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Food contamination is a major worldwide risk for human health. Dynamic plant uptake of pollutants from contaminated environments is the preferred pathway into the human and animal food chain. Mechanistic models represent a fundamental tool for risk assessment and the development of mitigation strategies. However, difficulty in obtaining comprehensive observations in the soil-plant continuum hinders their calibration, undermining their generalizability and raising doubts about their widespread applicability. To address these issues, a Bayesian probabilistic framework is used, for the first time, to calibrate and assess the predictive uncertainty of a mechanistic soil-plant model against comprehensive observations from an experiment on the translocation of carbamazepine in green pea plants. Results demonstrate that the model can reproduce the dynamics of water flow and solute reactive transport in the soil-plant domain accurately and with limited uncertainty. The role of different physicochemical processes in bioaccumulation of carbamazepine in fruits is investigated through Global Sensitivity Analysis, which shows how soil hydraulic properties and soil solute sorption regulate transpiration streams and bioavailability of carbamazepine. Overall, the analysis demonstrates the usefulness of mechanistic models and proposes a comprehensive numerical framework for their assessment and use.

An application of different mulch materials may lead to changes in soil properties. Our previous study, focused on the impact of various mulches during the 4-year period, showed that the change in some properties can be very rapid (e.g., soil pH), but in other cases such as hydraulic properties, the changes can be gradual. To find out, whether the extension of the mulching period will further affect the studied soil properties, the experiment continued for another 2 years. Differences between values of organic carbon content (Cox), soil physical quality (Sinf), gravitational water (GW) and readily available water (RAW) of soils not covered by any mulch and under various mulches (bark chips; wood chips; wheat straw; Agrotex EKO+ decomposable matting; polypropylene fabric covered bark chips; crushed stone) were much larger than those observed in our previous study. On the other hand, the opposite trend was observed for the water stable aggregates (WSA) index or soil pH. Differences between additionally measured hydraulic conductivities at the pressure head of −2 cm and repellency index (RI) were mostly insignificant. Results indicated that organic mulches can either positively (e.g., increase WSA index and Cox, and decrease GW) or negatively (e.g., decrease Sinf and RAW, and increase RI) affect soil properties.

The goal of this study was to evaluate the effect of products from a municipal wastewater treatment plant on the H2O and CO2 effluxes from two soils. The net H2O and CO2 effluxes were measured at the surface of nine beds with two different soils (Cambisol and Arenosol) and two crops (maize or vegetables). Soils in some beds were amended with stabilized sewage sludge (bed with Cambisol and maize) or composted sewage sludge (two beds with Cambisol and both crops) or were irrigated with treated wastewater (two beds with Cambisol and both crops, and one bed with Arenosol and vegetable). Remaining beds were irrigated with tap water (two beds with Cambisol and both crops, and one bed with Arenosol and vegetable). While stabilized and composted sewage sludge positively affected the CO2 emission, the effect of treated wastewater was not confirmed. Different treatments had negligible effect on the water efflux, which was mainly affected by the plant canopy that influence the temperature of the soil surface. Statistical analyses showed that trends of the CO2 efflux with respect to various scenarios measured on different days changed during the season. No significant correlations were found between the average H2O and CO2 effluxes and measured soil properties.

Soil hydraulic conductivities of topsoils were studied at 5 points of the hillslope transects delineated at 4 geomorphologically diverse areas, where the original soil types (Chernozem, Luvisol and two Cambisols) were due to erosion transformed into different soil unites. Hydraulic conductivities of saturated soils and for a pressure head of –2 cm were measured directly in the field using a Guelph permeameter (Ks,GP) and mini disk tension infiltrometer (Kh=–2,MDI), and in the laboratory using a multistep outflow method (Ks,MSO, Kh= –2,MSO). While Ks,GP ≈ Ks,MSO in the Chernozem and Cambisol (sandy loam) regions, and Ks,GP < Ks,MSO in the Luvisol and Cambisol (loam) regions. The Ks values obtained using different methods showed different trends along the hillslope transects. The Kh= –2 values obtained using different methods showed similar trends along the transects in the Chernozem and Luvisol regions. These trends could be explained by the position within the transects (i.e., different stages of erosion/accumulation processes). No relationships were found between the Kh=–2 values in the Cambisol regions. The pressure head at an inflection point of the a soil-water retention curve was the main parameter, which appeared to associate (negative correlation) with Kh=–2 and Ks,MSO in the Chernozem and Luvisol regions.

