Abstract
The treatment method for wastewater containing surfactant is discussed. The biodegradability of nonionic surfactants such as nonylphenol ethoxylates is low. In addition, it is difficult to treat them by a coagulation process. The adsorption method using activated carbons is quite effective in treating them. Activated carbons effectively adsorb all kinds of surfactants and are especially effective with nonionic surfactant, which have the highest adsorbability. The order of adsorbability of surfactants is as follows: nonionic>cationic>anionic. It has been recently shown that nonylphenol (NP), a biodegradation product of nonylphenol ethoxylates, has endocrine disrupting effects on aquatic life. It is a pressing issue to establish a method to remove NP. The author has examined the adsorbability of 67 endocrine disruptors including NP. The results showed that almost all endocrine disruptors are effectively adsorbed onto activated carbons at quite low concentration. It has been found that alkylphenols with different lengths of alkyl chains have high adsorbability onto activated carbons. Microporous carbons made from various kinds of organic waste, such as used textile products, could be utilized to adsorb endocrine disruptors.
