Biosolids Remediate Metal Contaminated Soils #sewage sludge #mine pollution

Here's just the tip of the iceberg as far as the research on biosolids and their super-protetctive and remediating powers. I've seen it in a couple of places listed at the bottom. 

Internet Resource

National Biosolids Partnership Web site. Available from http://www.biosolids.org .

Peter S. Machno and Peggy Leonard

BIOSOLIDS REMEDIATE METAL-CONTAMINATED SOILS

The mining and processing of metal ores have contaminated soils in many countries. In the vicinity of lead (Pb) and zinc (Zn) mines and smelters, soils may have Pb and Zn concentrations as high as 20,000 mg/kg. These soils—with their high metals, low pH, and lack of nutrients and organic matter—are toxic to plants. Land around the mines is acidic and barren, often with blowing dust and metals leaching into ground and surface waters.


Three such sites on EPA's Superfund list—Palmerton, Pennsylvania; Leadville, Colorado; and Bunker Hill, Idaho—have demonstrated that biosolids mixtures can restore soils and vegetation. Biosolids combined with a calcium carbonate material such as lime or wood ash create a fertile soil and vigorous, self-sustaining plant growth. Iron and phosphates in biosolids adsorb lead and convert it to an insoluble compound, chloropyromorphite. Wood ash raises soil pH and prevents Zn from being taken up by plants or leached. Biosolids supply nutrients and organic matter for rebuilding soil and soil microbial communities.
Similar results have been reported in Upper Silesia, Poland, where lands have been contaminated by toxic coal and smelter wastes. New secondary treatment plants in the region will be producing a supply of biosolids for future restoration projects.

A douglas fir tree with (left cuts) and without (right cuts) biosolids application. There is a more than 100 percent increase in tree growth with biosolids. Each "tree ring" represents one year of growth. (King County photo by Ned Ahrens. AP/Wide World Photos. Reproduced by permission.)

http://www.pollutionissues.com/A-Bo/Biosolids.html


http://www.reclaimingtheculture.org/pollution-guide-2/biosolids-remediate-metalcontaminated-soils.html

Sustainability of Biosolids Recycling Confirmed using 20 Year Study #sewage sludge Fact Sheet: http://cals.arizona.edu/pubs/consumer/az1426.pdf

Sustainability of Biosolids Recycling Confirmed via a 20-year Study - Fact Sheet: http://cals.arizona.edu/pubs/consumer/az1426.pdf

The University of Arizona conducted this study in an attempt answer some of the most commonly asked questions regarding biosolids. Here are some of the questions answered by this study and presented in this factsheet.

• What Are Biosolids? (includes data - yeah!)
• What are the Biosolids Regulations?
• Land Application of Biosolids in Arizona and in the US
• History of Biosolids Research at the University of Arizona
• Biosolids Research in Arizona: Emerging Issues
• Biosolids Use for Land Reclamation
• Answers to Concerns about the Safety of Biosolids Land Use
• How can we contribute to the safe [use] of biosolids on land?
• Remember
• References and Websites of Interest

First, I love the Remember section and other blue-boxed sections: 

• "As the population grows so will the production of biosolids and the need for safer disposal options.

Biosolids can continue to be valuable renewable source nutrients for agricultural soils, rangeland, and land reclamation as long as the quality of these residues continues to improve.

This can be done by controlling unwanted chemicals (metals, synthetic chemicals, medicines) in sewage streams and by improving biosolids pathogen and pollutant reduction methods."

• "Healthy soils contain hundreds of millions of beneficial bacteria and other microorganisms per gram that recycle plant nutrients, and degrade pathogens and organic pollutants.

Also, healthy soils usually have an excess capacity (minerals, organic matter and favorable chemical conditions) to trap and retain metals preventing them from contaminating plants and polluting other environments.

Soils can continue to provide this valuable service as long as they are not overwhelmed by excessive amounts of wastes, pollutants or other adverse soil conditions."

• "Biosolids are not a significant health threat as long as they are treated, stored, handled, and applied to land following accepted guidelines and regulations.

But, federal and state biosolids guidelines, regulations and monitoring programs must continue to evolve. They must adapt to new concerns about biosolids based on new scientific information."

Although worded very scientifically-jargonistically, the scientists concluded that:

• "Application of biosolids for nonfood agricultural crop production at this arid southwest site seems to be sustainable with respect to soil chemical entities."
• "The study showed that land application of Class B biosolids had no significant long-term effect on soil pH and CaCO_3. However, land application significantly increased soil macro-nutrients (C, N and P). Soil nitrate values in plots that received biosolids or inorganic fertilizer amendments were high indicating the potential for groundwater contamination. In addition, total and available soil P concentrations increased to values above that necessary for plant growth but P values attenuated to background levels at a soil depth of 150 cm. Total metal concentrations attenuated rapidly with increasing soil depth, and were generally similar to values found in control soils at a depth of 150 cm."
• "Overall, the 20 annual land applications showed no long-term adverse effects, and therefore, this study documents that land application of biosolids at this particular site was sustainable throughout the 20-yr period, with respect to soil microbial properties."
• "Data show that land application of ClassB biosolids had no significant long-term effect on indigenous soil microbial numbers including bacteria, actinomycetes, and fungi compared to unamended control plots. Importantly, no bacterial or viral pathogens were detected in soil samples collected from biosolid amended plots in December (10 mo after the last land application) demonstrating that pathogens introduced via Class B biosolids only survived in soil transiently. However, plots that received biosolids had significantly higher microbial activity or potential for microbial transformations, including nitrification, sulfur oxidation, and dehydrogenase activity, than control plots and plots receiving inorganic fertilizers."