The aim of the study was to describe the impact of the soil water content and sulfamethoxazole, SUL, (antibiotic) concentration in soil on the net CO2 efflux. Soil samples were taken from topsoils of a Haplic Fluvisol and Haplic Chernozem. Soil samples were packed into the steel cylinders. The net CO2 efflux was measured from these soil columns after application of fresh water or SUL solution at different soil water contents. The experiments were carried out in dark at 20°C. The trends in the net CO2 efflux varied for different treatments. While initially high values for water treatment exponentially decreased in time, values for solution treatment increased during the first 250–650 minutes and then decreased. The total net CO2 effluxes measured for 20 hours related to the soil water content followed the second order polynomial functions. The maximal values were measured for the soil water content of 0.15 cm3 cm−3 (Haplic Fluvisol with water or solution, Haplic Chernozem with solution) and 0.11 cm3 cm−3 (Haplic Chernozem with water). The ratios between values measured for solution and water at the same soil water contents exponentially increased with increasing SUL concentration in soils. This proved the increasing stimulative influence of SUL on soil microbial activity.

Treated water from wastewater treatment plants that is increasingly used for irrigation may contain pharmaceuticals and, thus, contaminate soils. Therefore, this study focused on the impact of soil conditions on the root uptake of selected pharmaceuticals and their transformation in a chosen soil–plant system. Green pea plants were planted in 3 soils. Plants were initially irrigated with tap water. Next, they were irrigated for 20 days with a solution of either atenolol (ATE), sulfamethoxazole (SUL), carbamazepine (CAR), or all of these three compounds. The concentrations of pharmaceuticals and their metabolites [atenolol acid (AAC), N1-acetyl sulfamethoxazole (N1AS), N4-acetyl sulfamethoxazole (N4AS), carbamazepine 10,11-epoxide (EPC), 10,11-dihydrocarbamazepine (DHC), trans-10,11-dihydro-10,11-dihydroxy carbamazepine (RTC), and oxcarbazepine (OXC)] in soils and plant tissues were evaluated after harvest. The study confirmed high (CAR), moderate (ATE, AAC, SUL), and minor (N4AC) root uptake of the studied compounds by the green pea plants, nonrestricted transfer of the CAR species into the different plant tissues, and a very high efficiency in metabolizing CAR in the stems and leaves. The results showed neither a synergic nor competitive influence of the application of all compounds in the solution on their uptake by plants. The statistical analysis proved the negative relationships between the CAR sorption coefficients and the concentrations of CAR, EPC, and OXC in the roots (R = –0.916, –0.932, and –0.925, respectively) and stems (R = –0.837, –0.844, and –0.847, respectively).

The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM) composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i) coated, (ii) not coated (both intact), and (iii) aggregates from which coatings were removed (cut). The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT). A potential wettability index (PWI) was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT) and contact angles (CA) during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t) = at−b). For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75). The a parameter was significantly related to the WDPT (R2 = 0.84) and to the PWI (R2 = 0.64). The relations between the b parameter and the WDPT (R2 = 0.61) and the PWI (R2 = 0.53) were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64). In contrast to dry samples, no significant relationships were found between parameters a or b of CA(t) and WDPT or PWI for wet aggregate surfaces. The results suggest that the effect of the SOM composition of coatings on surface wettability decreases with increasing soil moisture. In addition to the dominant impact of SOM, the wettability of aggregate surfaces could be affected by different mineralogical compositions of clay in coatings and interiors of aggregates. Particularly, wettability of coatings could be decreased by illite which was the dominant clay type in coatings. However, the influence of different clay mineral fractions on surface wettability was not due to small number of measurements (2 and 1 samples from coatings and interiors, respectively) quantified.

