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Fractionation of levofloxacin and ofloxacin during their transport in NOM-goethite : Batch and column studies
2023
Qin, Xiaopeng | Zhong, Xiaofei | Wang, Bin | Wang, Guangcai | Liu, Fei | Weng, Liping
Adsorption and transport of levofloxacin (LEV) and ofloxacin (OFL) enantiomers in a matrix containing goethite and natural organic matter (NOM) were investigated using batch and column experiments. In batch studies, competition and enantioselectivity were observed in the adsorption of LEV and OFL. Enantioselectivity upon adsorption was investigated by comparing changes in the enantiomer fraction (EF) (the ratio of LEV to the sum of LEV and OFL remaining in the solution) after and before adsorption. At pH < 7, there was hardly any selectivity in adsorption of OFL and LEV to goethite. At pH > 7, OFL showed a stronger adsorption than LEV to goethite, and this preference remained when NOM samples of Leonardite humic acid (LHA) and Elliott Soil fulvic acid (ESFA) were added. However, when Suwannee River NOM (SRNOM) was added, the preference was reversed, and LEV was adsorbed more strongly. In single systems, the presence of different types of NOM increased adsorption of LEV and OFL, especially LEV. In column studies, preloaded NOM decreased the transport of LEV and OFL through goethite-coated sand. The EF values in the effluent increased with retention time and reached the largest values (0.59–0.72) at around 1.5 pore volume (PV), and then decreased again, reaching a stable value at 5.0–30.0 PV. Both batch and column experiments showed that, fractionation of LEV and OFL occurred during adsorption and transport in the presence of NOM-goethite complexes, which would eventually affect their environmental fate
Afficher plus [+] Moins [-]Benchmarking biochar with activated carbon for immobilizing leachable PAH and heterocyclic PAH in contaminated soils
2023
Carlini, Carlotta | Chaudhuri, Sampriti | Mann, Oliver | Tomsik, Daniel | Hüffer, Thorsten | Greggio, Nicolas | Marazza, Diego | Hofmann, Thilo | Sigmund, Gabriel
Remediation of residually contaminated soils remains a widespread problem. Biochar can immobilize polycyclic aromatic hydrocarbons (PAH). However, studies on its ability to immobilize PAH and N, S, and O substituted PAH (hetero-PAH) in real soils, and benchmarking with commercial activated carbon are missing. Here, we compared the ability of pristine biochar (BC), steam-activated biochar (SABC), and commercial activated carbon (AC) to immobilize PAH and hetero-PAH. The three carbons were tested on soils from four different contaminated sites in Austria. Different amendment rates (w/w) of the carbons were investigated (BC: 1.0, 2.5, and 5%; SABC: 0.5, 1.0, and 2.0%; AC: 1%) in batch experiments to cover meaningful ranges in relation to their performance. SABC performed better than AC, removing at least 80% PAH with the lowest application rate of 0.5%, and achieving a complete removal at an application rate of 1.0%. BC performed slightly worse but still acceptable in residually contaminated soils (40 and 100% removal at 1 and 5% amendment, respectively). The ability of BC and SABC to immobilize PAH decreased as the PAH-molar volume increased. PAH with three or more rings were preferentially removed by AC compared to SABC or BC. This can be explained by the difference in pore size distribution of the carbons which could limit the accessibility of PAH and hetero-PAH to reach sorption sites for π- π electron donor-acceptor interactions, which drive PAH and hetero-PAH sorption to carbons. Column percolation tests confirmed the results obtained in batch tests, indicating, that decisions for soil remediation can be derived from simpler batch experiments. In soil samples with 1% BC, a reduction of over 90% in the total concentration of PAH in the leached water was observed. Overall, BC and SABC were demonstrated to be valid substitutes for AC for stabilizing residually contaminated soils.
