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Effects of Heavy Metals on Cell Density, Size, Specific Growth Rate and Chlorophyll a of Tetraselmis Tetrathele Under Controlled Laboratory Conditions
Abstract
The effects of the varying levels of mercury (Hg) and cadmium (Cd) (0, 0.1, 0.3, 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mg L⁻¹) to the cellular density of the green microalgae Tetraselmis tetrathele were evaluated every 24 h for 120 h. Specific growth rate, cell sizes and chlorophyll a were also monitored in the 5.0 mg L⁻¹ Hg and Cd and were compared to the unexposed at 0, 12, 24, 36, 48 and 120h. Results showed that the algal density of T. tetrathele exposed to various levels of Hg were similar with the control up to 48 h. Variations on different concentrations at different times were observed but the results suggest that T. tetrathele was not affected by Hg even at concentrations up to 5.0 mg L⁻¹ for 48 h but started to show toxicity from 3.0 to 5.0 mg L⁻¹ after 72 h and longer. Cd on the other hand also showed toxicity at 3.0, 4.0 and 5.0 mg L⁻¹ beyond 24 h exposure. The specific growth rate of T. tetrathele exposed to both 5.0 mg L⁻¹ Hg and Cd was statistically similar with those of the unexposed from 0 to 12 h and negative growth rates then followed up to 36 h. The chlorophyll a was significantly lower in the metal -exposed algae than did those unexposed. Chlorophyll a also decreased in T. tetrathele exposed to both heavy metals but algal cell sizes were not affected with the presence of Hg or Cd in the culture system.
Effects of Heavy Metals on Cell Density, Size, Specific Growth Rate and Chlorophyll a of Tetraselmis Tetrathele Under Controlled Laboratory Conditions
Abstract
The effects of the varying levels of mercury (Hg) and cadmium (Cd) (0, 0.1, 0.3, 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mg L⁻¹) to the cellular density of the green microalgae Tetraselmis tetrathele were evaluated every 24 h for 120 h. Specific growth rate, cell sizes and chlorophyll a were also monitored in the 5.0 mg L⁻¹ Hg and Cd and were compared to the unexposed at 0, 12, 24, 36, 48 and 120h. Results showed that the algal density of T. tetrathele exposed to various levels of Hg were similar with the control up to 48 h. Variations on different concentrations at different times were observed but the results suggest that T. tetrathele was not affected by Hg even at concentrations up to 5.0 mg L⁻¹ for 48 h but started to show toxicity from 3.0 to 5.0 mg L⁻¹ after 72 h and longer. Cd on the other hand also showed toxicity at 3.0, 4.0 and 5.0 mg L⁻¹ beyond 24 h exposure. The specific growth rate of T. tetrathele exposed to both 5.0 mg L⁻¹ Hg and Cd was statistically similar with those of the unexposed from 0 to 12 h and negative growth rates then followed up to 36 h. The chlorophyll a was significantly lower in the metal -exposed algae than did those unexposed. Chlorophyll a also decreased in T. tetrathele exposed to both heavy metals but algal cell sizes were not affected with the presence of Hg or Cd in the culture system.
Basic Laboratory Study Guide
Preface:
The Laboratory Study Guide is an important resource for preparing for the certification exam and is arranged by chapters and sections. Each section consists of key knowledges with important informational concepts you need to know for the certification exam. This study guide also serves as a wastewater treatment plant operations primer that can be used as a reference on the subject. In preparing for the exams:
- Study the material! Read every key knowledge until the concept is fully understood and knownto memory.
- Learn with others! Take classes in this type of wastewater operations to improve your understanding and knowledge of the subject.
- Learn even more! For an even greater understanding and knowledge of the subjects, read and review the references listed at the end of the study guide.
Basic Laboratory Study Guide
Preface:
The Laboratory Study Guide is an important resource for preparing for the certification exam and is arranged by chapters and sections. Each section consists of key knowledges with important informational concepts you need to know for the certification exam. This study guide also serves as a wastewater treatment plant operations primer that can be used as a reference on the subject. In preparing for the exams:
- Study the material! Read every key knowledge until the concept is fully understood and knownto memory.
