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The sorption of organic contaminants in soils and sediment is a crucial factor affecting their mobility in the vadose zone environment. The Freundlich sorption isotherms were evaluated for eleven micropollutants and eight soils. The highest Freundlich sorption coefficients, K

This study was carried out to assess human health risk exposure, to apply a novel pollution assessment–based receptor model CF-PMF (contamination factor-positive matrix factorization), and to estimate the extent of contamination across seven cities in the Frydek-Mistek district. Nevertheless, the impact of agricultural production and industrial activities on urban soil and the livelihood of the indigenous peoples in the study area as well as the source contribution of the individual PTEs is unknown. This study collected 49 soil samples across seven towns in the Frydek-Mistek district, which are primarily agricultural and industrially oriented urbanized communities. The samples were air-dried, and the potentially toxic elemental (PTEs) (i.e., Pb, As, Cr, Ni, Mn, Cu, and Zn) concentrations measured using portable x-ray fluorescence. Nemerow Pollution index and modified contamination degree indicated that the urban contamination levels were between low and moderate contamination level with a few cases of high contamination levels. The degree of contamination and the contamination factor showed varying levels of contamination for PTEs, with a high level of contamination and a low to high level of contamination, respectively. PTEs displayed a low to high pattern of spatial distribution in urban soil around Trinec, Bystice, Hrcava, and Harirov. The source of the PTEs was detected using principal component analysis, and the source apportionment of the PTEs was further assessed using CF-PMF (contamination factor-positive matrix factorization). Comparison of the CF-PMF receptor model and the EPA-PMF receptor model revealed that the novel receptor model performed better. The root mean square error (RMSE) and the mean absolute error (MAE) of the new receptor model marginal errors reduced significantly. RMSE and MAE for the CF-PMF receptor model for all the PTEs for instance As, Cr, Cu, Mn, Ni, Pb, and Zn are 11.56, 97.85, 17.30, 527.26, 37.16, 32.12, and 68.02 (RMSE) and 11.58,95.00, 17.26, 520.85, 37.04, 32.13, and 68.03 (MAE) were lesser than the EPA.PMF receptor model respectively. Health risk computed indicated that there was no potential carcinogenic and non-carcinogenic risk being exposed to the people living within the study area. We propose using the novel receptor model CF-PMF because its output has shown to be optimal with minimal error and improved efficiency when compared to the parent model EPA-PMF. In general, continuous introduction of agro-related inputs and other anthropogenic activities surges PTEs levels in urban soils. Thus, constructive yet efficient steps, appropriate control, and mitigation measures are required to abate pollution sources that may be sowed to the soil.

The sustenance of humans and livestock depends on the protection of the soil. Consequently, the pollution of the soil with potentially toxic elements (PTEs) is of great concern to humanity. The objective of this study is to investigate the source apportionment, concentration levels and spatial distribution of PTEs in selected soils in Frýdek-Mistek District of the Czech Republic. The total number of soil samples was 70 (topsoil 49 and 21 subsoils) and was analysed using a portable XRF machine. Contamination factor and the pollution index load were used for the assessment and interpreting the pollution and distribution of PTEs in the soils. The inverse distance weighting was used for the spatial evaluation of the PTEs. The results of the analysis showed that the area is composed of low-to-high pollution site. PTEs displayed spatial variation patterns. The average PTE concentration decreases in this Fe > Ti > Ba > Zr > Rb > Sr > Cr > Y>Cu > Ni > Th order for the topsoil and also decreases in this Fe > Ti > Zr > Ba > Rb > Sr > Cr > Y > Cu > Ni > and Th order for the subsoil. These PTEs Cr, Ni, Cu, Rb, Y, Zr, Ba, Th, and Fe were far above the baseline European average value and the World average value level, respectively. The source apportionment showed the dominance of Cr, Ni, Rb, Ti, Th, Zr, Cu, Fe in the topsoil, while the subsoil was dominated by all the PTEs (factor 1 to 6) except Ba. The study concludes that indiscriminate human activities have an enormous effect on soil pollution.

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).

