The investigation of combined ventilation-biofilter systems using recycled treated wastewater on odor reduction efficiency

Objective: The present study aimed to evaluate the performance of odor abatement by using two different ventilation-biofilter systems with recycled stablized swine wastewater.Methods: The performance of odor removal efficiency was evaluated using two different ventilation-biofilter-recycled wastewater arrangements. A recirculating air-flow ventilation system connected to a vertical biofilter (M1) and a plug-flow ventilation system connected to a horizontal biofilter (M2) were installed. Water dripping over the surface of the biofilter was recycled at a flow rate of 0.83 L/h in summer and 0.58 L/h in winter to reduce odorous compounds and particulate matter (PM). The experiments were performed for 64 days with M1 and M2 to investigate how these two ventilation-biofilter systems influenced the reduction of odor compounds in the model houses. Odorous compounds, NH3 and volatile organic compounds (VOCs) were analyzed, and microclimatic variables such as temperature, humidity, and PM were monitored.Results: Ammonia concentration inside M1 was about 41% higher on average than that in M2. PM and total suspended particles (TSPs) inside M1 were about 62.2% and 69.9%, respectively, higher than those in M2. TSPs in the model house were positively correlated with the concentration of NH3 and VOCs.Conclusion: M2 emitted lower concentration of odorous compounds than M1. Moreover, M2 could maintain the optimum temperature condition for a swine house during the cooler season. The plug-flow ventilation–horizontal biofilter system could be used for pig houses to minimize air pollution produced by swine farming activities and maintain optimum microclimate conditions for pigs.

Swine House Floor Durability Enhancement Using Pozzolan-Containing Concrete Mix Designs

HighlightsThe CSF-FA floors performed better than the non-CFH and CFH floors, especially under spallation conditions. It thus makes economic sense for small- and industrial-scale swine farms to switch to CSF-FA floors due to longer durability and better investment return, in comparison with non-CFH and CFH floors.The statistical analysis indicated that the pozzolanic materials significantly improved the performance metrics of concrete mix designs (p<0.05), compared with the conventional non-CFH mix (control).The research findings are expected to be beneficial for civil engineers in the construction of concrete structures that are prone to acid corrosion or in areas with acidic soil.ABSTRACT. This research investigates the effect of pozzolanic materials on the performance of swine house concrete floor. The experimental pozzolans are fly ash (FA) and silica fume (SF), and the performance metrics are compressive strength, abrasion resistance, and resistance to lactic and sulfuric acids. There are nine experimental concrete mix designs: concrete without floor hardener (conventional concrete or non-CFH), concrete with floor hardener (CFH), concrete with 15%, 30%, 45% fly ash, and concrete with silica fume and fly ash (CSF4FA26, CSF6FA24, CSF8FA22, CSF10FA20). In acid resistance tests, a groove was cut across the specimen surface to simulate floor spallation. The results showed that the CFH floor had the highest abrasion and acid resistance but suffered from severe acid damage under spallation conditions. Meanwhile, the CSF10FA20 floor had the highest compressive strength and acid resistance under spallation conditions. The statistical analysis indicated that the pozzolanic materials significantly improved the performance metrics of concrete mix designs (p<0.05), compared with the non-CFH mix design (control). The construction costs of CSF-FA floors (THB 118 – 121) and non-CFH floor (THB 116) were comparable, but they were considerably lower than that of CFH floor (THB 196). The acid resistance of CSF-FA floors was higher than that of non-CFH and CFH floors. As a result, the CSF-FA concrete mix designs should be adopted for the construction of swine house floor due to longer durability and better investment return, in comparison with non-CFH and CFH floors which are commonly used in small- and industrial-scale swine farms. Keywords: Acid resistance, Concrete material, Durability, Farm buildings, Swine flooring.