Manure Composting
Bio-Raptor
Bio-Raptor
Introduction
A proprietary consortium of beneficial, naturally occurring microorganisms were used to treat approximately 225 cubic yards of horse manure mixed with sawdust and straw bedding at an equestrian manor in Rancho Santa Fe, California. The aim of this experiment was to reduce or eliminate the odor being emitted from the manure stockpile. Secondly, we were interested in the degradation of organic matter (similar to aged manure) and a possible decrease in certain constituents and characteristics of the manure. As Rancho Santa Fe is very exclusive suburb near San Diego, and a residential development was completed directly south and adjacent to the equestrian manor, fears of the residential community complaining of the odor problem prompted this pilot study.
Methods
The Bio-RaptorTM process, a patented soil remediation system designed to work in conjunction with U.S. Microbics’ proprietary “bugs”, was used for this study. The Bio-RaptorTM is a bioremediation shredder, conveyor, and sprayer system designed for hydrocarbon contaminated soil remediation as well as manure degradation applications.
Initially, on March 3, 1999, 50 lbs. of a mixed consortia (blended with diatomaceous earth) was dissolved in a water tanker truck holding 2000 gallons of water. The microbial blend then sat in the water for approximately 4 hours to allow for microbial activation. Manure was then placed onto the Bio-RaptorTM using a front loader. Following the treatment of 225 cubic yards of manure, the manure was spread over the ground to approximately 15 inches.
One week later, March 10, 1999, the process was repeated; this time using 25 lbs. of the mixed consortia dissolved in 2000 gallons of water. On March 24, 1999, two weeks after the second treatment, the process was once again repeated using 25 lbs. of mixed consortia dissolved in 2000 gallons of water.
Sampling was conducted on April 7, 1999 (five weeks after initial treatment) to verify measurable parameters of biodegradation. Wallace Labs (El Segundo, CA) completed a total compost analysis. Wallace Labs is a certified laboratory that specializes in soil fertility and structure analysis as well as in the complete analysis of organic soil amendments for fertility and structure (complete analysis in appendix).
Chemical Oxygen Demand (COD) analysis was conducted by Pacific Treatment Analytical Services, Inc. (San Diego, CA). For both analyses, a sample of fresh manure was used as a control. Odor was measured qualitatively none other than one of the most sensitive instruments known, the human nose.
Results
The objective of this treatment program, odor control, was reached. Prior to the second treatment, which occurred one week after the first treatment, the classic manure odor had completely disappeared. The treated manure had begun to take on a rich, humus texture. On what exact day the odor disappeared is unknown, however, it can be said that the disappearance of the odor occurred within one week. Measurable biodegradation results appear in the table below and in graphic view.
|
Parameter |
Untreated Manure | Treated Manure |
Net Difference |
| Chemical Oxygen Demand | 110,500 mg/kg | 37,200 mg/kg | 66% reduction |
| % Organic Matter-dry wt. Basis | 63.44% | 10.45% | 98% reduction |
| Bulk Density | 991 lb/yd3 | 1.806 lb/yd3 | 45% volume reduction |
| Ammonium as N (saturated extract) | 46.9 mg/kg | 2.6 mg/kg | 95% reduction |
| Nitrate as N (saturated extract) | 13.9 mg/kg | 21.7 mg/kg | 36% increase |
| Sulfate as S (saturated extract) | 190.9 mg/kg | 157.7 mg/kg | 17% reduction |
| % Total Nitrogen-dry wt. Basis | 0.62% | 0.21% | 93% reduction |
| Exchangeable ammonium-mg/kg dry wt. | 1,487 mg/kg | 26 mg/kg | 98% reduction |
| Phosphorus (saturated extract) | 114.7 mg/kg | 4.3 mg/kg | 96 % reduction |
| Potassium (saturated extract) | 1,029.3 mg/kg | 657.8 mg/kg | 36% reduction |
| Carbon:Nitrogen ratio | 46.5:1 | 40.4:1 | not applicable |