Various micropollutants (including pharmaceuticals, UV filters, cosmetics, cleansers, etc.), are increasingly being detected in the environment because of their partial or incomplete removal from wastewater in wastewater treatment plants (WWTPs). These compounds can be taken up by plants if treated wastewater is used for irrigation or if biosolids are used for soil amendment. Previous studies focused on this subject were usually performed under greenhouse conditions. Therefore, the aim of this study was to evaluate a behavior of studied compounds under natural climatic conditions. Experiment was carried out directly in the wastewater treatment plant, where nine raised beds were installed, which contained soils taken from topsoil of two soil types Arenosol (two beds) and Cambisol (seven beds). Either maize or a mixture of different vegetables (lettuce, carrot and onion) was grown in these beds. Of the seven beds with the Cambisol, one of the beds containing either maize or vegetables was irrigated with tap water and other pair of beds (maize or vegetables) was irrigated with treated wastewater (i.e., WWTP effluent). In another pair of beds (maize or vegetables), composted sludge from WWTP Three beds containing both types of biosolids were irrigated with tap water. Only vegetables were grown in the beds with the Arenosol, which were irrigated with either tap water or treated wastewater. Climatic data, irrigation doses, drainage water volumes, soil water contents and plant growth were monitored during the experiment. Selected compounds concentrations were measured in WWTP effluent, both biosolids, drainage water, soils, and plant tissues. Fifty five of 77 analyzed compounds were quantified in WWTP effluent. Main compounds were pharmaceuticals (e.g., telmisartan, gabapentin, diclofenac, carbamazepine, and its metabolites), UV filters (e.g., phenylbenzimidazole sulfonic acid) and compounds used in anticorrosive paints (e.g., 1H-benzotriazole). In the case of both biosolids, the dominant compounds were telmisartan, sertraline, trazodone, citalopram, diclofenac (i.e., pharmaceuticals) and 1H-benzotriazole. Uptake of different compounds by plants depended on a plant and properties of organic molecules, which affected their sorption in soils and mainly their ability to be taken up and translocated in plants. For instance, pharmaceuticals carbamazepine, gabapentin tramadol and venlafaxine were mainly found in lettuce leaves. Acknowledgement: Study was supported by the Ministry of Agriculture of the Czech Republic, project "The fate of selected micropollutants, which occur in treated water and sludge from wastewater treatment plants, in soil" (No. QK21020080) and partly also by the European Structural and Investment Funds, projects NutRisk (No. CZ.02.1.01/0.0/0.0/16_019/0000845).

This study focuses on the assessment of herbicide adsorption and degradation in three soils (Haplic Chernozem, Haplic Fluvisol, and Arenic Regozem) from different agricultural regions of the Czech Republic where sunflower is cultivated. Soil samples were used in laboratory batch adsorption and degradation experiments for six herbicides commonly used on sunflower crops. The findings are used to examine the effect of soil and herbicide properties on adsorption and degradation, as well as to determine the possible relationship between the two processes. The (Kf) sorption coefficient ranged from 1.07 to 135.37 cm3/nμg1−1/ng−1, and sorption increased in the following order: dimethenamid-p

Soils can be contaminated by pharmaceuticals. The aim of this study was to evaluate the impact of soil conditions (influencing sorption and persistence of pharmaceuticals in soils) and plant type on the root uptake of selected pharmaceuticals and their transformation in plant-soil systems. Four plants (lamb's lettuce, spinach, arugula, radish) planted in 3 soils were irrigated for 20 days (26) with water contaminated by one of 3 pharmaceuticals (carbamazepine, atenolol, sulfamethoxazole) or their mixture. The concentrations of pharmaceuticals and their metabolites in soils and plant tissues were evaluated after the harvest. Sulfamethoxazole and atenolol dissipated rapidly from soils. The larger concentrations of both compounds and an atenolol metabolite were found in roots than in leaves. Sulfamethoxazole metabolites were below the limits of quantifications. Carbamazepine was stable in soils, easily uptaken, accumulated, and metabolized in plant leaves. The efficiency of radish and arugula (both family Brassicaceae) in metabolizing was very low contrary to the high and moderate efficiencies of lamb's lettuce and spinach, respectively. Compounds' transformations mostly masked the soil impact on their accumulation in plant tissues. The negative relationships were found between the carbamazepine sorption coefficients and its concentrations in roots of radish, lamb's lettuce, and spinach.

