Co-digestion of agricultural and municipal waste to produce energy and soil amendment

Abstract

In agriculture, manure and cotton gin waste are major environmental liabilities. Likewise, grass is an important organic component of municipal waste. These wastes were combined and used as substrates in a two-phase, pilot-scale anaerobic digester to evaluate the potential for biogas (methane) production, waste minimisation, and the digestate value as soil amendment. The anaerobic digestion process did not show signs of inhibition. Biogas production increased during the first 2 weeks of operation, when chemical oxygen demand and volatile fatty acid concentrations and the organic loading rate to the system were high. Chemical oxygen demand from the anaerobic columns remained relatively steady after the first week of operation, even at high organic loading rates. The experiment lasted about 1 month and produced 96.5 m³ of biogas (68 m³ of CH₄) per tonne of waste. In terms of chemical oxygen demand to methane conversion efficiency, the system generated 62% of the theoretical methane production; the chemical oxygen demand/volatile solids degradation rate was 62%, compared with the theoretical 66%. The results showed that co-digestion and subsequent digestate composting resulted in about 60% and 75% mass and volume reductions, respectively. Digestate analysis showed that it can be used as a high nutrient content soil amendment. The digestate met Class A faecal coliform standards (highest quality) established in the United States for biosolids. Digestion and subsequent composting concentrated the digestate nitrogen, phosphorus, and potassium content by 37%, 24%, and 317%, respectively. Multi-substrate co-digestion is a practical alternative for agricultural waste management, minimisation of landfill disposal, and it also results in the production of valuable products.

Keywords

Anaerobic digestion biogas production cotton gin waste dairy manure organic fraction of municipal waste two-phase anaerobic digester

Get full access to this article

View all access options for this article.

References

Adelard

Poulsen

Rakotoniaina

(2015) Biogas and methane yield in response to co- and separate digestion of biomass wastes. Waste Management & Research 33: 55–62.

APHA/AWWA/WEF (1989) Standard Methods for the Examination of Water and Wastewater. 17th ed. Lenore

Greenberg

Trussell

(eds). Washington, DC: American Public Health Association/American Water Works Association/Water Environment Federation.

Code of Federal Regulations (2016) Title 40: Protection of Environment. Part 503—Standards for the Use or Disposal of Sewage Sludge. Available at: http://www.ecfr.gov/ (accessed August 2016).

Dias

Fragoso

Duarte

(2014) Anaerobic co-digestion of dairy cattle manure and pear waste. Bioresource Technology 164: 420–423.

Ebner

Labatut

Lodge

et al . (2015) Anaerobic co-digestion of commercial food waste and dairy manure: Characterizing biochemical parameters and synergistic effects. Waste Management 52: 286–294.

EPA (2015) Advancing Sustainable Materials Management: 2013 Fact Sheet Assessing Trends in Material Generation, Recycling and Disposal in the United States. Available at: https://www.epa.gov/sites/production/files/2015-9/documents/2013_advncng_smm_fs.pdf (accessed July 2016).

Goswami

Chattopadhyay

Shome

et al . (2016) An overview of physico-chemical mechanisms of biogas production by microbial communities: A step towards sustainable waste management. 3 Biotech 6: 1–12.

Han

Tong

Jin

et al . (2013) Evaluation of organic contamination in urban groundwater surrounding a municipal landfill, Zhoukou, China. Environmental Monitoring and Assessment 185: 3413–3444.

Holt

Barker

Baker

et al . (2000) Characterization of cotton gin byproducts produced by various machinery groups used in the ginning operation. Transactions of the ASAE 43: 1393.

10.

Chen

(2010) Biogas production from anaerobic co-digestion of food waste with dairy manure in a two-phase digestion system. Applied Biochemistry and Biotechnology 160: 643–654.

11.

Linville

Shen

et al . (2015) Current state of anaerobic digestion of organic wastes in North America. Current Sustainable/Renewable Energy Reports 136–144.

12.

Lou

Nair

(2009) The impact of landfilling and composting on greenhouse gas emissions – A review. Bioresource Technology 100: 3792–3798.

13.

Macias-Corral

Samani

Hanson

et al . (2005) Producing energy and soil amendment from dairy manure and cotton gin waste. Transactions of the ASAE 48: 1521–1526.

14.

Macias-Corral

Samani

Hanson

et al . (2008) Anaerobic digestion of municipal solid waste and agricultural waste and the effect of co-digestion with dairy cow manure. Bioresource Technology 99: 8288–8293.

15.

NASS (2016) USDA National Agricultural Statistics Service (NASS). Milk Cows and Milk Production. Available at: https://www.nass.usda.gov/Charts_and_Maps/Milk_Production_and_Milk_Cows/ (accessed July 2016).

16.

Owen

Silver

(2015) Greenhouse gas emissions from dairy manure management: A review of field-based studies. Global Change Biology 21: 550–565.

17.

Panyadee

Petiraksakul

Phalakornkule

(2013) Biogas production from co-digestion of phyllanthus emblica residues and food waste. Energy for Sustainable Development 17: 515–520.

18.

Penn State College of Agricultural Sciences (2014) The Agronomy Guide 2015–2016. Code# AGRS-026.

19.

Rotz

Montes

Chianese

(2010) The carbon footprint of dairy production systems through partial life cycle assessment. Journal of Dairy Science 93: 1266–1282.

20.

Tian

Duan

Lin

et al . (2015) Anaerobic co-digestion of kitchen waste and pig manure with different mixing ratios. Journal of Bioscience and Bioengineering 120: 51–57.

21.

USDA (2012) 2012 Census of Agriculture United States. USDA

22.

Wang

Yang

Feng

et al . (2012) Optimizing feeding composition and carbon-nitrogen ratios for improved methane yield during anaerobic co-digestion of dairy, chicken manure and wheat straw. Bioresource Technology 120: 78–83.

23.

Wang

Yang

et al . (2013) Evaluation of two statistical methods for optimizing the feeding composition in anaerobic co-digestion: Mixture design and central composite design. Bioresource Technology 131: 172–178.

24.

Samani

Hanson

et al . (2002) Energy recovery from grass using two-phase anaerobic digestion. Waste Management 22: 1–5.

25.

Zheng

Liu

Yuan

et al . (2015) Effect of dairy manure to switchgrass co-digestion ratio on methane production and the bacterial community in batch anaerobic digestion. Applied Energy 151: 249–257.