Carbon Markets for Livestock Operations: Manure Treatment and Handling

The first in a series of 3 webinars, this presentation introduces the fundamentals of carbon emissions, as well as technologies, practices and market opportunities available to agricultural producers are critical to that transition on the livestock operation. This presentation was originally broadcast on November 18, 2022. Continue reading “Carbon Markets for Livestock Operations: Manure Treatment and Handling”

Decision-Support Tools

ManureTech DST

The decision-support tool being developed by the MaNuRe Project is based on user-based knowledge of soil chemistry, fertilization needs, crop selection, livestock production, desired level of wastewater treatment, water use, wastewater production, and regulatory requirements.

Newtrient

Newtrient helps dairy farmers, technology providers, and other stakeholders to assess manure management opportunities and challenges to make informed decisions.  Their mission is to “reduce the environmental footprint of dairy and make it economically viable to do so.” They have three priorities: 1) manure-based products, 2) ecosystem service markets, and 3) innovative technologies and effective practices.

Newtrient was founded by 12 leading milk cooperatives representing almost 20,000 dairy farmers that produce approximately half of the nation’s milk supply. To learn more about Newtrient, go to FAQs – Newtrient.

 

MaNuRe About

Management of Nutrients for Reuse (MaNuRe) aims to address the need in livestock agriculture to better manage and reuse both water and nutrient resources. MaNuRe is a multi-university, multi-disciplinary project to develop, assess, and support the best in manure treatment technology.

With the combination of continued global population growth and trend of extreme climate events and the resulting variability in reliable water resources, the requirement of water recycling becomes an integral part of agriculture wastewater resource management. Important nutrients are also lost to wastewaters, but could be recycled and reused for food production. Water treatment and nutrient needs vary geographically and change based on production, thus the user-driven strategy inherently demands a systems-based, flexible decision-making approach.

Mission and Goals

Our Team

Articles and Publications

Extension and Outreach

ManureTech DST

Research

Impact of Swine Sludge Inclusion Rate on the Composting Process and Compost Quality

Purpose

The purpose of this study was to develop and analyze potential recipes for composting swine lagoon sludge. Composting is a simple treatment; it is widely adopted on farms, generates a stable value-added stackable product, and conserves organic matter and nutrients. All these benefits along with an affordable cost and lower environmental emissions make it a potential candidate for the management of lagoon sludge, a byproduct of swine operations in southeast US.

Sludge accumulation in lagoons can result in increased odor from lagoons, impact animal productivity, increase risk of environmental and social consequences and lead to operation non-compliance. Developing affordable sludge management alternatives is important because current practices (land application post dredging and dewatering using organic polymers and geo-bags) are not widely adoptable, cost-prohibitive and non-sustainable (Owusu-Twum and Sharara, 2020, Soil facts) and current farm nutrient management plans do not consider management of sludge nutrients.

What Did We Do?

We developed two recipes by mixing different sludge amounts with locally available low-cost amendments: poultry litter, Bermuda hay, yard debris and lagoon liquid. We composted these recipes in triplicates using 13-cubic feet in-vessel composters and recorded changes in temperatures, weight loss, volume, moisture, and organic matter. We also recorded greenhouse gases emitted from the piles at regular intervals. Forced, intermittent aeration was maintained during composting for replicates to ensure adequate oxygen supply and avoid prematurely drying mixtures. Finally, we analyzed the final compost to determine its suitability as a soil amendment.

We used the observations from the experiments to evaluate if proposed recipes resulted in successful compost and determine whether sludge inclusion significantly impacts composting process and product quality. We also analyzed which factors influence weight and organic matter losses in the piles and if the proposed recipes have comparable cumulative GHG and NH3 emissions to previous observations.

What Have We Learned?

We learned that sludge can be composted at both 10% and 20% inclusion rates using the above ingredients, as the process met time and temperatures for pathogen reduction (15A NCAC, 13B.1406) and the final product were stable (TMECC, US Composting council). For 100 lbs. of an initial wet mixture (60.8 to 61.4% moisture) both recipes experienced a total weight loss of 33.8-35.2 lbs. with 24.5 to 25.4 lbs. being lost as moisture and 8.8 to 9.7 lbs. lost as organic matter during the active phase of composting (31 days). Post-screening the recipes resulted in 42.3 to 48.6 lbs. of the stable final product (45 to 47% moisture) that can be directly land applied.

We learned that the composting process generated similar GHG, and ammonia emissions as reported in the previous studies however, most of the methane (CH4) and nitrous oxide (N2O) were generated in the later stages of composting, which can be potentially reduced by proper management of the composting process. Another observation was larger losses in ammonia in the earlier stages of composting which on reduction; using certain additives, changes in recipe or management practices, can result in optimal utilization of nitrogen, increase product value, and reduce environmental impacts.

