Chemical batch tests were conducted to investigate the amount of nutrients that were released from the wasted activated sludge during microwave heating. For this study, three types of activated sludge were obtained from A2/O, MLE and oxidation ditch (OD) processes. Polyphosphate-accumulating organisms in the activated sludge have a unique trait: they releases phosphate from the cell when they are exposed to high temperatures. The sludge obtained from the A2/O process released the largest amount of phosphate, followed by those from the MLE and OD processes. The release of phosphate increased with increasing polyphosphate content in the sludge under strongly alkaline or acidic conditions. Furthermore, ammonia and heavy metals were released with phosphorous. The largest amount of ammonia was observed from the sludge obtained from the MLE process. The release of heavy metals strongly depends on the pH conditions. Therefore, the chemical analysis results strongly suggest that both phosphorus and ammonia react with Mg2+ or Ca2+ to form metal complexes such as magnesium ammonium phosphate or hydroxyapatite under alkaline conditions.

Abstract
 I. 서 론
 II. 실험 장치 및 방법
  1. 잉여 슬러지 채취 및 특성
  2. 회분식 실험
  3. 화학적 분석
 III. 결과 및 고찰
  1. 잉여 슬러지의 생태학적 특징
  2. 마이크로웨이브 가온과 인산염 방출
  3. 마이크로웨이브 가온과 암모니아 방출
  4. 금속이온의 거동
 IV. 결 론
 References

• 양회원(유지포스포(주), 조선대학교 환경공학과) | Hoiweon Yang (UG Phospho Co., Ltd., Department of Environmental Engineering, Chosun University)
• 안조환((주)한경이앤씨) | Johwan Ahn (Hankyung E&C Co., Ltd.) Corresponding author
• 김장호((주)한경이앤씨) | Jangho Kim (Hankyung E&C Co., Ltd.)
• 김정환(유지포스포(주)) | Junghwan Kim (UG Phospho Co., Ltd.)