scholarly journals Factors Affecting Temporal and Spatial Variations of Microcystins in Gonghu Bay of Lake Taihu, with Potential Risk of Microcystin Contamination to Human Health

2010 ◽  
Vol 10 ◽  
pp. 1795-1809 ◽  
Author(s):  
Qing Wang ◽  
Yuan Niu ◽  
Ping Xie ◽  
Jun Chen ◽  
Zhimei Ma ◽  
...  
Keyword(s):  
Lake Taihu ◽  
Human Beings ◽  
Water Safety ◽  
Factors Affecting ◽  
Chl A ◽  
Drinking Water Safety ◽  
Physicochemical Factors ◽  
Littoral Zones ◽  
Negative Exponential ◽  
Pelagic Area

A field survey of the seasonal variation of microcystin (MC) concentration was performed in Gonghu Bay (a total of 15 sampling sites) of Lake Taihu from January to December 2008.Microcystis spp.biomass and intra-/extracellular MCs were significantly correlated with water temperature, suggesting the importance of temperature in cyanobacterial blooming in the lake. Higher MC concentration was found in summer and autumn, and peaks ofMicrocystis biomassand intra-/extracellular MC concentrations were all present in October. Spatially, risk of MCs was higher in littoral zones than in the pelagic area. There were significant correlations between N or P concentrations, andMicrocystis biomassor MC content, suggesting that N and P levels affected MC production through influencingMicrocystis biomass. Intra-/extracellular MCs andMicrocystis biomasshad negative exponential relationships with TN:TP, and the maximum values all occurred when TN:TP was <25. Multivariate analyses by pcca indicated that intra- and extracellular MC concentrations had better correlations with biological factors (such asMicrocystis biomassand chl-a) than physicochemical factors. The maximum concentration reached up to 17 µg/L MC-Lreq, considerably higher drinking water safety standard (1 µg/L) recommended who. So it is necessary take measures reduce exposure risk of cyanobacterial toxins human beings.

scholarly journals Spatiotemporal Patterns and Threshold of Chlorophyll-a in Lake Taihu Based on Microcystins

2021 ◽  
Author(s):  
xuemei fu ◽  
Mingxia Zheng ◽  
Jing Su ◽  
Beidou Xi ◽  
Daichun Wu ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Chlorophyll A ◽  
Lake Taihu ◽  
Water Quality Management ◽  
Water Security ◽  
Water Safety ◽  
Chl A ◽  
Guideline Value ◽  
Guideline Values

Abstract Chlorophyll-a (Chl- a ) is considered an indicator of phytoplankton biomass dynamically reflecting the growth of algae. Therefore, determination of Chl- a threshold is of vital importance to the health of aquatic ecosystems and drinking water security. This research is aimed to investigate the spatial and temporal distributions of Chl- a and microcystin (MC) concentrations using Geographic Information System (GIS) and identify the Chl- a threshold in Lake Taihu based on available guideline values of MCs. Nearly the same characteristics of spatiotemporal variation of Chl- a and MCs were observed in Lake Taihu. Overall, the lakewide distributions of Chl- a and MCs were highly variable over time and space. The Chl- a concentration in the winter and spring was relatively low, and gradually increasing in summer and autumn, with the maximum concentration observed in August. But the maximum MCs concentration appeared in October, two months lagging behind the Chl- a . The highest annual average Chl- a and MCs concentrations were observed in Zhushan Bay, Meiliang Bay, Gonghu Bay in northwest of Lake Taihu, following by West Zone and Center Zone. Dongtaihu Bay, East Zone and South Zone always present good water quality. Referring to the guideline value of MCs, the Chl- a threshold was determined as 10-15 mg·m -3 based on the linear regression correlation between Chl- a and MCs. The establishment of Chl- a threshold is useful for eutrophication control, water quality management and drinking water utilities in developing water safety plans.