Knowledge of the distribution of plant roots in a soil profile (i.e. root density) is needed when simulating root water uptake from soil. Therefore, this study focused on evaluating barley and wheat root densities in a sand-vermiculite substrate. Barley and wheat were planted in a flat laboratory box under greenhouse conditions. The box was always divided into two parts, where a single plant row and rows cross section (respectively) was simulated. Roots were excavated at the end of the experiment and root densities were assessed using root zone image processing and by weighing. For this purpose, the entire area (width of 40 and height of 50 cm) of each scenario was divided into 80 segments (area of 5×5 cm). Root density in each segment was expressed as a root percentage of the entire root cluster. Vertical root distributions (i.e. root density with respect to depth) were also calculated as a sum of root densities in each 5 cm layer. Resulting vertical root densities, measured evaporation from the water table (used as the potential root water uptake), and the Feddes stress response function model were used for simulating substrate water regime and actual root water uptake for all scenarios using HYDRUS-1D. All scenarios were also simulated using HYDRUS-2D. One scenario (areal root density of barley sown in a single row, obtained using image analysis) is presented in this paper (because most scenarios showed root water uptakes similar to results of 1D scenarios).

The aim of the study was to describe the impact of the soil water content and sulfamethoxazole, SUL, (antibiotic) concentration in soil on the net CO2 efflux. Soil samples were taken from topsoils of a Haplic Fluvisol and Haplic Chernozem. Soil samples were packed into the steel cylinders. The net CO2 efflux was measured from these soil columns after application of fresh water or SUL solution at different soil water contents. The experiments were carried out in dark at 20°C. The trends in the net CO2 efflux varied for different treatments. While initially high values for water treatment exponentially decreased in time, values for solution treatment increased during the first 250–650 minutes and then decreased. The total net CO2 effluxes measured for 20 hours related to the soil water content followed the second order polynomial functions. The maximal values were measured for the soil water content of 0.15 cm3 cm−3 (Haplic Fluvisol with water or solution, Haplic Chernozem with solution) and 0.11 cm3 cm−3 (Haplic Chernozem with water). The ratios between values measured for solution and water at the same soil water contents exponentially increased with increasing SUL concentration in soils. This proved the increasing stimulative influence of SUL on soil microbial activity. [ABSTRACT FROM AUTHOR]

Abstract: This study focused on the effects of organic carbon contents and soil hydraulic conditions on CO2 efflux. Samples were collected at 5 positions (summit, shoulder, backslope, footslope, and toeslope) of the elevation transect affected by erosion and the parent material (loess). Initially, air‐dried soil samples were placed on top of a clay tank, and the samples were wetted by capillary rise to soil saturation, and soil CO2 efflux was measured. Numerical inversions of the measured cumulative capillary rise and evaporation data using the HYDRUS‐1D program were applied to simulate the water regime in the columns and estimate the soil hydraulic parameters. In all cases, the net CO2 efflux (NCER) rapidly increased at the beginning of the wetting. NCER decreased with increasing soil–water content (summit, shoulder, backslope, and loess) or remained relatively stable (footslope and toeslope). The average soil–water content values at the maximal values of NCER (maxNCER) for the summit, shoulder, and footslope were similar. Lower average soil–water contents at maxNCER were simulated for the backslope, toeslope, and loess, which were attributed to the high contents of loess substrate in topsoil samples. The maxNCER measured on topsoils were closely related to the organic carbon contents (R = 0.94) and the maxNCER obtained on all samples correlated with the parameters αRES (R = 0.856) and nRES (R = −0.876) of the soil–water retention curves and saturated hydraulic conductivity (R = 0.856). [ABSTRACT FROM AUTHOR]

