Pilot-Scale H2S and Swine Odor Removal System Using Commercially Available Biochar

Kyoung S. Ro,Bryan Woodbury,Philip J. Silva,Mindy Spiehs,Okhwa Hwang,Sungback Cho,Ariel A. Szogi

doi:10.3390/agronomy11081611

Abstract

Although biochars made in laboratory seem to remove H2S and odorous compounds effectively, very few studies are available for commercial biochars. This study evaluated the efficacy of a commercial biochar (CBC) for removing H2S and odorous volatile organic compounds (VOCs). We found that the well-known Ergun equation may not be adequate in predicting pressure drop for properly sizing a ventilation system. The H2S breakthrough adsorption capacity of the CBC was 2.51 mg/g under humid conditions, which was much higher than that for dry conditions. The breakthrough capacity increased with the influent concentration of H2S. The efficacy of a pilot-scale biochar odor removal system (PSBORS) for removing 15 odorous VOCs was evaluated by placing it in a swine gestation stall continually treating the inside air for 21 days. All VOCs in the PSBORS effluent were below detection limit except for acetic acid. However, due to the very high odor threshold of acetic acid, its contribution to the odor would be minimal. It appeared that the CBC could be used to reduce both H2S and odorous VOCs with the potential of recycling the spent CBC for soil health improvement after using it for H2S and odor removal.

Highlights

The removal of trace malodorous compounds from the air inside livestock buildings and ventilation streams is increasingly essential because of the rise in civil complaints and concerns for animal and human health [1,2,3,4,5]
The pH of commercial biochar (CBC) used in this study is 6.7, which is similar to the pH of 6.8 for the biochar made from pine wood chip at pyrolysis temperature of 465 ◦C (465BC) [32]
Ro reported the decrease in biochar volatile matter (VM) and increase in fixed carbon (FC) with pyrolysis time [33]

Summary

Introduction

The removal of trace malodorous compounds from the air inside livestock buildings and ventilation streams is increasingly essential because of the rise in civil complaints and concerns for animal and human health [1,2,3,4,5]. Odor emissions from livestock operations disrupt the quality of life in rural and suburban communities [6,7]. Many other malodorous volatile and semi-volatile organic compounds from animal feeding operations have been identified in the literature [8,9,10,11,12,13]. Others suggested the use of biochar to reduce odor emission [15,16]

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Conclusion