Should We Use the Biosolids from Sewage Treatment Plants as Agricutural Fertilizer?

What are sewage treatment plants?


Nowadays, more wastewater is germinated by our industrial, residential, commercial activities. It contains a variety of substances such as organic matter, toxic materials, pathogenic microorganisms and nutrients. If wastewater is discharged without treatment, it may cause serious water pollution. Therefore, the sewage treatment plant helps to remove the toxins or industry effluent from the wastewater to protect the environment. Sewage treatment plants have two primary functions. They treat wastewater to a level that allows its re-introduction to surface or ground waters; and they treat the solids produced in this process to either be recycled or disposed properly.

How it works?


What is biosolid?
The sewage is separated into liquids and solids during the treatment. Biosolids are a product of those solids that has undergone a further treatment to reduce the harmful chemical matters or organic matter significantly.



In some parts of the world, Biosolids are used to improve and maintain productive soil and stimulate plant growth (just as agricultural fertilizer), what are the pros and cons?

Pros:
-disposal of the biosolids is very expensive; using the biosolids as fertilizers can reduce the costs
-biosolids are rich in phosphorus, nitrogen, organic matter which are essential plant nutrients
-using biosolids as fertilizer germinate less liquid waste
-create jobs

Cons:
-trace of chemical matter or toxic materials may linger in the biosolids
-using biosolids as fertilizers may be harmful to the environment and to people's health because we are bringing back those chemical matters to our environment
-biosolid may contain chemical substances which can affect the plant growth

Potential stakeholders in this issue could be farmers because biosolid is cheaper than agricultural fertilizers; government because they do not have to pay a lot of money to disposal the biosolids; and it can create more job opportunities for us. I think using biosolids as fertilizer still needs further studies, so that we can ensure biosolids don’t contain any substances that would be harmful to our environment and our health.

Refernce:
http://saferenvironment.wordpress.com/2008/11/07/sewage-treatment-%E2%80%93-for-recycling-of-waste-water-use-of-biosolids-and-to-generate-renewable-energy-for-cleaner-safer-and-greener-environment/

http://www.environmentalhealthnews.org/ehs/newscience/soy-plants-accumulate-drugs-antibacterials-from-biosolids

http://lancaster.unl.edu/enviro/biosolids/fertil.shtml

The importance of Various Technologies

In the passing centuries, different technologies are invented to improve our understanding of internal body system such as digestive, circulatory system, etc. Also, different technologies are introduced to us to cure some diseases that we used to see them as incurable diseases.

Endoscope



Endoscope was developed in 1806 by Philipp Bozzini and he called his invention ‘Lichtleiter’ or ‘light conductor’. He used it to examine cavities, canals and hollow organs of the human body. Yet, this idea was disapproval by people who believed it is too invasive. Many scientists have tried to improve the ‘Lichtleiter’ and used it to know more about the inside of human body after Bozzini brought this new, fresh idea.

Endoscope is a medical device consisting of a long, thin, flexible, tube which has a light and a video camera. The inside of the patient’s body’s images can be seen on the screen. We can use the endoscope to examine the interior surfaces of an organ or tissues.

What is the function of endoscope?

-to confirm a diagnosis;
the endoscope can help to find out the degree of illnesses, so that the doctor can make decision on the best treatment for the patients. Stomach ulcers, breathing disorder and internal bleeding are often diagnosed with an endoscope.

-Biopsies;
the endoscope can also used for the diagnosis of cancers and used to proceed a biopsies (taking samples of tissue to see whether it is cancerous.

-Surgery;
a modified endoscope can take out tumors or foreign objects from the lungs or stomach; it can also destroy gallstones.

-Inspection;
Specific endoscope can inspect the gastrointestinal tract (such as esophagus, stomach, small intestine), the respiratory tract (such as nose, bronchi), ear, female reproductive system, etc.

The invention of endoscope is important to help us to understand the inside of our body.

Cardiac Catheterization

Before the cardiac catheterization is invented, doctors can only diagnose the coronary artery blockage by the external symptoms such as rapid breathing, lack of energy, etc.

Cardiac Catheterization is the insertion of a catheter (small, thin, plastic tube) into a chamber or vessel of the heart to diagnose or treat certain heart conditions. The Cardiac Catheterization is invented by Claude Bernard (1813-1878), who used it on animal models.



What does Cardiac Catheterization actually mean?
To know more about Cardiac Catheterization, watch this video^_^
http://www.youtube.com/watch?v=f1mdGDu4LK8



How does Cardiac Catheterization process?
The catheter is passed into a leg vein, a dye visible on x-ray film is injected into the catheter. The dye travels through the blood vessels and the heart. The images can be seen on a monitor. The catheter can even reach the coronary artery.