The leakage of pharmaceuticals present in soils towards groundwater is largely controlled by sorption of those compounds in soils. In some soils, soil aggregates are covered by coatings, which may have considerably different composition in comparison to that in an inner part of the aggregates. The aim of this study was to evaluate the sorption of three pharmaceuticals, which were applied in single or all compounds solutions, onto soil samples taken from the Bt horizon of a Haplic Luvisol. Analyses were performed on three types of disturbed soil samples: (1) entire aggregates, (2) aggregates from which coatings were removed, and (3) clay-organic coatings. Sorption of atenolol onto material from coatings was slightly higher than that onto material from the inner parts of the aggregates. On the other hand, sorption of sulfamethoxazole onto material from the coatings was lower than that from the aggregate interior. Both associates with a dominant fraction of clay particles (that are mostly negatively charged) in the coatings in comparison to soil composition in interiors and thus larger cation exchange capacity, which increased sorption of the positively charged atenolol and decreased sorption of the negatively charged sulfamethoxazole. Sorption of carbamazepine, which was in neutral form, did not substantially differ. The sorption of all three compounds did not decrease due to the competition between these compounds for the same sorption sites when applied simultaneously. Atenolol sorption was similar for both applications. Sorption of sulfamethoxazole increased when applied in solution with the other two compounds in comparison to its negligible sorption measured for the single compound solution likely due to sorption of the positively charged molecules of atenolol onto the negatively charged surface of soil components and reduction of repulsion between the soil components and the negatively charged molecules of sulfamethoxazole. Carbamazepine sorption also increased probably due to ionization of molecules due to dipole - induced dipole interaction between non-polar and polar molecules in solution. [ABSTRACT FROM AUTHOR]

Twelve different soil types that represent the soil compartments of the Czech Republic were fortified with three antibiotics (clindamycin (CLI), sulfamethoxazole (SUL), and trimethoprim (TRI)) to investigate their fate. Five metabolites (clindamycin sulfoxide (CSO), hydroxy clindamycin sulfoxide (HCSO), S -(SDC) and N -demethyl clindamycin (NDC), N 4 -acetyl sulfamethoxazole (N 4 AS), and hydroxy trimethoprim (HTR)) were detected and identified using HPLC/HRMS and HRPS in the soil matrix in this study. The identities of CSO and N 4 AS were confirmed using commercially available reference standards. The parent compounds degraded in all soils. Almost all of the metabolites have been shown to be persistent in soils, with the exception of N 4 AS, which was formed and degraded completely within 23 days of exposure. The rate of degradation mainly depended on the soil properties. The PCA results showed a high dependence between the soil type and behaviour of the pharmaceutical metabolites. The mentioned metabolites can be formed in soils, and the most persistent ones may be transported to the ground water and environmental water bodies. Because no information on the effects of those metabolites on living organism are available, more studies should be performed in the future to predict the risk to the environment. [ABSTRACT FROM AUTHOR]

Soils may be contaminated by human or veterinary pharmaceuticals. Their behaviour in soil environment is largely controlled by sorption of different compounds in a soil solution onto soil constituents. Here we studied the sorption affinities of 4 pharmaceuticals (atenolol, trimethoprim, carbamazepine and sulfamethoxazole) applied in solute mixtures to soils taken from different horizons of 3 soil types (Greyic Phaeozem on loess, Haplic Luvisol on loess and Haplic Cambisol on gneiss). In the case of the carbamazepine (neutral form) and sulfamethoxazole (partly negatively charged and neutral), sorption affinity of compounds decreased with soil depth, i.e. decreased with soil organic matter content. On the other hand, in the case of atenolol (positively charged) and trimethoprim (partly positively charged and neutral) compound sorption affinity was not depth dependent. Compound sorption affinities in the four-solute systems were compared with those experimentally assessed in topsoils, and were estimated using the pedotransfer rules proposed in our previous study for single-solute systems. While sorption affinities of trimethoprim and carbamazepine in topsoils decreased slightly, sorption affinity of sulfamethoxazole increased. Decreases in sorption of the two compounds could be attributed to their competition between each other and competition with atenolol. Differences between carbamazepine and atenolol behaviour in the one- and four-solute systems could also be explained by the slightly different soil properties in this and our previous study. A great increase of sulfamethoxazole sorption in the Greyic Phaeozem and Haplic Luvisol was observed, which was attributed to elimination of repulsion between negatively charged molecules and particle surfaces due to cation sorption (atenolol and trimethoprim) on soil particles. Thus, our results proved not only an antagonistic but also a synergic affect of differently charged organic molecules on their sorption to soil constituents. [ABSTRACT FROM AUTHOR]

