APnEO

The non-ionic surfactant alkylphenol polyethoxylates (APnEOs) are used widely in pesticide formulations, detergents, and industrial products for many years due to their favorable physico-chemical properties. 4-Nonylphenol polyethoxylate (NPnEO) is one of the most commonly used APnEO, which is produced by addition of ethylene oxide to a mixture of branched 4-nonylphenol (NP) isomers. Released into the environment or entered into sewage treatment systems, APnEOs are biodegraded, resulting in shortening of ethoxy chain and/or carboxylation at the terminal ethoxy unit (alkylphenoxy carboxylates; APECs) that ultimately release alkylphenols (APs).