scholarly journals In-situ electrochemical Fe(VI) for removal of microcystin-LR from drinking water: comparing dosing of the ferrate ion by electrochemical and chemical means

2018 ◽  
Vol 16 (3) ◽  
pp. 414-424 ◽  
Author(s):  
K. L. Dubrawski ◽  
M. Cataldo ◽  
Z. Dubrawski ◽  
A. Mazumder ◽  
D. P. Wilkinson ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Oxidation ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Normal Operation ◽  
Small Water ◽  
Initial Ph ◽  
Contaminate Drinking Water ◽  
Small Water Systems

Abstract Harmful algal blooms (HAB) release microtoxins that contaminate drinking water supplies and risk the health of millions annually. Crystalline ferrate(VI) is a powerful oxidant capable of removing algal microtoxins. We investigate in-situ electrochemically produced ferrate from common carbon steel as an on-demand alternative to crystalline ferrate for the removal of microcystin-LR (MC-LR) and compare the removal efficacy for both electrochemical (EC) and chemical dosing methodologies. We report that a very low dose of EC-ferrate in deionized water (0.5 mg FeO42− L−1) oxidizes MC-LR (MC-LR0 = 10 μg L−1) to below the guideline limit (1.0 μg L−1) within 10 minutes' contact time. With bicarbonate or natural organic matter (NOM), doses of 2.0–5.0 mg FeO42− L−1 are required, with lower efficacy of EC-ferrate than crystalline ferrate due to loss of EC-ferrate by water oxidation. To evaluate the EC-ferrate process to concurrently oxidize micropollutants, coagulate NOM, and disinfect drinking water, we spiked NOM-containing real water with MC-LR and Escherichia coli, finding that EC-ferrate is effective at 10.0 mg FeO42− L−1 under normal operation or 2.0 mg FeO42− L−1 if the test water has initial pH optimized. We suggest in-situ EC-ferrate may be appropriate for sporadic HAB events in small water systems as a primary or back-up technology.

scholarly journals Associations between chlorophyll a and various microcystin-LR health advisory concentrations

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 151 ◽  
Author(s):  
Jeffrey W. Hollister ◽  
Betty J. Kreakie
Keyword(s):  
Drinking Water ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Field Measurements ◽  
World Health ◽  
Health Advisory ◽  
Adverse Health Effects ◽  
Wide Range ◽  
Recreational Use

Cyanobacteria harmful algal blooms (cHABs) are associated with a wide range of adverse health effects that stem mostly from the presence of cyanotoxins. To help protect against these impacts, several health advisory levels have been set for some toxins. In particular, one of the more common toxins, microcystin-LR, has several advisory levels set for drinking water and recreational use. However, compared to other water quality measures, field measurements of microcystin-LR are not commonly available due to cost and advanced understanding required to interpret results. Addressing these issues will take time and resources. Thus, there is utility in finding indicators of microcystin-LR that are already widely available, can be estimated quickly and in situ, and used as a first defense against high concentrations of microcystin-LR. Chlorophyll a is commonly measured, can be estimated in situ, and has been shown to be positively associated with microcystin-LR. In this paper, we use this association to provide estimates of chlorophyll a concentrations that are indicative of a higher probability of exceeding select health advisory concentrations for microcystin-LR. Using the 2007 National Lakes Assessment and a conditional probability approach, we identify chlorophyll a concentrations that are more likely than not to be associated with an exceedance of a microcystin-LR health advisory level. We look at the recent US EPA health advisories for drinking water as well as the World Health Organization levels for drinking water and recreational use and identify a range of chlorophyll a thresholds. A 50% chance of exceeding one of the microcystin-LR advisory concentrations of 0.3, 1, 1.6, and 2 g/L is associated with chlorophyll a concentration thresholds of 23.4, 67.0, 83.5, and 105.8, respectively. When managing for these various microcystin-LR levels, exceeding these reported chlorophyll a concentrations should be a trigger for further testing and possible management action.

scholarly journals Associations between chlorophyll a and various microcystin health advisory concentrations

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 151 ◽  
Author(s):  
Jeffrey W. Hollister ◽  
Betty J. Kreakie
Keyword(s):  
Drinking Water ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Field Measurements ◽  
World Health ◽  
Health Advisory ◽  
Adverse Health Effects ◽  
Wide Range ◽  
Recreational Use

