BioCycle October 2007, Vol. 48, No. 10, p. 6
EPA Focuses On Recovered Materials For Composting
To support markets for recycled-content products, EPA is adjusting the Comprehensive Procurement Guidelines Landscaping Products category and will focus on a Recovered Materials Advisory Notice, making these two changes: EPA will consolidate compost designations under the heading, “made from recovered organic materials.” The old description referred to compost made from yard trimmings and food waste. The revised version also includes compost made from biosolids and manure and does not limit the designation to those four specific types of recovered organic materials. EPA is also providing companion guidance to agencies purchasing compost and fertilizers made from recovered organic materials. Under the Resource Conservation and Recovery Act (RCRA), procuring agencies will be required to begin purchasing the newly-designated items within one year from the date that this rule is published in the Federal Register.
Cocompost Used As Biofilter To Remove Ammonia
Biofiltration has been gaining increased interest for removing odor and unwanted compounds in exhaust air from farms, biogas plants and composting sites. Ammonia is an important compound as it contributes to both odor emission and to atmospheric deposits of nitrogen which may disturb “delicate ecosystems.” Now researchers at Aalborg University in Denmark have compared yard waste and sludge compost to their efficiency as biofilter material for removing ammonia from air. All filter columns using the compost were able to remove more than 95 percent of the ammonia in the inlet regardless of compost type and applied air flow rate. Ammonia concentration profiles inside the compost columns measured at the end of the experiments indicated that sewage sludge compost removes ammonia at significantly higher specific rates than yard waste compost. The likely explanation, the researchers report in the latest issue of Compost Science & Utilization, is that sewage sludge compost contains higher numbers of nitrifying bacteria originating from the wastewater treatment process.
To get a copy of Compost Science & Utilization and to subscribe for a full year of these issues, visit www.compost-science.net or call 610-967-4135, ext. 21.
Readers Respond To Food “Waste” Word
The editorial in the August 2007 BioCycle titled “Food ‘Waste’ By Any Other Name Is …” invited readers to send us their suggestions for a replacement word for ‘waste.’ Our request brought these responses:
From Alex Cuyler: “Food discards is my choice … it doesn’t imply wasting.” Cuyler is Recycling and Solid Waste Analyst, Eugene, Oregon Planning and Development Department.
From Terry March in Bristol, England: “What is wrong with the term food ‘waste’? Whilst admittedly, there is an amount of food material that has to be discarded (e.g., plate scrapings, etc.), too much food is often wasted by careless over purchasing by consumers and generally careless attitude to food. Therefore, the correct term to use for this is ‘waste’ – so why not make it clear to the householder what it is rather than dress it up in some other name. Of course, this ‘waste’ should be utilized as a resource by processing into useful products and energy. In Britain, we are driven by EU legislation to divert as much biodegradable waste as possible away from landfill.” March is with T. March Consultants.
From Morgan Harriman: “How about ‘leftover food’ composting?” Harriman is Commercial Waste Reduction Planner with MassDEP in Boston.
From Joe Goicochea: “I completely agree with the need to change the term food ‘waste’. I think it’s important that you bring this to your readers’ attention, which includes regulators, as many people don’t pay much attention. One of our compost facility operators and I were talking about the food scraps initiative in Ohio. At the time, it was called the food ‘waste’ initiative. He iterated that the term waste is not only inaccurate, but more importantly gives businesses and individuals a ‘wasteful’ perspective of this material. People think of waste as something that is not recoverable. Fortunately, Ohio is in the midst of its five-year rule review, and we plan to update our definition from food waste to food scraps. Hopefully, the composting industry can also promote use of scraps (or something else) and more communities and business will become educated on how this material is better off going to a composting facility or anaerobic digester.” Goicochea is an Environmental Specialist in Composting and Infectious Waste Programs with Ohio EPA.
From Gary Wegner: “I work with the dairy industry to better utilize their manure nutrients. The best way to describe these materials is ‘Nutrients in Transition’ – think of it like a wayward child in ‘transition’ back to a productive life. The nutrients are in one form, and we use nature’s biology to assimilate them to new and more useful forms. As a farmer, we have used over 300,000 tons of biosolids in a very beneficial way. So I know for sure that these are nutrients in transition!” Wegner is with Wegner Ranch/Circulus Systems.
