Abstract
In this study, the sewage sludge dryer is installed before and after dehydration of the sludge and aqueous phase composition, the heavy metal content, and measurement and analysis were investigated. The removal efficiency of water content of sewage sludge was about 95.7% in the sewage sludge dryer. The removal efficiency of water content for primary dryer was designed for 35% of primary drying, secondary drying to remove the water content to 10%, but as the measurement revealed that 20.8% of primary drying, the second dryer 3.3% a better effect to the actual operation respectively. Before the installation of the sewage sludge dryer, the content of heavy metal was as follows, Cu:352~614 ppm, Hg: 1.3~1.44ppm, Cd : 1.1~1.86ppm, Pb : 17.25~ 28.93 ppm, As : 1ppm. And after the installation of the sewage sludge dryer, the content of heavy metal changed to as follows, Cu : 340~350 ppm, Hg : 0 ppm, Cd : 0~0.021 ppm, Pb : 0 ppm, As : 0~0.043 ppm which is Also below the legal limits. Also, the sewage sludge dryer produce 1/4 of the sewage sludge into dried sludge.
본 연구에서는 A 지역의 하수슬러지 건조장치가 설치되기 전과 후 탈수슬러지의 조성 및 성상, 중금속함유량 등을 측정 및 조사 분석을 하였다. 분석결과 건조로 설치전보다 약 95.7%의 제거효율을 보였으며, 설계값으로 1차건조로 35%, 2차건조로 10% 함수율을 제거하지만, 측정해본결과 1차건조로 20.8%, 리본 3.3%로 실제 운전효과가 더 좋은 것으로 나타났다. 중금속 함유량은 건조장치 설치 전 Cu : 352~614ppm, Hg : 1.3~1.44ppm, Cd : 1.1~1.86ppm, Pb : 17.25~ 28.93 ppm, As : 1ppm 이고 설치 후 Cu : 340~350 ppm, Hg : 0 ppm, Cd : 0~0.021 ppm, Pb : 0 ppm, As : 0~0.043 ppm으로 건조장치설치 전과 후 모두 법정 기준치에 초과하지 않음을 확인하였다. 또한 건조장치를 통과한 하수슬러지는 평균적으로 ${\frac{1}{4}}$의 건조슬러지가 발생하였다.