The purpose of Cardiac Catheterization:
-diagnose heart conditions such as minor heart surgery
-blood samples, the blood samples can be taken by the catheter to determine how much oxygen is in the blood in different chambers
-monitor pressures in each of the heart chambers
-a specific catheter (with a tiny balloon attached) can be used to scrape and collect debris from a blockage; this technique is known as angioplasty

Both cardiac catheterization and endoscope are important techniques; they can help us to know more about the interior of our body. Also, both of them can help doctors to diagnose a disease/illness with more confidence and give the best treatment to patients. The specific cardiac catheterization/endoscope can help to scrape debris and remove tumor.

Reference:
http://www.medicalnewstoday.com/articles/153737.php
http://www.helium.com/items/1807307-the-history-of-the-endoscope
http://www.nhlbi.nih.gov/health/dci/Diseases/cath/cath_what.html
http://en.wikipedia.org/wiki/Cardiac_catheterization
http://www.youtube.com
Nelson Biology 11

Is Artificial Selection Good or Bad?

Artificial Selection means intentionally breeding for certain traits, or combination of traits. Artificial is a term that utilized by Charles Darwin to contrast natural selection. We have been taking advantage from this. We produce plants and animals that satisfy our need and want. For example, animal breeders are often able to change the characteristics of animals by selecting those individuals with the most desirable qualities to reproduce such as milk production in cows, trail scenting in dogs.

What are the reasons for artificial selection?

-good Appearance



There are over 150 different dog breeds, from tiny Chihuahuas to giant Great Danes, but they are the same species and all are descendants of wolves. A dog with a good-looking may sell a good price.

-increase its nutritional value

-higher-yielding and better food quality



selective breeding modifies teosinte's few fruitcases (left) into modern corn's rows of exposed kernels (right).

There is no corn ten thousands years ago, corn is a product of artificial selection. Corn is evolved from teosinte. But why and how do human do that? A teosinte ear is only 2-3 inches long with five to 12 kernels, Teosinte kernels are also encased in a hard coating. For humans, the tooth-cracking coating was to hard to eat. So, these kinds of characteristics seem as undesirable and have to selectively reduce. Eventually, human have evolved corns from teosinte. A corn has 12 inches ear that boasts 500 or more kernels, and corn is encased by a paper-thin, translucent tissue.
The artificial selection of corn has resulted a hardier, higher-yielding and better appearance corn plants.

More examples of artificial selection…



wild sunflowers (left) and domestic sunflower-result of artificial flowers (right)

milk production in cows (to have higher yielding)



Wild tomatoes (left) and domestic tomatoes (right)

How do process artificial selection?



Is there any disadvantage?

Everything has an opposite side. Some of the disadvantages of artificial selection are, it may cause mutation or produce new problems.

For example, there is a new way of breeding chickens. However, these chickens do not have feathers. The male chickens may not able to mate because they cannot flap their wings. Also, these “feather-free” chickens are more often attacked by mosquito than the normal chickens. They are more often to get sunburn because they do not have feather to protect their skin.In this example, we have produced chickens that satisfy our want, we can make more money; but how about the chicken? They are suffering from their appearance. another example is Plants/animals without these characteristics are less likely to survive as they do not have the fertilizers and pesticides which provide by human.

We have transformed our lifestyle and environment by evolving all the major crops that we depend upon today: corn, rice. It seems a good idea to process artificial selection to provide more food (higher-yielding) and better food quality (better taste and increase of nutritional value). However, there are also some advantages such as more susceptible to disease or mutations.

Reference:
http://evolution.berkeley.edu/evolibrary/news/070201_corn
http://www.nsf.gov/news/news_summ.jsp?cntn_id=104207
http://en.wikipedia.org/wiki/Artificial_selection#Historical_development

Designer Babies

Designer babies are the term to describe the future of modifying or selecting our children’s genes for desirable characteristics, both medical and cosmetic. It’s an interesting topic which many people or communities have given their opinions.

Couples have opportunity to screen the gender of the children and the genetic diseases since a few years ago. But recently, scientists have made rapid advances in our ability to modify and change genes. So that means the couples are able to “cure” the characteristics which they don’t like by replacing the DNA. The couples can select their desirable characteristics such as gender, eye colour, hair colour, etc when they pay some companies to do so. But is this morally? Are we destroying the rules of the nature? Is this good for the children and parents?

How is it done?



Pre-implantation Genetic Diagnosis (PGD)
Advanced reproductive techniques involve using In-Vitro Fertilisation to fertilize eggs with sperm in 'test-tubes' outside the mother's body in a laboratory. These techniques allow doctors and parents to reduce the chance that a child will be born with a genetic disorder. Only selected embryos are implanted back into the mother's womb.

What are the pros of designer babies?

-It could allow the parents to screen embryos for genetic diseases and select healthy embryo

-“cure” the genetic diseases in embryos by replacing faulty sections of DNA with healthy DNA

-the technique could weed out the X-linked disorders including hemophilia, Duchene muscular dystrophy and Fragile X syndrome

Take the cases of some families:

The case of Cindy and John Whitley, their first child died at the age of 9 months from a deadly genetic disorder called spinal muscular atrophy. Genetic analysis uncovered that the Whitley’s statistically had a 1 in 4 chance of creating a child with spinal muscular atrophy each time they conceived. Unwilling to risk having another child with the deadly disorder, the Whitley’s used PGD to conceive three children, all healthy.

