On the other hand, there are treatment plants for waste-water, which treat human waste and other contaminants which were created by us, as when you flush the toilet, that then goes to a treatment facility where it is treated so it is safe to go back into the environment without creating an environmental disaster. What they primarily do is take out all the solids and other contaminants and make it safe to re-enter the environment again. In what is a water treatment plant, we are primarily concerned with treatment facilities that make water supplies safe for human consumption and use.
At these facilities, they provide treatment of the water which includes the steps used to make water safer and remove water contaminants. These water can then be safely used as drinking water, industrial processes, medical and many other uses. The goal of all water treatment processes is to remove existing contaminants in the water, or reduce the concentration of such contaminants so the water becomes fit for human consumption, or safe for its other uses. One such use is returning water that has been used back into the natural environment without creating adverse ecological impacts, such as untreated sewage.
We can follow a drop of water from the source that it came from through the entire treatment process. Water may be treated differently in different communities depending on the quality of the water which enters the plant. Groundwater is water located under ground and typically requires less treatment than water from lakes, rivers, and streams.
The processes involved in treating water for drinking purpose may be solids separation using physical processes such as settling and filtration, and chemical processes such as disinfection and coagulation. Biological processes are also employed in the treatment of waste-water and these processes may include, for example, aerated lagoons, activated sludge or slow sand filters.
What is a Water Treatment Plant?
Water purification is the primary goal at these facilities, which includes the removal of contaminants from untreated water to produce drinking water that is pure enough for the most critical of its intended uses, usually for human consumption. Substances that are removed during the process of treatment for drinking water include suspended solids, bacteria, algae, viruses, fungi, minerals such as iron, manganese and sulfur, and other chemical pollutants such as fertilizers.
Measures taken to ensure water quality not only relate to the treatment of the water, but to its conveyance and distribution after treatment as well. It is therefore common practice to have residual disinfectants in the treated water in order to kill any bacteriological contamination during distribution.
World Health Organization (WHO) guidelines are generally followed throughout the world for drinking water quality requirements. In addition to the WHO guidelines, each country or territory or water supply body can have their own guidelines in order for consumers to have access to safe drinking water.
Here is a typical step-by-step guide describing what happens at each stage of the treatment process and how pollutants are removed to help keep our water supplies safe.
Empty aeration tank for iron precipitation
Tanks with sand filters to remove precipitated iron (not working at the time)
- A combination of the following processes is used for the municipal treatment of drinking water supplies worldwide:
- Pre-chlorination – for algae control and arresting any biological growth
- Aeration – along with pre-chlorination for removal of dissolved iron and manganese
- Coagulation – for flocculation
- Coagulant aids, also known as poly-electrolytes – to improve coagulation and for thicker floc formation
- Sedimentation – for solids separation, that is, removal of suspended solids trapped in the floc
- Filtration – removing particles from water
- Desalination – Process of removing salt from the water, typically used near coastlines where they utilize the vast expanse of ocean water which contains saline and in it’s natural form is unsafe for human or animal consumption
- Disinfection – for killing bacteria.
- Ultra-Violet Treatment
- Oxidation Filtration
- Reverse Osmosis or Membrane Filtration
There is no unique solution (selection of processes) for any type of water. Also, it is difficult to standardize the solution in the form of processes for water from different sources. Treat-ability studies for each source of water in different seasons need to be carried out to arrive at most appropriate processes.
The above mentioned technologies are well developed, and generalized designs are available that are used by many water utilities (public or private). In addition to the generalized solutions, a number of private companies provide solutions by patenting their technologies. There is considerable amount of automation happening in Water treatment plant and Waste Water facilities. These are commonplace in the developed world, however there still are problems in developing nations.
In Developing Countries
As of 2006, waterborne diseases are estimated to cause approximately 1.8 million deaths each year. These deaths are attributable to inadequate public sanitation systems and in most cases, proper sewerage (or other options as small-scale treatment for waste-water) need to be installed. This is a major concern, as the clean water water shortage crisis worsens.
Appropriate technology options in treatment for water supplies include both community-scale and household-scale point-of-use (POU) designs. Military surplus treatment units for water like the ERDLator are still seen in developing nations, however newer military style Reverse Osmosis Water Purification Units (ROWPU) are portable, self-contained water treatment plants and are becoming more widely available for public use.
In order to decrease the instances of waterborne diseases and for the treatment plans to be consistent and have long lasting effects, water treatment programs implemented by research and development groups in developing countries must be sustainable and be able to be maintained by the local populations. This can ensure the long term effects and efficiency of such programs after the departure of the research team as monitoring is difficult because of the remoteness of many of these locations.
- Resources & Related Articles:
- Drinking Water Contaminants: Disinfection Byproducts
- Drinking Water Contaminants: Disinfectants
- Drinking Water Contaminants: Micro Organisms
- Drinking Water Standards
- Tap Water Safe
- Clean Water for a Healthy World
- Looming Water Crisis
What is a water treatment plant can be a little confusing, but we hope we answered your question! Peace my friends!