to Sentinel-3 Ocean Land Color Imager (OLCI) data for assessment of cyanoHABs and the change over time, even with issues such as variable data acquisition frequency or sensor calibration uncertainties between satellites. CyanoHAB magnitude can support monitoring and management decision-making for recreational and drinking water sources.

Impact of vacuum UV on natural and algal organic matter from cyanobacterial impacted waters

2020 ◽  
Vol 6 (3) ◽  
pp. 829-838
Author(s):  
Flavia Visentin ◽  
Siddharth Bhartia ◽  
Madjid Mohseni ◽  
Sigrid Peldszus ◽  
Sarah Dorner ◽  
...  
Keyword(s):  
Water Quality ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Cyanobacterial Bloom ◽  
Remote Communities ◽  
Taste And Odor ◽  
Potential Applicability ◽  
Algal Organic Matter ◽  
Drinkable Water ◽  
Vacuum Uv

Cyanobacterial bloom events produce toxins and taste and odor issues, disturbing drinkable water quality. Vacuum UV (VUV) is a promising advanced oxidation process used to treat impacted water, with potential applicability in small and remote communities.

scholarly journals Comparison of the physical, chemical and biological parameter magnitudes and cyanobacterial bloom in the Alagados reservoir of Ponta Grossa - PR

2018 ◽  
Vol 13 (3) ◽  
pp. 1
Author(s):  
Andressa Beló ◽  
Alvaro Luiz Mathias ◽  
Carlos Alberto Ubirajara Gontarski
Keyword(s):  
Water Quality ◽  
Cyanobacterial Bloom ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Quality Parameters ◽  
Reservoir Water ◽  
Physico Chemical ◽  
Ecological Complexity ◽  
Chemical Products ◽  
Chemical Conditions

The cyanobacterial bloom is a consequence of eutrophication in a lentic environment. It is attributed to the contribution of nutrients related to anthropic action, as well as geographic and physico-chemical conditions. Water quality parameters of Alagados reservoir, which supplies Ponta Grossa, were determined between 08/2013 and 08/2014 to evaluate their effects on the occurrence of bloom. Some parameters, such as pH (9.1), DO (4.2 mg L-1), BOD (39 mg L-1), TP (0.86 mg L-1) and number of cyanobacterial cells (372,536 cells mL-1), were outside the limits recommended by CONAMA 357/05 for Class II and Decree 2,914/11 of the Ministry of Health. The bloom was predominantly caused by the overdevelopment of Cylindrospermopsis sp. and required additional use of chemical products in the treatment of municipal water supplies, to include coagulant (19.6%), polymer (21.0%) and activated carbon (1,889%), with a corresponding cost increase of 58%. The Water Quality Index confirmed the worsening of reservoir water quality during bloom. The Principal Component Analysis of historical data (01/2003 to 08/2014) did not discriminate the cyanobacteria levels classes (< 2,000, 2,000-20,000, 20,000-50,000 and > 50,000 cells mL-1) based on Brazilian standards, which was confirmed by the Hierarchical Cluster Analysis; although it confirmed a logical correlation between some parameters (climatic condition-reservoir rainfall-reservoir level and BOD-COD). The unidentified correlations can be attributed to the adaptability of Cylindrospermopsis sp. and the ecological complexity that requires higher sampling frequency.

scholarly journals Water quality assessment in a shallow lake used for tourism

2015 ◽  
Vol 15 (4) ◽  
pp. 155-164 ◽  
Author(s):  
Ewa A. Dembowska ◽  
Patrycja L. Pul
Keyword(s):  
Water Quality ◽  
Shallow Lake ◽  
Cyanobacterial Bloom ◽  
Ecological Status ◽  
Water Quality Assessment ◽  
Current State ◽  
Environmental Monitoring System ◽  
Microcystis Wesenbergii ◽  
Desmodesmus Communis ◽  
Stephanodiscus Hantzschii

Abstract The routine evaluation of water quality is limited to lakes with the largest area. In Poland, only lakes with an area exceeding 50 hectares are monitored by the State Environmental Monitoring System. For many local communities, however, small lakes are more important. This applies mainly to areas with a small number of lakes, where even the smallest lakes are used for various purposes. This paper presents the results of phytoplankton analysis in a small and shallow lake used for recreation. The study was conducted at three sites located in different parts of the lake. A total of 122 algae taxa were identified in the phytoplankton, mainly diatoms and green algae. The most constant taxa in the lake were: Stephanodiscus hantzschii, Desmodesmus communis, Pediastrum tetras and Crucigenia tetrapedia. The average phytoplankton biomass was 37 mg l−1. The maximum biomass, almost 140 mg dm−3, was recorded in late July at the site located near the beach. At that time, there was a massive cyanobacterial bloom composed of Microcystis wesenbergii and Aphanizomenon issatschenkoi. Based on these studies, the lake should be classified as hypertrophic with bad ecological status. This lake should not be used for recreational purposes in the current state.

scholarly journals Extending Landsat 8: Retrieval of an Orange contra-Band for Inland Water Quality Applications

2020 ◽  
Vol 12 (4) ◽  
pp. 637 ◽  
Author(s):  
Alexandre Castagna ◽  
Stefan Simis ◽  
Heidi Dierssen ◽  
Quinten Vanhellemont ◽  
Koen Sabbe ◽  
...  
Keyword(s):  
Water Quality ◽  
Atmospheric Correction ◽  
Cyanobacterial Bloom ◽  
Quality Parameters ◽  
Retrieval Algorithm ◽  
Percentage Error ◽  
Landsat 8 ◽  
Base Line ◽  
Band Ratio ◽  
Water Types