This study focuses on the assessment of herbicide adsorption and degradation in three soils (Haplic Chernozem, Haplic Fluvisol, and Arenic Regozem) from different agricultural regions of the Czech Republic where sunflower is cultivated. Soil samples were used in laboratory batch sorption and degradation experiments for six herbicides commonly used on sunflower crops. The findings are used to examine the effect of soil and herbicide properties on adsorption and degradation, as well as to determine the possible relation between the two processes. The (Kf) sorption coefficient ranged from 1.07 to 135.37 cm3/n μg1-1/n g-1, and sorption increased in order: dimethenamid-p < pethoxamid < s-metolachlor < flurochloridone < aclonifen < pendimethalin. Sorption of all six herbicides was positively correlated with organic matter content (p < 0. 001), and cation exchange capacity (p < 0.001). pH was negatively correlated with the sorption of all six compounds (p < 0.001). Degradation rates of herbicides ranged from 0. 012 to 0. 048 day-1, which corresponding to (DT50) half-lives between 14 - 57 days respectively. The longer half-lives were always found in Haplic Fluvisol with higher organic matter content. Results showed that both adsorption and degradation of herbicides is mainly controlled by soil organic matter. A negative relationship was found between the sorption coefficient and the rate of degradation. It can be concluded that the Freundlich sorption coefficient (Kf) can be a good predictor for soil degradation of the studied herbicides.

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 DT50,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 (DT50,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 DT50,S values were even higher than the DT50,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 (DT50,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).

Pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2, 6-dinitrobenzenamine] is a herbicide used worldwide to control most annual grasses and common weeds in cereals, fruit, and vegetables. Its degradation in Haplic Chernozem under controlled greenhouse conditions was studied in this paper. The effect of recommended and doubled pendimethalin doses, as well as the effect of the biopreparate EM-EKO ProBio Plus on pendimethalin degradation in soil and on soil microorganisms was investigated. Pendimethalin half-life ranged from 24.4 to 34.4 days and the double dose did not increase the pendimethalin half-life. Thirty-eight days after pendimethalin application there was no statistical difference between the pendimethalin concentration in soil when applied at the recommended and doubled dose. No effect of pendimethalin on the amount or the activity of soil microorganisms was observed. The effect of EM-EKO ProBio Plus was apparent only on the first sampling of double-dose pendimethalin, however, this bio-preparate had no significant effect on the half-life of pendimethalin, as observed at the end of the experiment.

BACKGROUND Lettuce (Lactuca sativa L.) is a crop that is very sensitive to herbicide contamination owing to its short growing season. The use of long-residual herbicides and non-woven fabric coverings could therefore influence pendimethalin concentrations in soil and lettuce. RESULTS The pendimethalin half-life in soil ranged between 18 and 85 days and was mainly affected by season (i.e. weather), and especially by soil moisture. Pendimethalin degradation in soil was slowest under dry conditions. A longer pendimethalin half-life was observed under the non-woven fabric treatment, but the effect of varying application rate was not significant. Pendimethalin residue concentrations in lettuce heads were significantly influenced by pendimethalin application rate and by non-woven fabric cover, especially at the lettuce's early growth stages. The highest pendimethalin concentration at final harvest was determined in lettuce grown on uncovered plots treated with pendimethalin at an application rate of 1200 g ha−1 (7–38 µg kg−1). Depending on growing season duration and weather conditions, pendimethalin concentrations in lettuce grown under non-woven fabric ranged from 0 to 21 µg kg−1. CONCLUSION Use of transparent non-woven fabric cover with lettuce can help to reduce application rates of soil herbicides and diminish the risk of herbicide contamination in the harvested vegetables. © 2016 Society of Chemical Industry

