Supporting information:
ATTENUATION OF PHENANTHRENE AND PYRENE ADSORPTION BY SEWAGE SLUDGE-DERIVED BIOCHAR IN BIOCHAR-AMENDED SOILS
Anna Zielińska, Patryk Oleszczuk*
Department of Environmental Chemistry, Faculty of Chemistry, 3 Maria Curie-Skłodowska Square, 20-031 Lublin, Poland
Correspondence to: Patryk Oleszczuk, Department of Environmental Chemistry, University of Maria Skłodowska-Curie, pl. M. Curie-Skłodowskiej 3, 20-031 Lublin, Poland, tel. +48 81 5375515, fax +48 81 5375565; e-mail:
Journal: Environmental Science and Pollution Research
Number of pages:8 (including this page)
Number of figures:1
Number of tables: 3
2. Materials and methods
2.4. Sorption experiments
The GC-MS was equipped with a single quadrupole and used under the selected ion monitoring mode. A Rxi®-5ms crossbond® 5 % diphenyl and 95 % dimethyl polysiloxane fused capillary column (30 m x 0.25 mm ID x 0.25 μm film thickness) from Restek (USA) was used with helium as the carrier gas at a constant flow rate of 1 mL min-1. The GC oven temperature was programmed to ramp from 50 oC (hold time – 2 min) to 100 oC at 20 oC min-1, then to 200 oC at 5 oC min-1, then to 300 oC at 20 oC min-1 and to held for 12 min at this temperature. The injector and detector temperatures were 280 oC and 300 oC, respectively. Mass spectra were acquired at the electron ionization mode, while selected ion monitoring (SIM) mode was carried out using the molecular ions selective for individual PAHs.
The concentration of PHE/PYR on POM passive samplers was calculated according to the equation (S1):
(S1)
where mPHE/PYR is the mass of PAH determined via GC/MS and m2POM is the mass of two, used POM passive samplers.
The concentration of the initial PHE or PYR in soils or biochar-amended soils was taken into account by subtracting the CPOM-control for control from CPOM for soils or biochar-amended soils.
The concentration of PHE or PYR in waterafter 21 days of mixing was calculated on the basis of equation (S2):
(S2)
where KPOM-w is the sorbate POM-water partitioning coefficient (log KPOM-w of 4.20 L kg-1 for PHE and 4.55 L kg-1 for PYR) obtained from Hawthorne et al. (Hawthorne et al., 2011).
The concentration of PHE or PYR on soils or biochar-amended soils was calculated on the basis of equation (S3):
(S3)
where CPHE/PYR is the initial concentration of PHE or PYR in the water solution of sodium azide, Vr is the volume of extractant (here acetone plus heptane, 0.02 L), msorbent is the mass of sorbent used for the experiment (here 0.00019 kg of soil or 0.00020 kg of biochar-amended soil).
2.5. Data analysis
Four different models were applied to fit the adsorption data:
Freundlich: (S4)
Langmuir: (S5)
Temkin: (S6)
Dubinin-Radushkevich: (S7)
where CS(μg kg-1)is the solid-phase concentration, CW(μg L-1)is the equilibrium solution-phase concentration,KF ((μg kg-1) (μg L-1)-n)is the Freundlich constant or capacity factor, n (dimensionless) is the Freundlich exponent, KL(μg kg-1) is the maximum monolayer sorption capacity, KL(Lμg-1) is the adsorption equilibrium constant corresponding to the inverse of the concentration that produces half maximal adsorption capacity, R(8.314 J mol-1 K-1) is the universal gasconstant,T (K) is the absolutetemperature (here 298 K), b (J mol-1) is the heat of adsorption, A (L μg-1) is the binding constant, QD(μg kg-1)is themicropores adsorption capacityand E (J mol-1) is the bonding energy for the ion-exchange mechanism.
To assess the extent to which a compound is associated with solid phase in a given system at equilibrium, we need to know the ratio of the compound total equilibrium concentration in the solid and in the aqueous solution. We denote this solid-water distribution coefficient as:
(S8)
When dealing with nonlinear isotherms the value of this ratio may apply only at the given solute concentration (here at SW and at CW = 0.01 Sw and at CW = 0.1 SW, where SW is aqueous solubility of PHE (1150.0 µg L-1) or PYR (135.0 µg L-1)).
In the case of used here Freundlich model, where CS can be obtained on the basis of equation (S9):
(S9) the solid-water distribution coefficient Kd takes the following form:
(S10)
Assuming that sorption of biochar-amended soil was the combination of the independent sorption by soil and biochar, the predicted total sorption of biochar-amended soil at a given equilibrium concentration (CW) was estimated on the basis of equation (S9) taking into account the mass fractions of soil (fsoil) and biochar (fbiochar) as follows:
(S11)
3. Results and discussion
Fig. S1. Freundlich linearized adsorption isotherms of phenanthrene (PHE)and pyrene (PYR) by biochars BC500 and BC700(A)and soils SL-BIT and SL-COK (B). Lines represent the model predicted data fittings.
