Essay About Use Of Fertilizers And Main Type Of Waste

Effects on the World
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Man has had many far-reaching effects on the environment over the years. Global
warming, pollution and the damage to the ozone layer are a few of the major things that can be
heard about in the news. Man has damaged the earth gradually over the years and this damage
cannot be reversed, we are now trying to stop any more damage being caused to the
environment. For example, hedgerows have been destroyed but now people have realized what
effects this is having on the environment the government are paying farmers to replant them
instead of fencing. Not all of mans effects on the environment are harmful some are beneficial.
Conservation work is going on across the country and this is helping to preserve the wildlife and
countryside that we have left. The expanding human population has placed a huge demand on
the food production of the country. The resources are limited but the population is increasing
quite rapidly so the problems are growing. The demand for food means that crops need to be
perfect so the use of fertilizers and herbicides is increasing too.
One of the problems in the countryside affecting the environment is the disposal of
effluent and other pollutants. The main type of waste that we have to dispose of is organic
effluent particularly from farms and sewage works. This is disposed of in several ways, the main
one being pumping it into the sea and rivers around the country. In more recent years sewage
recycling plants have been developed to reuse the water in the waste. Water treatment works are
used to treat the waste before it is pumped into the river or sea.
The disposal of the waste is accomplished in several ways. Direct removal into a stream
or lake is the most commonly used means of disposal. In parts of the world that are faced with
worsening shortages of water for both domestic and industrial use, authorities are reusing
appropriately treated wastewater for, irrigation of non-edible crops, industrial processing,
recreation, and other uses. In one such project, the Potable Reuse Demonstration Plant in
Denver, Colorado, the treatment process uses normal primary and secondary treatment followed
by lime clarification to remove suspended organic compounds. During this process, an alkaline
state is created to improve the process. In the next step, re-carbonation is used to bring the pH
level to neutral. Then the water is filtered through several layers of sand and charcoal, and
ammonia is removed by ionization. Pesticides and any other dissolved organic materials still
present are absorbed by a granular, activated-carbon filter. Viruses and bacteria are then killed
by ozonisation. At this stage the water should be cleansed of all contaminants, but, for added
reliability, second-stage carbon absorption and reverse osmosis are used, and chlorine dioxide is
added to obtain the highest possible water standard.
The other main place that effluent is disposed of from is industry. Industrial plants put
their waste into the main drains, because they pump it into the main drains it has to be a
particular pH i.e. neutral (between pH6 and pH10). If the pH fluctuates out of this range, there
are valves along the main pipe line from the industrial works that close to prevent the effluent
leaking into the main sewage system. The pH can then be regulated by either adding caustic soda
(an alkaline) or hydrochloric acid to neutralize it again. If the valves did not close and the
effluent were allowed to travel into the sewage works then it would kill all the nitrifying and
denitrifying bacteria that break down the waste. The bacteria are very sensitive to the chemicals
that are used and if these levels fluctuate too much, it will kill the bacteria and the whole
decomposition process will be affected. The bacteria remove the ammonia in the effluent. There
are filters in the water treatment works that sieve out a lot of the suspended solids and there are
chemicals which are added to make the rest of the solids bind together with the help of bacteria
so that they come to the surface and can then be filtered off. The water that eventually comes out
is pumped from an outlet into the river unless it is to be recycled then it goes on for further
cleansing. The effluent that is pumped into the streams gives the decomposers in the water a
huge food supply, therefore they use up much of the oxygen and eutrophication – death of the
waterway – results. The decomposers deprive the other organisms such as fish and crustaceans of
oxygen causing them to die. This in turn affects the whole food chain.
Phosphates are products formed by the replacement of some or all of the hydrogen of a
phosphoric acid by metals. Depending on the number of hydrogen atoms that are replaced, the
resulting compound is described as a primary, secondary, or tertiary phosphate. Also known as
trisodium phosphate, tertiary sodium phosphate is used as a detergent