The Operational Land Imager (OLI) onboard Landsat 8 has found successful application in inland and coastal water remote sensing. Its radiometric specification and high spatial resolution allows quantification of water-leaving radiance while resolving small water bodies. However, its limited multispectral band set restricts the range of water quality parameters that can be retrieved. Identification of cyanobacteria biomass has been demonstrated for sensors with a band centered near 620 nm, the absorption peak of the diagnostic pigment phycocyanin. While OLI lacks such a band in the orange region, superposition of the available multispectral and panchromatic bands suggests that it can be calculated by a scaled difference. A set of 428 in situ spectra acquired in diverse lakes in Belgium and The Netherlands was used to develop and test an orange contra-band retrieval algorithm, achieving a mean absolute percentage error of 5.39% and a bias of −0.88% in the presence of sensor noise. Atmospheric compensation error propagated to the orange contra-band was observed to maintain about the same magnitude (13% higher) observed for the red band and thus results in minimal additional effects for possible base line subtraction or band ratio algorithms for phycocyanin estimation. Generality of the algorithm for different reflectance shapes was tested against a set of published average coastal and inland Optical Water Types, showing robust retrieval for all but relatively clear water types (Secchi disk depth > 6 m and chlorophyll a < 1.6 mg m − 3 ). The algorithm was further validated with 79 matchups against the Ocean and Land Colour Imager (OLCI) orange band for 10 globally distributed lakes. The retrieved band is shown to convey information independent from the adjacent bands under variable phycocyanin concentrations. An example application using Landsat 8 imagery is provided for a known cyanobacterial bloom in Lake Erie, US. The method is distributed in the ACOLITE atmospheric correction code. The contra-band approach is generic and can be applied to other sensors with overlapping bands. Recommendations are also provided for development of future sensors with broad spectral bands with the objective to maximize the accuracy of possible spectral enhancements.

scholarly journals Potential Impacts on Treated Water Quality of Recycling Dewatered Sludge Supernatant during Harmful Cyanobacterial Blooms

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 99
Author(s):  
Kanarat Pinkanjananavee ◽  
Swee J. Teh ◽  
Tomofumi Kurobe ◽  
Chelsea H. Lam ◽  
Franklin Tran ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Environmental Protection Agency ◽  
Cyanobacterial Bloom ◽  
The United States ◽  
Cyanobacterial Blooms ◽  
World Health ◽  
Treated Water ◽  
Cell Counts ◽  
Dewatered Sludge

Cyanobacterial blooms and the associated release of cyanotoxins pose problems for many conventional water treatment plants due to their limited removal by typical unit operations. In this study, a conventional water treatment process consisting of coagulation, flocculation, sedimentation, filtration, and sludge dewatering was assessed in lab-scale experiments to measure the removal of microcystin-LR and Microcystis aeruginosa cells using liquid chromatography with mass spectrometer (LC-MS) and a hemacytometer, respectively. The overall goal was to determine the effect of recycling cyanotoxin-laden dewatered sludge supernatant on treated water quality. The lab-scale experimental system was able to maintain the effluent water quality below relevant the United States Environmental Protection Agency (US EPA) and World Health Organisation (WHO) standards for every parameter analyzed at influent concentrations of M. aeruginosa above 106 cells/mL. However, substantial increases of 0.171 NTU (Nephelometric Turbidity Unit), 7 × 104 cells/L, and 0.26 µg/L in turbidity, cyanobacteria cell counts, and microcystin-LR concentration were observed at the time of dewatered supernatant injection. Microcystin-LR concentrations of 1.55 µg/L and 0.25 µg/L were still observed in the dewatering process over 24 and 48 h, respectively, after the initial addition of M.aeruginosa cells, suggesting the possibility that a single cyanobacterial bloom may affect the filtered water quality long after the bloom has dissipated when sludge supernatant recycling is practiced.

scholarly journals Icyano: a cyanobacterial bloom vulnerability index for drinking water treatment plants

2020 ◽  
Vol 20 (8) ◽  
pp. 3517-3530
Author(s):  
Mário U. G. Barros ◽  
João I. R. Leitão ◽  
Thaís R. B. T. Aranha ◽  
Serhat Simsek ◽  
Riley P. Buley ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Environmental Changes ◽  
Cyanobacterial Bloom ◽  
Cyanobacterial Blooms ◽  
Treatment Technology ◽  
Treatment Unit ◽  
Direct Filtration ◽  
Water Treatment Plants ◽  
Pre Treatment

Abstract Managing freshwater systems has become a challenge for global water utilities given that cyanobacterial blooms have been increasing in frequency and intensity. Consequently, a water quality index that uses conventional measurements to assess toxic cyanobacterial hazards and guide the selection of proper treatment technologies could benefit water resource managers about water quality parameters routinely analyzed in line with environmental changes. An index model, called Icyano, showed that chlorophyll-a, cyanobacterial concentration, and total nitrogen were most important for the index. All reservoirs classified as good by Icyano used direct filtration water treatment technology. Many of the medium Icyano-classified reservoirs used a pre-treatment unit followed by a direct filtration unit. Two reservoirs that were classified as bad or very bad have been utilizing pre-treatment + direct filtration or a complete cycle technology, respectively. As the Icyano index increases, water treatment plants should switch from direct filtration to using a pre-treatment to improve finished water quality. Findings from this project suggest that the direct filtration technology initially used in water treatment plants is not capable of meeting the current water quality guidelines in reservoirs that contain adverse water quality conditions, mostly related to an increase in toxic cyanobacterial blooms. As such, based on our findings, we recommend prioritizing financial resources towards pre-treatment technology or changes to more advanced technologies when Icyano index values increase.

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