Table S1
Linear parameters of Langmuir, Temkin and Dubinin-Radushkevich isotherms for phenanthrene (PHE) and pyrene (PYR) adsorption onto biochars BC500 and BC700, soils SL-COK and SL-BIT and biochar-amended soils.
Adsorbent / Langmuir / Temkin / Dubinin-RadushkevichQLa / KLb / Radj.2c / bd / Ae / Radj.2c / QDf / Eg / Radj.2c
Phenanthrene (PHE)
SL-COK / 34972.90 / 0.49 / 0.980 / 0.16 / 3.99 / 0.874 / 30872.76 / 1416.42 / 0.711
SL-COK + 5 % BC500 / 41469.95 / 0.47 / 0.992 / 0.17 / 4.99 / 0.884 / 32148.83 / 1489.91 / 0.768
SL-COK + 5 % BC700 / 35826.26 / 0.73 / 0.986 / 0.18 / 6.60 / 0.879 / 33077.06 / 1657.72 / 0.782
SL-BIT / 44785.74 / 0.17 / 0.984 / 0.14 / 1.75 / 0.835 / 27252.26 / 1013.87 / 0.630
SL-BIT + 5 % BC500 / 33516.31 / 0.29 / 0.976 / 0.15 / 2.21 / 0.816 / 25846.96 / 1169.77 / 0.627
SL-BIT + 5 % BC700 / 19787.93 / 0.75 / 0.968 / 0.16 / 3.08 / 0.840 / 15700.73 / 1571.32 / 0.697
BC500 / 938253.53 / 0.42 / 0.982 / 0.18 / 12.83 / 0.872 / 368425.77 / 1939.53 / 0.883
BC700 / 268239.62 / 8.71 / 0.996 / 0.22 / 64.71 / 0.797 / 393450.41 / 3017.71 / 0.889
Pyrene (PYR)
SL-COK / 49136.34 / 0.62 / 0.993 / 0.15 / 7.50 / 0.882 / 36215.59 / 1736.01 / 0.801
SL-COK + 5 % BC500 / 36944.35 / 1.12 / 0.989 / 0.16 / 10.23 / 0.859 / 35067.33 / 1939.34 / 0.810
SL-COK + 5 % BC700 / 56302.01 / 0.72 / 0.998 / 0.16 / 11.01 / 0.860 / 37806.62 / 1919.76 / 0.852
SL-BIT / 57528.13 / 0.20 / 0.997 / 0.15 / 2.92 / 0.863 / 31063.23 / 1195.65 / 0.726
SL-BIT + 5 % BC500 / 27656.66 / 0.70 / 0.966 / 0.17 / 4.33 / 0.833 / 27841.85 / 1525.02 / 0.680
SL-BIT + 5 % BC700 / 22282.85 / 1.14 / 0.949 / 0.18 / 5.15 / 0.819 / 26912.55 / 1694.12 / 0.659
BC500 / -5394063.29 / -0.07 / 0.987 / 0.01 / 12.02 / 0.839 / 412429.76 / 1864.86 / 0.858
BC700 / 168295.20 / 8.48 / 0.916 / 0.02 / 30.01 / 0.658 / 297385.64 / 2756.06 / 0.705
aThe maximum monolayer sorption capacity(μg kg-1); bThe adsorption equilibrium constant corresponding to the inverse of the concentration that produces half maximal adsorption capacity (L μg-1); cThe adjusted coefficient of determination: Radj.2 = 1 – [(1 – R2) (m – 1) (m – b – 1)-1], where m is the number of data points used for fitting and b the number of coefficients in the fitting equation; dThe heat of adsorption (J mol-1); eThe binding constant(L μg-1), fThe micropores adsorption capacity (μg kg-1); gBonding energy for the ion-exchange mechanism (J mol-1).
Table S2
Linear parameters of Langmuir, Temkin and Dubinin-Radushkevich isotherms for phenanthrene (PHE) and pyrene (PYR) adsorption onto soils SL-COK and SL-BIT and biochar-amended soilsafter two months of aging.
