Pig manure treatment by organic bed biofiltration

Research and development work to optimize the BIOSORTM-Manure, a biofiltration process for pig manure treatment, have been realized on the site of a piggery (Île d’Orléans, Québec, Canada) using a 400 m3 biofiltration system. Despite strong variations in BOD5 (10,000–20,000 mg/L), in SS (10,000–20,000 mg/L), in TKN (2000– 3800 mg/L) and in Ptot (500–900 mg/L), the BIOSORÔ system was able to maintain an overall pollutant removal performance averaging > 95% for the BOD5, > 97% for the SS, > 84% for the TKN and > 87% for the Ptot. By reducing the raw manure’s organic load by more than 95%, the process eliminates over 80% the odour intensity coming from the production installations, the storage, the transportation and the spreading of the manure. The results obtained show that the BIOSORTM-Manure process is an efficient, simple and performing technology bringing a global solution to pig manure problems.

Pig manure is a waste product with high concentrations of phosphated and nitrogenated organic matter and suspended solids. Moreover, it is characterized by wide variations in load and foul odours. The values obtained are 60–100 times greater than those for domestic sewage. Studies of the pollutant removal rates show that the BIOSORÔ system performed well despite variations in temperature and organic load of the liquid fraction of the pig manure. Despite wide variations of BOD5 (10,000–20,000 mg/L), SS (10,000–20,000 mg/L), TKN (2000–3800 mg/L) and Ptot (500–900 mg/L), the BIOSORÔ system maintained overall average pollutant removal rates of > 95% for the BOD5, > 97% for the SS, > 84% for the TKN and > 87% for the Ptot. The treated manure can be used as washwater for the manure recuperation systems from the buildings, as irrigation water or it can be discharged into a disposal field. The results of olfactometric evaluations indicate that there is a noticeable difference between raw manure and treated manure. The treatment by biofiltration gives a very marked reduction in odour intensity. In addition, the raw manure quali- fied as unacceptable is deodorized to reach an acceptable level after passing through the biofilter. This project’s results show that the organic bed biofiltration process is a very promising alternative to treat and recover the liquid from pig farms. Indeed, the BIOSORÔ technology is a process that treats pig manure globally. It reduces the polluting load of pig manure by more than 90% and eliminates over 80% the odour intensity coming from buildings, storage, transportation and spreading. The system is installed directly at pork producers without modifying their production practices. It enables existing storage installations to be recuperated. The reduction of transportation costs associated with spreading will no doubt contribute to increasing the manure acceptability rate within economic distances. In light of these results, there is no doubt that the BIOSORÔ process is a sound, simple and effective technique that provides a global solution to the environmental problems associated with manure management. This technology now makes it possible to reconcile people’s environmental concerns with the pork industry’s potential for growth.