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Showing posts with label sewage treatment. Show all posts
Showing posts with label sewage treatment. Show all posts

Thursday, December 30, 2010

ENDOCRINE DISRUPTORS- NEW ALARMS BEING RAISED

A report some time back implicated uncontrolled pollution of Thames River in the UK with birth control pills, for the fish to change their sex with females predominating over males! It is known that estrogens present in water can be endocrine disruptors causing fertility problems and other adverse health effects. While well protected water supply systems are supposed to be free from such contaminants, most of the population exposed to untreated or semi-processed water are in danger of consuming significant levels of estrogens and other endocrine disruptor that can have undesirable health implications. Recent studies, though some what limited in its scope, have highlighted this problem more succinctly. It is scary to imagine that improper sewage treatment and stable nature of the estrogen contaminant can affect the fertility in human beings. This is especially true in many developing countries where open defecation is so common and natural streams and rivers are exposed to contamination from human waste. Unfortunately no worth while study has been carried out in this area so far in these countries.

"Amber Wise, Kacie O'Brien and Tracey Woodruff note ongoing concern about possible links between chronic exposure to estrogens in the water supply and fertility problems and other adverse human health effects. Almost 12 million women of reproductive age in the United States take the pill, and their urine contains the hormone. Hence, the belief that oral contraceptives are the major source of estrogen in lakes, rivers, and streams. Knowing that sewage treatment plants remove virtually all of the main estrogen -- 17 alpha-ethinylestradiol (EE2) -- in oral contraceptives, the scientists decided to pin down the main sources of estrogens in water supplies. Their analysis found that EE2 has a lower predicted concentration in U.S. drinking water than natural estrogens from soy and dairy products and animal waste used untreated as a farm fertilizer. And that all humans, (men, women and children, and especially pregnant women) excrete hormones in their urine, not just women taking the pill. Some research cited in the report suggests that animal manure accounts for 90 percent of estrogens in the environment. Other research estimates that if just 1 percent of the estrogens in livestock waste reached waterways, it would comprise 15 percent of the estrogens in the world's water supply".

it is time that a concerted effort is made to assess the situation vis-à-vis the extent of presence of estrogens in public water bodies in countries like India. Naturally one assumes that exposure to natural elements and action of soil organisms would have broken down these harmful substances before reaching the water bodies. In a lighter vein one may ask why the fertility rate is so high in most developing countries if the water consumed by the population has high levels of anti-fertility estrogens originating from human and animal wastes? Similary has any one estimated the presence of estrogen like substances in organically grown produce materials as natural fertilizers are used for raising the crops? Probably these issues need some clarification through further scientific efforts.


V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

Sunday, May 2, 2010

SEWAGE "POWER"- POTENTIAL AND REALITY


With the fossil fuel era coming to an end soon, there are frantic efforts all over the world to find alternative energy sources so that there is no major hiccups in the present way of living in this planet. Energy from sustainable sources like sun, wind, ocean, geothermal, nuclear and others are in advanced stages of becoming economically viable soon. In this relentless search for energy, one source being ignored is the perpetual availability of sewage in thousands of urban areas which contain recoverable energy through appropriate technology and investments. The UK seems to have taken the lead by installing sewage derived energy systems in the city of London which is reported to be generating enough power, accounting for 14% of the power needs of the area and saving $ 23 million annually in electricity bills from the conventional suppliers

"Sludge, the solids that remain after sewage has been cleaned into effluent, has a high B.T.U. content (a measurement of fuel's energy); it burns efficiently and well. Other aspects of wastewater treatment can also reap energy: anaerobic digestion (whereby bacteria munch on the organic contents) produces methane, which with turbines can become combined heat or power. Microbial fuel cells can use bacteria to get electricity from sewage, while gasification, a high-temperature process, can reap fuel-ready gas from sludge".

The US with about 16000 sewage treatment plants does not produce any power for use, though about 1000 of them with daily supply of more than 5 million liters of sewage could generate viable quantity of power. Already 544 of them are producing enough methane through anaerobic digestion just to be flared out. This could have generated about 340 MW energy sufficient to power 0.34 million houses, off setting emission of 2.3 million tons of green house gas emission equivalent to creating a 0.64 million acres of forest!. Probably the force of circumstances may still persuade that country to go for sewage power in the near future. As for India, no data is available about the number of captive sewage plants in working condition that could be candidates for producing energy.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com