- Learn with others! Take classes in this type of wastewater operations to improve your understanding and knowledge of the subject.
- Learn even more! For an even greater understanding and knowledge of the subjects, read and review the references listed at the end of the study guide.
Boiler Water Quality Requirements and Associated Steam Quality for Industrial/Commercial and Institutional Boilers
Introduction:
The purpose of this publication is to acquaint engineers, purchasers and operators of industrial, commercial and institutional (ICI) boilers with ABMA's judgment as to the relationship between boiler water quality and boiler performance. This document is published for general guidance as a supplement to detailed operating manuals supplied by the equipment manufacturers. It should also be noted that the information presented is directed to steel boiler designs, as opposed to cast iron sectional or copper finned tube boilers. Furthermore Utility Boilers and Combined Cycle Boilers, which require extremely close control of water quality and steam purity, are not the topic of this document. This new document combines two previous ABMA Guideline documents, namely “Boiler Water Requirements and Associated Steam Purity for Commercial Boilers” (1998), and “Boiler Water Limits and Achievable Steam Purity for Water tube Boilers”, (1995). The document discusses the effect of various feed water and condensate systems on the boiler operation. It also provides information on boiler water and steam testing as well as system care and maintenance. It is recognized that specific boiler usage and water treatment will vary and may require values different from these recommendations. Boiler users therefore, need to define limits, equipment and operating parameters for their particular application. These recommendations are for information only. Everyone is free to accept or reject the conclusions of these suggestions as their own judgment warrants in all aspects of the conduct of their business. The ABMA does not represent or warrant that any level of steam purity depicted will be achieved by any particular boiler or boilers.
Boiler Water Quality Requirements and Associated Steam Quality for Industrial/Commercial and Institutional Boilers
Introduction:
The purpose of this publication is to acquaint engineers, purchasers and operators of industrial, commercial and institutional (ICI) boilers with ABMA's judgment as to the relationship between boiler water quality and boiler performance. This document is published for general guidance as a supplement to detailed operating manuals supplied by the equipment manufacturers. It should also be noted that the information presented is directed to steel boiler designs, as opposed to cast iron sectional or copper finned tube boilers. Furthermore Utility Boilers and Combined Cycle Boilers, which require extremely close control of water quality and steam purity, are not the topic of this document. This new document combines two previous ABMA Guideline documents, namely “Boiler Water Requirements and Associated Steam Purity for Commercial Boilers” (1998), and “Boiler Water Limits and Achievable Steam Purity for Water tube Boilers”, (1995). The document discusses the effect of various feed water and condensate systems on the boiler operation. It also provides information on boiler water and steam testing as well as system care and maintenance. It is recognized that specific boiler usage and water treatment will vary and may require values different from these recommendations. Boiler users therefore, need to define limits, equipment and operating parameters for their particular application. These recommendations are for information only. Everyone is free to accept or reject the conclusions of these suggestions as their own judgment warrants in all aspects of the conduct of their business. The ABMA does not represent or warrant that any level of steam purity depicted will be achieved by any particular boiler or boilers.
Rapid Assessment of Drinking Water Quality
Introduction
The provision of water was one of the eight components of primary health care identified by the World Health Assembly in Alma Ata in 1978. The Alma Ata Declaration on Primary Health Care expanded the concept of health care to include broader concepts of affordability, accessibility, self-reliance, inter-sectoral collaboration, community participation, sustainability and social justice. The importance of water supply continues to be emphasised as critical to reducing poverty and improving the health and well-being of the World's children and adults. The global community has committed itself to halving the proportion of the world's population who are unable to reach or to afford safe drinking water by 2015. Although great strides have been made in meeting this challenge in terms of provision of services, the safety of many water supplies remains unknown and uncertain. The recent Global Water Supply and Sanitation Assessment 2000 Report provided statistics regarding access to technologies that were either 'improved' or 'unimproved'. This was done on the assumption that some technologies were likely to be better for health, although it was recognised that would not always be the case. However, there was no information provided on water quality within the assessment. The inclusion of information regarding water quality in future assessments of the degree of access to water supplies is desirable. This handbook is designed to help in the implementation of rapid assessments of water quality to improve the knowledge and understanding of the level of safety of water supplies. There is significant value in reporting of independently verifiable water quality data to support national Governments and the international community in measuring progress in achieving the international development targets. Such data provides useful information regarding current conditions, deriving the likely public health burden relate to inadequate water supply and to gain an understanding of the extent of major water quality problems in developing countries. These data would, therefore, provide an indication of future investment priorities and needs on a country, regional and global basis.