Future Plans

We plan to further analyze the impact of the composting process on total nutrients and water-extractable fractions, this will provide information on land use rate and potential losses in runoffs. This information is critical for swine lagoon sludge-derived products due to the high concentration of P, Zn, and Cu in sludge as losses can lead to eutrophication in surface and marine waters and potential toxicity in soils.

Future work proposed also involves techno-economic evaluation of this process to determine the cost of treatment, and fair price of the final product. We also plan to conduct a cradle to gate life cycle assessment of the process to determine global warming potential, eutrophication, acidification, and particulate matter generation for farm and large-scale systems. These efforts will help guide further research to improve the technology and provide knowledge to stakeholders and producers on alternative sludge management options.

Figure 1. Swine lagoon sludge composting process and products.

 

References

Authors

Piyush Patil, Ph.D. Candidate, Bio&Ag. Engineering, North Carolina State University

Corresponding author

Mahmoud Sharara, Asst. Professor and Extension Specialist, Bio&Ag. Eng. North Carolina State University

Corresponding author email address

msharar@ncsu.edu

Additional authors

Stephanie Kulesza, Assistant Professor, Crop & Soil Sciences, North Carolina State University

Sanjay Shah, Professor and Extension specialist, Bio&Ag. Eng. North Carolina State University

John Classen, Associate Professor, Bio&Ag. Eng. North Carolina State University

Additional Information

Publication is in progress currently so best resource is the corresponding author.

Acknowledgements

We would like to acknowledge the support from Joseph Stuckey and Chris Hopkins (Poultry, livestock, and animal waste management facility, NCSU).

Funding sources

Bioenergy Research Initiative (BRI) – Contract No #17-072-4015, North Carolina Department of Agriculture & Consumer Services

National Institute of Food and Agriculture (NIFA) – Critical Agricultural Research and Extension (CARE) – Award No. 2019-68008-29894, U.S. Department of Agriculture

 

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.

Exploring the Effect of a Peptide Additive on Struvite Formation and Morphology: a High-Throughput Method

Purpose

Precipitation of struvite (MgNH4PO4·6H2O), a slow-release fertilizer, provides a means of recycling phosphorus from wastewater streams. In this work, a method for high-throughput struvite precipitation is developed to investigate the effects of a peptide additive.

What Did We Do?

The reactions occurred in small volumes (300 μL or less of magnesium, ammonium, and phosphate solutions) in a 96-well plate for 45 minutes. The formation of struvite was monitored by fitting absorbance at 600 nm over time to a first-order model with induction time. The impact of struvite seed dosing was also investigated, highlighting the importance of optimization when peptide is present. The composition of the precipitate was confirmed through Fourier-transform infrared spectroscopy, while morphology and crystal size were analyzed through optical microscopy. Finally, the utility of the high-throughput platform was demonstrated with a 25 full factorial design to capture the effects and interactions of: magnesium dose, mixing time, seed dose, pH, and temperature.

What Have We Learned?

The addition of peptide induced significant changes to the yield parameter and formation constant in the model. Crystals grown in the presence of peptide were morphologically different, having a higher aspect ratio than crystals grown in the absence of peptide. Controlling the shape of the crystal may impact the dissolution properties of struvite.

Future Plans

We anticipate that the general technique investigated can be applied to more complex water matrices (e.g. wastewater), with purity investigated spectroscopically or through other high-throughput assays. Future work will focus on identifying the mechanism by which the peptide acts. The use of a sequence-defined peptide paves the way for further developments in favorably modifying struvite formation and growth. With the effects of shADP5 documented, other similar peptides can be explored via either computational simulations or experimentation to modulate the quality and yield of struvite – potentially increasing its value as a fertilizer. Further computational studies also need to be explored to elucidate the exact mechanism by which shADP5 modulates the thermodynamics of struvite crystallization.

Authors

Presenting author

Jacob D Hostert, PhD candidate, Case Western Reserve University

Corresponding author

Julie N. Renner, Assistant professor, Case Western Reserve University

Corresponding author email address

Jxr484@case.edu

Additional authors

Olivia Kamlet, undergraduate, Case Western Reserve University

Zihang Su, Postdoctoral scholar, Columbia University

Naomi S. Kane, B.S., Case Western Reserve University

Additional Information

Hostert, J. D.; Kamlet, O.; Su, Z. H.; Kane, N. S.; Renner, J. N. Exploring the effect of a peptide additive on struvite formation and morphology: a high-throughput method. RSC Advances 2020, 10 (64), 39328-39337, Article. DOI: 10.1039/d0ra06637k.

