From South Africa to India, countries from all around the world are beginning to suffer from water crisis. Moreover, if there’s even an ounce of truth in scientific evidence, we are in for much more. Therefore, any direction we take in conserving water is of prime importance. Apart from opting from rainwater harvesting, there are plenty of other things too that we can do. Getting back portable water through waste water plants could also help us in staving off the crisis. In fact, many waste water plants from around the world are doing the same.
Why recycle wastewater?
Recycling water is essential for the wellbeing of mankind. There are several countries and regions on our earth where the inhabitants do not get sufficient amount of clean drinking water. Because of industrialisation, there is a rise in the number of pollutants that we throw into the water canals and rivers. Such dirty and polluted water can spread diseases and cause an epidemic.
The waste water plants help in cleansing and purifying wastewater so that we can use it once again. These plants are working relentlessly so that thousands of people get clean and safe drinking water. Several wastewater plants around the world use the latest technologies and relentlessly work to safeguard thousands of life. In the following, some of the best waste water plants have been listed.
5 – Important Waste water plants from around the world
1. Stickney Water Reclamation Plant, Chicago:
This wastewater plant cleanses 1.44 billion gallons of water daily. It belongs to the Metropolitan Water Reclamation District or MWRD. Built upon 570 acres of sprawling grounds in Cicero, Illinois, this plant has been consistently serving 43 suburban communities. It supplies clean and safe water to more than 2.4 million people.
The Mainstream Pumping Station of Stickney Water Reclamation Plant is the biggest underground sewage pumping station of the entire world. It has a deep tunnel system for lifting the sewage.
2. Deer Island Sewage Treatment Plant:
This wastewater plant is a result of a court order. It was in regard to taking necessary steps for cleaning the wastewater of the harbor area in 1986. $3.6 billion dollars was spent on constructing this magnificent wastewater plant. It took 11 years to build this plant.
Three pump chambers bring the influent in and then it flows to the grit chambers. The 48 primary treatment clarifiers help in purifying the dirty water and separate the pollutants. Located in Boston, Deer Island Sewage Treatment Plant purifies 1.27 billion gallons of water every day. It serves over 2.5 million people in this area.
3. Gabel el Asfar Wastewater Treatment Plant:
Owned by Holding Company for Water and Wastewater, the Gabel el Asfar Wastewater Treatment Plant is capable of cleaning 449 million gallons of water everyday. It lies on the northeast periphery of Cairo in Egypt. It supplies clean and safe water to around six million residents of the city. The plant conducts primary treatment of water, removes grit and uses sedimentation, clarification and chlorination techniques for purifying water completely. The cleansed water from this plant helps in growing olive, jojoba and flowers in a 40 acre stretch of land adjoined to it.
4. Bailonggang Wastewater Treatment Plant:
The Bailonggang Wastewater treatment Plant is the largest wastewater plant in Asia. It cleanses 528 million gallons of water daily. Owned by Shanghai Municipal Sewerage Company, this plant started functioning in 1999. In 2008, it was expanded. New technology includes anaerobic sludge digesters, sludge drying and a disposal facility. It decreases the amount of sludge through digestion process. Its state of the art infrastructure allows utilizing thermal drying technique on the digested sludge.
5. Seine Aval Wastewater Treatment Plant:
This plant is located in Paris, France and cleanses 449 million gallons of water everyday. The SIAAP owned wastewater cleansing plant started its operations in 1940. It is the largest wastewater plant of Europe. However, despite that it does not look like any of the industrial waste water plants of Asia and the US. The sloppy roofs of the sludge treatment facilities have been caringly covered with green grass and there are rows of trees surrounding the plants. At present it is going through a modernization phase which will be completed in 2015. Around $1.3 billion dollars have been spent on modernizing this plant.
Producing clean hydrogen from wastewater
Fossil fuels have been the main source of energy that continued to feed the world economy in the present time. Our developmental prospects greatly depend on the availability and usage of these finite resources of energy. But, the very fact that these resources are ‘finite’, questions the sustainable growth and its continuation. This has led to the search for alternatives that can replace the non-renewable resources of energy and guarantee the sustenance of development and technical growth.
Hydrogen: An eco-friendly energy source
The search for alternatives reveals hydrogen as one of the leading contenders. But a problem in this regard is very characteristic of hydrogen being a carrier of energy rather than a source. In addition, pure hydrogen does not occur naturally. Energy generated from fossil fuels is necessary to manufacture and produce it.
Researchers at the Pennsylvania state have developed a technology. With its help, we can manufacture pure hydrogen that costs no electricity usage and is carbon neutral. Furthermore, we can use it in any place wherever wastewater seems to be present near the seashore.
Microbial electrolysis cells
Microbial electrolysis cells (MECs) stand as the basis of the research work. It is a technology related to microbial fuel cells (MFCs). These are known to produce electric current from the microbial decomposition of organic compounds. In addition, the process is partially reversed by the MECs in order to generate hydrogen from organic material but they require some electrical input to do so.
Bruce E. Logan, professor of Environmental Engineering and a postdoctoral fellow Younggy Kim have opted for reverse – electrodialysis (RED) rather than relying on the grid for the electricity required for their MECs. Previous times have seen the use of RED to generate electricity. It utilizes salt water from the North Sea and freshwater from the Rhine for this purpose. The researchers are following the same principle of extracting energy from the ionic differences between salt water and fresh water to accomplish their cause.
A RED stack includes alternating positive and negative ion-exchange membranes, and hence each RED is seen to contribute to the electrical output. Splitting of water into hydrogen and oxygen using RED technology would require 1.8 volts of electricity which would require the involvement of about 25 pairs of such membranes, leading to increased pumping resistance. But with the combination of RED technology with exoelectrogenic bacteria, which are the bacteria that consume organic substances and produce electric currents in return, the researchers could successfully reduce the number of RED stacks required to only five membrane pairs.
Why aren’t we using it?
Previous attempts with MECs revealed that they could generate about 0.3 volts of energy by themselves but not the 0.414 volts that is needed to generate hydrogen in these fuel cells. With the addition of less than 0.2 volts of outside electricity, hydrogen could be successfully released. Presently, by incorporating 11 membranes – five membrane pairs producing about 0.5 volts – the cells successfully produced hydrogen thus reducing the energy required.
According to Logan, biodegradable liquids and cellulose wastes are present in abundance, and with no energy in and hydrogen out, wastewater and by-products can be easily got rid of. Logan further acclaimed it as an inexhaustible source of energy.
The research works whose results were published in the Sept. 19 issue of the Proceedings of the National Academy of Sciences, shows that the limitless supplies of sea water and river water along with biodegradable organic matter can eventually produce pure hydrogen.
With this revolutionary finding, the researchers at Pennsylvania State University have successfully accomplished the objective of reducing the dependence on the limited sources of non – renewable resources of energy.
The growing needs of mankind and the decreasing availability of resources to serve human developments have raised a lot of eyebrows. However, with the emergence of such commendable alternatives ways of satisfying our needs without overexploiting natural elements have certainly been suggested. Researchers all over the world in their attempts to come up with such unique ideas have gifted mankind with many appreciable wonders.
The waste water plants are the lifeline of several urban and suburban regions. They cleanse polluted water and return it to common people for regular use. By opting for eco-friendly water purifiers, you can do the same without harming the environment.