Blog Entry #12: Bio-solids

Blog Entry #12: Biosolids 
In other parts of the world, biosolids (human waste) from sewage treatment plants are treated and used as sustainable agricultural fertilizer. 


What are biosolids?
Biosolids, also known as sludge, are highly treated solid waste separated from waste water. The solid in the waste water gets treated at the plants where they get thickened, and pumped into large digestors. Here, they are heated to at least 95°F, and slowly broken down by anaerobic bacteria for about 15 days. Finally, they become biosolids and are reused in a variety of ways.

Are Biosolids safe?

If the biosolids were approved by the government, have gone through laboratory analysis, and have met certain standards, no doubt that they would be safe. The highly treated biosolids have low metal concentrations and only a small amount of bacteria. And to make sure they're safe, biosolids must meet special standards for use and disposal.These standards contain limitations for metals, monitoring rules, regulations for reduction of harmful bacteria and site selection for land application as well as crop harvesting. As a result, the biosolids are non-hazardous, and non-toxic. 

On the up side of Biosolids...

Biosolids are beneficial in many ways. They're rich in phosphorus and nitrogen, as well as copper, iron, and zinc, which are micro-nutrients. These micro-nutrients compliment the biosolids, making it a good fertilizer and allows plants to grow in an enhanced soil structure. With that being said, not only do biosolids help the crops and the soil, it also helps the farmers. Farmers can use biosolids that naturally come with all those things rather than spending their money to purchase micro-nutrients and other resources needed to grow their plants. Biosolids are good for growing crops such as corn, soy beans, and canola. Biosolids also improves pasture, and gradually decreases the need for commercial fertilizers that can have harmful chemicals.  In addition, using biosolids on agricultural lands enables the municipalities to recycle a treatment process by-product in a cost effective manner. Finally, the people practically gets to collect the benefits. 

And the down side...

Aside from the many benefits of biosolids as fertilizers, there are still concerns closing in on the process: the odor of the biosolids, and concern about contaminants in biosolids. In many samples of biosolids, organic pollutants, pesticides, and heavy metals were found. Also, even though metals, such as copper and zinc, are a necessity for plant growth, a heap of metals can cause problems with both animal health and plant growth. Since biosolids contain nitrogen and phosphorous, these micro-nutrients, in excess, can move into ground or surface water and cause problems for animals. Lastly, there are also issues about the amount of pathogens in biosolids. A pathogen is a bacterium, or a virus, that can cause disease.

Finale

In my opinion, I think biosolids is a realistic alternative to current agricultural practices. It seems to me that the benefits of biosolids surpasses its disadvantages. There are some issues, concerns, and risks surrounding biosolids. But really, what doesn't come with all of those? When used as fertilizers, the land and the crops planted in the land are not the only ones benefiting from biosolids; it is also beneficial to the society. How? Well, if you think about it, it's like a simple chain: biosolids would keep the farmers in business and make a living, sell whatever product they've grown to markets, and the markets then sells it to consumers. Even though there many issues about biosolids, I think it's a safe alternative. Besides, biosolids, as aforementioned, go through a bunch of tests, and approvals from the government. I don't think the government would send these biosolids out to be used on land if it contained contaminants and pathogens. So to sum it all up, despite having it seem so unsanitary and irksome, I think biosolids should be used as fertilizers. People need to get past the first thing that comes to mind and realize the benefits.

Sources:

 "CAES Publications | UGA." The College of Agricultural and Environmental Sciences at the University
of Georgia. Web. Apr. 2012. <http://www.caes.uga.edu/publications/>

"Sewage Biosolids: A valuable Nutrient Source." Ontario Ministry of Agriculture and Rural Affairs

/ Ministère De L'Agriculture, De L'Amentation Et Des Affaires Rurales. Web. Apr. 2012.

<http://www.omafra.gov.on.ca/english/nm/nasm/sewbiobroch.htm>.

"CWWA - FAQ - Biosolids." CWWA/ACEPU. Web. Apr. 2012.

<http://www.cwwa.ca/faqbiosolids_e.asp>.

"Supplemental Content." National Center for Biotechnology Information. U.S. National Library of

Medicine. Web. Apr. 2012. <http://www.ncbi.nlm.nih.gov/pubmed/18023841>.

"Biosolids.com | About Biosolids: Biosolids Benefits." _. Web. Apr. 2012.

<http://www.biosolids.com/benefits.html>.

