Measurement and control of odorous and polluting gases from wastes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Soil Science at Massey University, Palmerston North, New Zealand

Abstract

Management of odorous and polluting gases from wastes is a world-wide challenge. Gaseous losses of nitrogen and sulphur from stored manure and sewage biosolids can be considerable, and these gaseous are offensive and undesirable. Hence, it is necessary to quantify these gas emissions from waste to determine the impact on air quality as well as to find out the efficient and effective control measures. A field observation indicated that amendment of dairy manure with natural materials, such as soil and wood shavings can reduce gaseous emission. To understand the mechanism for reduction of gaseous emissions and to select an optimum natural medium, laboratory incubation studies were conducted to measure the gaseous loss of ammonia (NH3 ) and hydrogen sulfide (H2 S) from stored manure and biosolids under aerobic and anaerobic conditions for a period of about 7 weeks. Natural materials such as soil, untreated pine bark, sawdust and wood savings, were evaluated for their potential to reduce these gaseous emissions. Ammonia emission rate was typically peak within two days of the experiment and declined rapidly under aerobic and anaerobic condition from stored manure and sewage biosolids. NH3 emission was higher during aerobic than anaerobic incubation but in the case of biosolids the difference was very small. The total nitrogen loss due to NH3 emission was very low. It was around 1.23% from manure and 1.87% from biosolids under aerobic incubation. Around 49 mg NH3 was emitted from a kg of cattle manure during aerobic incubation and it was 1155 mg from biosolids. H2 S emissions were higher during anaerobic than aerobic incubation from manure and biosolids. Around 9.2 mg H2 S was emitted from a kg of manure and it was around 150.7 mg from biosolids under anaerobic incubation. All materials tested were found to have an effect on the NH3 and H2 S emission. However, pine bark and top soil amendment reduced the emission efficiently. NH3 emission was reduced by 78% under anaerobic condition when 20g bark was amended with lOOg manure and it was around 56% in biosolids. Soil amendment reduced the NH3 emission by 50% in manure and 46% in biosolids. Pine bark reduced the H2 S emission by 80% from manure and by 83.5% from biosolids. Top soil amendment reduced the H2 S emission by 50% from manure and 79% from biosolids. Therefore, the addition of natural materials, such as pine bark and soil, as amendments to manure and biosolids during storage Offers potential for reducing emissions of NH3 and H2 S