Acknowledgements

This work was supported by the United States Department of Agriculture (Award No. 2018-68011-28691) and the National Science Foundation (Award No. 1739473).

 

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.

Dairy Anaerobic Digestion Simulation Software

Purpose

Co-digestion of organic material with dairy manure represents an opportunity to provide both a revenue stream to anaerobic digester operations, through the collection of a tipping fee and/or increased biogas/electricity production, as well as a means for waste generators to dispose of their product in a beneficial way.

However, there are many factors for an operator to consider when deciding on whether to accept organic waste.  A major consideration is the volume of biogas that the material will generate when co-digested.  This can be used both to assign a value to the waste through increased biogas production and/or electricity sales, as well as to size equipment for producing, treating and potentially selling/using the biogas.   Estimating the biogas produced is a complicated process, encompassing many different factors of digester design, waste characteristics, and environmental factors.

To assist in this estimation, we have developed software that allows a user to predict the biogas production from mixed wastes and dairy manure based on changing herd sizes, as well as providing the ability to vary the timing and volume of addition of multiple organic wastes, throughout the course of a simulated year.  With this user-friendly tool, we hope to enable producers to better explore the opportunities that co-digestion offers.

What Did We Do?

The originally developed Cornell Anaerobic Digester Simulations software allowed the user to input a herd size and to select how much (if any) of seven wastes would be co-digested with the dairy manure.  This rudimentary method of simulation assumed that the same volume/mass would be applied to the digester in a steady-state constant fashion for the entire year that the simulations were run for.  However, that is unlikely to be the case in a real-world production environment.

In the new version of the software, we have incorporated the characteristics of over 200 wastes into a user selectable interface.  Once a waste type is selected, the user has the option to select when the waste is placed into the digester, whether that be on an everyday, weekly, monthly or custom basis with the option to select to which months of the year the additions occur.  When selecting a weekly or monthly basis, the user can select which day(s) of the week or month wastes are added, and in the custom basis, the user can select which days of the year additions occur.

Once the timing of addition is completed, the user can select how much of the waste is applied during each addition.  Whether that be a constant volume for each addition, or a custom volume for each addition.

The data for the specific wastes includes the dry matter and organic matter content as well as the biogas and methane yields.  Based on the type of waste we have also assigned a “digestibility” curve to the particular waste which when assuming a first order kinetic model of gas production, can provide the production of gas a function of time.  The production of biogas from all added wastes and the added manure is then summed for each day of the year to provide an estimate of the biogas production, on a daily basis, that can be summarized with a minimum/maximum/average on a monthly and annual basis.

What Have We Learned?

During the process of developing the software, we examined a few different techniques for estimating the timing of biogas production from co-digested wastes.  There are more complicated models available such as Anaerobic Digestion Model #1 (ADM1), however many more parameters must be known/estimated for each waste type, (not to mention requiring a much more complicated user interface).  We felt that using a simplified first order kinetic model provides a good way to add the necessary complexity to model biogas production over time without overly complicated calculations.  The simplification allowed us to include a more complicated and yet more real world means of modeling the addition of wastes to a digester that wouldn’t be possible with more complicated digestion/biogas production models.

Future Plans

Currently, the Cornell Dairy Anaerobic Digestion Simulation Software is capable of predicting the amount of heat necessary to maintain digester temperatures, as well as the parasitic electrical load.  Future additions will include modeling the energy usage (and effects on biogas) of treatment processes to produce Renewable Natural Gas (RNG) from biogas.

We would also like to include the ability to track nutrients through the process of digestion.  Nutrient additions from the co-digestion of wastes also represent an important consideration for farm as they may or may not have the land base/crop requirements to use all of the imported nutrients.  The cost of treatment of the effluent from the digester to remove nutrients, or the shipment of effluent off site may have to be added into the determination of how much of a “tipping fee” a farmer would need to charge for taking an organic waste for co-digestion.

We hope to make the program freely available to the public to use.  Currently, the software is written in MATLAB which ordinarily requires a license to operate, however it is possible to create an executable standalone program that can be shared and run without the need to purchase MATLAB.

Authors

Timothy Shelford, Extension Associate, School of Integrated Plant Science, Cornell University

Corresponding author email address

tjs47@cornell.edu

Additional authors

Curt Gooch, Senior Extension Associate Emeritus, Department of Biological and Environmental Engineering, Cornell University

Peter Wright, Agricultural Engineer, Department of Animal Science, Cornell University

Lauren Ray, Agricultural Energy Systems Engineer, Cornell University

 

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.