Factors Affecting Bioconcentration of Trace Organic Contamination in Waters

1989 ◽  
Vol 21 (2) ◽  
pp. 147-150 ◽  
Author(s):  
D. W. Hawker ◽  
D. W. Connell
Keyword(s):  
Molecular Weight ◽  
Bioconcentration Factor ◽  
Aqueous Solubility ◽  
Organic Chemicals ◽  
Organic Contamination ◽  
Hydrophobic Organic Chemicals ◽  
Factors Affecting ◽  
Water Partition Coefficient ◽  
Physicochemical Factors ◽  
Trace Organic

The influence of some important biological and physicochemical factors on the bioconcentration of hydrophobic organic chemicals is outlined. For non-ionizable, persistent compounds the bioconcentration factor can be related to a compound's octanol/water partition coefficient, aqueous solubility and molecular weight, while the lipid content of an organism also affects the bioconcentration potential of these compounds. The effect of ionization and biodegradation of organic chemicals on bioconcentration is also discussed.

scholarly journals Biosensing Near the Exceptional Point Based on Resonant Optical Tunneling Effect

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 426
Author(s):  
Yang Liu ◽  
Pengyun Yan ◽  
Feng Liu ◽  
Aoqun Jian ◽  
Shengbo Sang
Keyword(s):  
Exceptional Point ◽  
Tunneling Effect ◽  
Coupled Mode Theory ◽  
Environment Protection ◽  
Label Free ◽  
Liquid Sample ◽  
Water Safety ◽  
Coupled Mode ◽  
Drinking Water Safety ◽  
Optical Tunneling

Inspired by exceptional point (EP) sensing in non-Hermitian systems, in this work, a label-free biosensor for detecting low-concentration analytes is proposed, via a special multilayer structure: a resonant optical tunneling resonator. Due to the square root topology near the exceptional point, a recognized target analyte perturbs the system deviated from the exceptional point, leading to resolvable modes splitting in the transmission spectrum. The performance of the designed sensor is analyzed by the coupled-mode theory and transfer matrix method, separately. Here, the simulation results demonstrate that the obtained sensitivity is 17,120 nm/imaginary part unit of refractive index (IP) and the theoretical detection limit is 4.2 × 10−8 IP (regarding carcinoembryonic antigen (CEA), the minimum detection value is 1.78 ng). Instead of the typical diffusion manner, the liquid sample is loaded by convection, which can considerably improve the efficiency of sample capture and shorten the response time of the sensor. The sketched sensor may find potential application in the fields of biomedical detection, environment protection, and drinking water safety.

Study on Mechanism Design of Rural Drinking Water Safety Engineering Project Financing Guarantee

2013 ◽  
Vol 361-363 ◽  
pp. 674-681
Author(s):  
Wei Li
Keyword(s):  
Drinking Water ◽  
Mechanism Design ◽  
Safety Engineering ◽  
Project Financing ◽  
Water Safety ◽  
Public Fund ◽  
Engineering Project ◽  
Drinking Water Safety ◽  
Project Construction ◽  
Set Up

As more and more non-public fund entering rural drinking water safety engineering project market; it becomes very necessary to built rural drinking water safety engineering project guarantee mechanism. This paper proposes three steps of mechanism design. Firstly, history data is used to fit multivariate linear equation set up describing relationship between bank loss and key risk factors. Secondly, guarantee fee is calculated through model regression, which is threefold of possible bank loss. Thirdly, guarantee fee is adjusted according to variety of key risk factor in the process of project construction and operating.

Implementation of Alberta's drinking water safety plans

2013 ◽  
Vol 49 (1) ◽  
pp. 5-9 ◽  
Author(s):  
D. C. Reid ◽  
K. Abramowski ◽  
A. Beier ◽  
A. Janzen ◽  
D. Lok ◽  
...  
Keyword(s):  
Drinking Water ◽  
Effective Action ◽  
Main Element ◽  
Quality And Safety ◽  
Biological Parameters ◽  
Water Safety ◽  
Drinking Water Safety ◽  
Regulatory Approach ◽  
Water Safety Plans ◽  
Safety Of Drinking Water

Traditionally, the regulatory approach to maintaining the quality and safety of drinking water has largely been a prescriptive one based on the ability of any given supply to meet standards set for a number of different chemical and biological parameters. There are a number of issues around the assumptions and the limitations of a sampling and analysis regime. The basis for such regimes is essentially reactive rather than proactive and, consequently, the cause of the concern may already have impacted consumers before any effective action can be taken. Environment and Sustainable Resource Development has developed a template for recording drinking water safety plans together with guidance notes to help complete them. The template has been developed in MS-Excel and has been designed in a straightforward step-wise manner with guidance on the completion of each sheet. It includes four main risk tables covering each main element of water supply which are pre-populated with commonly found ‘generic’ risks and these are carefully assessed before considering what action is required to deal with significant risks. Following completion of the risk tables, key risks are identified and the interventions required to bring them into control.