Sorption of pharmaceuticals, which can occur in soils, may differ when present in a soil solution as a single compound or in a solution with other pharmaceuticals. Therefore, the sorption isotherms described by the Freundlich equations were evaluated for 6 compounds, which were applied in solutions of a single pharmaceutical, two pharmaceuticals or all pharmaceuticals to seven soils. Study mainly focused on a behavior of fexofenadine and irbesartan that occurred in soils in 3 forms (cationic, zwitter-ionic or neutral, anionic). Sorption of both compounds slightly increased (in some soils) when applied together, largely increased when applied with carbamazepine (neutral), and extremely increased when applied in solutions with citalopram (strongly sorbed cation), which could be explained by a cooperative multilayer sorption on soil constituents. On the other hand, sorption of both compounds moderately decreased when applied with clindamycin (cation and neutral) or sulfamethoxazole (neutral or anion). The magnitude of an increase or decrease in the Freundlich sorption coefficient (KF) for a particular compound depended on soil conditions, a form of compound's molecule and its interaction with molecules of other compounds. Despite sorption being influenced by other compound(s) in solution, the KF coefficients evaluated for a particular compound under the different conditions were mostly correlated with the same soil properties: KF,CAR with an organic carbon content, KF,CIT and KF,CLI with a base cation saturation, KF,SUL with hydrolytic acidity, and KF,FEX and KF,IRB with sorption complex saturation.

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.

Adjuvants are used to improve pesticides’ performance. It is expected that adjuvants should increase sorption and persistence, as well as decrease mobility of pesticides in soils. Impact of the “Grounded” brand adjuvant on the behaviour of two herbicides, pendimethalin and dimethenamid-P, was investigated in a Haplic Chernozem. Both herbicides were tested in a laboratory batch sorption experiment with and without adjuvant. The sorption experiment showed that adjuvant negligibly increased dimethenamid-P sorption (KF = 2.12 and 2.15 cm3/n μg1 − 1/n g−1) but significantly increased pendimethalin sorption (KF = 270.1 and 3096.4 cm3/n μg1 − 1/n g−1). In field conditions, both herbicides were retained mainly in the topsoil layer (0–5 cm). The pendimethalin dissipation half-lives were similar for all treatments (ranging from 43.0 to 44.6 days) and were not influenced by either irrigation (p = 0.86) or adjuvant (p = 0.9). The dimethenamid-P dissipation half-lives ranged from 8.8 days for irrigated treatment without adjuvant to 12.9 days for non-irrigated treatment with adjuvant. Dimethenamid-P dissipation half-life in treatments with adjuvant was significantly longer (p = 0.049) than was half-life in a treatment without adjuvant. Significantly longer dissipation half-life was observed also in non-irrigated treatments than in irrigated treatments (p = 0.044).

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, KF (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 KF value for n = 1 was 1838 cm3 g−1) followed by fexofenadine (KF = 35.1 cm3/n μg1−1/n g−1, n = 1.19) and irbesartan (KF = 3.96 cm3/n μg1−1/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 KF values for different compounds (RIRB,FEX = 0.895, p-value

Sewage sludge from wastewater treatment plants, which may contain various contaminants including pharmaceuticals, is often used as a soil amendment. These contaminants may subsequently be taken up by plants. In the present study we examined uptake of select pharmaceuticals from sewage sludge applied to soils by spinach plants. Seven soils were amended with sewage sludge from two wastewater treatment plants (A and B). Concentrations of compounds in plant tissues (roots and leaves) of spinach planted 45 days in these soils under greenhouse conditions were evaluated after harvest. The largest bioaccumulation in the roots and leaves was observed for sertraline (bioaccumulation factors (BAF) of 3.3-37.9 and 1-13.4, respectively), tramadol (1.3-10.0 and 4.8-30.0), and carbamazepine (2.2-17.2 and 6.1-48.8) and its metabolite carbamazepine 10,11-epoxide (not-quantified to 7.3 and 9.3-96.7). Elevated bioaccumulation in spinach roots was also identified for telmisartan (3.0-20.3) and miconazole (4.3-15.1), and leaves for metoprolol acid (not-quantified to 24.3). BAF values resulting from application of sludge B were similar to or moderately higher than BAFs from sludge A. The BAF values of carbamazepine and carbamazepine 10,11-epoxide in all tissues were negatively correlated with soil cation exchange capacity (CEC). This negative correlation between BAF and CEC was also observed for tramadol (A-roots and B-leaves), citalopram (B-roots), and telmisartan (B-roots) or between BAF and clay content for metoprolol acid (A-leaves and B-roots), tramadol (B-roots and A-leaves) and venlafaxine (B-roots). However, in the case of some other compounds (i.e. sertraline, amitriptyline, mirtazapine, metoprolol), uptake and the subsequent translocation and transformation from 3 soils of a higher pH and base cation saturation (Stagnic Chernozem Siltic, Haplic Chernozem and Greyic Phaeozem) significantly differed from 4 soils with a lower pH and base cation saturation (Haplic Luvisol, Haplic Cambisol, Dystric Cambisol and Arenosol Epieutric). Such observations proved strong compound dependent influences of soil conditions on various compounds bioaccumulations in plants and necessity of studying these processes always in diverse soils.