Cyanobacteria harmful algal blooms (cHABs) are associated with a wide range of adverse health effects that stem mostly from the presence of cyanotoxins. To help protect against these impacts, several health advisory levels have been set for some toxins. In particular, one of the more common toxins, microcystin, has several advisory levels set for drinking water and recreational use. However, compared to other water quality measures, field measurements of microcystin are not commonly available due to cost and advanced understanding required to interpret results. Addressing these issues will take time and resources. Thus, there is utility in finding indicators of microcystin that are already widely available, can be estimated quickly and in situ, and used as a first defense against high levels of microcystin. Chlorophyll a is commonly measured, can be estimated in situ, and has been shown to be positively associated with microcystin. In this paper, we use this association to provide estimates of chlorophyll a concentrations that are indicative of a higher probability of exceeding select health advisory concentrations for microcystin. Using the 2007 National Lakes Assessment and a conditional probability approach, we identify chlorophyll a concentrations that are more likely than not to be associated with an exceedance of a microcystin health advisory level. We look at the recent US EPA health advisories for drinking water as well as the World Health Organization levels for drinking water and recreational use and identify a range of chlorophyll a thresholds. A 50% chance of exceeding one of the specific advisory microcystin concentrations of 0.3, 1, 1.6, and 2 μg/L is associated with chlorophyll a concentration thresholds of 23, 68, 84, and 104 μg/L, respectively. When managing for these various microcystin levels, exceeding these reported chlorophyll a concentrations should be a trigger for further testing and possible management action.

scholarly journals Performance of a Handheld Chlorophyll-a Fluorometer: Potential Use for Rapid Algae Monitoring

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1409
Author(s):  
Hamdhani Hamdhani ◽  
Drew E. Eppehimer ◽  
David Walker ◽  
Michael T. Bogan
Keyword(s):  
Chlorophyll A ◽  
Surface Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Water Quality Monitoring ◽  
Ambient Light ◽  
Calibration Equation ◽  
Field Samples ◽  
Potential Use

Chlorophyll-a measurements are an important factor in the water quality monitoring of surface waters, especially for determining the trophic status and ecosystem management. However, a collection of field samples for extractive analysis in a laboratory may not fully represent the field conditions. Handheld fluorometers that can measure chlorophyll-a in situ are available, but their performance in waters with a variety of potential light-interfering substances has not yet been tested. We tested a handheld fluorometer for sensitivity to ambient light and turbidity and compared these findings with EPA Method 445.0 using water samples obtained from two urban lakes in Tucson, Arizona, USA. Our results suggested that the probe was not sensitive to ambient light and performed well at low chlorophyll-a concentrations (<25 µg/L) across a range of turbidity levels (50–70 NTU). However, the performance was lower when the chlorophyll-a concentrations were >25 µg/L and turbidity levels were <50 NTU. To account for this discrepancy, we developed a calibration equation to use for this handheld fluorometer when field monitoring for potential harmful algal blooms in water bodies.

Using Decision Trees to Predict Drinking Water Advisories in Small Water Systems

Opflow ◽  
2016 ◽  
Vol 108 ◽  
pp. E109-E118 ◽  
Author(s):  
Heather M. Murphy ◽  
Munir Bhatti ◽  
Richard Harvey ◽  
Edward A. McBean
Keyword(s):  
Drinking Water ◽  
Decision Trees ◽  
Water Systems ◽  
Small Water ◽  
Small Water Systems

scholarly journals Synergistic Recapturing of External and Internal Phosphorus for In Situ Eutrophication Mitigation

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 2 ◽  
Author(s):  
Minmin Pan ◽  
Tao Lyu ◽  
Meiyi Zhang ◽  
Honggang Zhang ◽  
Lei Bi ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Pilot Scale ◽  
P Adsorption ◽  
Control Approach ◽  
P Concentration ◽  
Water Ph ◽  
Low Levels ◽  
P Removal

In eutrophication management, many phosphorus (P) adsorbents have been developed to capture P at the laboratory scale. Existing P removal practice in freshwaters is limited due to the lack of assessment of the possibility and feasibility of controlling P level towards a very low level (such as 10 μg/L) in order to prevent the harmful algal blooms. In this study, a combined external and internal P control approach was evaluated in a simulated pilot-scale river–lake system. In total, 0.8 m3 of simulated river water was continuously supplied to be initially treated by a P adsorption column filled with a granulated lanthanum/aluminium hydroxide composite (LAH) P adsorbent. At the outlet of the column (i.e., inlet of the receiving tanks), the P concentration decreased from 230 to 20 µg/L at a flow rate of 57 L/day with a hydraulic loading rate of 45 m/day. In the receiving tanks (simulated lake), 90 g of the same adsorbent material was added into 1 m3 water for further in situ treatment, which reduced and maintained the P concentration at 10 µg/L for 5 days. The synergy of external and internal P recapture was demonstrated to be an effective strategy for maintaining the P concentration below 10 µg/L under low levels of P water input. The P removal was not significantly affected by temperature (5–30 °C), and the treatment did not substantially alter the water pH. Along with the superior P adsorption capacity, less usage of LAH could lead to reduced cost for potation eutrophication control compared with other widely used P adsorbents.

scholarly journals Is Occurrence of Harmful Algal Blooms in the Exclusive Economic Zone of India on the Rise?

