Alkylphenol ethoxylate discussion

The environmental compatibility of silicone softeners is generally favourable [495,496]. The discussion here concerns only the silicone component of the formulation and not the supporting emulsifying system. For the most part this is nonionic, preferably based on linear ethoxylated fatty alcohols, although alkylphenol ethoxylates are still used in some countries [496]. The salient points regarding the environmental influence of silicones can be summarised as follows ... 

Gas chromatography (GC) has developed into the most powerful and versatile analytical separation method for organic compounds nowadays. A large number of applications for the analysis of surfactants have emerged since the early 1960s when the first GC papers on separation of non-ionics were published. The only major drawback for application of GC to surfactants is their lack of volatility. This can be easily overcome by chemical modification (derivatisation), examples of which will be discussed extensively in the following paragraphs. This chapter focuses on surfactant types, and in addition discusses some structural aspects of alkylphenol ethoxylates (APEOs) that are important for, as well as illustrative of, aspects of separation and identification that are linked to the complexity of the mixtures of surfactants that are involved. 

This paper will review the biodegradation of nonionic surfactants. The major focus will be on alcohol ethoxylates and alkylphenol ethoxylates—the two largest volume nonionics. In this paper the effect of hydrophobe structure will be discussed, since hydrophobe structure is considered more critical than that of the hydrophile in biodegradability of the largest volume nonionics. The influence of the hydrophobe on the biodegradation pathway will be examined with an emphasis on the use of radiolabeled nonionics. 

It is common practice to put the experimentally obtained values for biodegradation and aquatic toxicity into a kind of matrix, as is illustrated by Fig. 2. The shaded areas in the matrix are the approved areas . Out of the six product types discussed above linear alkylbenzene sulfonates, alcohol ethoxylates, and ester quats lie within the shaded areas, while branched alkylbenzene sulfonates, alkylphenol ethoxylates and stable quats do not. 

In this chapter, all four types of sediment and sludge sample handling techniques for non-ionic surfactants will be discussed and compared. Most of the studies published on non-ionics focus on APEOs and their degradation products, viz. the alkylphenols, but some extraction methods for alcohol ethoxylates (AEOs) and coconut diethanol amides will also be discussed. 

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