Sorption of Sulfonamide Antibiotics to Soil Organic Sorbents: Batch Experiments with Model Compounds and Computational Chemistry

Table 2

Parameters of the Freundlich equation describing the sorption and desorption of the sulfonamides SAA, SPY, and SDT to Fluka humic acid (HA) and a vanillin enzymatic oligomer structure (VEO) at different pH values.

		Sorption						Desorption
pH	𝐾𝑓	Error	𝑛	Error	𝑅^2		𝐾𝑓	Error	𝑛	Error	𝑅^2	1−H
						HA
						SAA
4.5	49	0.52	0.66	0.02	1.00		180	15	0.68	0.04	0.99	−0.03
6.0	30	0.63	0.56	0.04	0.98		89	15	0.54	0.08	0.96	0.04
7.5	48	0.84	0.50	0.02	1.00		140	37	0.50	0.12	0.94	0.00
						SPY
4.5	84	1.7	0.45	0.03	0.98		297	15	0.60	0.03	0.99	−0.33
6.0	44	0.66	0.50	0.02	0.99		291	39	0.87	0.08	0.97	−0.74
7.5	66	1.4	0.49	0.03	0.99		219	23	0.58	0.05	0.98	−0.18
						SDT
4.5	211	37	0.87	0.15	0.91		656	36	0.98	0.05	0.99	−0.13
6.0	124	12	1.01	0.10	0.97		533	12	0.97	0.03	1.00	0.04
7.5	37	2.9	0.26	0.08	0.76		95	14	0.39	0.05	0.93	−0.50
						VEO
						SAA
4.5	20	0.50	0.78	0.05	0.96		252	36	0.82	0.05	0.97	−0.05
6.0	11	0.52	1.16	0.14	0.91		53	11	0.72	0.10	0.86	0.38
7.5	21	0.89	0.68	0.07	0.94		67	7.6	0.56	0.05	0.97	0.18
						SPY
4.5	32	0.83	0.54	0.02	0.98		265	12	0.68	0.02	1.00	−0.26
6.0	29	1.5	0.71	0.10	0.86		265	24	0.96	0.05	0.97	−0.35
7.5	38	0.91	0.74	0.04	0.98		293	20	0.93	0.04	0.98	−0.26
						SDT
4.5	497	34	0.77	0.05	0.97		1152	67	0.82	0.03	0.99	−0.06
6.0	56	6.6	0.72	0.10	0.88		550	23	1.06	0.04	0.99	−0.47
7.5	22	0.46	0.54	0.03	0.97		30	15	0.21	0.17	0.74	0.61