A fatal waterborne disease epidemic in Walkerton, Ontario: comparison with other waterborne outbreaks in the developed world

2003 ◽  
Vol 47 (3) ◽  
pp. 7-14 ◽  
Author(s):  
S.E. Hrudey ◽  
P. Payment ◽  
P.M. Huck ◽  
R.W. Gillham ◽  
E.J. Hrudey
Keyword(s):  
Drinking Water ◽  
Water Security ◽  
Reference Source ◽  
Water Safety ◽  
Drinking Water Safety ◽  
Public Inquiry ◽  
Contaminated Drinking Water ◽  
The Government ◽  
Safety Of Drinking Water ◽  
Developed World

An estimated 2,300 people became seriously ill and seven died from exposure to microbially contaminated drinking water in the town of Walkerton, Ontario, Canada in May 2000. The severity of this drinking water disaster resulted in the Government of Ontario calling a public inquiry by Mr. Justice Dennis O’Connor to address the cause of the outbreak, the role (if any) of government policies in contributing to this outbreak and, ultimately, the implications of this experience on the safety of drinking water across the Province of Ontario. The circumstances surrounding the Walkerton tragedy are an important reference source for those concerned with providing safe drinking water. Although some circumstances are obviously specific to this epidemic, others are uncomfortably reminiscent of waterborne outbreaks that have occurred elsewhere. These recurring themes suggested the need for attention to broad issues of drinking water security and they present the challenge for how drinking water safety can be managed to prevent such tragedies in the future.

Rapid drinking water safety estimation in cities: Piloting a globally scalable method in Cochabamba, Bolivia

2019 ◽  
Vol 654 ◽  
pp. 1132-1145 ◽  
Author(s):  
Lucas Rocha-Melogno ◽  
Rebecca Yoo ◽  
Osvaldo Broesicke ◽  
Achilles Kallergis ◽  
José Garcia ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Safety ◽  
Drinking Water Safety ◽  
Safety Estimation

scholarly journals Studies of factors affecting stability and efficiency of anion exchanger

2020 ◽  
Vol 177 ◽  
pp. 03020
Author(s):  
Nigora Mukhtarova ◽  
Bakhodir Aliev ◽  
Sadritdin Turabdzhanov ◽  
Latofat Rakhimova
Keyword(s):  
Ion Exchange ◽  
Anion Exchanger ◽  
Analytical Data ◽  
Polycondensation Reaction ◽  
Water And Wastewater Treatment ◽  
Factors Affecting ◽  
Exchange Processes ◽  
Physicochemical Factors ◽  
Swelling Capacity ◽  
Water And Wastewater

Various industries such as mining and the chemical industry are one of the most used ion exchange processes for water and wastewater treatment. The first section of this work presents the mechanism of the polycondensation reaction to obtain the polymer matrix of anion exchanger. Elemental analytical data conformed that anion exchanger holds 34,99% of nitrogen atoms and 44,47% oxygen atoms in the structure. In addition to the synthesis of the anion exchanger, physicochemical factors have a significant effect. The temperature of reactions for a certain time using a Lewis catalyst, the choice of the optimal solvent for improving swelling capacity of the starting monomers, due to their advantages as effective materials at a low price, are described in the second section. The information in the last section of the paper is devoted to the sorption properties and the ion-exchange processes in where the obtained anion exchanger was studied and used.

scholarly journals Dominant meteorological factors affecting cyanobacterial blooms under eutrophication in Lake Taihu

2019 ◽  
Vol 31 (5) ◽  
pp. 1248-1258
Author(s):  
LUO Xiaochun ◽  
◽  
HANG Xin ◽  
CAO Yun ◽  
HANG Rongrong ◽  
...  
Keyword(s):  
Meteorological Factors ◽  
Lake Taihu ◽  
Cyanobacterial Blooms ◽  
Factors Affecting
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