This section is also worth including. Consumer awareness, responsibility, and actions are critical for all environmental issues!

    “What can be done to make biosolids a safer and more valuable fertilizer source?

• As end-users of numerous household products that contain toxic and hazardous chemicals, limiting the use and disposal of these products into the sewage system will continue to improve the quality of biosolids. What should we do?
• Use no or low phosphate, biodegradable soaps and detergents at manufacturer recommended amounts.
• Do not dump leftover household chemicals such as oil products, pesticides, paints, solvents and medicines down the toilet or sink. Instead, take unused or spent products to local recycling centers.
• Do not use or limit the outdoor use of yard pesticides and avoid chemical spills on driveways, as these activities can contaminate runoff water entering the sewage system.”

Sewage Sludge has Super Powers that Protect Metals from Uptake into Plants!!

Heavy metals in sewage sludge (aka biosolids) and their potential for environmental impact has been a concern over the years, especially when it comes to recycling treated sewage sludge on farmland and composting it for home garden use.

This is exactly why I again enlisted the help of Rufus Chaney, a long-experienced USDA researcher on metals in biosolids and soils and plant uptake who worked for decades on this subject with a very long list of peer-reviewed journal articles. He even mentored another legend, Sally Brown with University of Washington who has also done some amazing work with biosolids, carbon sequestration, and greenhouse gas calculations (theme for another article).

It is important to recognize the difference between knowing that a metal or any other compound is present and knowing whether it is actually taken up by the plants that you may grow and eat. Nature can be very complicated in this way. Rufus to the rescue! He has worked with romaine lettuce as an indicator for highly sensitive crops - those that should up take the most bioavailable metals.

In the presentation below and the similarly titled peer-reviewed paper, the research compares control (unamended with biosolids soils) to biosolids amended soils which had received high rates of biosolids applications and contained significant concentrations of metals. Despite higher total soil cadmium, lettuce accumulation of cadmium was significantly lower in biosolids-amended soils than control soils that had never received biosolids. This was true for soils even decades after the applications occurred, meaning that the amazing biosolids properties stay in tact for as long as we can measure. You can see that the plants consistently accumulate more metals from the control soils even if there is a lot more of the metal present in the biosolids / sewage sludge.

I have heard Rufus present in person, and he is emphatic about the importance of the ratio of cadmium to zinc. If they are present in a ratio of 1:100, for instance, (for every one part cadmium there are 100 parts of zinc), then there will be a enough zinc to prevent the uptake of cadmium by the plant at any significant level; even protective of people eating large amounts of the lettuce. We often hear of a potentially similar "protection" mechanism in our bodies when we take zinc supplements to try to boost our immune systems during the flu season. Luckily, most biosolids have lots of zinc and iron (another protective metal that likes to bind with lots of compounds).

The implications of these finding go far beyond whether biosolids is safe to use in crops and home gardens. It means that biosolids have amazing assimilative and protective powers! For instance, urban soils often contain high levels of metals (from car brake pads, emissions, etc.). Biosolids have been added to these soils to remediate these contaminated soils so that inner city folks can again garden and play in the soils safely. Biosolids have been used to remediate mine tailings with high levels of metals. (Good fodder for future articles!)  

Another note from this study is that because of the tremendous success of modern industrial source control programs (they require prevention or treatment onsite at industries that discharge metals and other pollutants), modern biosolids - treated sewage sludges do not contain levels of metals that would be of concern for uptake. For instance, the metals in Orange County's sewage has been reduced by over 95% since the 1970's when the Clean Water Act began implementation. This equates to proportional reductions in the final biosolids - treated sewage sludge. The metals in these biosolids are significantly under the EPA's most restrictive criteria, which means they are so low that the cumulative loading is not of concern.

In other words, our nation has made great strides in cleaning up metals in the environment, which ensures that biosolids can be safely recycled to fertilize farms as well as turned into compost for home use. And our gardens and farms will actually be protected by the biosolids! Now that is Amazing!!

On a sad note, it is so unfortunate, disappointing, disheartening, and potentially an environmental disaster when fear and politics rule and biosolids are ban from use, forcing municipalities to use technologies with larger carbon footprints (it takes lots of energy to dry biosolids or refine into another product), and frankly, it’s a waste of significant resources. We are wasting precious non-renewable phosphorus that otherwise needs to be mined from the earth again to replenish fields. We put more pressure on farmers to turn to expensive, non-renewable, synthetic fertilizers. Banning biosolids is creating the environmental disaster that the politicians are ironically trying to prevent. 


VOICE YOUR SUPPORT! http://www.ipetitions.com/petition/biosolids/ 

Kukier chaney-2005-effect of biosolids on phytoavailability of cd

View more presentations from Deirdre Bingman.