Properly Treated, Human Biosolids Are Good Fertilizer

Posted on October 27, 2000 by Alex Avery

CHURCHVILLE, Va. — Chinese peasants and today’s organic farmers have long shared an important idea: We can’t afford to waste our wastes.

Today, that includes “biosolids”–residue from sewage treatment plants. Some of my neighbors are nervous about living near fields where biosolids are being applied.

Oddly enough, they seem totally secure about the idea of living next to an organic farm. Yet the use of biosolids is far safer for neighbors, workers and consumers than is organic farming.

For centuries, China has had “sustainable” agriculture, using human wastes to fertilize its rice paddies. The Chinese had no other source of nitrogen for their crops, and no better way to deal with huge amounts of human waste.

Modern sewage treatment produces millions of tons a year of what we call biosolids. Industrial plants, such as milk and other food-processing plants, produce additional millions of tons.

We can process these biological residues into safe forms, and use them as valuable soil conditioners on farmland and forests. Or we can waste them, using up lots of valuable landfill space. Incineration is even more expensive than putting waste in landfills and adds more greenhouse gases to the atmosphere.

Biosolids contain essential such plant nutrients as nitrogen and phosphorous. They also contain organic matter, the single most important component of the world’s most important substance, topsoil. Virtually all the life on this planet ultimately depends on topsoil converting sunlight into plants and trees.

Our livestock and poultry farms also produce hundreds of millions of tons of manure a year. Properly handled, animal manure is just as valuable as biosolids.

Mainstream farmers use it mainly on feed crops. They use chemical fertilizer on food crops because it doesn’t carry the risk of pathogenic bacteria.

Organic farmers refuse to use chemical fertilizers, so they feel they must put manure on food crops. It’s the bacteria that make organic farming more dangerous for its workers and neighbors.

Modern societies can also afford to make their wastes much safer to land-apply than China’s night soil. Organic farmers usually compost their manure by stacking it in piles for some months and letting the natural heat of fermentation kill bacteria.

Biosolids are treated still more intensively. They’re typically put into a sealed digester and composted at much higher temperatures than most organic farmers achieve. They’re also checked before land application to make sure the pathogens are killed, which is not true for organic farms.

Recently, health authorities retested some biosolids that had allegedly caused flu-like symptoms among workers spreading them. The biosolids were found to be as safe as the garden dirt in my backyard, with none of the pathogenic bacteria that attack humans (salmonella, shigella, E. coli, etc.).

This indicates there was no residual biological activity from the sewage sludge. In fact, the high concentrations of environmental fungi and bacteria in the biosolids re-emphasized how good the biosolids are for soil microorganisms.

While no food crops can be harvested from land that has received biosolids for 12 to 38 months (limits enforced by individual states), organic farmers have only a voluntary commitment to wait three months before harvesting food from fields where they have spread raw manure.

This disparity, three months instead of 12 to 38 months, exists even though most organic farmers use cattle manure, which is the major reservoir of the most virulent new bacterial threat in our food, E. coli O157:H7.

Researchers at the Department of Agriculture say they have found O157 on every cattle farm and ranch they’ve tested, even extensive cattle ranches in western Canada. Infections from this bacterium are primarily associated with undercooked hamburger, but this strain has also been found on vegetables and fruits. It can kill even healthy people and often leaves its survivors with damage to internal organs such as the liver and the kidneys.

The Centers for Disease Control say America is getting at least 25,000 of these cases a year, and about 250 deaths. There are no known deaths from pesticide residues or biosolids.

Isn’t it time we made organic food production as safe as our use of biosolids?

Source: 
"Properly Treated, Human Biosolids Are Good Fertilizer." Center for Global Food Issues. Web. Apr. 2012. <http://www.cgfi.org/2000/10/properly-treated-human-biosolids-are-good-fertilizer/>.

Stuff About the Article:
Knowing that the author of the article is an expert on agriculture, environment, world hunger issues, biotechnology and pesticides, and is also the director of research and education with the Center for Global Food Issues at Hudson Institute, I'd say that this article is indeed accurate. Alex Avery was a McKnight research fellow at Purdue University, where he worked to develop drought-resistant sorghum varieties for the Sudan of Africa. Also, Avery wrote about agricultural, food safety, and regulatory issues for major newspapers, including The Wall Street Journal, USA Today, The Washington Times, New York Post, St. Louis Post-Dispatch, Fort Worth Star-Telegram, Atlanta Journal-Constitution, and the Des Moines Register. The article is basically an article that informs the readers regarding biosolids. It is biased in a way that the author mostly just talked about China's situation.