CONFIDENTIAL 

Title ASSESSMENT OF THE REMOVAL OF DUOMEEN 218i IN BIOLOGICAL TREATMENT 

SYSTEMS THROUGH READ ACROSS. 

To E. Perez (ANSC Chicago)

Author C.G. van Ginkel and R. Geerts

Doc. No F 14055 CG 

Date 02-05-2014

Introduction 

Duomeen 218i is a N,N-dialkyl propylene diamine synthesized with isooctadecanoic acid. 

AkzoNobel Surface Chemistry would like to submit an US chemical notification for this fatty 

amine derivative. Duomeen 218i is chemically similar to Duomeen 2HT, for which data on 

its behaviour in activated sludge plants (biological treatment) already exists. 

The fate of organic substances in biological wastewater treatment systems is mainly 

determined by their biodegradability, capacity to adsorb, and volatility. Test results 

obtained with Duomeen 2HT in a continuously-fed activated sludge (CAS) test (OECD 303), 

information on the biodegradability, potential to adsorb, and volatility of both fatty amines 

are used to assess the removal of Duomeen 218i in biological treatment systems (read 

across). 

Physical and chemical properties 

Table Henry’s law constants and log Koc values for the N,N-dialkyl propylene diamines 

calculated with EPIsuite (US EPA, 2013). Values of log Koc were estimated from log Kow 

values of the protonated molecule. 

Name Log Koc (l/kg) Henry’s law constant 

(atm. m3 mol-1) 

Duomeen 218ia 10.0 (MCI)

9.7 (log Kow) 

6 10-4

Duomeen 2HTa,b 10.4 (MCI)

9.8 (log Kow) 

4 10-

4

a

 structures in figure 

a

 calculated by assuming octadecyl chains 

Substances with Henry’s law constants of <10-3 atm. m3

 mol-1 do not volatilize (Table). Loss 

of both fatty amine derivatives to air can therefore be excluded. The potential to adsorb of 

both N,N-dialkyl propylene diamines is also comparable (Table). The log Koc values strongly 

indicate that both substances have a high potential to adsorb onto activated sludge particles. 

Biodegradability 

Mono branching with a methyl group at the end of both alkyl chains is the only difference in 

structure compared to Duomeen 2HT (Figure). The perception that branched-chain alkyl 

chains are difficult to degrade is primarily based on the recalcitrance of substances with 

multi branched alkyl groups. Nonetheless several bacterial strains can degrade pristane, an 

alkane with multiple methyl branching, easily. The oxidation of pristane has been shown to 

be common and many microorganisms have acquired pathways for assimilation of branched 

Environmental 

Chemistry 

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Page 2 of 4

carboxylic acids derived from this alkane (Pirnik, 1977; Watkinson and Morgan, 1990). 

Microorganisms degrading isoprenoids (e.g. citronellol) and methyl branched amino acids 

(e.g valine) are also very common. Isoprenoids are characterized by methyl-branched 

molecular structures derived from isoprene. Several bacteria, particularly Pseudomonas sp. 

utilize these compounds as sole carbon source (Cantwell et al, 1978 and Díaz Pérez et al. 

2004). The branched fatty acid, isobutyric acid (2-methyl-propionic acid) is an intermediate 

in the microbial degradation of valine (dePaul Marshal and Sokatch, 1972). Amino acids and 

isoprenoids are readily biodegradable. The ready biodegradability of mono branched alkyl 

sulphates has been demonstrated (Battersby et al, 2000). Microorganisms capable of 

degrading 2-butyloctyl sulphate (mono-branched) as sole carbon and energy source were 

isolated from activated sludge of a plant treating primarily domestic wastewater (Ellis et al, 

2004). 

The ability of microorganisms to utilize many organic compounds with mono branching 

(alkanes, isoprenoids, carboxylic acids and amino acids) demonstrates that enzyme 

recruitment results in a high biodegradation potential of these substances. Substances with 

one alkyl especially methyl branching along the alkyl chain are therefore considered as 

rapidly and completely biodegradable like their linear counterparts. 

Removal of Duomeen 2HT in biological wastewater treatment plants (OECD 303) 

The removal of Duomeen 2HT in biological treatment plants was assessed in CAS unit fed 

with domestic wastewater spiked with the fatty amine derivative (AkzoNobel, 2010). The 

CAS tes was performed according to the OECD 303 test guideline in compliance with GLP. 

Duomeen 2HT was exposed to activated sludge maintained by addition of domestic 

wastewater in the CAS test. The mean carbon removal percentage of calculated over 15 

measurements of the test was 104±1%. Formation of water soluble compounds during 

biological treatment of Duomeen 2HT can therefore be excluded. The mean removal 

percentage of Duomeen 2HT from the influent was >99.9%. Mean removal percentages of 

Duomeen 2HT through adsorption onto sludge assessed was 1.3% demonstrating that 

Duomeen 2HT is primarily removed by biodegradation. 

Read across 

Negligible evaporation and comparable potential to biodegrade and adsorb of Duomeen 2HT 

and Duomeen 218i demonstrate that read-across is justified. Duomeen 218i is based on 

read-across expected to be removed from wastewater by >99.9% primarily as the result of 

biodegradation. Less than 2% of the Duomeen 218i entering a wastewater treatment facility 

is expected to be removed by adsorption. 

References 

x Akzonobel (2010) Determination of the primary and ultimate biodegradation of N,Ndi(hydrogenated tallow-alkyl)-1,3-propanediamine in a continuously-fed activated 

sludge unit treating domestic wastewater. Report doc. 2.421.206 T09066 CAS. 

x Battersby NS, Kravetz L, Salanitro JP (2000) Effect of branching on the biodegradability 

of alcohol-based surfactants, In 5th World Surfactant Congress. Federchimica, Milan, 

Italy pp 1397-1407. 

x Cantwell SG, Lau EP, Watt, DS and Fall RR (1978) Biodegradation of acyclic isoprenoids 

by Pseudomonas species. Journal of Bacteriology, 135 (2). 324-333. 

x dePaul Marshall V, Sokatch JR (1972) Regulation of valine catabolism in Pseudomonas 

putida J Bac 110 (3) 1073-1081. 
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x Diaz Perez AL, Zavala-Hernandez AN, Cervantes C, and Campos Garcia AJ (2004) The 

gnyRDBHAL cluster is involved in acyclic isoprenoid degradation in Pseudomonas 

aeruginosa. Applied and Environmental Microbiology, 70(9), 5102-5110. 

x Ellis AJ, hales SG, Ur-Rehman GA and White GF (2002) Novel alkylsulfatases required 

for biodegradation of the branched primary alkyl sulfate surfactant 2-butyloctyl sulfate. 

Appl Environ Microbiol 68 31-36. 

x U.S. Environmental Protection Agency (2013). EPIWEB v 4.1. US EPA. [2012]. 

Estimation Programs Interface SuiteTM for Microsoft® Windows, v 4.1. United States 

Environmental Protection Agency, Washington, DC, USA. 

x Watkinson RJ and Morgan P (1990) Physiology of aliphatic hydrocarbon-degrading 

microorganisms. Biodegradation 1 79–92. 
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Figure Chemical structures of Duomeen 2HT (left) of Duomeen 218i (right).