This study focused on developing a method for estimating topsoil organic carbon content from measured massspecific magnetic susceptibility in Chernozems heavily affected by water erosion. The study was performed on a 100 ha area, whereby 202 soil samples were taken. A set of soil samples was divided into 3 subsets: A (32 samples), B (67 samples), and C (103 samples). The mass-specific magnetic susceptibility using low (χlf) and high (χhf) frequency, and organic carbon content were measured at all soil samples. The contents of iron and manganese, extracted with a dithionite-citrate solution (Fed, Mnd) and ammonium oxalate (Feo, Mno), were quantified in A and B samples. Models for predicting organic carbon content from magnetic susceptibilities were designed as follows: (1) subset A was used as the training set for calibration, and subsets B and C were used as the test sets for model validation, either separately (subset B only), or together (merged subsets B and C); (2) merged subsets A and B were used as the training set and subset C was used as the test set. Results showed very close correlations between organic carbon content and all measured soil properties. Obtained models relating organic carbon content to mass-specific magnetic susceptibility successfully predicted soil organic carbon contents. [ABSTRACT FROM AUTHOR]

Summary: Soil aggregates are in some soils and their horizons covered by organomineral coatings, which may significantly influence water and solute transfer into the aggregates. Knowledge of a coating occurrence, their structure and hydraulic properties is required for a more precise description of water flow and contaminant transport in soils. The aim of this study was to describe hydraulic properties of clay and organic matter coatings in the iluvial (Bt2) horizon of Haplic Luvisol. Sets of 30 unsorted aggregates, 24 aggregates with mostly clay coatings and 24 aggregates with clay-organic coatings, respectively, were studied to evaluate an impact of various coating composition. The coatings were removed from a half of the aggregates of each set. First, the wetting soil–water retention curve was measured on all soil aggregates. Then the capillary rise from the saturation pan into the multiple aggregates (set of 14 or 15 aggregates) without and with coatings was measured. Numerical inversion of the measured cumulative capillary rise data using the HYDRUS-1D program were applied to estimate the saturated hydraulic conductivities of the aggregates, Ks,aggr , and their coatings, Ks,coat . Results were compared with saturated hydraulic conductivities evaluated analytically using the sorptivity method, which was proposed previously. Data of the soil–water retention curves, measured on aggregates with and without coatings, did not allow distinguishing between retention curve parameters of the soil aggregates and their coatings. Therefore the same parameters were evaluated for both. Capillary rise into the soil aggregates without coatings was always faster than into the aggregates with coatings. As result the optimized saturated hydraulic conductivities, Ks,coat , of the clay and the organic matter coatings (the average values for unsorted, mostly clay and clay-organic coatings were 3.69×10−7, 2.76×10−7 and 1.81×10−7 cmmin−1, respectively) were one to two order of magnitude lower than the saturated hydraulic conductivities, Ks,aggr , of the aggregates (the average values for corresponding aggregates were 3.87×10−6, 6.52×10−6 and 1.11×10−5 cmmin−1, respectively). Slightly variable Ks,aggr (or Ks,coat ) values were obtained for different bottom pressure heads, and the lower Ks,aggr (or Ks,coat ) values were estimated from the second run of the tests compare to the first run of tests for each set of aggregates. No statistically significant differences between Ks,coat values obtained for coatings of various compositions were found. Resulting Ks,aggr values were in the range of the values obtained analytically. [Copyright &y& Elsevier]

