2,4,6-trichloroaniline

Endpoint summary

Description of key information

Adsorption/desorption:

The adsorption coefficient of test substance 2,4,6-trichloroaniline (CAS No.634-93-5) was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined  to be 3.466± 0.004 at 25°C. By considering log Koc value it can be concluded that test chemical has moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

Additional information

Adsorption/desorption:

Various experimental studies from different journals and experimental report have been reviewed for adsorption and desorption endpoint of test chemical2,4,6-trichloroaniline(CAS No.634-93-5).

 

The first study was experimental report (2015) in this study the adsorption coefficient (Log Koc) on soil and on sewage of 2,4,6-trichloroaniline (CAS No.634-93-5) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Kocrange of the test substance and generalized calibration graph was prepared. The reference substances were 4 chloroaniline, 4 methylaniline, N methylaniline, 2 Nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, Benzamide, phenanthrene having Kocvalue ranging from 1.239 to 4.09.

The Log Kocvalue was determined to be 3.466± 0.004 at 25°C temperature.

By considering log Koc value it can be concluded that test chemical has moderate sorption to soil and sediment and therefore has slow migration potential to ground water.

 

 

Next study was reviewed from jouranal Environmental Pollution (2005) in this study the Batch experiments have been performed in order to evaluate the ability of the two reference clays kaolinite (KGa-1) and Na montmorillonite (SWy-1) to retain 2, 4, 6-trichloroaniline. 100 mL of solutions of test chemical 2,4,6-trichloroaniline was put in contact under constant agitation with 2.0 g of, respectively kaolinite and Na-montmorillonite. The experiments have been performed at four concentration levels (1.0, 2.5, 5.0 and 10.0 mg/L) in a pH range between 5.0 and 5.5 for kaolinite and between 8.8 and 9.3 for Na montmorillonite.

The Kd (L g-1) value for the test substance 2, 4, 6- trichloroaniline were determined to be 0.0389 and 0.0488 for kaolinite (KGa-1) and Na montmorillonite (SWy-1) clays respectively. The test chemical 2, 4, 6- trichloroaniline is sorbed by clay standard kaolinite and Na-montmorillonite at different extents and likely by different mechanisms. The test chemical 2,4,6-trichloroaniline showed 8 % adsorption on clay standard kaolinite at all four concentrations of test chemicals (10, 5, 2.5 and 1.0 mg/L) , 10 % adsorption on clay Na-montmorillonite at 10 and 5 mg/L concentrations.X-ray analysis suggests that the 2, 4, 6 trichloroaniline investigated is preferentially sorbed on mineral surface on kaolinite, while when sorption on montmorillonite is considered, a progressive swelling of the structure can be observed, due to sorption processes that also take place in the interlayer, as shown by the study carried out on the dehydrated Na-montmorillonite system.

 On the basis of percent adsorbed it can be concluded that test chemical 2, 4, 6- trichloroaniline has low sorption on clay standard kaolinite and Na-montmorillonite.

 

Another experimental study was reviwed from Environmental Science and Pollution Research journal (2006) in this study the sorption experiments were carried out by immersing 2.00 g of clay mineral namely kaolinite KGa-1 and montmorillonite in 100.0 mL of test chemical solutions at concentrations of 10.0, 50.0, 100.0 and 200.0 mg/L. Experiments with kaolinite KGa-1 were carried outat both pH 4.8 (the natural pH of kaolinite in water) and at pH 9.9 (to compare the sorption results with those of montmorillonite). The systems were electromagnetically stirred for at least 1 week and, at regular intervals, 500μLof the suspension were collected, centrifuged (4500 rpm, 6 minutes), filtered(0.45μm) and analysed by HPLC analysis to deduce the amount of test chemical retained.

For the desorption experiments, suspensions resulting from the sorption experiments were centrifuged (4500 rpm, 10 minutes), and the solid phase containing the sorbed test chemical was air-dried and then submerged in ultra pure water at the same solid/liquid ratio as in the sorption experiments (2.00 g/100.0 mL) The new system was stirred electromagnetically for 7 days and then 500μL of the suspension were collected, filtered and injected into the HPLC system for direct determination of the desorbed fraction.The substance 2, 4, 6-trichloronailine was strongly retained, with sorption of up to 8 mg/g, by the soil clays kaolinite KGa-1 and Na montmorillonite SWy-1. In desorption experiments, 2,4,6-trichloroaniline was the least desorbed from montmorillonite irreversibly retained on kaolinite.

 For sorption on kaolinite (KGa-1),equilibrium is achieved in less than four days 2, 4, 6-trichloroaniline is sorbed (from an initial concentration of 200.0 mg/L) at a rate of 7.3 mg per gram of mineral clay, comparable with that sorbed by montmorillonite. The desorption experiments carried out on the adsorbed kaolinite for the 2, 4, 6-trichloroaniline reveal no significant desorption, at least as detected by the HPLC method. This suggests that the test chemical and the clay mineral form irreversible interactions, capable of resisting the desorption strength of simulated leaching.

 

 

Last experimental study was reviewed from chemosphere journal (2008) in this study the sorption experiments are carried out in triplicate by putting in batch conditions 2.00 g of the sorbing material in 100.00 mL of test material aqueous solution at concentration 200.00 mg/L. The systems are electromagnetically stirred for a total time of 15 days, 1.00 mL of the surnatant is collected, centrifuged (4500 rpm, 6 min), filtered on 0.20 µm polypropylene membrane (VWR International, West Chester, PA, USA) and submitted to HPLC analysis for the determination of the amount of test chemical still present in solution. From the amount initially present the quantity retained is calculated and expressed as mg of test chemical retained in batch conditions by 1.00 g of sorbent material.

 To evaluate the amount of test chemical desorbed by the different leaching agents, the suspension obtained after 15 d of contact is centrifuged (4500 rpm, 10 min) and the solid phase (that contains the pollutant sorbed) is air-dried, weighed and submerged in the leaching solution in the same solid/liquid ratio as in the sorption experiments (2.00 g/100.00 mL). The new system is electromagnetically stirred for 15 d and then 1.00 mL of the supernatant is collected, filtered and injected into the HPLC system for the direct determination of the desorbed fraction of the test chemical. All the experiments are performed in triplicate.

 The test chemical 2,4,6-trichloroaniline adsorbed on clay Na-montmorrilonite(SWy-2) were 10.0 ± 0.6 and 3.1 ± 0.7 mg/g , on clay kaolinite (KGa-1b) 7.3 ± 0.9 and 5.5 ± 1.3 mg/g and on clay BCR_-700 10.0 ± 1.5 and 3.3 ± 0.4 mg/g of clay.

Further, the test chemical desorbed from all three types of clays was < 0.1 %.

Thus on the basis of adsorption values on all three types of clays it can be conclude that test chemical2,4,6-trichloroaniline shows capability to adsorb on different types of clays.

 

By considering results of all the studies mentioned above it can be concluded that test chemical 2,4,6-trichloroaniline(CAS No.634-93-5) shows moderate to low sorption to different types of clays and soil.