# Neutralization of Toxic Malodorous Gases from Cattle Slurry
## 3 Results
### Deodorization Effect of Cattle Slurry by Microorganisms
\begin{table}
\begin{tabular}{c c c c c} \hline  & \multicolumn{2}{c}{**Ammonia**} & \multicolumn{2}{c}{**Hydrogen Sulfate**} \\ \cline{2-5} \multicolumn{1}{c}{**Time**} & \multicolumn{1}{c}{**Unshaken Culture**} & \multicolumn{1}{c}{**Culture Aeration**} & \multicolumn{1}{c}{**Unshaken Culture**} & \multicolumn{1}{c}{**Culture Aeration**} \\ \cline{2-5} \multicolumn{1}{c}{} & **Concentration (ppm)** & **Concentration (ppm)** & **Concentration (ppm)** & **Concentration (ppm)** & **Concentration (ppm)** \\  & **(\% Reduction \({}^{\bullet}\))** & **(\% Reduction \({}^{\bullet}\))** & **(\% Reduction \({}^{\bullet}\))** & **(\% Reduction \({}^{\bullet}\))** \\ \hline Day 2 & 54.0 \(\pm\) 7.8 (35.8\%) & 16.0 \(\pm\) 3.0 (75.0\%) & 12.5 \(\pm\) 3.2 (65.1\%) & 6.9 \(\pm\) 0.7 (80.7\%) \\ Day 4 & 33.0 \(\pm\) 7.0 (42.2\%) & 12.0 \(\pm\) 1.8 (81.0\%) & 5.1 \(\pm\) 1.5 (81.4\%) & 1.8 \(\pm\) 0.3 (93.4\%) \\ Day 6 & 15.4 \(\pm\) 2.0 (66.5\%) & 7.2 \(\pm\) 1.5 (84.4\%) & 0.0 \(\pm\) 0.0 (100.0\%) & 0.0 \(\pm\) 0.0 (100.0\%) \\ Day 8 & 8.9 \(\pm\) 1.9 (77.9\%) & 1.1 \(\pm\) 0.4 (97.4\%) & 0.0 \(\pm\) 0.0 (100.0\%) & 0.0 \(\pm\) 0.0 (100.0\%) \\ Day 10 & 2.3 \(\pm\) 0.6 (94.1\%) & 0.0 \(\pm\) 0.0 (100.0\%) & 0.0 \(\pm\) 0.0 (100.0\%) & 0.0 \(\pm\) 0.0 (100.0\%) \\ \hline \end{tabular} Notes: The table shows mean values and standard deviations; \({}^{\star}\) reduction (%) compared to the control sample.  
\end{table} 
Table 6: Change in odorant concentration in cattle slurry after the bacterial consortium (_Bacillus subtilis_ KKP 3903 and _Pseudomonas fluorescens_ KKP 3909, 1:1) treatment. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline  & \multicolumn{6}{c}{**Hydrogen Sulfide Reduction (\%)**} \\ \cline{2-11} \multicolumn{1}{c}{**Tested**} & \multicolumn{3}{c}{**After 2 Days**} & \multicolumn{3}{c}{**After 4 Days**} & \multicolumn{3}{c}{**After 6 Days**} & \multicolumn{3}{c}{**After 8 Days**} & \multicolumn{3}{c}{**After 10 Days**} \\ \cline{2-11} \multicolumn{1}{c}{**Strain**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} \\ \cline{2-11} \multicolumn{1}{c}{} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} & \multicolumn{1}{c}{**R1**} & \multicolumn{1}{c}{**R2**} \\ \hline KKP 3899 & 67\({}^{\mathrm{d}}\)\(\pm\) 11 & 88\({}^{\mathrm{c}}\)\(\pm\) 4 & 59\({}^{\mathrm{ab}}\)\(\pm\) 8 & 90\({}^{\mathrm{b}}\)\(\pm\) 2 & 96\({}^{\mathrm{b}}\)\(\pm\) 2 & 99\({}^{\mathrm{b}}\)\(\pm\) 0 & 99\({}^{\mathrm{c}}\)\(\pm\) 1 & 100\({}^{\mathrm{a}}\)\(\pm\)Better results were obtained in the variant with mixing. Aeration of the slurry inoculated with the bacterial consortium intensified the neutralization of odorous compounds. The concentration of hydrogen sulfide and ammonia was lower on each day of the deodorization process, compared to the tests without mixing, as shown in Table 6.  
The use of the biological method for odor treatment not only completely removes hydrogen sulfide and ammonia from the slurry but also reduces the loss of ammonium ions and the risk of pathogenic microorganisms developing in the ammonia-rich atmosphere. The content of macro-elements and heavy metals in deodorized cattle slurry was investigated. The results indicate that the addition of a bacterial consortium to the slurry had a positive effect on its chemical composition. This is important because CS is used for agricultural production as a fertilizer. The slurry is a significant source of macro-elements such as phosphorus, potassium, and nitrogen. Nitrogen and phosphorus can occur in the slurry in both organic and mineral compounds [45].