Afficher plus [+] Moins [-]Fractionation of levofloxacin and ofloxacin during their transport in NOM-goethite : Batch and column studies
2023
Qin, Xiaopeng | Zhong, Xiaofei | Wang, Bin | Wang, Guangcai | Liu, Fei | Weng, Liping
Adsorption and transport of levofloxacin (LEV) and ofloxacin (OFL) enantiomers in a matrix containing goethite and natural organic matter (NOM) were investigated using batch and column experiments. In batch studies, competition and enantioselectivity were observed in the adsorption of LEV and OFL. Enantioselectivity upon adsorption was investigated by comparing changes in the enantiomer fraction (EF) (the ratio of LEV to the sum of LEV and OFL remaining in the solution) after and before adsorption. At pH < 7, there was hardly any selectivity in adsorption of OFL and LEV to goethite. At pH > 7, OFL showed a stronger adsorption than LEV to goethite, and this preference remained when NOM samples of Leonardite humic acid (LHA) and Elliott Soil fulvic acid (ESFA) were added. However, when Suwannee River NOM (SRNOM) was added, the preference was reversed, and LEV was adsorbed more strongly. In single systems, the presence of different types of NOM increased adsorption of LEV and OFL, especially LEV. In column studies, preloaded NOM decreased the transport of LEV and OFL through goethite-coated sand. The EF values in the effluent increased with retention time and reached the largest values (0.59–0.72) at around 1.5 pore volume (PV), and then decreased again, reaching a stable value at 5.0–30.0 PV. Both batch and column experiments showed that, fractionation of LEV and OFL occurred during adsorption and transport in the presence of NOM-goethite complexes, which would eventually affect their environmental fate
Afficher plus [+] Moins [-]Benchmarking biochar with activated carbon for immobilizing leachable PAH and heterocyclic PAH in contaminated soils
2023
Carlini, Carlotta | Chaudhuri, Sampriti | Mann, Oliver | Tomsik, Daniel | Hüffer, Thorsten | Greggio, Nicolas | Marazza, Diego | Hofmann, Thilo | Sigmund, Gabriel
Remediation of residually contaminated soils remains a widespread problem. Biochar can immobilize polycyclic aromatic hydrocarbons (PAH). However, studies on its ability to immobilize PAH and N, S, and O substituted PAH (hetero-PAH) in real soils, and benchmarking with commercial activated carbon are missing. Here, we compared the ability of pristine biochar (BC), steam-activated biochar (SABC), and commercial activated carbon (AC) to immobilize PAH and hetero-PAH. The three carbons were tested on soils from four different contaminated sites in Austria. Different amendment rates (w/w) of the carbons were investigated (BC: 1.0, 2.5, and 5%; SABC: 0.5, 1.0, and 2.0%; AC: 1%) in batch experiments to cover meaningful ranges in relation to their performance. SABC performed better than AC, removing at least 80% PAH with the lowest application rate of 0.5%, and achieving a complete removal at an application rate of 1.0%. BC performed slightly worse but still acceptable in residually contaminated soils (40 and 100% removal at 1 and 5% amendment, respectively). The ability of BC and SABC to immobilize PAH decreased as the PAH-molar volume increased. PAH with three or more rings were preferentially removed by AC compared to SABC or BC. This can be explained by the difference in pore size distribution of the carbons which could limit the accessibility of PAH and hetero-PAH to reach sorption sites for π- π electron donor-acceptor interactions, which drive PAH and hetero-PAH sorption to carbons. Column percolation tests confirmed the results obtained in batch tests, indicating, that decisions for soil remediation can be derived from simpler batch experiments. In soil samples with 1% BC, a reduction of over 90% in the total concentration of PAH in the leached water was observed. Overall, BC and SABC were demonstrated to be valid substitutes for AC for stabilizing residually contaminated soils.
Afficher plus [+] Moins [-]Retention of coumaric acid by soil and its colloidal components
1990
Riffaldi, R. (Pisa Univ. (Italy). Inst. of Agricultural Chemistry) | Saviozzi, A. | Levi-Minzi, R.
Estimation method of residual alkylating agents in water treated with chlorine-containing oxidant
1990
Tingfa, D. (Changsha Inst. of Technology, Changsha, Hunan (China). Dept. of Applied Chemistry) | Shiguang, Z.
Adsorption of mercury compounds by tropical soils, 3: adsorption isotherms
1987
Semu, E. (Agricultural Univ. of Norway, Aas (Norway). Dept. of Soil Fertility and Management) | Singh, B.R. | Selmer-Olsen, A.R.
Defluoridation of water by adsorption on fly ash
1990
Chaturvedi, A.K. (Banaras Hindu Univ., Varanasi (India). Dept. of Applied Chemistry) | Yadava, K.P. | Pathak, K.C. | Singh, V.N.
Sulfate adsorption-desorption in a Swedish forest soil
1998
Gobran, G.R. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research) | Selim, H.M. | Hultberg, H. | Andersson, I.
Influence of methanol and hexane on soil adsorption of atrazine
1988
Miller, N.A. (Arkansas Univ., Fayetteville (USA). Dept. of Agronomy) | Wolf, D.C. | Scott, H.D.