Carbon footprint of dairy manure management chains in response to nutrient recovery by aerobic pre-treatment

Mostafa Sobhi; Jiabao Zheng; Bowen Li; Mohamed S Gaballah; Dominic Aboagye; Jianbin Guo; Renjie Dong

doi:10.1016/j.jenvman.2022.116975

Carbon footprint of dairy manure management chains in response to nutrient recovery by aerobic pre-treatment

J Environ Manage. 2023 Feb 15:328:116975. doi: 10.1016/j.jenvman.2022.116975. Epub 2022 Dec 15.

Authors

Mostafa Sobhi¹, Jiabao Zheng², Bowen Li², Mohamed S Gaballah³, Dominic Aboagye⁴, Jianbin Guo⁵, Renjie Dong²

Affiliations

¹ College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Beijing, 100083, PR China; Agricultural and Bio-systems Engineering Department, Faculty of Agriculture, Alexandria University, Alexandria, 21526, Egypt.
² College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Beijing, 100083, PR China.
³ College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Beijing, 100083, PR China; National Institute of Oceanography and Fisheries, Cairo, Egypt.
⁴ Department of Chemical Engineering, Universitat Rovira i Virgili, Tarragona, 43007, Spain.
⁵ College of Engineering (Key Laboratory for Clean Renewable Energy Utilization Technology, Ministry of Agriculture), China Agricultural University, Beijing, 100083, PR China. Electronic address: Jianbinguo@cau.edu.cn.

PMID: 36527801
DOI: 10.1016/j.jenvman.2022.116975

Abstract

Aerobic pre-treatment of liquid dairy manure has previously been reported as an effective nutrient export and emissions mitigation approach. The first objective of this study was to experimentally determine the optimal intermittent aeration ratio for nutrient recovery from liquid dairy manure through an on-site pilot-scale reactor to partially reduce the required energy for the aerobic process. The second objective was to theoretically investigate the total carbon footprints of direct manure spreading on croplands and permanent manure storage in open anaerobic lagoons in response to nutrient removal by the optimal determined intermittent aerobic treatment ratio. Four scenarios (S) were included; S1 was the traditional scenario of manure spread on croplands without the aerobic pre-treatment, S2 was the modified scenario of manure spread on croplands that included the aerobic pre-treatment, S3 was the traditional scenario of manure storage in lagoons, and S4 was the modified scenario of manure storage in lagoons that included the aerobic pre-treatment. The results showed that comparable nutrient removal efficiencies could be obtained with a 5:1 intermittent aeration ratio. Total nitrogen (TN) and total phosphorus (TP) were recovered were 41.5 ± 1.3% and 37.0 ± 4.0%, respectively, in ammonium sulfate and phosphorus-rich sludge, while 55.3 ± 1.4% of the chemical oxygen demand (COD) was removed. The estimated total carbon footprint for S1, S2, S3, and S4 were 24.4, 37.9, 45.3, and 45.9 kg _CO2-eqton^-1, respectively. However, the total carbon footprint of S2' and S4', which used renewable-based energy to run the reactor instead of fossil-based energy used in S2 and S4, were estimated to 29.5 and 37.5 kg _CO2-eqton^-1, respectively. Clearly, applying the aerobic pre-treatment increased the total carbon footprint of all cases except S4', in which the total carbon footprint was mitigated by -17.2%. Accordingly, the aerobic pre-treatment is only recommended in the case of S4' from a carbon footprint point of view although it is an effective nutrient recovery technology.

Keywords: Aerobic treatment; Carbon footprint; Emissions mitigation; Greenhouse gas; Intermittent treatment; Manure treatment.

MeSH terms

Biological Oxygen Demand Analysis
Carbon Dioxide / analysis
Carbon Footprint*
Manure*
Nitrogen
Phosphorus

Substances

Manure
Carbon Dioxide
Nitrogen
Phosphorus