ORIGINAL ARTICLE Assessment of the effects of anaerobic co-digestion of water primrose and cow dung with swine manure on biogas yield and biodegradability Huyen Thu Thi Nong 1,2 & Yuwalee Unpaprom 2,3 & Kanda Whangchai 4 & Sermsuk Buochareon 1 & Rameshprabu Ramaraj 1,2 Received: 2 October 2020 /Revised: 19 October 2020 /Accepted: 23 October 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract This study aims to investigate the potential of water primrose for biogas production in batch anaerobic digestion. To examine the ability of co-digestion with other substrates, cow dung and swine manure was chosen to mix with pretreated water primrose in a ratio of 1:1 (w/w, based on dry matter of water primrose). The pretreatment of water primrose was conducted by using sodium hydroxide at 2% concentration for one week. A modified Gompertz equation was employed to estimate parameters, including estimated biogas yield potential (Y m ), maximum biogas production rate (R m ), and duration of lag phase (λ). The equation showed a good approximation of cumulative biogas production with a coefficient of determination (R 2 ) over 0.997. The overall results indicate that all treatments had successfully produced biogas production in the range of 4285 to 6150 mL with methane (CH 4 ) content above 50%. The maximum biogas yield of 6150 mL was obtained at co-digestion with cow dung and high methane content of 63.88%. This value was given 25.50 MJ/m 3 for high calorific value (HCV) and 22.97 MJ/m 3 of low calorific value (LCV). Keywords Water Primrose . Cow dung . Swine manure . Biogas production . Energy analysis . Kinetic model 1 Introduction In the 21st century, the widespread assumption of fossil fuels reflects the ease of its application and product diversity com- pared to other energy sources, mainly because petroleum and natural gas are considered the largest sources from it [1, 2]. As a result, fossil fuel production is becoming increasingly ex- pensive, yet, it is difficult to access due to this source is non- renewable [3, 4] and when burned, the large quantities regard to the emission of carbon dioxide (CO 2 ) produced which contributes to climate change and global warming [5]. For those reasons, fossil fuels are not attributed as sustainable energy in correlation with ecology and environment. According to Kang et al. [6], to counteract the decline of fossil fuel, it is necessary to accelerate finding alternative renewable energy sources, minimizing dependence. In this regard, bioenergy, such as biogas, biodiesel, and bioethanol, appears as clean. Renewable energy could be the best option for an alternative path of sustainability which is a suitable solution to ecological-environmental problems against the degradation time of fossil fuels and the reduction of CO 2 emission [7]. For useful energy generation in biorefinery, natural sources such as biomass material, including lignocellulosic biomass, animal waste, or municipal waste, have been widely investi- gated through anaerobic digestion process by numerous stud- ies [8, 9] because of its wide distribution, less expensive and renewable. Different types of biomass waste are used as a feedstock under an anaerobic digestion system and decomposed with microorganisms’ help to form biogas as the final product that could convert to various forms of energy, such as heating, electricity, transportation, and hydrogen through biorefinery technologies [10, 11]. * Rameshprabu Ramaraj rameshprabu@mju.ac.th; rrameshprabu@gmail.com 1 School of Renewable Energy, Maejo University, Chiang Mai 50290, Thailand 2 Sustainable Resources & Sustainable Engineering Research Lab, Maejo University, Chiang Mai 50290, Thailand 3 Program in Biotechnology, Faculty of Science, Maejo University, Chiang Mai 50290, Thailand 4 Center of Excellence in Bioresources for Agriculture, Industry and Medicine, Chiang Mai University, Chiang Mai 50200, Thailand Biomass Conversion and Biorefinery https://doi.org/10.1007/s13399-020-01115-z