Sorption of chlorinated pesticides such as 2,4-dichlorophenoxyacetic acid (2,4-D) and atrazine onto natural clays (montmorillonite and zeolite) modified with cationic surfactant, hexadecyltrimethyl-ammonium (HDTMA) and a natural soil was investigated using batch adsorbers. The clays were transformed from hydrophilic to hydrophobic by the cation exchange between clay surface and HDTMA up to 100% of the cation exchange capacity (CEC). Physicochemical characteristics of the sorbents such as pH, PZC (point of zero charge), organic carbon content (foc), fourier transform infrared spectroscopy (FT-IR), differential thermogravimetric analysis (DTGA) and X-ray diffraction (XRD) were analyzed. Sorption isotherm models such as Freundlich and Langmuir were fitted to the experimental data, resulting Langmuir model (R2 > 0.986) was fitted better than Freundlich model (R2 > 0.973). Sorption capacity (Q0) for 2,4-D and atrazine was in the order of HDTMA-montmorillonite > HDTMA-zeolite > natural soil corresponding to the increase in organic carbon content (foc). The sorption of the pesticides was also affected by pH. The sorption of 2,4-D decreased with the increase in pH, whereas that of atrazine was not changed. This indicated that the sorption capacity (Q0) of 2,4-D and atrazine was not affected by the solution pH because they exist as anionic (deprotonated) forms at pH above pKa. The results indicate that organoclay has a promising potential to reduce chlorinated pesticides in the effluent from golf courses.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 재료
  2.2. 수착실험
  2.3. 수착 모델
 3. 결과 및 고찰
  3.1. 수착제 개질 특성 분석 결과
  3.2. 수착제의 물리화학적 특성 분석결과
  3.3. 등온수착 실험결과
  3.4. 유기탄소 함량(foc)의 영향
  3.5. 옥탄올-물 분배계수(Kow)의 영향
  3.6. pH의 영향
 4. 결 론
 참 고 문 헌

• 최지연(경북대학교 환경공학과) | Ji Yeon Choi (Department of Environmental Engineering, Kyungpook National University)
• 신원식(경북대학교 환경공학과) | Won Sik Shin (Department of Environmental Engineering, Kyungpook National University) Corresponding Author