Soil-water System Research Articles

Sorption and degradation of 17β-estradiol-17-sulfate in sterilized soil–water systems

To identify abiotic processes that govern the fate of a sulfate conjugated estrogen, 17β-estradiol-17-sulfate (E2-17S), soil batch experiments were conducted to investigate the dissipation, sorption, and degradation of radiolabeled E2-17S under sterilized conditions. The aqueous dissipation half-lives (DT50) for E2-17S ranged from 2.5 to 9.3h for the topsoil of high organic carbon (OC) content (1.29%), but E2-17S remained at ∼80% of applied dose in the low OC (0.26%) subsoil by 14d. The non-linear sorption isotherms indicated limited sorption of E2-17S, and the concentration-dependent log KOC values were 2.20 and 2.45 for the topsoil and subsoil, respectively. Additionally, two types of hydroxyl E2-17S (OH-E2-17S and diOH-E2-17S) were found as major metabolites in the aqueous phase, which represented 9–25% and 6–7% of applied dose for the topsoil and subsoil at 14d, respectively. Free estrogens, 17β-estradiol (E2) and estrone (E1), were detected from the sorbed phase of the soil–water systems.

Evaluating oxidation–reduction properties of dissolved organic matter from Chinese milk vetch (Astragalus sinicus L.): a comprehensive multi-parametric study

Green manuring is a common practice in replenishment of soil organic matter and nutrients in rice paddy field. Owing to the complex interplay of multiple factors, the oxidation–reduction (redox) properties of dissolved organic matter (DOM) from green manure crops are presently not fully understood. In this study, a variety of surrogate parameters were used to evaluate the redox capacity and redox state of DOM derived from Chinese milk vetch (CMV, Astragalus sinicus L.) via microbial decomposition under continuously flooded (CF) and non-flooded (NF) conditions. Additionally, the correlation between the surrogate parameters of CMV–DOM and the kinetic parameters of relevant redox reactions was evaluated in a soil–water system containing CMV–DOM. Results showed that the redox properties of CMV–DOM were substantially different between the fresh and decomposed CMV–DOM treatments. Determination of the surrogate parameters via ultraviolet–visible/Fourier transform infrared absorption spectroscopy and gel permeation chromatography generally provided high-quality data for predicting the redox capacity of CMV–DOM, while the surrogate parameters determined by elemental analysis were suitable for predicting the redox state of CMV–DOM. Depending on the redox capacity and redox state of various moieties/components, NF-decomposed CMV–DOM could easily accelerate soil reduction by shuttling electrons to iron oxides, because it contained more reversible redox-active functional groups (e.g. quinone and hydroquinone pairs) than CF-decomposed CMV–DOM. This work demonstrates that a single index cannot interpret complex changes in multiple factors that jointly determine the redox reactivity of CMV–DOM. Thus, a multi-parametric study is needed for providing comprehensive information on the redox properties of green manure DOM.

Effects of Water Management, Arsenic and Phosphorus Levels on Rice Yield in High-Arsenic Soil-Water System

Aerobic rice (Oryza sativa L.) cultivation is considered an alternative production system to combat increased water scarcity and arsenic (As) contamination in the food chain. Pot experiments were conducted at the Wheat Research Centre, Dinajpur, Bangladesh to examine the role of water management (WM), As and phosphorus (P) on yield and yield attributes of boro (variety BRRI dhan 29) and aman (variety BRRI dhan 32) rice. A total of 18 treatment combinations of the three levels of As (0, 20 and 40 mg/kg) and P (0, 12.5 and 25.0 mg/kg) and two WM strategies (aerobic and anaerobic) were investigated. Yield attributes were significantly affected by increasing As levels. Grain yields of BRRI dhan 29 and BRRI dhan 32 were reduced from 63.0 to 7.7 and 35.0 to 16.5 g/pot with increasing As application, respectively, indicating a greater sensitivity of BRRI dhan 29 than BRRI dhan 32. Moreover, As toxicity was reduced with aerobic compared to anaerobic WM for all P levels. During early growth stages, phytotoxic symptoms appeared on BRRI dhan 29 and BRRI dhan 32 rice stems with increasing As levels without applying P under anaerobic WM. Under anaerobic and As-contaminated conditions, BRRI dhan 29 was highly susceptible to straighthead, which dramatically reduced grain yields. There were significant relationships between the number of effective tillers per pot and root dry weight, grain yield, and number of fertile and unfertile grains per pot for both BRRI dhan 29 and BRRI dhan 32 (P < 0.001). Our findings indicate that rice could be grown aerobically in As-contaminated areas with a reduced risk of As toxicity and yield loss.

