Tag: mixing

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Concise Composting

Purpose

Timber Creek Recycling has operated a turned windrow composting operation using manure and food waste processing by-products and green waste for over a decade in Meridian, Idaho. Pressure from suburban encroachment and the availability of increasingly difficult feedstocks that had excessive odor, created the need to move operations from a farm to an industrial site. Land costs were greater, and potential odor impacts would increase in this move. The owner also requested that the number of touches be reduced to minimize the current workload for compost operators. There are some essential operational & design considerations to manage manure composting on a concise footprint and a limited budget. This presentation describes the operation and design considerations that can apply to any composting operation.

What Did We Do?

Green Mountain Technologies considered three different models of concise composting. Radial stacker bunkers, using a central pivot telescopic conveyor to place and cover active compost piles. Also inwardly turned circular aerated piles, which use a side discharge compost turner to turn the compost towards the center of a large circle. Timber Creek Recycling decided to use a narrow profile rectangular shaped turned aerated pile composting approach. This form uses a long concrete aeration floor that allows the owner to build capacity in six phases and increase the operating efficiencies with each additional phase. This approach kept the expansions in line, so that delivery trucks could unload directly in front of the piles and so that side discharge compost turners could be used to mix feedstocks into one side of the pile and move the composting material through different aeration floor capacities and finally to a long collection belt that directly fed a compost screener. This and the aeration floor reduced touches from 12 to 9, compared to non-aerated windrows, and provided a once a week turning frequency, reducing compost, and curing time from 90 to 45 days.

Steps taken to reach this point.

Industrial land was purchased in Nampa, Idaho, permits received and phase one of construction has been completed and operated for over 9 months. The design compacted a 30-acre operational site to a 12-acre operational site with significantly more capacity than the original. Odor reduction steps were taken to reduce the odor of cheese whey waste activated sludge being delivered to the site by using a lime additive during the screw press step at the cheese manufacturer. A small straddle windrow turner was used to mix the delivered feedstocks, and a food waste de-packager was installed to manage out-of-date or off-specification foods.

What Have We Learned?

The use of reversing direction aeration was not necessary when using positive aeration using a cap of wet wood chips or screened compost covers on top of the piles for the first 7 to 10 days. Odors have not been a problem at the new site using forced aeration compared with turned windrows (un-aerated) at the old site. The higher horsepower side discharge conveyor compost turners do not make economic sense just for phase one but will for all three phases. Wastewater collection and reuse is difficult to manage and needs to be incorporated into the mixing and turning process using an underground main and hose reel located at the far end of the aeration pads.

Take home messages

Aeration using blowers and airpipes below a concrete floor can effectively keep composting operations with challenging feedstocks from smelling bad and increase the biological efficiency and throughput. Use of a woody moist bio cover over the top of the pile is essential for the first 7-10 days for these feedstocks.

Force air through a compost pile at least 6 times per hour using on/off timers to control pile temperatures between 125° and 145° F and to keep oxygen above 13% using a rate of 3-5 CFM/cubic yard. Automated temperature feedback controllers make this simpler and more dependable.

Turn and re-water at least 2 times in the first month, either by top irrigation within 30 minutes before turning, or using a hose reel and spray bar connected to the turner (better) or simply turn piles at least 30 minutes after a big rain event.

Piles shrink over time- Double up the piles after 2 weeks and cure with less forced air at 1-2 CFM/cubic yard for an additional 2 weeks.

Adding capacity over time without increasing travel distances requires delivery directly to the initial composting area and collection from the distant piles using conveyors. On-farm generated feedstocks and the composting operations should be placed together as close as possible. Have delivery and storage of outside amendments be alongside your manure or processing waste discharge locations.

Each touch of the material should be limited, and with each touch involving several key feedstock preparation actions while entering a composting system, such as metering materials together in the correct proportions, and mixing thoroughly while watering and delivering into the first composting stage. Examples include building windrows proportionally with loaders and turning and watering with a windrow turner that can apply pond wastewater as it turns. Second example, if a conveyor is used to collect and discharge a manure in a CAFO, add bulking materials prior to the last conveyor and place into an in-line pug mill before stockpiling or placement on an aeration floor. The third example when using side dump delivery trucks, have trucks unload manure in a long low windrow, and then place the amendment in another long low windrow alongside about 22 feet apart, then use a side discharge windrow turner with a spray bar to apply wastewater to combine and then mix the windrows together using the turner in 2 passes. Large loaders move about 500 cubic yards per hour, compost turners move over 4000 cubic yards per hour. So each touch is cheaper per unit.

Future Plans

Phases two and three are under development to move the entire windrow operation from Meridian Idaho to the new site within 2 years.

Authors

Presenting authors

    • Jeffrey Gage, Director of Consulting, Green Mountain Technologies, Inc.
    • Mike Murgoitio, President, Timber Creek Recycling
    • Caleb Lakey, Vice President, Timber Creek Recycling, LLC

Corresponding author

Jeffrey Gage, Director of Consulting, Green Mountain Technologies, Inc., jeff@compostingtechnology.com

Additional author

Caleb Lakey, Vice President, Timber Creek Recycling, LLC.

