Environmental chemistry deals with the study of chemical processes that occur in the environment and affect the activities of human kind. Environmental chemistry can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments and the effect of human activity on these.
The Environmental Chemistry concerns with the chemical and biochemical phenomena of atmosphere. It involves the study of impact of chemical species on the environment and other surrounding substances like air, water, soil, terrestrial etc. The main focus is on the fundamental research process for the nature of chemical processes occurs in the environment. Environmental chemistry starts by understanding how the uncontaminated environment works. It identifies the chemicals that are present naturally.
It includes the soil, analytical, atmospheric, and aquatic science fields. Thus the basic of the environmental chemistry is to study the pollutants effect on the environment and reduction process for contamination and proper management of environment.
Radiochemical is the substances which emits radioactive materials in atmosphere that are harmful for human beings. The counter like particle and scintillation counters are used to measure the radiochemical. The radio chemical parameters are also measured in environmental chemistry.
- The toxicity of any substance depends mainly on three factors which are the nature, concentration, and distribution of chemical substance. The distribution of any substance in atmosphere is the major criteria for its exposure in the environment.
- The viability of chemical substances can be understood by knowing the behavior of the substances in the environment. The behavior of substance is studied from transport, effect and fate of chemical.
- The transport of chemical is a process of distribution of chemicals in the environment while the fate of chemical deals with eventual disposition of chemicals. The main focus area involves the detection of pollutant levels and their behavior.
- The samples are first collected and then analyzed with various techniques. Different types of quantitative and qualitative analytical techniques, spectroscopic, and chromatography techniques are used to measure the chemical processes and their content.
- Some of them are gravimetric method, volumetric method, electrochemical methods, mass spectroscopy, IR spectroscopy, the combined technique of gas chromatography-mass spectroscopy etc.
Applications of environmental chemistry
The major application area of environmental chemistry are as below.
The indicators are the substances which are used to analyze the change that occurs in any system and helps to understand complex realities. Environmental indicators are simple measures that tell us what is happening in the environment. Since the environment is very complex, indicators provide a more practical and economical way to track the state of the environment than if we tried to record every possible variable in the environment.
- Risk or Hazard assessments of Environmental Impact- The risk factor of the chemicals is determined for safety of environment. This is detected by various
- Management of Environmental - The environmental Chemistry studies the development of new chemical products and their behavior on the atmosphere. The complete life cycle of chemical is used for proper handling and storage methods of chemicals that are helpful for detecting the adverse effect on environment.
- Groundwater Protection - The ground water is polluted by polluted soil and waste site leachate. So the pollutant identification is done in environmental chemistry by knowing the concentration, distribution and fate of hazardous chemicals.
- Protection of surface water - The effect of contaminants in the water and sediments phase is measured for checking the quality of surface water. This is done by sedimentation processes, bacteriological processes, radiation processes etc.
- Soil Protection - The soil quality is checked by measuring the impact of soil contaminants on the soil. This is analyzed by various chemical and eco-toxicological indicators.
- Cleaner Production and Waste Management - This includes the management and re-use of waste and site remediation. The re-use and site remediation is done by analyzing the pollutants in environmental samples and knowing about their nature. The re-use of waste involves the innovative uses of waste products.
Some are chemical indicator like methyl-orange, phenolphthalein etc. Others like Health Indicators, Environmental Indicators etc. The environmental Indicators are used to know the realities that relate to good or adverse effect on the environment. The specific indicators are used for a particular area and definite components.
The principle work of indicators is to quantify and measure the data of particular changes that takes place due to a specific substance which helps in making decision about the process of change and good or harmful effect of that particular substance on surrounding and living organism.
Like the measurement of pollution level of any pollutants and its effect on eco system or on air, water, land and on health conditions. The environmental indicators are thus the effective and reliable detecting system that assesses and analyzes the harmful impacts of anthropogenic activities on the environment.
The various indicators are bio-indicators, ecological indicators, some are used for productivity of soil, agriculture, micro-organism impact on living organism, pollutant effects etc. They are used both at the national and municipal level. The Environmental Indicators have three main principle functions which are simplify, quantify and communicate the gathered data about the particular chemical substance. These are completed in a sequence. They indicate and understand the environmental conditions.
The environmental indicators should be scientifically measured and defensible and easy to understand. They must be very sensitive to the changes so that the measurement process can be completed with quite accuracy. The information and data of indicators must be easily available.
Important factors to be kept in mind while using the Environmental Indicators are:
1) The development of indicators is possible only with accurate information and data.
2) The appropriate targets must be set for measurement process.
3) The change in indicators can change the whole system.
Some common environmental indicators are biological markers or bio markers which are used for understanding and preventing diseases in humans and animals. Examples of environmental indicators are,
The concentration of ozone is measured in the stratosphere in which the effect of chlorofluorocarbons is detected. It shows the increment in level of ultraviolet radiation. The function of aquatic ecological system is measured by analyzing the number of organisms in a stream. The environmental indicators are grouped into three categories according to their uses. These are described below:
1. State of the Environment Indicators
- The main function is to gather the information with the existing information.
- They are used to measure the state of environment.
