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Adsorption/desorption:

Percent adsorption of test chemical 4-[(5-amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)azo]-2,5-dichlorobenzenesulphonic acid (Acid yellow 49) was determined by analyzing test material. This test material is dye and matrix used for adsorption was obtained from Screened raw waste water from greater Cincinnati Mill Creek sewage treatment plant was used as influent (INF) to three pilot scale activated sludge biological treatment systems (Two experimental and one control). Each system consists of primary clarifier, complete mix aeration basin and secondary clarifier. Influent was spiked with test material at concentration of 1 mg/L and 5 mg/L. Then Dye analytical studies were conducted by purified dye compound in organic free influent waste water and mixed liquor. Then influent, primary influent filtrate was passed through column packed with resin. The filter paper and resin were soaked in an ammonia – acetonitrile solution and then soxhlet extracted with ammonia – acetonitrile. The extract was concentrated and brought upto 50 ml volume with methanol/dimethyl formamaide solution. All extracted samples were analyzed by HPLC with ultraviolet detector. Percent adsorption from mass balance data determined was 1 % in both low spiked high spiked samples.On the basis of percent adorption value it is concluded that this test material is shows low sorption.

Additional information

Adsorption/desorption:

Two experimental data studies and one predicted data study for target chemical 4-[(5-amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)azo]-2,5-dichlorobenzenesulphonic acid (Acid yellow 49) and one experimental study for its structurally similar read cross chemical have been conducted anf their results are summarized.

The first experimental study was done from Chemosphere Vol 22 pp 107-119 1991 by Glenn M Shaul, Thomas J Holdsworth, Clyde R. Dempsey, and Kenneth A. Dostal in this study the percent adsorption of test chemical 4-[(5-amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)azo]-2,5-dichlorobenzenesulphonic acid (Acid yellow 49) was determined by analyzing test material. This test material is dye and matrix used for adsorption was obtained from Screened raw waste water from greater Cincinnati Mill Creek sewage treatment plant was used as influent (INF) to three pilot scale activated sludge biological treatment systems (Two experimental and one control). Each system consists of primary clarifier, complete mix aeration basin and secondary clarifier. Influent was spiked with test material at concentration of1 mg/L and 5 mg/L. Then Dye analytical studies were conducted by purified dye compound in organic free influent waste water and mixed liquor. Then influent, primary influent filtrate was passed through column packed with resin. The filter paper and resin were soaked in an ammonia – acetonitrile solution and then soxhlet extracted with ammonia – acetonitrile. The extract was concentrated and brought upto 50 ml volume with methanol/dimethyl formamaide solution. All extracted samples were analyzed by HPLC with ultraviolet detector. Percent adsorption from mass balance data determined was 1 % in both low spiked high spiked samples. On the basis of percent adorption value it is concluded that this test material is shows low sorption.

 

Next experimental study was done from Fresenius Environmental Bulletin, vol. 13 no.11a, 2004 by Mahir Alkan, Özkan Demirbaş and Mehmet Doğan in this study adsorption experiments were carried out by shaking 0.5 g sepiolite ( Clay mineral of white colour) samples with 50 mL aqueous solution of acid yellow 49 of desired concentration at various ionicstrengths (0.1-0.5 M NaCl solutions in water), pHs (3-11), temperatures (25-55oC)for 1 h (the required time for acid yellow 49 to reach the equilibrium concentrations). A thermostated shaker bath was used to keep the temperature constant. The initial concentrations of dye solutes, C0, were in the range of 1x10-4- 30 x10-4mol L-1. All adsorption experiments were performed at 25oC and pH 6.0 except those in which the effects of temperature and pH of the solution were investigated. At the end of the adsorption period, the solution was centrifuged for 15 min at 3000 rpm and then the concentration of the residual acid yellow 49, Ce, was determined with the help of Cary -1E-UV Visible Spectrophotometer (Varian). The adsorbed amounts of acid yellow 49 were calculated from the concentrations in solutions before and after adsorption according to the following equation

Qe= (C0-Ce) V/W

Results obtained at different pH, temperature, and ionic strength were mentioned in table 1 on the basis value obtained by both Isotherms is is concluded that the adsorbed amount of acid yellow 49 decreased with increasing pH, and increased with increasing temperature and ionic strength. If considered values obtained only at pH 6 and temperature 25 oC Adsorption coefficient Kf value by Freundlich isotherm of test chemical Acid yellow 49 obtained was 1900 dimensionless at pH 6 and at temperature 25 oC on sepiolite clay mineral. On the basis of this value it is concluded that test chemical Acid yellow 49 shows low sorption.

In next supporting study the Soil Adsorption Coefficient i.e Koc value of test substance 4-[(5-amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)azo]-2,5-dichlorobenzenesulphonic acid (CAS no.12239 -15 -5) was estimated using Adsorption Coefficient module (v12.1.0.50374) program od Advanced Chemistry Development ACD/I-lab predictive module as Koc 1.0 dimensionless (log Koc= 0.0). This log Koc value indicates that the test substance 4-[(5-amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)azo]-2,5-dichlorobenzenesulphonic acid has a negligible sorption to soil and therefore has rapid migration potential to groundwater.

Last study was supporting Study done from UERL laboratory (2017) in this study the adsorption coefficient Koc in soil and in sewage sludge of read across 5-amino-2-chlorobenzenesulfonic acid (CAS No.88-43-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the read cross substance and generalized calibration graph was prepared. The reference substances were 4-chloroaniline, 4-methylaniline (p-Tolouidine), Aniline, 2,5-Dichloroaniline, Xylene, Ethylbenzene, Toluene, Naphthalene, 1,2,3-trichlorobenzenewere chosen having Koc value ranging from 1.239 to 2.4.

The Log Koc value of read across chemical 5-amino-2-chlorobenzenesulfonic acid was determined to be 1.397 dimensionless at 25°C. Based on the value of log Koc it is concluded that this read cross chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

 On the basis of all the studies mentioned above it is concluded that test substance 4-[(5-amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)azo]-2,5-dichlorobenzenesulphonic acid has a negligible sorption to soil and therefore has rapid migration potential to groundwater.