Additional Information

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Reporting 15 year’s of experience in WISE Aeration at manure and wastewater treatment ponds (updated)

Purpose

This presentation offers information about a low-energy high-performance manure and/or wastewater aeration technology.  Referred to as “Widespreading Induced Surface Exchange” (WISE) aeration, its performance is from 4 to 10 times more efficient per watt of energy used compared to traditional bubble blower technology for aeration.  Even though Aeration is well known to provide extensive odor reduction or elimination, its use has not been implemented because of the high energy costs associated with running blowers.  This explains why very little is published about other value offered by aeration.  The presentation discusses WISE aeration, many unexpected benefits, and unstudied results.

This presentation will quickly review the 2019 Waste to Worth presentation previously offered and will then offer additional information learned in the past 3 years, including approximately 20 key points.    For those wanting to visit an actual working site before or after the conference, equipment is installed at a regional composting facility approximately 1 hr away from the Waste to Worth facility, near Wauseon OH.

What Did We Do?

Different manufacturers have created “floating aerators” over the past decades. Some have different issues than others, but all are installed in one of the most hostile environments at any enterprise.  PondLift brand equipment has been installed at various farms, domestic wastewater treatment sites, and composting facilities to bring their ponds into full aerobic treatment, with most sites desiring odor elimination, while also allowing their effluent to be sent to growing crops through irrigation equipment, lowering their effluent handling costs while increasing the value of their effluent since it is often foliar fed, offering as much as 70% yield increase per unit of fertilizer.   The author has been at each site to maintain equipment and learn more of its performance and learn more about results, expected and unexpected.  Among the PondLift equipment installations, there are 3 pond installation sites in Ohio, and another at a dairy farm near Paw Paw MI, easily visited for those who would want to personally visit such sites.  Other sites are further distance from Ohio.

What Have We Learned?

The installations have confirmed that odor elimination is very much possible through low-energy-use WISE aeration, while also preparing the effluent to be used by irrigation equipment for foliar feeding.  Although Odor elimination is valuable, probably the most environmentally valuable result of aeration was the dramatic change in texture of the effluent (in both liquids and solids) so that when applied by traditional means, being “knifed in”, the treated manure was absorbed into the soil much faster than raw manure is absorbed into that soil.  The timeframe is hours instead of days, reducing the potential runoff timeframe significantly, potentially eliminating significant runoff events.  Given this observation at almost every site having WISE aeration, it became obvious that a method for quantifying the phenomena is needed, and this equipment needs to be defined so as to compare aerobically treated effluent to raw manure, preferably in a “side by side” process, while also being able to quantify manure runoff on different soil types, and different slopes of soils.  While the presentation will also offer other phenomena data, the final portion of the presentation defines this equipment and procedures that might be adopted so as to study and quantify runoff, and compare runoff quantities to traditional distribution methods.

And for those who are interested in performing foliar feeding through automated manure nutrient distribution through irrigation equipment, the presentation will expand on several items recently identified, including the stratification that results from WISE Aeration, allowing irrigation without plugging pivot/circle nozzles.  In addition, the presentation includes information about Struvite formation and its harvesting opportunity as well as control methods.

Future Plans

PondLift intends to offer equipment for use in studies focused on any phenomena of interest in manure or liquid waste treatment, as well as commercial use at farms.  The political climate in future years will insist that potential runoff issues be addressed, updating Best Management Practices.  In addition, it is now possible that manure odor be eliminated with a process which is financially feasible for farms.

A short discussion: Automation is valuable at farms.  Bringing WISE Aeration to dairies and other farms which store liquid manure can help automate the manure storage/handling/disposal process.  It is the opinion of the author that the small family dairy farm will continue to survive and thrive, given the advances in feeding/health/genetics at today’s farms, even though such farms offer a small percentage of milk products.

The fact that so many farms have limited potentially useable farm acres at small hilly locations, leads us to focus on improving their automation and reducing equipment and time spent on manure related work.  To this end, work is progressing through PondLift, on a low cost “drop-in-place” sand separator which can easily be placed between the barn and the manure storage pit, allowing operators to remove sand before it gets to storage, which then allows the storage pit to be converted to aerobic treatment, which then allows automated manure nutrient distribution methods to be considered.  Lastly, work continues through an associated enterprise on the SPEWPLI (self-propelled extremely-wide portable linear irrigator) which will be able to attach to a manure pumpers hose at a distant field, and distribute manure nutrients to the crop at the 1,500gpm rate often used by manure pumpers. This is important for farms which are more suited to pumping at high rates to distant fields.

Authors

John Ries, Managing Member PondLift LLC, retired professional engineer

Corresponding author email address

ries@iw.net

Additional Information

PondLift.com

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

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