Evaluation of Hospital Sewage Sludge Used for Agricultural Purposes

摘要

This study was to determine the hospital sewage sludges in northern part of Thailand. Sampling analysis was performed from 12 hospital locations activated sludge treatment plants in the north of Thailand. The sludge was classified into 3 major groups, according to size of hospital ( by the number of beds); more than 500 beds, 300-500 beds and less than 300 beds, respectively. The results showed that the parasitological risk was higher than the limitation regarded to sludge using for agricultural amendment by USEPA, part 503. However, the sludge was rich in nutrient such as nitrogen and phosphorus (N:P ratio of 2.0 : 0.44). The amount of heavy metal cation which contaminated in the three sources were lower than USEPA, part 503 limitation.