Monday, August 6, 2012

Monitoring and Detection Methods of Water Pollution.


Water pollution


Water pollution is the contamination of water. It occurs when pollutants are discharged directly or indirectly into water bodies without enough treatment to remove harmful materials/compounds from it.




Water pollution will affect plants and organisms living in these water bodies. It can also contaminate drinking water and cause spreading of diseases. Water pollution has taken place in many parts of the world, it is inevitable yet we are able to help reduce the amount of pollution in these waters. These waters may have to be our future drinking supply. If we do not do anything about this water, we may run out of water faster than oil. Therefore, in order to ensure this water will be safe, we have to do monitoring of these water bodies.






Monitoring water pollution

Monitoring water pollution involve sampling the chemical condition of water, sediments, and fish tissue to determine dissolved oxygen and other parameters of water pollution. Monitoring of physical conditions such as temperature is also needed.

Monitoring is usually conducted at a fixed station on continuous basis. Other times where monitoring is needed is during emergency situation (such as after an oil spill). Main focus for a monitoring program is to collect enough data by sampling and analysing, studying and evaluating of the results to give an evaluation of the water quality. The result is only available to that one place of sampling and the time of which the sample is being taken.

oil on the surface of the water reflecting light

Why do monitoring for water pollution?
Monitoring is conducted for many purposes.

  • Identify specific existing or emerging water pollution problems.
  • Gather information to design specific pollution prevention or remediation programs
  • Determine whether compliance with pollution regulations or implementation of effective pollution control actions are being met
  • Respond to emergencies, such as spills and floods.

Monitoring methods

»        Software system

Commercial software such as the Environmental monitoring data management systems are becoming more commonly used as a method to monitor water quality for water pollution. They can monitor progress, allow managing of all monitoring data in a single central place and flag up inconsistencies or omissions [automated to send alerts].The software can also generate regulatory and other reports that is useful and make it easier for monitoring.

»         EcoMapper

Without having to go underwater, collecting of good quality data would be easy. The EcoMapper is a Autonomous underwater vehicle. It helps to map out water quality, the currents of the water and bathymetry. It gives many flexible options in water quality, mapping out the bottoms of the seas and even profiles the current of the water. There is side scan sonar that can be added on. However only one person can deploy the EcoMapper, it has a 8-14hour life span at the speed of 2-4knots. EcoMapper constantly gives data as it moves through the water.






»     Robotic Fish

A robotic, powered by a battery, fish is made, this mechanical fish is designed and tested. The cost is $3.6million. With the help of this fish, oxygen levels of the water can be measured. Oil slicks and other contaminant that is present in the water will be detected more easily. It is the first of its kind and data that is being retrieved is of utmost important because it implicates with global warming and the state of water resources. With the fish about 5 feet long is can withstand pressures and currents. As it collects the data, it will move at a speed of 1m/s, with an on-board guidance system will prevent them from bumping into rocks, other fishes and even ships. They have a form of sonar attach to them, allowing them to communicate in the water. With enough data collected, it will come to the surface and transmit to the control center, wireless. This will aid in creating a 3 dimensional map of the pollution in the water body. If the battery is depleting, it will go back to the power hub on its own for recharging. You can see how the fish moves in this link.


Detection methods of water pollution

Waterborne disease outbreaks are rising due to the tremendous amount of bacteria infiltrating the water bodies around the world. Microbial pathogens continue to contaminate the drinking water supplies despite the measures taken to prevent and control the spread of microbial pathogens in public and individual water systems. Detecting early stages of water pollution is a vital stage to improve water effluent quality and also ensures safer drinking water for the general public for consumption. With the advance technology of development of detection methods for water pollution, we are going to look at some of the methods that is best used for treating water pollution.


»         Using tadpole to detect water pollution is an innovative method that is brought up. African clawed frog tadpoles, in response to a pollutant can light up and will indicate the presence of several chemical species at the same time. This method is easy to use, less time consuming and less labour intensive than traditional detection methods for heavy metal detection in water.

"In this work we combined genetically modified tadpoles with a detection system developed at UW to detect the presence of heavy metal pollution in river water in real time.” --
http://phys.org/news179084594.html#jCp





»        Microbial Source Tracking: Methods

Microbial source tracking (MST) is a method used to determine the various host that contributes to faecal pollution in water bodies. The concept that the origin of faecal pollution can be traced using microbiological, genotypic, phenotypic, and chemical methods has been termed microbial source tracking. The application of MST is to provide a tool for identifying the source of pollution and allowing proper remediation and preventive measures.  Water contaminated with human faeces are generally regarded as more hazardous to human health. For MST to be done, indicator microorganisms are introduced to predict and detect the presence of pathogenic microbes. Indicator organisms are very useful in as they function the need to assay for every pathogen that may be present and detected in water. Many advantages of using this method is that indicators are non-pathogenic, rapidly detected, easily enumerated, have survival characteristics that are similar to those of the pathogens of concern, and can be strongly associated with the presence of pathogenic microorganisms. Some examples of indicators microbes are E.coli, Enterococcus spp, C. perfringens.

Total and faecal coliforms have been used extensively as indicators for many years to determine sanitary quality of surface waters. However, because of the great diversity of microbial pathogens, current indicators of water quality may not detect all types of
microbial contamination. Some pathogens do not co-occur with faecal pollution and bacterial indicators have greater sensitivity to disinfection. Due to this sensitivity, there would be a lack in results of consistent correlations between indicator absence and absence of pathogens. Therefore, quantitative methods that can detect a variety of arrays of microorganisms are needed.

 



»        Swimming Behavioural Spectrophotometer (SBS) method

It is the method of detecting pollution through the behaviour of a protozoa in water called genus Tetrahymena. This method was awarded as 2010 “Better World” technology by the Association of University technology Mangers. By comparing the movement of the protozoa which is placed in a control and the movement of the protozoa which is placed in the sampling water allow the digital camera along with specialized software which stored over 50 behaviour of protozoan in 3D motion to identify the pollutants. Any other movements which are not programmed indicate a problem in the water which requires further testing. This method can detect both chemical and biological pollution such as heavy metal, pesticides and industrial chemical. The advantage of this method is that it can identify the water pollutants immediately however, the disadvantage is that you are unable to identify the exact pollutant until further analyses.



»        Algae detection method

A new and faster method was developed in Israel by Dr. Yulia Pinchasov. Traditional method is a time consuming and costly method. However, this method is faster, more cost efficient and accurate. By Shining laser beam onto the algae allows researcher to determine the amount of contamination from the sound waves emitted under the water. As the laser beam encourages photosynthesizing of algae, the rate at which it photosynthesize and the condition of the algae determines the amount of heat shot back into the water which creates the sound waves. Underwater microphones are used to capture the sound waves which are analyzed to determine the health of the algae as well as status of the water. Different kinds of pollution affecting the algae will emit different sound.


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