- The major focus is on giving the information about the changes and improvements in the environment and charting trends.
- Some examples of state of the environment are driving force indicator for green house gas emission, pressure indicator for carbon dioxide emission, impact indicator for global temperature, response indicators for green house gas removal.
2. Sustainability Indicators
- These indicators are used to analyze the sustainability of the environment.
- They are focused on time factor and threshold.
- They have capability to measure more than one parameter at a time like equity, efficiency, quality etc.
- For example, the measurement of consumed renewable energy with total energy consumed, percentage of renewal forest, emission of CO2 and residential materials recovery per capita.
3. Performance environmental Indicators
- These are used for monitoring and tracking of progress in stated goals.
- They are mainly focused on the comparison of the actual conditions with standard conditions.
The word contamination stands for the presence of unwanted species or substances in environment, any material or human body etc.
These unwanted species are known as contaminants.
All the chemical substances have some degree of contamination.
The contaminants show the level of pollutants in atmosphere, the presence of harmful toxins, microorganism in food, medicines or drugs etc.
Contamination is a major risk factor for research and development methods, production activities, technical process, and also for human beings. Because the contamination causes the damage of products, reduction in manufacturing yields etc. So it is very necessary to control the contamination.
There are different types of contamination. and some of them are described below.
1. Particulate Contaminants
This is one of the most common types of contaminant. It can be easily controlled and measured. The particulate contaminants are generated in hydraulic systems.
It can be inside or outer side of hydraulic systems.
Like in metal particles, the particulates are originated inside the system while particulates are generated outside the system of soil, dirt, rag fibers etc. There are three ways by which the efficiency of particulates contaminants can be robbed form hydraulic systems. They are abrasion, fatigue and silting.(a) Abrasion
The metal is scrapped with abrasive particles and thus it creates wear metal. Thus the metal is damaged by the continue flow of abrasive particles to other part of metal system. (b) Fatigue
It involves the repeated stress load on metal at high pressure. This causes the breaking of metal into its components and metal gets contaminated. (c) Silting
The silting is the flow of small particles present on the surface of metal. It reduces the efficiency of system due to the jammed between the components of valve.
2. Chemical Contaminants
The chemical contaminants generates other contaminants in the form of oxidation and acids with heat, water and air. They also generated like the particulate contaminants inside or outside the hydraulic systems.
The chemicals like arsenic, fluoride, nitrate, manganese, iron, and the other heavy metals are also contaminated in water and soil in which the arsenic, fluoride, and nitrate contaminated drinking water is very harmful for living organism.
3. Cross contamination
- The cross contamination is main cause of food poisoning.
- It spreads with the transfer of bacteria from one food stuff to another.
- This is because of unwashed hands, cutting boards, knives or other tools of kitchen.
- As the bacteria can be easily killed by cooking but the cross contamination spreads when the same tools is used for the other food item which does not need cooking. Example: If same cutting board is used for cutting the raw chicken and then the fresh tomato.
- The use of raw eggs is also the source of salmonella bacteria.
- Thus the food safety methods are essential to avoid these kind of cross contamination.
- Usage of different cutting boards for different food items, wash the vegetables before cooking etc.
4. Gaseous contamination
The corrosion in the electronic equipments is the main reason for the gas contamination. This spreads by outside pollution smog which contains components like sulfur, bromine and chlorine, in manufacturing process etc.
5. Microbiological contamination
This is considered as one of the most dangerous contamination. It refers to the unwanted introduction of infectious harmful material called microbiological pathogens which causes the infections.
The microbiological pathogens include yeast, mould, bacteria, fungi, virus, protozoa or toxins and their by-products. The contamination may occur through the natural sources like air, water etc, indirect transmission like mosquitoes, flies, surface, floor etc.
Identification of Contaminants
Two methods is used for identifying the contamination which are particle count and
spectrographic analysis. 1. Spectrographic Analysis
This technique is useful for the metals and alloys with the approx size of 10 to 15 microns. The analysis is based on measuring the present constituents in the oil.
The measurement is done in parts per million. 2. Particle Count
This is useful for any kind of substance having the size to one to 200 microns.
The count of particle is completed in terms of number and volume of fluid.
Effect of contamination
The contaminated system has low efficiency, productivity power, low yields, high operating cost and break down etc. the effect of contamination is very difficult to detect as the effect of contamination shows very slowly on system.
Prevention of contamination
1) The contamination takes place in the hydraulic systems during its processes.
2) Manufacturing and assembly process, Operation and maintenance process of machine, and repairing process.
3) The contamination can be controlled by using protective clothes like face masks, hats, and suits.
4) The airborne contamination is controlled with the use of filter of high-efficiency particulate air, airlocks and clean-room suits.
5) The high-efficiency particulate air filters are used in medical fields mainly to kill the harmful bacteria.
6) The filter media is used to trap the bacteria.
7) The sufficient flooring system is used to reduce the growth of organism through the floor level.
8) Polymer mats and polymeric flooring are used for this purpose which makes a good contact with shoes and wheels and trap the particles.
9) The copper-alloy surface is sued to control the contamination of microbes as they have the ability to quickly destroy microorganism.
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