Humus Quality For Composts Evaluated In New Publication From Europe
Authored by Katharina Meissl, Ena Smidt, Johannes Tintner and Erwin Bonner, who are with the Institute of Waste Management at BOKU University in Vienna, the book Humus: A Quality Criterion for Composts, provides excellent insights into high-grade end products. They explain how their research has led to a method to determine humic acid contents very quickly by means of infrared spectroscopy and appropriate evaluation tools. “Due to the fast investigation, corrective actions can be taken during the composting process. Such intervention stands for a step toward quality management and cost savings. It also shows which input materials and process conditions are favorable to promote synthesis of humic acids.”
To obtain a copy of the book or get more details, contact K. Meissl via e-mail at: email@example.com. Or write: University of Natural Resources and Applied Life Sciences, Vienna Institute of Waste Management, Muthgasse 107, 1190 Vienna, Austria.
Launching A Biogas Plant In Gedsted, Denmark
In operation for two months, the biogas facility in Gedsted, Denmark is operated by farmer Tom Larsen, processing feedstock from about 800 milking cows. Most of the gas comes from additional feedstocks – primarily in the form of a glycerol by-product from biodiesel production. The biogas is piped about 1 km from the farm to the CHP site in Gedsted.
Twenty years ago, there was discussion about whether biogas plants could be developed from ordinary concrete slurry tanks. After some attempts, Lundsby Industries, owner of the Gedsted site and a slurry tank producer, took on the challenge and has now succeeded. The company has a number of sites in Denmark, a second plant is underway in Germany, plus a license production in Ireland. Lundsby Industries have supplied many digesters for these facilities, and a report by Soren Tafdrup is planned for a future issue of BioCycle.
In the long run for Denmark, the goal is to replace fossil fuels completely with renewable energy, with 50 new centralized biogas plants to be built before 2025 (roughly three new plants per year). Energy supply is considered a matter of national security, so Denmark shall continue being self-sufficient with energy. Renewables shall increase to at least 30 percent of total consumption by 2025 (from 15 percent today).
The history of Danish biogas use includes data on the oil crises in 1973, leading to an energy policy that included biogas from manures. Between 1975 and 1983, the biogas plants that were built mostly failed due to technical problems. From 1984 to 1986, centralized plants were suggested, combined with agricultural and environmental interests. Great involvement was shown by farmers.
In 1987, the Government Action Program, or Centralized Biogas Plants, had 10 demonstration sites, and 10 additional locations were built between 1993 and 1998. Between 1995 and 2006, liberalization of the electricity supply sector put a hold on new centralized biogas sites due to unknown future electricity sales prices – 50 to 60 new on-farm biogas plants were built, existing centralized sites were consolidated and several expanded to higher capacity. By 2007, renewed political interest in clarifying long-term preconditions allowed for new centralized sites to be built.
Landscape Architects Rate Green Roof Performance
The American Society of Landscape Architects (ASLA) installed a green roof on its Washington, DC headquarters, which retained 27,500 gallons of storm water in the first year, significantly lowered outdoor air temperature and reduced building energy costs by several hundred dollars per month. “Because landscape architects are leading in the design of green roofs across the country, it was important for us to build a demonstration project and measure the impact green roofs have on their surrounding communities,” says Nancy Somerville, Executive Vice President and CEO of ASLA. “The findings show that our green roof delivered significant economic and environmental benefits.”
In 2006, ASLA replaced the conventional roof on its downtown Washington, DC headquarters with a green roof, installing equipment to gather data on stormwater runoff, water quality and temperature. From July 2006 to May 2007, the green roof prevented nearly 75 percent of all precipitation on the roof from flowing into the overburdened sewer and stormwater system. Except during repeated heavy rains, the roof only created runoff during rainfalls that exceeded one inch. The water runoff itself contained fewer pollutants than typical runoff.
ASLA’s green roof lowered air temperature by as much as 32 degrees in the summer when compared to a neighboring tarred roof, helping mitigate the urban heat island effect. “Collectively, green roofs can save billions of dollars in urban infrastructure costs, which is why more and more cities are encouraging them through tax and other incentives,” Somerville continued. The roof also reduced the building’s energy costs – especially in the winter. Engineering analysis showed that the green roof’s extra insulation lowered energy usage in the winter by 10 percent with a potential of two to three percent in the summer.