Pharmaceuticals constitute a significant group of emerging pollutants (EPs). The use of pharmaceuticals in animal breeding causes them to reach the soil environment in excrement and fertilizers. ...Depending on their chemical properties, pharmaceuticals can be sorbed to the soil or be washed out with rainfall and eventually be entered into groundwater. This paper evaluates the mobility of tramadol (TRA) and carbamazepine (CBZ), and two transformation products, O-desmethyltramadol (O-DMTRA) and 10,11-dihydro-10-hydroxycarbamazepine (10-OH-CBZ) in soils. Both pharmaceuticals are applied in human and animal treatment, which makes them enter the environment in native and metabolized form in high doses. Experiments were carried out in accordance with the OECD 106 procedure (batch tests) and DIN 19528:2009-01 procedure (percolation column test). The adsorption coefficients (Kd) for TRA, CBZ, O-DMTRA and 10-OH-CBZ were, respectively, 1.41 ± 0.10, 1.87 ± 0.06, 0.90 ± 0.03 and 0.37 ± 0.07 for sandy soil RS04, and 18.09 ± 0.78, 2.56 ± 0.05, 10.89 ± 0.17 and 0.56 ± 0.38 L kg−1 for loamy soil RS06. The percolation column test was carried out for sandy soil RS04. The results obtained for TRA and O-DMTRA under static conditions indicated a high mobility of these compounds in soil, whereas the column leaching experiment showed that these compounds bind strongly to soil particles. A correlation between static and dynamic tests was observed in the case of CBZ and 10-OH-CBZ. These compounds will probably be characterized by a high or moderate mobility in soil.
•Batch test provides different results in comparison to the column leaching test.•CBZ and 10-OH-CBZ will be characterized by a high or moderate mobility in soil.•The column leaching test showed that TRA and O-DMTRA bind strongly to soil particles.
Per- and polyfluoroalkyl substances (PFAS) contaminated compost materials have been applied over the last few decades to agricultural fields in Germany, resulting in large-scale diffuse PFAS plumes. ...The leaching behavior of PFAS from the first two identified contaminated agricultural sites in Germany were investigated, one at Brilon-Scharfenberg, North Rhine-Westphalia (BS-NRW), and the other at Rastatt/Mannheim, Baden-Württemberg. The specific objectives of this study were to assess the longevity of the PFAS agricultural sources and compare standardized column percolation tests to long-term leaching of PFAS from contaminated sites. The advection-dispersion model (ADM) was used to compare the leaching behavior of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from standardized column percolation tests and long-term field leaching data from the BS-NRW site. Column leaching tests conducted with PFOS and PFOA contaminated soil simulated the initial rapid decline but did not predict the long-term behavior (tailing) observed at the field site over 12 years. Trend analyses of the PFAS field data from the BS-NRW showed that concentrations had stabilized and that individual PFAS exhibited distinct seasonal fluctuations; the latter is likely due to the ongoing transformation of precursors and a seasonal influence on production rates of mobile PFAS. Mass balances conducted at both sites indicate that complete removal of these compounds will likely take years to decades to occur, which is expected from the results of the column leaching tests.
•12-years field-scale leaching data trends from the first documented PFAS contaminated agricultural site in Germany.•PFAS column leaching tests do not reflect the long-term tailing observed at the field site over 12 years.•Long-term tailing is potentially caused by transformation of precursor substances into PFOA and PFOS.•Field data of short chain PFAS show a distinct seasonal patter.•These case studies demonstrate that it will take decades for PFAS to leach from agricultural topsoils.