Most of the herbicides used on sunflower are registered for pre-emergent application. The re- sidual activity of these herbicides ensures control of weed emergence, but the environmental and crop safety risks are higher. The efficacy of pre- emergent herbicides is significantly affected by soil moisture; under dry conditions, their efficacy usually decreases. However, intense precipitation after the application of these herbicides can cause ABSTRACT The aim was to compare the efficacy, selectivity to sunflower and dissipation of three chloracetamide herbicides (acetochlor, metolachlor and pethoxamid) in dependence on precipitation after application. A small plot field trial was carried out with sunflower in Central Bohemia in 2010 and 2011. The remaining concentration of active ingre - dient in the soil of all studied herbicides was lower in the year with a higher temperature and a low level of total natural precipitation at the beginning of the growing season. Higher leaching of metolachlor and pethoxamid was recorded in irrigated plots. No leaching was found in the case of acetochlor. The highest leaching was found for metolachlor (9.2-25.5% in soil layer 5-10 cm). The highest phytotoxicity was found for acetochlor (9.8%) > pethox- amid (4.6%) > metolachlor (1.8%). The mean phytotoxicity in the irrigated plots was 6.9%, compared with 3.9% in the non-irrigated plots. The efficacy of the tested herbicide was affected by wet conditions. The highest efficacy on Chenopodium album, Amaranthus retroflexus , Echinochloa crus-galli and Solanum physalifolium was recorded af- ter application of acetochlor and irrigation.

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.

Lettuce (Lactuca sativa L.) is a crop that is very sensitive to herbicide contamination owing to its short growing season. The use of long-residual herbicides and non-woven fabric coverings could therefore influence pendimethalin concentrations in soil and lettuce.The pendimethalin half-life in soil ranged between 18 and 85 days and was mainly affected by season (i.e. weather), and especially by soil moisture. Pendimethalin degradation in soil was slowest under dry conditions. A longer pendimethalin half-life was observed under the non-woven fabric treatment, but the effect of varying application rate was not significant. Pendimethalin residue concentrations in lettuce heads were significantly influenced by pendimethalin application rate and by non-woven fabric cover, especially at the lettuce's early growth stages. The highest pendimethalin concentration at final harvest was determined in lettuce grown on uncovered plots treated with pendimethalin at an application rate of 1200 g haUse of transparent non-woven fabric cover with lettuce can help to reduce application rates of soil herbicides and diminish the risk of herbicide contamination in the harvested vegetables. © 2016 Society of Chemical Industry.

Influence of temperature on soil water content measured by ECH2O-TE sensorsThe aim of this study was to investigate the influence of temperature on water content value measured by ECH2O-TE sensors. The influence of temperature on measured soil water content values was clearly demonstrated. Soil water content values measured during the day apparently oscillated with oscillating soil temperatures. Average daily temperature and soil water content were calculated for selected periods. Regression relationships between deviations of soil temperature and soil water content from their daily average values were evaluated. Correlation between the soil water content and temperature deviations increase with the soil depth due to the lower influence of rainfall and evaporation at the soil surface on measured soil water content values in deeper soil layersegsoil water content oscillation was controlled mostly by oscillating temperature. The guideline values of linear regression equations (R2>0.8) were very similar, close to value 0.002 and the intercept values were equal to zero. The equation for recalculation of measured soil water content values at given temperature to reference soil water content for reference soil temperature, was propozed on the basis of this analysis.