The aim of this study was to examine in greenhouse experiments seed emergence of 14 lucerne varieties (mostly of the Czech origin) under different soil conditions (Luvisol, Chernozem and Cambisol). Soil conditions significantly influenced seed emergence in seven varieties. Their seed emergence was lower in Cambisol (72%) than in Chernozem (80%) and Luvisol (91%). In other varieties the soil effect was not significant. The effect of variety could not be separated from the effect of seed lot in our experiment. However, germination, occurrence of hard seeds, germinative energy and thousand-seed weight were not significantly different between the groups of varieties that could be classified as sensitive and tolerant to the examined soil conditions. The obtained results indicated that the selection of suitable lucerne variety or seed lot could be a tool for improving emergence in deteriorated soil conditions. [ABSTRACT FROM AUTHOR]

The sorption of 3 pharmaceuticals, which may exist in 4 different forms depending on the solution pH (irbesartan in cationic, neutral and anionic, fexofenadine in cationic, zwitter-ionic and anionic, and citalopram cationic and neutral), in seven different soils was studied. The measured sorption isotherms were described by Freundlich equations, and the sorption coefficients, K F (for the fixed n exponent for each compound), were related to the soil properties to derive relationships for estimating the sorption coefficients from the soil properties (i.e., pedotransfer rules). The largest sorption was obtained for citalopram (average K F value for n  = 1 was 1838 cm 3  g −1 ) followed by fexofenadine ( K F  = 35.1 cm 3/n μg 1−1/n g −1 , n  = 1.19) and irbesartan ( K F  = 3.96 cm 3/n μg 1−1/n g −1 , n  = 1.10). The behavior of citalopram (CIT) in soils was different than the behaviors of irbesartan (IRB) and fexofenadine (FEX). Different trends were documented according to the correlation coefficients between the K F values for different compounds (R IRB,FEX  = 0.895, p-value<0.01; R IRB,CIT  = −0.835, p-value<0.05; R FEX,CIT  = −0.759, p-value<0.05) and by the reverse relationships between the K F values and soil properties in the pedotransfer functions. While the K F value for citalopram was positively related to base cation saturation (BCS) or sorption complex saturation (SCS) and negatively correlated to the organic carbon content (Cox), the K F values of irbesartan and fexofenadine were negatively related to BCS, SCS or the clay content and positively related to Cox. The best estimates were obtained by combining BCS and Cox for citalopram (R 2  = 93.4), SCS and Cox for irbesartan (R 2  = 96.3), and clay content and Cox for fexofenadine (R 2  = 82.9). [ABSTRACT FROM AUTHOR]

The presence of human and veterinary pharmaceuticals in the environment is recognized as a potential threat. Pharmaceuticals have the potential to contaminate soils and consequently surface and groundwater. Knowledge of contaminant behavior (e.g., sorption onto soil particles and degradation) is essential when assessing contaminant migration in the soil and groundwater environment. We evaluated the dissipation half-lives of 7 pharmaceuticals in 13 soils. The data were evaluated relative to the soil properties and the Freundlich sorption coefficients reported in our previous study. Of the tested pharmaceuticals, carbamazepine had the greatest persistence (which was mostly stable), followed by clarithromycin, trimethoprim, metoprolol, clindamycin, sulfamethoxazole and atenolol. Pharmaceutical persistence in soils was mostly dependent on the soil-type conditions. In general, lower average dissipation half-lives and variability (i.e., trimethoprim, sulfamethoxazole, clindamycin, metoprolol and atenolol) were found in soils of better quality (well-developed structure, high nutrition content etc.), and thus, probably better microbial conditions (i.e., Chernozems), than in lower quality soil (Cambisols). The impact of the compound sorption affinity onto soil particles on their dissipation rate was mostly negligible. Although there was a positive correlation between compound dissipation half-life and Freundlich sorption coefficient for clindamycin (R = 0.604, p < 0.05) and sulfamethoxazole (R = 0.822, p < 0.01), the half-life of sulfamethoxazole also decreased under better soil-type conditions. Based on the calculated dissipation and sorption data, carbamazepine would be expected to have the greatest potential to migrate in the soil water environment, followed by sulfamethoxazole, trimethoprim and metoprolol. The transport of clindamycin, clarithromycin and atenolol through the vadose zone seems less probable. [ABSTRACT FROM AUTHOR]

