Prediction of pollutant discharge loads from swine manure purification treatment facilities using nutrient reduction scenario analysis

This study aimed to calculate the pollution discharge load resulting from the transition of a 3,000-head pig farm's manure treatment method from resource recovery to purification treatment, following the Total Pollution Load Management Technology Guidelines, and to develop reduction measures.The results indicated that for the 3,000-head farm (with a total generation flow of 25.80 m/day), the total pollution loads of BOD, T-N, and T-P were 327.00 kg/day, 75.00 kg/day, and 36.60 kg/day, respectively.Compared to resource recovery, the transition to purification treatment showed changes in point source conversion rates, non-point source reduction rates, and total pollution reduction rates as follows: in specific regions, BOD showed 3.08%, -46.44%, -43.36%,T-N 15.10%, -35.70%, -20.60%, and T-P 33.01%, -34.95%, -1.94%.In other regions, BOD showed 9.24%, -46.56%, -37.33%,T-N 31.46%,-38.27%, -6.80%, and T-P 82.52%, -37.38%, 45.15%.It was confirmed that purification treatment is more effective than resource recovery in reducing pollution discharge loads, except for T-P in other regions.To reduce T-P pollution discharge loads in other regions, adjusting the effluent quality standard sensitivity from T-P 100 mg/L to 40 mg/L resulted in a point source conversion rate of 33.01%, a non-point source reduction rate of -34.95%, and a total pollution reduction rate of -1.94%, indicating a decrease in pollution load.