Knowledge about the impact that various organic amendments have on the behavior of pesticides in soils is essential when assessing groundwater contamination risk. The aim of this study was to evaluate the impact of a compost amendment on chlorotoluron mobility in the A horizon of the Luvic Chernozem. Soil was mixed with compost material and placed into plastic cylinders. Eight mixtures (A, B, C, D, E, F, G and H) of various compost fractions (from 1 to 8% of mixture weight) were prepared. Chlorotoluron solution was applied on the top of the soil samples and a rainfall simulator was used to apply distilled water on the soil surfaces with controlled infiltration rates. Measured pressure heads at 3 positions, water outflow from the bottom, and final chlorotoluron concentrations within the soil samples were used to optimize soil hydraulic and herbicide transport parameters via numerical optimization using the HYDRUS-1D code. Optimized soil hydraulic parameters did not show noticeable changes (demonstrating an improvement of soil hydro-physical properties) with increasing compost fraction. Final chlorotoluron distribution in soil columns and estimated transport parameters also showed high variability. However, results indicated that while chlorotoluron mobility decreased up to a compost fraction of 6%, herbicide mobility noticeably increased in G (7%) samples and slightly increased in H (8%) samples. These finding corresponded to herbicide adsorption studied using a batch experiment. Multiple linear regressions revealed that other properties (not only organic carbon content) play a noticeable role in pesticide adsorption in soils. A negative impact of pH KCl (which was positively affected by compost addition), clay content, and CaCO 3 content (which were mostly properties of soil, but could be affected by compost composition as well) was documented.

When soil structure varies in different soil types and the horizons of these soil types, it has a significant impact on water flow and contaminant transport in soils. This paper focuses on the effect of soil structure variations on the transport of pesticides in the soil above the water table. Transport of a pesticide (chlorotoluron) initially applied on soil columns taken from various horizons of three different soil types (Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol) was studied using two scenarios of ponding infiltration. The highest infiltration rate and pesticide mobility were observed for the Bt(1) horizon of Haplic Luvisol that exhibited a well-developed prismatic structure. The lowest infiltration rate was measured for the Bw horizon of Haplic Cambisol, which had a poorly developed soil structure and a low fraction of large capillary pores and gravitational pores. Water infiltration rates were reduced during the experiments by a soil structure breakdown, swelling of clay and/or air entrapped in soil samples. The largest soil structure breakdown and infiltration decrease was observed for the Ap horizon of Haplic Luvisol due to the low aggregate stability of the initially well-aggregated soil. Single-porosity and dual-permeability (with matrix and macropore domains) flow models in HYDRUS-1D were used to estimate soil hydraulic parameters via numerical inversion using data from the first infiltration experiment. A fraction of the macropore domain in the dual-permeability model was estimated using the micro-morphological images. Final soil hydraulic parameters determined using the single-porosity and dual-permeability models were subsequently used to optimize solute transport parameters. To improve numerical inversion results, the two-site sorption model was also applied. Although structural changes observed during the experiment affected water flow and solute transport, the dual-permeability model together with the two-site sorption model proved to be able to approximate experimental data.

