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Trong chương này, tự nhiên hữu cơ sẽ được d @ ed và nguồn gốc của họ desded. Optiom Dzferent nghiên cứu tự nhiên sourcesfor orgdnics discztssed. Sau đó, phương pháp characterisdtion sẽ được xem xét và charactenstics mô tả. Những đặc điểm này rekvant cho các chất hữu cơ và thường có thể được liên quan đến andfouling loại bỏ. Trong MAV nghiên cứu điều trị, điều trị các vùng biển có chứa nat ~ ral như characteristicsa n negkcted | Chapter 2 CHARACTERISATION OF NATURAL ORGANICS A REVIEW ỉn this chapter natural organics will be defined and their origin described. Different options ofi natural organics sources for research are discussed. Then characterisation methods will be reviewed and characteristics described. These characteristics are relevant for the treatment of waters containing natural organics and can often be related to removal and fouling. In many treatment studies such characteristics are neglected. Methods to obtain natural organics from surface waters their purification and fractionation will be reviewed. Many of the techniques described were used m this study. Subsequently this led to the selection of a suitable process for NOM concentration for this study see Appendix 1 . The variation of the natural organics characteristics with changes in solution chemistry their interaction with cations and other compounds and their interactions with inorganic colloids will also be discussed. I hese interactions occur in natural waters and may also influence treatability. A brief description of colloid characterisation and aggregation mechanisms is also given. Finally a brief overview is given over the issues of natural organics in water treatment. These issues include disinfection byproductformation biofouling and conditioningfilms as well as treatment process options. 5 Copyright 2001 by Andrea I. Schafer 6 CHARACTERISATION OF NATURAL ORGANICS A REVIEW 2.1 Introduction Humic substances HS research has been through a renaissance in recent years after it became recognised that these compounds are the precursors of chlorination disinfection by-products such as trihalomethanes haloacetic acids and chlorophenols. Much research has been done on the use of alternative oxidants such as chloramines uv and ozone but all if efficient disinfectants cause byproducts. The by-products might be of a completely different family but are potentially carcinogenic and not always well known. This implies that .