Excavated rock and sediment in which arsenic release naturally occurs is necessary to be treated with an appropriate technique such as chemical immobilization. The physical condition such as particle ...size ratio of rock to the immobilization material possibly enhances/suppresses the effects of arsenic immobilization because arsenic should be contacted and reacted with the immobilization material in the rock pores for the immobilization. This study prepared the up-flow column percolation test using the excavated rocks with the different particle sizes and immobilization material with constant particle size to determine a suitable ratio of the diameter of the average particle size in the rock samples to that in the immobilization material. The column percolation test showed that the contribution of arsenic immobilization by the immobilization material was higher in the larger particle size of excavated rock while the arsenic retention capacity of excavated rock was high in the smaller particle size. The arsenic concentrations in the leaching water were the lowest and the percentage of arsenic retained during the column percolation test was the highest in the particle size of 1.0–2.0 mm of excavated rock. Based on these results, this study suggests that the suitable particle size ratio of excavated rock to the immobilization material was 2 to 10.
Chemical immobilization using a hydroxyapatite is one of the promising approach to soil with high level lead (Pb) contamination. To enhance the effectiveness of Pb immobilization by the ...hydroxyapatite, it is important to understand that how Pb reacts with the hydroxyapatite and forms insoluble Pb phases in the soil pore. This study conducted the up-flow-unsaturated column percolation test with the combined application of X-ray diffraction (XRD) analysis to understand the relation between the amount of Pb migrated and Pb transformed into pyromorphite in the water-unsaturated soil with regarding to the distance of Pb migration. The XRD analysis could quantify the amounts of Pb as pyromorphite formed during the water percolation test. Pb existed as water-soluble gradually migrated from the soil in the layer to the soil in the next layer with the water percolation despite the presence of hydroxyapatite. In opposite, the formation of pyromorphite was favor in the soil near the inflow side.
Automobile tires require functional rubber additives including curing agents and antioxidants, which are potentially environmentally available from tire and road wear particles (TRWP) deposited in ...soil and sediment. A novel methodology was employed to evaluate the environmental fate of three commonly-used tire chemicals (N-cyclohexylbenzothiazole-2-sulfenamide (CBS), N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine (6-PPD) and 1,3-diphenylguanidine (DPG)), using a road simulator, an artificial weathering chamber, column leaching tests, and OECD 308 sediment/water incubator studies. Environmental release factors were quantified for curing (fC), tire wear (fW), terrestrial weathering (fS), leaching from TRWP (fL), and environmental availability from TRWP (fA) by liquid chromatography–tandem mass spectroscopy (LC/MS/MS) analyses. Cumulative fractions representing total environmental availability (FT) and release to water (FR) were calculated for the tire chemicals and 13 transformation products. FT for CBS, DPG and 6-PPD inclusive of transformation products for an accelerated terrestrial aging time in soil of 0.1years was 0.08, 0.1, and 0.06, respectively (equivalent to 6 to 10% of formulated mass). In contrast, a wider range of 5.5×10−4 (6-PPD) to 0.06 (CBS) was observed for FR at an accelerated age of 0.1years, reflecting the importance of hydrophobicity and solubility for determining the release to the water phase. Significant differences (p<0.05) in the weathering factor, fS, were observed when chemicals were categorized by boiling point or hydrolysis rate constant. A significant difference in the leaching factor, fL, and environmental availability factor, fA, was also observed when chemicals were categorized by log Kow. Our methodology should be useful for lifecycle analysis of other functional polymer chemicals.