Rapid Assessment of Drinking Water Quality
Introduction
The provision of water was one of the eight components of primary health care identified by the World Health Assembly in Alma Ata in 1978. The Alma Ata Declaration on Primary Health Care expanded the concept of health care to include broader concepts of affordability, accessibility, self-reliance, inter-sectoral collaboration, community participation, sustainability and social justice. The importance of water supply continues to be emphasised as critical to reducing poverty and improving the health and well-being of the World's children and adults. The global community has committed itself to halving the proportion of the world's population who are unable to reach or to afford safe drinking water by 2015. Although great strides have been made in meeting this challenge in terms of provision of services, the safety of many water supplies remains unknown and uncertain. The recent Global Water Supply and Sanitation Assessment 2000 Report provided statistics regarding access to technologies that were either 'improved' or 'unimproved'. This was done on the assumption that some technologies were likely to be better for health, although it was recognised that would not always be the case. However, there was no information provided on water quality within the assessment. The inclusion of information regarding water quality in future assessments of the degree of access to water supplies is desirable. This handbook is designed to help in the implementation of rapid assessments of water quality to improve the knowledge and understanding of the level of safety of water supplies. There is significant value in reporting of independently verifiable water quality data to support national Governments and the international community in measuring progress in achieving the international development targets. Such data provides useful information regarding current conditions, deriving the likely public health burden relate to inadequate water supply and to gain an understanding of the extent of major water quality problems in developing countries. These data would, therefore, provide an indication of future investment priorities and needs on a country, regional and global basis.
A Manual On Water Quality Treatment Methods At Community And Household Level
About this book :
This book is a compilation work of various techniques adopted at different parts of the world for removal of a range of chemical parameters which are present beyond the permissible limit in drinking water. The different technologies those are described in this book are mainly limited to household level and for community level. The stepwise pictorial presentation for treatment of contaminated water to remove different chemical parameters and biological treatment will possibly be appreciated by the readers of this book. The authors of this book have tried their best, put their utmost thought and taken maximum care while compiling the available information so that this piece of work will be accepted by every individual. This book in general comprises three sections and eight chapters are within these sections. Section-I comprises only one chapter which describes different water quality problems in India with specific interest to Odisha and for whom this book is designed. Similarly, the section-II encompasses four chapters. Water quality standards, water quality occurrence in different parts of the state and its presentation in shape of a map are reflected in these chapters. Section –III, which is the most important section of this book, illustrates identification of problems and their mitigation measures at household level as well as at community level. Material quantification and maintenance procedures are also depicted in this section.
A Manual On Water Quality Treatment Methods At Community And Household Level
About this book :
This book is a compilation work of various techniques adopted at different parts of the world for removal of a range of chemical parameters which are present beyond the permissible limit in drinking water. The different technologies those are described in this book are mainly limited to household level and for community level. The stepwise pictorial presentation for treatment of contaminated water to remove different chemical parameters and biological treatment will possibly be appreciated by the readers of this book. The authors of this book have tried their best, put their utmost thought and taken maximum care while compiling the available information so that this piece of work will be accepted by every individual. This book in general comprises three sections and eight chapters are within these sections. Section-I comprises only one chapter which describes different water quality problems in India with specific interest to Odisha and for whom this book is designed. Similarly, the section-II encompasses four chapters. Water quality standards, water quality occurrence in different parts of the state and its presentation in shape of a map are reflected in these chapters. Section –III, which is the most important section of this book, illustrates identification of problems and their mitigation measures at household level as well as at community level. Material quantification and maintenance procedures are also depicted in this section.
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