The impact of varying soil micromorphology on soil hydraulic properƟ es and, consequently, on water fl ow and herbicide transport observed in the fi eld is demonstrated on three soil types. The micromorphological image of a humic horizon of Haplic Luvisol showed higher-order aggregates. The majority of detectable pores corresponding to the pressure head interval between −2 and −70 cm were highly connected, separaƟ ng higher-order peds with small intrapores that possibly formed zones with immobile water. Herbicide was regularly distributed in this soil. The majority of detectable large capillary pores in a humic horizon of Greyic Phaeozem were separated and aff ected by clay coaƟ ngs and fi llings. The herbicide transport in this soil was highly aff ected by preferenƟ al fl ow. Macropores corresponding to pressure heads higher than −2 cm were detected in a humic horizon of Haplic Cambisol. However, preferenƟ al fl ow only slightly infl uenced the herbicide transport in this soil. Single-porosity and either dual-porosity or dual-permeability fl ow and transport models in HYDRUS-1D were used to esƟ mate the soil hydraulic parameters from laboratory mulƟ step ouƞ low and ponded infi ltraƟ on experiments via numerical inversion and to simulate the herbicide transport experimentally studied in the fi eld. Appropriate models were selected on the basis of the soil micromorphological study.

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

Study is focused on the numerical modeling of fly-ash transport in three sands, which was experimentally studied in the laboratory. Sands were packed in glass cylinders with diameter of 5.52 cm and height of 18 cm. Sands were also packed in plastic cylinders with diameter of 30 cm and height of 40 cm. The fly-ash and pulse infiltrations were applied on the top of all cylinders. Visually observed and gravimetrically evaluated fly-ash migration in small cylinders corresponded to fly-ash mobility in large columns detected using the SM400 Kappameter. The HYDRUS-1D code was used to simulate observed fly-ash transport. Parameters of soil hydraulic functions were either obtained using the Tempe cells and the RETC program or estimated using numerical inversion of transient water flow data measured in both types of columns using HYDRUS-1D. Parameters characterizing colloid transport in sands were then estimated from the final fly-ash distribution in sandy columns using attachment/detachment concept in HYDRUS-1D. Fly-ash mobility increased with increasing sand particle sizes, e.g. pore sizes. Particle sizes and pore water velocity influenced the attachment coefficient, which was calculated assuming filtration theory. The same longitudinal dispersivity, sticking efficiency and detachment coefficient sufficiently characterized fly-ash behavior in all sands.

Study was focused on the evaluation of pesticide adsorption in soils, as one of the parameters, which are necessary to know when assessing possible groundwater contamination caused by pesticides commonly used in agriculture. Batch sorption tests were performed for 11 selected pesticides and 13 representative soils. The Freundlich equations were used to describe adsorption isotherms. Multiple-linear regressions were used to predict the Freundlich adsorption coefficients from measured soil properties. Resulting functions and a soil map of the Czech Republic were used to generate maps of the coefficient distribution. The multiple linear regressions showed that the K(F) coefficient depended on: (a) combination of OM (organic matter content), pH(KCl) and CEC (cation exchange capacity), or OM, SCS (sorption complex saturation) and salinity (terbuthylazine), (b) combination of OM and pH(KCl), or OM, SCS and salinity (prometryne), (c) combination of OM and pH(KCl), or OM and ρ(z) (metribuzin), (d) combination of OM, CEC and clay content, or clay content, CEC and salinity (hexazinone), (e) combination of OM and pH(KCl), or OM and SCS (metolachlor), (f) OM or combination of OM and CaCO(3) (chlorotoluron), (g) OM (azoxystrobin), (h) combination of OM and pH(KCl) (trifluralin), (i) combination of OM and clay content (fipronil), (j) combination of OM and pH(KCl), or OM, pH(KCl) and CaCO(3) (thiacloprid), (k) combination of OM, pH(KCl) and CEC, or sand content, pH(KCl) and salinity (chlormequat chloride).

Chlortoluron transport was studied in five different soil types in five locations in the Czech Republic. There were considerable differences in herbicide transport with varying soil types and locations. The BPS mathematical model (Kozak and Vacek, 1996) was used to simulate chlortoluron transport. The chlortoluron concentrations that were predicted by the model were similar to the measured data except in the Greyic Phaozem, where preferential flow may have greatly influenced solution transport.