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•Studied two vulcanization accelerators and an antioxidant additive used in tire tread•Integrated several laboratory methods to assess environmental fate of tread additives•Considered CBS, DPG, 6-PPD and 13 transformation products in analysis•Evaluated curing, tire wear, weathering, transformation and leaching processes•Measured chemical environmental availability for tire and road-wear particles (TRWP)
Chemical immobilization using hydroxyapatite is one of the promising approaches to handling soil with high-level lead contamination. To enhance the effectiveness of lead immobilization by ...hydroxyapatite, it is important to understand how lead reacts with hydroxyapatite and forms pyromorphite, insoluble lead phases. The up-flow suction percolation test was conducted in this study by the combined application of an X-ray diffraction analysis using fine-grained and sandy soils. The aim of the test was to understand how the availability of lead and phosphorus depends on the formation of pyromorphite in water-unsaturated soil. The results revealed that the available phosphorus derived from hydroxyapatite remained in the sandy soil after the percolation test, but it did not remain in the fine-grained soil. The X-ray diffraction analysis was able to quantify the amounts of lead as pyromorphite formed during the water percolation test. The presence of hydroxyapatite suppressed 48% and 76% of the lead leaching from the contaminated fine-grained and sandy soils, respectively. In the fine-grained soil, much of the pyromorphite formed in the soil near the inflow side; however, as the distance from the inflow side increased, the pyromorphite formation decreased, and lead, as water-soluble, remained. In contrast, in the sandy soil, phosphorus added as hydroxyapatite was extracted, as available. Therefore, pyromorphite homogeneously formed regardless of the distance from the inflow side, resulting in no lead as the water-soluble phases. Thus, hydroxyapatite application for lead immobilization is suitable for soil with a low phosphorus sorption ability.
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Ways to reduce the duration of column percolation tests specified in ISO/TS 21268-3 were proposed.Four equilibrium periods and two flow rates on four different soils were ...tested.The time to perform column percolation tests can be shortened from 20 to 30days to 7⿿9 days.The recommended initial equilibrium period is 12⿿16h, shorten from 48h.The recommended flow rate is 36mL/h which is three times that specified in ISO/TS 21268-3.
Column percolation tests may be suitable for prediction of chemical leaching from soil and soil materials. However, compared with batch leaching tests, they are time-consuming. It is therefore important to investigate ways to shorten the tests without affecting the quality of results. In this study, we evaluate the feasibility of decreasing testing time by increasing flow rate and decreasing equilibration time compared to the conditions specified in ISO/TS 21268-3, with equilibration periods of 48h and flow rate of 12mL/h. We tested three equilibration periods (0, 12⿿16, and 48h) and two flow rates (12 and 36mL/h) on four different soils and compared the inorganic constituent releases. For soils A and D, we observed similar values for all conditions except for the 0h⿿36mL/h case. For soil B, we observed no appreciable differences between the tested conditions, while for soil C there were no consistent trends probably due to the difference in ongoing oxidation reactions between soil samples. These results suggest that column percolation tests can be shortened from 20 to 30days to 7⿿9days by decreasing the equilibration time to 12⿿16h and increasing the flow rate to 36mL/h for inorganic substances.
A 3-years field test and laboratory leaching test have been conducted to assess the environmental impact of land application of sewage sludge compost in conjunction with wheat and rice crops. ...Considering the complexity and variability of field conditions, we compared the result of laboratory test with the field test to understand the accuracy and uncertainty associated with using the laboratory test to evaluate the field scenario. The laboratory test with cycling of compost additions and water percolation was a high time-efficient and feasible method to simulate the annually repeated additions of compost in the field application scenario. The results of laboratory test were congruent to the 3-years field test regarding the leaching characteristics and geochemical speciation of toxic trace elements. Both the laboratory and the field test showed that repeated additions of compost to soils can increase leaching concentrations of toxic trace elements at neutral to alkaline pH. Increased toxic trace elements leaching was caused by the increase of organic matter from compost application and organic matter dissolution at alkaline pH. Uncertainties of the laboratory test mainly included the negligibility of crop growth and the strongly reducing condition formed with continuous percolation procedure.
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•Plant uptake and leaching of TTEs were studied in a field test with SSC additions.•The field and lab test results were compared to show similarities and differences.•The column test with repeated additions of SSC well simulated the real scenario.
In assessing the environmental risk of contaminated soil and waste, it is crucial to understand the contaminants’ leaching characteristics. There are various leaching test methods such as single ...batch leaching test, serial batch leaching test, column water flow test, and tank leaching test. This paper outlines the test method and the results of the accuracy evaluation test of the up-flow percolation test.
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