Use of cationic polymers to reduce pathogen levels during dairy manure separation

Area of Science:

• Environmental Science
• Agricultural Engineering
• Water Treatment

Background:

• Livestock operations generate substantial animal waste.
• Land application of waste necessitates pathogen load reduction for public and animal health.
• Effective solid/liquid separation is crucial for waste management.

Purpose of the Study:

• To evaluate cationic polymers as flocculents for reducing pathogen indicators in animal waste.
• To compare the efficacy of low charge density cationic polyacrylamide (CPAM) and high charge density cationic polydicyandiamide (PDCD).
• To assess the combined effect of CPAM and PDCD on solids separation and pathogen reduction.

Main Methods:

• Investigated the use of CPAM and PDCD as flocculents in animal waste solid/liquid separation.
• Assessed the performance of individual polymers and their sequential application.
• Measured pathogen indicator load reduction and solids separation efficiency.

Main Results:

• CPAM demonstrated superior performance in manure coagulation and flocculation compared to PDCD.
• PDCD was more effective than CPAM in reducing pathogen indicator loads.
• The sequential application of CPAM followed by PDCD yielded optimal results, enhancing both solids separation and pathogen indicator reduction.

Conclusions:

• Cationic polymers, particularly PDCD, show promise in mitigating pathogen loads in animal waste.
• Combined application of CPAM and PDCD offers a synergistic approach for efficient waste treatment.
• This strategy supports safer land application of recycled animal waste streams.