The Effect of Co-Additives (Biochar and FGD Gypsum) on Ammonia Volatilization during the Composting of Livestock Waste

Abstract

The effectiveness of co-additives for improving livestock waste composting (reduction of air pollution and conservation of nutrients) was investigated. Biochar and Flue gas desulphurization gypsum (FGD gypsum) were used to supplement the composting of a mixture of slaughter waste, swine slurry, and sawdust. Different compositions of additives (0% or 5% each, 10% biochar or FGD gypsum) were tested in triplicate on the laboratory scale. In addition, the effects of two different aeration schemes (continuous and intermittent) were also investigated. Ammonia volatilization, physicochemical characteristics, and compost maturity indices were investigated. The results indicated that the use of the co-additive (Biochar and FGD gypsum) during composting of livestock waste led to a reduction of ammonia volatilization by 26-59% and to a 6.7-7.9-fold increase of nitrate accumulation. The total ammonia volatilization of intermittent aeration treatment was lower than that of continuous aeration using co-additives treatment. It was concluded that co-additives (biochar and FGD gypsum) might be utilized in livestock waste composting to reduce ammonia volatilization and improve nutrient conservation.Sustainability 2018, 10, 795 2 of 18 both the aeration rate and the ratio of bulking agent to waste during composting [8,9]. Among the potential odor compounds, ammonia (NH 3 ) is a major component that causes odors nuisance and toxicity to humans and plants [10]. Nitrogen losses that occurred during composting resulted in the emission of ammonia (NH 3 ) gas (ammonia volatilization) accounted for 24-33% of the initial N in household waste [11], 46.8-77.4% of the initial N of a mixture of straw and manure [12], 62% of the initial N was during composting of poultry layer manure [13], and 24-64% of the nitrogen was in organic waste [14]. The volatilization of ammonia deteriorating both human health and the environment would reduce the fertilizer value of the organic waste. Barrington et al. [15] reported that carbon availability, bulking agent, particle size, moisture content, and aeration regime are the factors that determine whether composting results in N volatilization as odor or N immobilization into organic components. The odor emission rate was correlated with both the aeration rate and the ratio of bulking agent to waste when composting [8].The utilization of chemical and biological additives to mitigate ammonia volatilization and nitrogen loss during the composting process has been extensively studied. These additives have included wood fly ash, lime, phosphor-gypsum, polyethylene glycol, jaggery [16], zeolite [17], bentonite [18], superphosphate [19], and microbial inoculants [20]. Among these additives, biochar was popular to be amended in the composting mixture. Biochar is a carbon rich material produced by the thermal decomposition of biomass, was effective for reducing volatilization of ammonia during the composting of a mixture of sewage sludge and wood chips [21]. The faster decomposition process in the bio-oxidative phase...

Improving the Sustainability of Dairy Slurry by A Commercial Additive Treatment

“…The measurement protocol was designed to investigate the short-term performance of the additive (T4 and T7) and whether potential washout effects occurred after two weeks when no further additive was applied (T26). The time interval for this study is in line with other works on emissions from manure [25,28].…”

“…However, the addition of gypsum has a great capacity to prevent N loss from manure and reduce odor since it reduces NH 3 volatilization during the composting process [27]. NH 3 volatilization reduction has also been confirmed by other authors such as Febrisiantosa et al, Li et al,and Yang et al [24,25,28]. Yang, et al [25] found that phosphogypsum reduced CH 4 and NH 3 emissions from poultry manure composting whilst, on the other hand, tended to increase emissions of N 2 O.…”

“…With regard to the reduction of NH 3 emissions, the results were in line with Lim, et al [41] that found that the addition of phosphogypsum led to an NH 3 volatilization reduction of 56-69% after 25 days. Febrisiantosa et al [28] found that the supplementation of flue gas desulphurization (FGD) gypsum resulted in a reduction of NH 3 volatilization (26-59%). These reductions could be attributed to a lower pH and to NH 3 absorption affected by the addition of these types of gypsum.…”

Effects of SOP Lagoon Additive on Gaseous Emissions from Stored Liquid Dairy Manure

“…After inducing strong acidification of manure with sulphuric acid, Petersen et al observed a reduction of CH 4 and NH 3 emissions from cattle slurry [18]. Forms of gypsum as an additive to mitigate emissions from manure have also been tested in numerous studies [19][20][21][22]. The addition of gypsum has shown a reduction in NH 3 emissions during the storage and composting phases of manure, but the results on GHG have not been as clear.…”

Quantifying the effects of co-composting organic biomass mixtures with inorganic amendments to obtain value-added bio-products

“…Various studies highlighted fertilizers' role as an additive in composting process to reduce nitrogen loss [37,38]. Few studies focused on the addition of fertilizers in composting process of increasing fertilizer utilization efficiency.…”