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
K. B. Padmakumar ◽  
N. R. Menon ◽  
V. N. Sanjeevan
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Exclusive Economic Zone ◽  
Prorocentrum Lima ◽  
Clear Cut ◽  
The Past ◽  
Spatial Coverage ◽  
Indian Waters ◽  
Frequency Intensity

Occurrence, increase in frequency, intensity and spatial coverage of harmful algal blooms during the past decade in the EEZ of India are documented here. Eighty algal blooms were recorded during the period 1998–2010. Of the eighty algal blooms, 31 blooms were formed by dinoflagellates, 27 by cyanobacteria, and 18 by diatoms. Three raphidophyte and one haptophyte blooms were also observed. Potentially toxic microalgae recorded from the Indian waters were Alexandrium spp., Gymnodinium spp. Dinophysis spp., Coolia monotis, Prorocentrum lima, and Pseudo-nitzschia spp. Examination of available data from the literature during the last hundred years and in situ observations during 1998–2010 indicates clear-cut increase in the occurrence of HABs in the Indian EEZ.

Effectiveness of Stormwater Best Management Practices in Headwater Streams to Mitigate Harmful Algal Blooms

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Jennifer Braswell Alford ◽  
Elizabeth Caporuscio
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Best Management Practices ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Outdoor Recreation ◽  
Management Practices ◽  
Headwater Streams ◽  
Best Management

Pollution inputs in surface waters have resulted in extensive impairments to water resources; however, the effectiveness of stormwater best management practices (BMPs) in reducing pollution inputs related to harmful algal blooms (HABs) in headwater streams has not been widely reported. Skypark, Santa’s Village, is an outdoor recreation area in the semiarid San Bernardino National Forest, California. Recreational activities and impervious surfaces at the site contribute pollution to Hooks Creek, a first-order headwater tributary of the Mojave River. The Natural Resources Conservation Service designed and constructed a stormwater sediment erosion control basin system to reduce site gully erosion and improve surface water quality in situ and downstream. Basin water quality was tested biweekly for parameters associated with HABs including temperature, dissolved oxygen, pH, turbidity, conductivity, nitrate (NO3−), and ammonium (NH4+) in situ during wet and dry seasons, with periodic testing for total suspended solids (TSS), total dissolved solids (TDS), total coliform (TC), and Escherichia coli (EC). The BMP structure was effective in lowering temperature and pH and reducing NO3−, TDS, and turbidity during precipitation events, and increased pH levels and lower concentrations of TSS, TC, and EC were present during the dry season. Despite these advantages, the BMP was ineffective in reducing (NH4+) concentrations, a primary contributor to HABs, with 100% of the samples exceeding regulatory criteria throughout the study period. Results highlight the benefits and limitations of stormwater BMPs in protecting water resources from downstream HABs to ensure water resources are protected for current and future generations.

scholarly journals Pathology in Ecological Research With Implications for One Health: Session Summary

2019 ◽  
Vol 47 (8) ◽  
pp. 1072-1075 ◽  
Author(s):  
Wanda M. Haschek ◽  
May Berenbaum ◽  
David E. Hinton ◽  
Michelle Cora ◽  
Neil Chernoff ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
One Health ◽  
Animal Health ◽  
Toxin Production ◽  
Health Science ◽  
Environmental Carcinogens ◽  
Colony Losses ◽  
Bee Colony ◽  
Contaminate Drinking Water

This session explored the effects of pollutants on One Health at the ecosystem level that included microbes, insects, fish, and humans. The concept of One Health seeks to synergize medical, veterinary, and other health science disciplines to more effectively advance human and animal health. Presentations explored the interactions of pesticides, pathogens, phytochemicals, and xenobiotic biotransformation in bee colony losses critical for food security (bees have been recently listed under the 2017 US Food and Drug Administration (FDA) veterinary feed directive); the role of pathology in identifying the effects of pollutants on fish as sentinels for human health; the effects in rats of per- and polyfluoroalkyl substances (PFAS) that can persist in the environment and contaminate drinking water; harmful algal blooms and toxin production leading to animal and human disease; and the processing of environmental carcinogens by intestinal microbiota.

scholarly journals Cryptosporidium in small water systems in Puerto Rico: a pilot study

2015 ◽  
Vol 13 (3) ◽  
pp. 853-858 ◽  
Author(s):  
Guy Robinson ◽  
Harvey A. Minnigh ◽  
Paul R. Hunter ◽  
Rachel M. Chalmers ◽  
Graciela I. Ramírez Toro
Keyword(s):  
Drinking Water ◽  
Puerto Rico ◽  
Pilot Study ◽  
Immunomagnetic Separation ◽  
Water Systems ◽  
Small Water ◽  
Cryptosporidium Oocysts ◽  
Small Water Systems ◽  
Potential Public Health ◽  
Drinking Water Systems

A pilot study was undertaken to investigate the occurrence of Cryptosporidium in four very small drinking water systems supplying communities in rural Puerto Rico. Water samples (40 L) were collected and oocysts were concentrated by calcium carbonate flocculation, recovered by immunomagnetic separation and detected by immunofluorescence microscopy. Cryptosporidium oocysts were identified in all four systems. This is the first report of evidence of the potential public health risk from this chlorine-resistant pathogen in Puerto Rican small water systems. Further work is warranted to fully assess the health risks that Cryptosporidium and other protozoa pose to populations served by community-managed small drinking water systems.

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