by Wesley Brookes
History, politics, and chemistry, all mixed will a little cutting edge innovation…this was the theme at the annual Pacific Regional Society of Soil Science Spring Workshop and AGM. Titled “Soil and the Waste Cycle: Utilizing regenerative cycles in the face of global change”, the conference featured speakers from diverse (but related) backgrounds.
Dr. Ken Ashley from UBC Civil Engineering spoke of wastewater, environmental protection and resource recovery. Beginning with a brief history of waste management, (or a lack of really), where toilets existed only to flush the smelly stuff into the backyard. Ken noted how far we’ve come since then with the most responsible and technologically savvy urban centers having complex wastewater treatment procedures resulting in a product that can be gulped down on a hot summer’s day. Ken then went on to describe what he believes to be a new paradigm, where rather than treating waste water as a liability, waste become a resource. He mentioned that phosphorous is a major problem in the treatment of waste water because it cannot be destroyed in the sense that it has no gaseous state. Therefore a large portion of this phosphorous is released into the environment resulting in the eutrophication of our waters.
Ken has been an integral part of a team that has developed a biological phosphorous removal method that can be coupled with existing waste water treatment; his method removes all the excess nitrogen too! This is done via the use of bacteria that are fed into the treatment process wherein they fix the phosphorous and nitrogen into their tissues. Then all that is needed to capture and remove these nutrients is to screen out the bacteria! However, this hasn’t proved to be a silver bullet; one of the by-products of this process causes waste water treatment managers big headaches. This headache goes by the name of Struvite, magnesium ammonium phosphate (MAP), or NH4MgPO4·6H2O (or the stuff that kidney stones are made of). Anyways, this “stuff” clogs the water pipes of treatment plants costing $100 000s/year in maintenance. Introducing innovation number two! A solution to the Struvite problem? Let’s bring in some of the best minds in Canada (…or the world?). Sounds like a job for UBC. A pilot project developed right here at UBC has resulted in a reactor, which prevents the clogging of the pipes while recovering the phosphorous inside! Amazing. The product of this has only one name, Crystal Green; a sustainably recovered renewable resource. Partly due to this innovation, Struvite now sells on the market for up to $3000.00/ton. So you had better start saving those kidney stones. On second thought, maybe not.
Ok so, if all this isn’t enough, this process is now being tested to use on dairy farms for the processing of manure. This innovation uses microwaves, hydrogen peroxide and a whole lot of cow pies to produce Struvite. The process increases the recovery rate of phosphorous and increases methane production by 4-6x! This process has been so successful it has been predicted that in the future dairy farmers will make more money selling methane than milk!
Wow, ok now, if you weren’t already gleaming with hope for the future of wastewater treatment, Mr. Allan McCammon with the Ministry of Environment showed us that the government has got our back when it comes to cleaning up the soil and preventing it from getting dirty in the first place. Allan explained the laws and bureaucratic processes involved in the remediation and redevelopment of contaminated sites and brownfields in BC. The laws include extensive rules on liability for these sites based upon a “polluter pays” principle. The laws are designed to address the protection of human health through the protection of our drinking water; environmental protection, which focuses on aquatic habitats; and providing a clear and streamlined framework to identify, investigate, and remediate contaminated sites. Some examples of contaminated sites in BC include the coast of False Creek in Vancouver, most gas stations, and, you know, almost the entire city of Trail. Sometimes there’s not much that can be done for certain sites and so one of the most pleasant uses for these sites is to establish community gardens using raised beds.
Mike Van Ham was up next, representing Sylvis Environmental. A Vancouver based consulting firm that has existed for 15 years providing environmental monitoring and assessment, land reclamation and restoration, and residuals recycling. This last service and its relevance regarding the sustainable production of nitrogen was the topic of Mike’s lecture. To start off, Mike treated us to a history lesson on the development and use of nitrogen as a fertilizer. The Roman god Sterculius (literally translated: “manure”) was believed to supervise the basics of organic fertilization. Not just the Romans, but the Inca and Aztecs also realized the power of poo; finding that bat guano did the trick! However, it wasn’t until 1850 that a man named Jean-Baptiste Boussingault began to link the proportion of nitrogen in a soil to its productivity. Next, John Bennet Lawes and Joseph Henry Gilbert conducted a series of long term field experiments with the use of nitrogen and confirmed the importance of nitrogen in agriculture. At this time, besides the small quantities found in manure, there was only one form of nitrogen available to be mined on an industrial scale. This nitrogen was found in the mountains of bat guano located on the Chincha Islands off the coast of Peru. As a result of this precious and rare commodity, Peru’s Gross Domestic Product increased by 900 %. Still, this supply proved to be insufficient to meet world demand. It wasn’t until a crazy chemist met an exploitative industrialist and the combination of their unique talents resulted in a process that enabled the conversion of atmospheric nitrogen to ammonium. These two men, Fritz Haber and Carl Bosch, developed what is now known as the Haber-Bosch process and, which is now used to produce 133 metric tons of ammonium per year. This process revolutionized agriculture and resulted in massive crop yields around the world. The world’s carrying capacity during this period increased from 1.9 persons to 4.8 persons per hectare! We have come to depend on this process so heavily that it is now estimated that over 3 billion people would not be fed without it. Unfortunately this dependence has put us in a tough situation because it’s now being revealed that all this nitrogen isn’t very good for the environment. A major issue is that most of the nitrogen applied to agricultural fields is not assimilated into plant or microbial tissues and so ends up in our water, or in our atmosphere as nitrous oxide (the third most potent greenhouse gas).
Mike listed 4 ways in which we can mitigate our impact on the nitrogen cycle: controlling nitrous oxide emissions during the combustion of fossil fuels, increasing efficiency in use of nitrogen fertilizers in agriculture, improving residuals management, and increasing waste water treatment. The third of these, improving residuals management, was the focus of the remainder of Mike’s talk. Residuals were described as the “solid stuff” left over after the waste water treatment process. These residuals, when passed through an extensive process, produce what are called biosolids. Biosolids are heavy with organic matter and contain significant macro and micronutrients, trace elements, and beneficial microorganisms making them ideal for use as fertilizers or for reclamation projects where they can be mixed with a mineral component to fabricate a soil!
Mike, Allan, and Ken gave us all a sense of hope by revealing the ingenuity of the people who care enough to devote their lives and careers to tackling these urgent waste-related environmental issues. Not only have they found solutions, they have developed efficient solutions. A big thank you to Mike, Allan, Ken, and all those involved!