Transport of human and veterinary pharmaceuticals in soils and consequent ground-water contamination are influenced by many factors, including compound sorption on soil particles. Here we evaluate the sorption isotherms for 7 pharmaceuticals on 13 soils, described by Freundlich equations, and assess the impact of soil properties on various pharmaceuticals' sorption on soils. Sorption of ionizable pharmaceuticals was, in many cases, highly affected by soil pH. The sorption coefficient of sulfamethoxazole was negatively correlated to soil pH, and thus positively related to hydrolytic acidity and exchangeable acidity. Sorption coefficients for clindamycin and clarithromycin were positively related to soil pH and thus negatively related to hydrolytic acidity and exchangeable acidity, and positively related to base cation saturation. The sorption coefficients for the remaining pharmaceuticals (trimethoprim, metoprolol, atenolol, and carbamazepine) were also positively correlated with the base cation saturation and cation exchange capacity. Positive correlations between sorption coefficients and clay content were found for clindamycin, clarithromycin, atenolol, and metoprolol. Positive correlations between sorption coefficients and organic carbon content were obtained for trimethoprim and carbamazepine. Pedotransfer rules for predicting sorption coefficients of various pharmaceuticals included hydrolytic acidity (sulfamethoxazole), organic carbon content (trimethoprimand carbamazepine), base cation saturation (atenolol and metoprolol), exchangeable acidity and clay content (clindamycin), and soil active pH and clay content (clarithromycin). Pedotransfer rules, predicting the Freundlich sorption coefficients, could be applied for prediction of pharmaceutical mobility in soils with similar soil properties. Predicted sorption coefficients together with pharmaceutical half-lives and other imputes (e.g., soil-hydraulic, geological, hydro-geological, climatic) may be used for assessing potential ground-water contamination. [ABSTRACT FROM AUTHOR]

Pharmaceuticals may enter soils due to the application of treated wastewater or biosolids. Their leakage from soils towards the groundwater, and their uptake by plants is largely controlled by sorption and degradation of those compounds in soils. Standard laboratory batch degradation and sorption experiments were performed using soil samples obtained from the top horizons of seven different soil types and 6 pharmaceuticals (carbamazepine, irbesartan, fexofenadine, clindamycin and sulfamethoxazole), which were applied either as single-solute solutions or as mixtures (not for sorption). The highest dissipation half-lives were observed for citalopram (average DT 50,S for a single compound of 152 ± 53.5 days) followed by carbamazepine (106.0 ± 17.5 days), irbesartan (24.4 ± 3.5 days), fexofenadine (23.5 ± 20.9 days), clindamycin (10.8 ± 4.2 days) and sulfamethoxazole (9.6 ± 2.0 days). The simultaneous application of all compounds increased the half-lives (DT 50,M) of all compounds (particularly carbamazepine, citalopram, fexofenadine and irbesartan), which is likely explained by the negative impact of antibiotics (sulfamethoxazole and clindamycin) on soil microbial community. However, this trend was not consistent in all soils. In several cases, the DT 50,S values were even higher than the DT 50,M values. Principal component analyses showed that while knowledge of basic soil properties determines grouping of soils according sorption behavior, knowledge of the microbial community structure could be used to group soils according to the dissipation behavior of tested compounds in these soils. The derived multiple linear regression models for estimating dissipation half-lives (DT 50,S) for citalopram, clindamycin, fexofenadine, irbesartan and sulfamethoxazole always included at least one microbial factor (either amount of phosphorus in microbial biomass or microbial biomarkers derived from phospholipid fatty acids) that deceased half-lives (i.e., enhanced dissipations). Equations for citalopram, clindamycin, fexofenadine and sulfamethoxazole included the Freundlich sorption coefficient, which likely increased half-lives (i.e., prolonged dissipations). Unlabelled Image • Soils groups according to basic soils properties and sorption of compounds matched. • Soils groups according to microbial community structure and half-lives corresponded. • Half-lives could be predicted using one microbial criterion and sorption coefficient. • Simultaneous application of all compounds mostly reduced their dissipation in soils. • The average increase in multiple-solute half-lives varied between 7 and 39%. [ABSTRACT FROM AUTHOR]