Chen, Y.; Inbar, Y.; Dovrat, A.
The anaerobic digestion of organic matter is a well known technology which is used to produce biogas from wastes, especially manures. The digested slurry is usually used for direct application in the field. We found that by sieving and leaching the digested slurry on a vibrating screen, two major products are obtained: (i) a fibrous material which resembles peat in its physical structure. This fraction is commercially named "cabutz", and may serve as a growth substrate. (ii) an effluent which is similar in its composition to liquid fertilizers. The cabutz has been tested for physical and chemical properties in our laboratory and was found to maintain high hydraulic conductivity and air capacity as well as an adequate water and nutrients retention. As a result of the high temperature in the digesters (55°C), plant disease problems were not observed in any of our experiments. The particle size of cabutz ranges from 1–5 mm, which is slightly larger than sphagnum peat moss from Finland. The bulk density is 0.08–0.12 g/cm3 and the porosity reaches 93–95%. Water and air capacity of the cabutz are 62% and 31–33%, respectively. Hydraulic conductivity at saturation is as high as 150 cm/h. Almost the same values were measured on peat moss. The chemical properties of cabutz are related to the leaching intensity and duration. The electrical conductivity ranges from 0.5–3.0 mmhos/cm or less if required, the pH range is 7.0–7.6 and the nutrient contents resembles that of enriched sphagnum peat moss from Finland. The cabutz can be used as a sole medium or as a component in a mixture at levels similar to those known for peat.
Chen, Y.; Inbar, Y.; Dovrat, A.
The anaerobic digestion of organic matter is a well known technology which is used to produce biogas from wastes, especially manures. The digested slurry is usually used for direct application in the field. We found that by sieving and leaching the digested slurry on a vibrating screen, two major products are obtained: (i) a fibrous material which resembles peat in its physical structure. This fraction is commercially named "cabutz", and may serve as a growth substrate. (ii) an effluent which is similar in its composition to liquid fertilizers. The cabutz has been tested for physical and chemical properties in our laboratory and was found to maintain high hydraulic conductivity and air capacity as well as an adequate water and nutrients retention. As a result of the high temperature in the digesters (55°C), plant disease problems were not observed in any of our experiments. The particle size of cabutz ranges from 1–5 mm, which is slightly larger than sphagnum peat moss from Finland. The bulk density is 0.08–0.12 g/cm3 and the porosity reaches 93–95%. Water and air capacity of the cabutz are 62% and 31–33%, respectively. Hydraulic conductivity at saturation is as high as 150 cm/h. Almost the same values were measured on peat moss. The chemical properties of cabutz are related to the leaching intensity and duration. The electrical conductivity ranges from 0.5–3.0 mmhos/cm or less if required, the pH range is 7.0–7.6 and the nutrient contents resembles that of enriched sphagnum peat moss from Finland. The cabutz can be used as a sole medium or as a component in a mixture at levels similar to those known for peat.