Nonylphenols biodegradation

Nonylphenol (NP) has high aquatic toxicity and low biodegradability. Furthermore, an extensive risk assessment showed that nonylphenol displays endocrine-disrupting properties, i.e. hormone disrupting showing oestrogenicity. The use of... 

Chang BV, Chiang BW, Yuan SY (2007) Biodegradation of nonylphenol in soil. Chemosphere 66 1857-1862... 

De Weert JPA, Vinas M, Grotenhuis T, Rijnaarts HHM, Langenhoff AAM (2011) Degradation of 4-n-nonylphenol under nitrate reducing conditions. Biodegradation 22 175-187... 

Koh YKK, Chiu TY, Boobis AR, Scrimshaw MD, Bagnall JP, Soares A, Pollard S, Cartmell E, Lester JN (2009) Influence of operating parameters on the biodegradation of steroid estrogens and nonylphenolic compounds during biological wastewater treatment processes. Environ Sci Technol 43 6646-6654... 

NPE (nonylphenol I /osXZ o— Household and - STPs effluents in Switzerland Readily biodegradable in... 

Octyl- and nonylphenol are well known raw materials used in the surfactant industry since the early 1960s, mainly for the production of their corresponding ethoxylated derivatives (APE). Today, these products have lost considerable importance in this industry as a consequence of substantial environmental threats, resulting from their relatively slow biodegradation, toxicity of their biodegradation metabolites and positive endocrine-disrupting reactions. 

Although the occurrence of the non-ionic surfactant nonylphenol ethoxylate (NPEO Fig. 6.7.1) and its biodegradation intermediates in the aquatic environment has attracted large interest [18] because of the potential of some biotransformation products to mimic estrogenic effects, their fate and distribution in soil environments has been only investigated in a few cases. 

Alkylphenol Ethoxylates (APE). The hydrophobes of most commercial APE are made by reacting phenol with either propylene trimer or diisobutylene to form nonylphenol or octylphenol. These products contain an aromatic moiety and extensive branching in their alkyl chains. It has been shown that APE biodegrade more slowly and less extensively than LPAE (3.15-20). The difference is more pronounced when the treatment system is operating under stress conditions such as low temperatures and high surfactant loadings. 

Jonkers N., R.W.P.M. Laane, and P. de Voogt. 2003. Fate of nonylphenol ethoxylates and their metabolites in two Dutch estuaries Evidence of biodegradation in the field. Environ. Sci Technol. 37 321-327. 

They are now being replaced by the polyoxyethylene derivative of straight-chain primary or secondary alcohols with C10-C18. These linear alcohol ethoxylate nonionic surfactants are more biodegradable than nonylphenol derivatives and have better detergent properties than linear alkylbenzenesulfonate. 

Derivatives of nonylphenol up to about the 12-mol ethoxylate are liquid at ambient temperature and do not require heated storage. They are used for reducing oil-water interfacial tension and are excellent for removing oily soils. The major drawback is the biodegradation resistance of the benzene ring, which limits the use to industrial applications in which waste can be treated before any discharge to waterways. However, their relative cheapness has maintained their use in some formulations destined for the household market in certain parts of the world. 

With the slow demise of the nonylphenol ethoxylate market due to legislation, the fatty alcohol market has the chance to design alternatives by subtle changes to the hydrophobe chain lengths and alkoxylate levels. The effects must be achieved with biodegradability as... 

The surfactant nonylphenol polyethoxylate is readily biodegradable, whereas its biodegradation products are persistent. See Figure 9.19. 

Cuzzola et al. [25-26] identified and characterized Fenton oxidation products of lauryl sulfate and AES. The Fenton reaction is a frequently applied oxidative treatment in STPs. The degradation prodncts of anionic surfactants have been objects of stndy as well, because their biodegradation products might involve the loss of the snlfate group, resulting in essentially nonionic surfactants (see below). According to Schroder [27], the biodegradation of nonylphenol ethoxy sulfates does not involve a loss of the sulfate. 

Following previous studies on lauryl sulfate and AES, Cuzzola et al. [44] also studied the Fenton oxidation products of AEO and NPEO. The aerobic biodegradation of AEO and NPEO and anaerobic biodegradation of NPEO were studied by Schroder [27] by means of FIA-MS and LC-MS and MS-MS in positive-ion and/or negative-ion APCI. Methyl ethers of AEO ate persistent in aerobic conditions. NPEO degradation results in NPEC. Anaerobic biodegradation of NPEO results in nonylphenols. 

Linear alkylbenzenesulfonates (LAS), alcohol ethoxylates (AEO), and nonylphenol ethoxylates (NPEO) are synthetic surfactants used in the formulation of detergents and other cleaning products and are widely applied in the dye and leather industry and other industrial processes. These compounds, considered as estrogenic, have aroused considerable interest due to the large quantities produced globally. Their low volatility and anionic form make LC-based methods the preferred approach [7]. Due to the presence of different positional isomers, to the biodegradation intermediates, and to the lack of reference standards, LC-MS, and in particular with ESI, is the only technique which enables their identification and quantification in environmental waters. 

The ohgomeric distribution of NPEO depends on the enviromnental compartment. In this respect, the dissolved phase of waters (seawater and wastewaters) contain higher ethoxamers, whereas river and marine sediments oidy contain nonylphenol and the lower oligomer derivatives (Fignre 4). Nonylphenol and its low-ethoxylated components have been identified in mechanical-biological sewage treated and in some biodegradation experiments", so that its preferential occurrence in the sediment may be due to these effects and/or to their preferent association to the particnlate material. 

Concern has increased recently about the wide usage of APEs because of these relatively stable biodegradation products, including 4-nonylphenol (4-NP), 4-terf-octylphenol (4-f-OP),... 

In recent years considerable attention has been given to the biodegradability of polyethoxylates and the role of their structure in this process. In consequence, there has been a move away from multi-branched alkyl side-chain in the starting alkylphenolic raw material towards more linear chains, a circumstance already adopted in the use of kerylbenzenes for the manufacture of alkylaryl sulphonates. Another practice adopted has been that of sulphation of the terminal hydroxyl group in the polyalkoxylate. Recent studies on a comparison of ethoxylates derived from the natural alkenylphenol, cardanol and from nonylphenol have indicated a considerable difference in biodegradability (ref. 24). 

Sodium anacardate is an excellent soap the water solubility of which has been used in a subsequent reaction (ref. 283). There has been, following work on the preparation of cardanol polyethoxylate (ref.284,285,286), by the reaction of cardanol with ethylene oxide at 180 C in the presence of a catalytic amount of potassium hydroxide, considerable interest in its ready biodegradability compared with that of ethoxylates derived from t-nonylphenol (ref.287). The individual ethoxy late oligomers were synthesised having values of n = 1 to 6 to identify the oligomers present in cardanol polyethoxylate and the ready biodegradation of cardanol and to a lesser extent that of of cardol polyethoxylates quantitatively established in comparison with that of t-nonylphenol polyethoxylate which remain comparatively undegraded. 

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