Adsorbent / Langmuir / Temkin / Dubinin-RadushkevichQLa / KLb / Radj.2c / bd / Ae / Radj.2c / QDf / Eg / Radj.2c
Phenanthrene (PHE)
SL-COK / 143160.36 / 0.20 / 0.999 / 0.13 / 8.20 / 0.816 / 40061.12 / 1728.33 / 0.835
SL-COK + 5 % BC500 / 128161.32 / 0.25 / 0.998 / 0.14 / 9.46 / 0.816 / 39314.50 / 1803.34 / 0.849
SL-COK + 5 % BC700 / 245988.45 / 0.13 / 0.998 / 0.14 / 9.70 / 0.819 / 40748.45 / 1795.45 / 0.862
SL-BIT / -399159.56 / -0.03 / 0.995 / 0.13 / 3.20 / 0.791 / 33533.38 / 1233.66 / 0.742
SL-BIT + 5 % BC500 / -493414.57 / -0.03 / 1.000 / 0.12 / 4.17 / 0.772 / 25846.96 / 1169.77 / 0.627
SL-BIT + 5 % BC700 / 68580.77 / 0.37 / 0.994 / 0.14 / 7.07 / 0.781 / 34315.45 / 1697.38 / 0.792
Pyrene (PYR)
SL-COK / 41172.07 / 1.86 / 0.991 / 0.16 / 17.08 / 0.864 / 41720.56 / 2233.34 / 0.858
SL-COK + 5 % BC500 / 48689.15 / 1.54 / 0.995 / 0.16 / 18.47 / 0.867 / 42067.35 / 2242.31 / 0.879
SL-COK + 5 % BC700 / 40648.21 / 2.07 / 0.990 / 0.16 / 19.77 / 0.852 / 41440.07 / 1919.76 / 0.867
SL-BIT / 479904.52 / 0.05 / 0.995 / 0.12 / 6.24 / 0.798 / 39339.75 / 1556.98 / 0.815
SL-BIT + 5 % BC500 / 117812.01 / 0.23 / 0.995 / 0.13 / 7.89 / 0.792 / 37658.03 / 1708.14 / 0.821
SL-BIT + 5 % BC700 / 56858.12 / 0.70 / 0.994 / 0.14 / 10.88 / 0.780 / 37512.80 / 2309.18 / 0.826
aThe maximum monolayer sorption capacity(μg kg-1); bThe adsorption equilibrium constant corresponding to the inverse of the concentration that produces half maximal adsorption capacity (L μg-1); cThe adjusted coefficient of determination: Radj.2 = 1 – [(1 – R2) (m – 1) (m – b – 1)-1], where m is the number of data points used for fitting and b the number of coefficients in the fitting equation; dThe heat of adsorption (J mol-1); eThe binding constant (L μg-1), fThe micropores adsorption capacity (μg kg-1); gBonding energy for the ion-exchange mechanism (J mol-1).
Table S3
Concentration of individual freely dissolved PAHs (in accordance with a retention time) in biochars(BC500 and BC700) and soils (SL-COK and SL-BIT) with standard deviation.
PAH / Cfree (ng L-1)BC500 / BC700 / SL-COK / SL-BIT
NAP / 25.28±1.11 / 17.45 ±0.32 / 517.41 ± 14.04 / 79.94 ± 6.01
ACY / 1.31 ±0.06 / 1.08 ±0.02 / 5.61 ± 0.35 / 0.87 ± 0.06
ACE / 46.36± 2.50 / 41.20 ±1.41 / 24.22 ± 1.56 / 10.33 ± 0.61
FLO / 28.81 ±1.80 / 26.33±0.61 / 4.65 ± 0.24 / 9.31 ± 0.73
PHE / 3.76 ±0.12 / 3.06 ± 0.05 / 19.02 ± 1.65 / 18.88 ± 0.98
ANT / 10.08 ±0.52 / 9.08 ±0.22 / 2.05 ± 017 / 1.35 ± 0.08
FLA / 4.96 ± 0.06 / 4.48 ± 0.09 / 9.45 ± 0.75 / 7.63 ± 0.35
PYR / 4.41 ± 0.13 / 3.98 ± 0.12 / 4.72 ± 0.24 / 5.63 ± 0.34
BaA / 0.73 ± 0.03 / 0.66 ±0.02 / 0.11 ± 0.01 / 0.25 ± 0.02
CHR / 0.71 ±0.05 / ND / 0.26 ± 0.02 / 0.57 ± 0.03
BbF / ND / ND / 0.02 ± 0.001 / 0.11 ± 0.01
BkF / ND / ND / 0.01 ± 0.001 / 0.07 ± 0.003
BaP / ND / ND / ND / 0.08 ± 0.01
IcdP / ND / ND / ND / 0.02 ± 0.01
DahA / ND / ND / ND / ND
BghiP / ND / ND / ND / 0.09 ± 0.003
Σ16 PAHs / 126.46 ± 5.93 / 107.40 ± 2.80 / 587.52 ± 18.00 / 135.15 ± 8.72
Values are mean of two repetitions. NAP - naphthalene; ACY - acenaphthylene; ACE – acenaphthene; FLO - fluorene; PHE – phenanthrene; ANT – anthracene; FLA – fluoranthene; PYR – pyrene; BaA - benzo(a)anthracene;CHR – chrysene; BbF - benzo(b)fluoranthene; BkF - benzo(k)fluoranthene; BaP- benzo(a)pyrene; IcdP- indeno(1,2,3-cd)pyrene; DahA – dibenz(a,h)anthracene; BghiP – benzo(ghi)perylene; ND – not detected.
References
Hawthorne, S.B., Jonker, M.T.O., van der Heijden, S.A., Grabanski, C.B., Azzolina, N.A., Miller, D.J., 2011. Measuring Picogram per Liter Concentrations of Freely Dissolved Parent and Alkyl PAHs (PAH-34), Using Passive Sampling with Polyoxymethylene. Anal. Chem. 83, 6754–6761. doi:10.1021/ac201411v