Windrow composting

Windrow turner used on maturing piles at a biosolids composting facility in Canada.

Maturing windrows at in In-vessel composting facility.

In agriculture, windrow composting is the production of compost by piling organic matter or biodegradable waste, such as animal manure and crop residues, in long rows (windrows). This method is suited to producing large volumes of compost. These rows are generally turned to improve porosity and oxygen content, mix in or remove moisture, and redistribute cooler and hotter portions of the pile. Windrow composting is a commonly used farm scale composting method. Composting process control parameters include the initial ratios of carbon and nitrogen rich materials, the amount of bulking agent added to assure air porosity, the pile size, moisture content, and turning frequency.

The temperatures of the windrows must be measured and logged constantly to determine the optimum time to turn the windrows for quicker compost production. Manually collecting data cannot be done continually and may expose the person collecting the data to harmful pathogens. Automatically collecting the data and transmitting the data wirelessly back to a centralized location allows composting temperatures to be continually recorded and logged, improving efficiency and reducing the time needed to complete a composting cycle.^[1]

Compost windrow turners

Compost windrow turners were developed to produce compost on a large scale by Fletcher Sims Jr. of Canyon, Texas. They are a traditionally a large machine that straddles a windrow of 4 feet (1.25 meters) or more high, by as much as 12 feet (3.5 meters) across. Although small machines exist for small windrows, most operations use larger machines for volume production. Turners drive through the windrow at a slow rate of forward movement. They have a steel drum with paddles that are rapidly turning. As the turner moves through the windrow, fresh air (oxygen) is injected into the compost by the drum/paddle assembly, and waste gases produced by bacterial decomposition are vented. The oxygen feeds the aerobic bacteria and thus speeds the composting process.

Recent compost emissions sampling by Environmental Management Consulting raises questions about the presence of methane in the emissions from windrow composting. One sample found that as much as 26 percent of the waste carbon may be emitted as methane and not carbon dioxide.^{[citation needed]}

Utilization

To properly use a compost windrow turner, it is ideal to compost on a hard surfaced pad. Heavy-duty compost windrow turners allow the user to obtain optimum results with the aerobic hot composting process. By using four wheel drive or tracks the windrow turner is capable of turning compost in windrows located in remote locations. With a self-trailering option this allows the compost windrow turner to convert itself into a trailer to be pulled by a semi-truck tractor. These two options combined allow the compost windrow turner to be easily hauled anywhere and to work compost windrows in muddy and wet locations.^[2]

Specific applications

Molasses based Distilleries all over the world generate large amount of effluent termed as spent wash or vinasse. For each liter of alcohol produced, around 8 liters of effluent is generated. This effluent has COD of 1,50,000 PPM and BOD of 60,000 PPM and even more. This effluent needs to be treated and the only effective method for conclusive disposal is by Composting.

Sugar Factories generate pressmud / cachaza during the process and the same has about 30% fibers as Carbon and has large amounts of water. This pressmud is dumped on prepared land in the form of 100 meters long windrows of 3 meters x 1.5 meters and spent wash is sprayed on the windrow while the windrow is being turned. Composting machines called Windrow King, Windrow Prince and Windrow Queen are used for this applications. These machines help consume spent wash of about 2.5 times of the volume of the pressmud, which means that a 100 meters of windrow accommodates about 166 MT of pressmud and uses about 415 m³ of Spent wash in 50 days.

Microbial Culture TRIO COM-CULT is used about 1 kg per MT of pressmud for fast de-composing of the spent wash. Lakhs (Indian term for 100,000) of m3 of spent wash is being composted all over the world in countries like India, Colombia, Brazil, Thailand, Indonesia, South Africa etc.

Composting machines Windrow King/Prince/Queen of various capacities of 336 HP, 153 HP and 80 Hp are being used all over the world for this application round the clock. The technology of composting spent wash / Vinasse is called TAS BIO-COM. The compost yard has to be prepared as per the norms of local countries however it has to be prepared in such a way that the land is impervious and does not allow the liquid effluent to pass down into the earth. The compost yard has to be located at a place where the smell of composting operations is not allowed to spread, as any composting operation generates foul smell. The compost thus generated, is of excellent quality and is rich in nutrients and it takes care of balance of nature. The products derived from nature go back to nature.

See also

• Aerated static pile composting
• In-vessel composting

References

• Coufal, Dr, Craig (2008). "In-House Windrow Composting Q and A". Production Management Featured Articles Web site. http://www.thepoultrysite.com/articles/1269/inhouse-windrow-composting-q-and-a. Retrieved August 27, 2009. 

1. ^ Banner Engineering (March 2009). "Application Notes". http://www.bannerengineering.com/en-US/wireless/surecross_web_appnotes 
2. ^ Triochem-tls.com

External links

• Windrow Dynamics
• Windrow Composting - Grass Straw (retrieved March 17, 2009)
• Manufacturer of indurstial composting equipment