Labile Al forms and species can be a threat in acid soils due to their potential toxicity to plants. However, there is no universally accepted extraction method. Several extraction reagents for Al release from soil have been tested. KCl (0.5 or 1 M) is recommended for extraction of exchangeable Al, while 0.5 or 0.3 M CuCl(2) is suggested for extraction of 'weakly organically bound Al'. Both 0.1 and 0.05 M Na(4)P(2)O(7) are shown to be suitable for the extraction of 'total organically bound Al'. These extractions are relatively simple, robust, and applicable to different soils and soil horizons. In the second part of the paper, detailed speciation of exchangeable soil Al by means of an HPLC instrument equipped with an ion column (IC) is presented. An experimental set-up is described and tested on a set of samples. Interpretation of the speciation results is proposed, based on the separation of Al ions and Al complexes according to their charge. Speciation is shown to be dependent mainly on soil pH and organic matter quality. A general scheme of Al fractionation and speciation in soil is proposed.

The chlorotoluron transport in the soil profiles was studied under field conditions on three different soil types of the Czech Republic. The herbicide was applied on 21. 4. 2005 on a four-square meter plot using an applica - tion rate of 2 kg/ha. Soil samples were taken on days 35 and 150 from the herbicide application to study the remain - ing chlorotoluron distributions in the soil profiles. The chlorotoluron distributions in the monitored soils were very similar 35 days after the herbicide application. The major part of chlorotoluron was detected in the top layer of the soil profile (0-8 cm). The highest concentration was obtained in the top 2 cm layer and it decreased gradually with the depth. The percentages of the remaining chlorotoluron 35 days after the herbicide application were similar in Haplic Luvisol (29.97%) and Greyic Phaeozem (30.78%), and slightly higher in Haplic Cambisol (38.58%). The chlorotoluron distributions in the monitored soils differed considerably 150 days after the herbicide application. Chlorotoluron was detected in the entire monitored soils profiles (0-50 cm). The highest concentration was found in all cases in the top 2 cm layer and it decreased gradually with the depth to the depth of approximately 10 cm. Below this level, the herbicide contents were low and the values oscillated randomly. The percentages of the remaining chlorotoluron 150 days after the herbicide application were in the increasing order: Greyic Phaeozem < (5.45%) < Haplic Luvisol (11.7%) < Haplic Cambisol (17.48%). The BPS mathematical model connected with the soil database was used to simulate the chlorotoluron distribution 35 and 150 days after the herbicide application. The comparison of the measured and simulated data indicated probably varying chlorotoluron half-life during the experiment. The results showed that, if the chlorotoluron half-life is estimated based on the remaining chlorotoluron content in the soil profile on the 150 th day

Chlortoluron transport was studied in five different soil types and under varying climatic conditions. The chlortolu-ron mobility in the monitored soils increases as follows: Albic Luvisol = Haplic Luvisol < Haplic Cambisol < Haplic Stagnosol < Greyic Phaozem. Significantly high concentrations in the top layer of Haplic Stagnosol were observed due to the high presence of coarse gravel (30–40%) and flow profile reduction up to 60%. The content of remaining chlortoluron in the soil profile corresponds to the herbicide mobility. The percentages of remaining chlortoluron were 46.1% in Albic Luvisol, 54.6% in Haplic Luvisol, 65.0% in Haplic Cambisol, 69.6% in Haplic Stagnosol and 102.9% in Greyic Phaozem. The highest herbicide degradations were at the locations with lower observed mobility and herbi-cide present mainly in the top layer. Occurrence of the remaining chlortoluron percentage in Greyic Phaozem higher than 100% was caused mainly by the herbicide transport through the preferential paths and restricted degradation in subsurface layers. Variability of chlortoluron distributions in the soil profiles observed at the three positions of the same location occurred due to the heterogeneity of the soil profile and an uneven distribution of chlortoluron on the soil surface. The BPS mathematical model (Kozak and Vacek 1996) connected with the soil database (Kozak et al. 1996) was used to simulate chlortoluron transport. The simulated chlortoluron concentrations follow approximately the measured data except for Greyic Phaozem, where a preferential flow highly influenced solution transport. The BPS model with the soil database can be used for estimation of the chlortoluron transport.Keywords: pesticides; chlortoluron; degradation; solution transport; field and numerical studySupported by the Ministry of Agriculture of the Czech Republic, Project No. QF 3250.