Take the other case of the Collinses family. This technology allows them to pick the sex of their child. It was first used to select for health due to the X-linked disorders.

Some couples are not able to have children because their children will have a genetic disease and die before they are born. These technologies could allow them to have healthy babies. For them, it is really good for them.

The social and ethical implications:

-Is this technique 100% safe? In recent years, there have been several deaths due to genetic-engineering. There are still huge risks that we may produce physical change. What if a designer baby is born with characteristics that the parents didn’t expect to have? It may probably change the life of the child and his family.

-There would be imbalance between rich people and poor people. This technique is very expensive, people may think why should only rich people be able to eradicate the genetic diseases, but the poor people are not.


-Will it lead to happier parents and children? What would the designer children think? Will they against the genetic changes that their parents chose for them? Will this lead to other social problems? What if they were designed for some purposes such as to help their siblings?

-Is this morally and is this unnatural? It feels like the couples are going to shop a baby that they want, they choose some desirable characteristics from a list of options, and then pay money. It sounds unnatural.

-If designer babies become a trend, it may cause social pressure and comparisons. Also, other problems need to consider is, will discrimination against the people born with disabilities.

Designer babies may be good for some couples that could not have a healthy child. It could reduce the chance to have genetic disorder. It may can save the child from suffering genetic diseases. But if some couples want to custom a baby just because they want a child with good-looking, it may be unnatural and will cause many other social problems.

Reference:
http://singularityhub.com/2009/02/25/designer-babies-like-it-or-not-here-they-come/
http://www.bionetonline.org/English/content/db_cont1.htm
http://www.time.com/time/magazine/article/0,9171,989987,00.html

Are human being stewards of the world, or the invader?

Are we being stewards of the world as we can greatly change an environment and impact living things that reside there or we are the invader as we have negative impacts to the environment?

In my opinion, we have made both positive and negative impact to the environment. Human invented a lot of new products to make our life better and more comfortable. In the other side, we are also destroying the environment.

Also, human has made negative impacts which affect our biodiversity of our ecosystems. Human has been participating many of excessive activities such as fishing, hunting, industry development which has been causing negative impacts to the environment. One of the impacts that many people recognize is global warming. Global warming brings a lot of effects such as the climate change; the sea level rises because the ice sheet is melting. While the industry is developing, it also makes a lot of pollution, such as water pollution, air pollution.





Who are the victims? The other species that living on the earth! Many animals and plants lost their home and some of them were extinct because we destroyed their homeland. Why do they have to take responsible of the impacts which were made by us!

Wood Bison



Wood Bison can only found in Canada. The wood bison is a subspecies of the North America Bison. But the wood bison is heavier and highest than the North America Bison. It is the largest mammal in the North America. Females give birth to two calves usually within three years.

Why they are endangered?
The population of the wood bison was over 160,000 before 1900. But, due to hunting, the population of wood bison reduced to less than 250 by 1900. Beside for hunting, diseases such as tuberculosis and anthrax are also threatened the population. Now, the wood bison populations have recovered to 9,000 due to the conversation efforts. But they still are endangered specie.

Because of human’s over-hunting and the diseases, the wood bison becomes less and less.

Chinese River Dolphin



The Chinese River Dolphin is only found in the Yangtze River in China and they may be extinct. It has a long, narrow snout. Its skin is light bluish-gray and white on its underside. Adult dolphins could grow up to eight feet and weigh up to 500 lb. Females give birth to one calf within six to twelve months.

Why they are endangered?
The Chinese River Dolphin could only grow in fresh water. Because they could only survive in the fresh water, the water pollution, over-fishing, accidents during heavy river traffic, human activities make the Chinese river dolphin to extinct. Conservationists concluded that the species may now be extinct in the summer of 2007.

The Chinese River Dolphin is a rare species, but because of the pollution, human activities on the river such as over-fishing, heavy river traffic, they may now be extinct.

Polar Bear



There is an recent article about cannibalism has happened among the polar bears. Some scientists believe that cannibalism incident among the polar bears is a result of climate change. Because the ice is melting, the mothers can’t keep the cubs away from males. When the male polar bears get hungry, the cubs would be the target. If this continue happens, there would be less polar bear in the Hudson Bay.


While we are inventing new technology or new products to improve our life, we may have made many negative impacts to our environment. Such as global warming, pollutions, some species lost their homeland because of these impacts. If one species is extinct, it would make a big change or impact on its ecosystem.

Since we have the capacity of changing an environment, we must be aware what we have done and serious influence we’ll give to the environment.


Reference:
Polar bear:
http://www.nationalpost.com/story.html?id=2322656
http://www.panda.org/what_we_do/where_we_work/arctic/area/species/polarbear/
list of endangered species:
http://www.earthsendangered.com/profile.asp?gr=&view=c&ID=9&sp=34