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Previous research by our team to develop a wireless hydrogen sulfide (H2S) detection system for use in swine housing indicate a multi-point detection system is needed to characterize in-house H2S concentrations both spatially and temporally during slurry agitation. Pulsed fluorescence H2S analyzers, while highly accurate at H2S concentrations less than 20 ppm, require asynchronous sampling to accommodate multiple measurement points with a single analyzer. Additionally, pulsed fluorescence H2S analyzers are not designed to measure the high H2S concentrations associated with burst releases during deep-pit swine manure agitation. The dynamic nature of the environment necessitates simultaneous sampling of multiple points with a sensor that can respond to very high (100 -500 ppm) H2S concentrations. This can be accomplished through the use of electrochemical sensors that have demonstrated the ability to perform similarly to pulsed fluorescence at high concentrations. The objective of this project was to develop a wireless H2S sensor network that can be used to characterize the spatial distribution of H2S that workers and swine in pork production facilities are exposed to in different facility types during different operating conditions. The wireless H2S sensor network developed in this project was designed to meet the following operational criteria: a) less than 5% sensor drift per 1000 ppm-hours, b) up to 50 m range, c) data collection interval less than 90 seconds, and e) H2S detection range of 0-500 ppm. KeywordsWireless sensor network, WSN, hydrogen sulfide, spatial and temporal H2S distribution, swine manure agitation, mesh network, Zigbee Disciplines Bioresource and Agricultural Engineering CommentsThis is an ASABE Meeting Presentation, Paper No. 096640.Abstract. Previous research by our team to develop a wireless hydrogen sulfide (H 2 S) detection system for use in swine housing indicate a multi-point detection system is needed to characterize inhouse H 2 S concentrations both spatially and temporally during slurry agitation. Pulsed fluorescence H 2 S analyzers, while highly accurate at H 2 S concentrations less than 20 ppm, require asynchronous sampling to accommodate multiple measurement points with a single analyzer. Additionally, pulsed fluorescence H 2 S analyzers are not designed to measure the high H 2 S concentrations associated with burst releases during deep-pit swine manure agitation. The dynamic nature of the environment necessitates simultaneous sampling of multiple points with a sensor that can respond to very high (100 -500 ppm) H 2 S concentrations. This can be accomplished through the use of electrochemical sensors that have demonstrated the ability to perform similarly to pulsed fluorescence at high concentrations. The objective of this project was to develop a wireless H 2 S sensor network that can be used to characterize the spatial distribution of H 2 S that workers and swine in pork production facilities are exposed to in different facility types during different operating conditions. The ...

Transient hazards to human and animal health can occur in swine barns due to sudden bursts of high concentration hydrogen sulfide (H2S) gas released when manure slurry is agitated during removal from subfloor pits. Studies have shown that H2S levels can go from harmless to deadly in a matter of minutes during pit agitation (Patni and Clarke, 2003). From 1983 to 1990, H2S poisoning was responsible for the death of 24 swine workers in the Midwest alone and at least 15 more deaths since 1994 (Walinga, 2004). Swine slurry removal workers and producers report swine deaths every year from slurry agitation in sub-floor storage, or pits. Hence, a system that can reliably and promptly report H2S concentrations in swine housing without direct exposure of the operator(s) to the potentially hazardous environment is of socioeconomic importance to the swine producers. This paper describes the development and testing of a wireless, portable H2S detection system, followed by the use of the system under field conditions by slurry removal workers to monitor H2S levels during slurry agitation and removal in deep-pit swine housing systems in Iowa. The system developed in this study has a component cost of $2,735 and is based on a Pemtech PT-295 electrochemical H2S sensor and a Phoenix Contact Wireless Transmitter / Receiver set. The portable H2S detection system has the following operational characteristics: a) 90% (t90) response to 10-500 ppm H2S within one minute, b) ± 5 % full scale accuracy, and c) < 2 hr warm-up time for operation.

Robert Burns, associate professor of agricultural and biosystems engineering; Nir Keren, assistant professor of agricultural and biosystems engineering; Ross Muhlbauer, research associate of agricultural and biosystems engineering; Hongwei Xin, professor of agricultural and biosystems engineering; Steve Hoff, professor of agricultural and biosystems engineering; Randy Swestka, graduate research assistant Summary and Implications Transient hazards to human and animal health can occur in swine barns due to sudden bursts of high concentration hydrogen sulfide (H 2 S) gas released when manure slurry is agitated during removal from sub-floor pits. This project will quantify the concentration of hydrogen sulfide (H 2 S) that workers and swine in pork production facilities are typically exposed to in different production facility types during different operating conditions. Results from this study will be used to make recommendations to increase worker and animal safety by reducing risks of H 2 S poisoning.