English

A quantitative evaluation of spatial and temporal distribution of groundwater recharge is a pre-requisite for the management of ground water resources system in an optimal manner. The amount of groundwater recharge depends upon the rate and duration of rainfall, as rainfall is the principal means for replenishment of moisture in the soil water system and recharge to ground water. This paper investigated the relationship between rainfalls and groundwater recharge within Ona River basin, southwest Nigeria, using soil moisture balance and water table fluctuation. Analysis of rainfall trends within the Ona River basin suggests that there is considerable high annual rainfall occurrence, with a mean of 1623.48. It must be noted that the mean annual lost due to evapotranspiration of 1361.68 mm is very high when compared to the rainfall (83.9%). The results obtained from the soil moisture balance when considering the three dominant soil types within the basin, that is, sandy loam, clay and find sand, having water capacity of root zone value of 70, 70, and 50 respectively, suggests that groundwater recharge follows a positive trend as the corresponding rainfalls. However, empirical relationships of: y = 0.540x – 606.2, with a coefficient of determination (r2) value of 0.719, for sandy loam and clay; and y = 0.552x – 621, with a coefficient of determination (r2) value of 0.726 for fine sand was established for the basin area. On the other hand, recharge ranging from 220.25 to 40.50 mm was computed from the water table fluctuation method. Key words: Rainfall–recharge relationship, soil types, soil moisture balance, Ona River basin, water table fluctuation.

Effects of soil properties and biosurfactant on the behavior of PAHs in soil-water systems

The interactions among biosurfactant, soil components and PAHs govern the efficiency of biosurfactant enhanced remediation, which was still poorly studied. In this study, we investigated effects of biosurfactant and soil properties on sorption and desorption of phenanthrene (PHE) and pyrene (PYR) in soil – water systems. Two kinds of soil samples (ditch and under plant) from the same petroleum contaminated site in western Canada were applied. The results indicate that soil organic matter (SOM) was the predominant factor that affects PAHs sorption onto soil. The SOM content in ditch soil was half of that in under plant soil, therefore ditch soil showed less sorption affinity to PAHs than under plant soil. We also examined the combined effects of soil DOM and biosurfactant on desorption of PAHs. The results indicated that more PAHs were desorbed from ditch soil than the under plant soil under the combined conditions. The SOM was still the key factor that determined desorption of PAHs. Besides, competitions among PAHs, DOM and surfactant for sorption sites exist. In high solute concentration system, the competition for sorption site was more severely than low concentration system and more PAHs were sequenced in soil phase in high PAH concentration system. Also in low biosurfactant system, less PAHs were desorbed from soil. The study results should be helpful in broadening knowledge of biosurfactant enhanced bioremediation of PAHs.

Long-term fate of nitrate fertilizer in agricultural soils

Increasing diffuse nitrate loading of surface waters and groundwater has emerged as a major problem in many agricultural areas of the world, resulting in contamination of drinking water resources in aquifers as well as eutrophication of freshwaters and coastal marine ecosystems. Although empirical correlations between application rates of N fertilizers to agricultural soils and nitrate contamination of adjacent hydrological systems have been demonstrated, the transit times of fertilizer N in the pedosphere-hydrosphere system are poorly understood. We investigated the fate of isotopically labeled nitrogen fertilizers in a three-decade-long in situ tracer experiment that quantified not only fertilizer N uptake by plants and retention in soils, but also determined to which extent and over which time periods fertilizer N stored in soil organic matter is rereleased for either uptake in crops or export into the hydrosphere. We found that 61-65% of the applied fertilizers N were taken up by plants, whereas 12-15% of the labeled fertilizer N were still residing in the soil organic matter more than a quarter century after tracer application. Between 8-12% of the applied fertilizer had leaked toward the hydrosphere during the 30-y observation period. We predict that additional exports of (15)N-labeled nitrate from the tracer application in 1982 toward the hydrosphere will continue for at least another five decades. Therefore, attempts to reduce agricultural nitrate contamination of aquatic systems must consider the long-term legacy of past applications of synthetic fertilizers in agricultural systems and the nitrogen retention capacity of agricultural soils.

Morphed block-crack preferential sedimentation in a reservoir bed: a smart design and evolution in nature

A pedological study of the reservoir bed of Al-Khoud Dam, Oman, revealed an unusual sedimentation pattern which evolved into an intricate composition of silt blocks surrounded by vertical cracks and horizontal layers filled with a “proppant” sand. The discovered soil morphology reflects the complex topology of water motion (infiltration–seepage–evaporation) through the sand-filled cracks/layers and blocks during both the rare flood events and ensuing periods of ponding, and the long, intervening dry periods. These naturally formed soils demonstrate an ability to preserve a large quantity of water inside the silty blocks at depths of 0.5 to 1.5 m, despite the high temperature and dryness of the topsoil. The hydrological optimality and “smartness” of these soils is attributed to the unique block-crack system. Natural, lush vegetation was found in adjacent zones of the reservoir bed, and acted as a footprint of the shallow “fractured perched aquifer”. Planted “ivy” (Convolvulaceae) in the vertical face of one pedon showed intensive growth without irrigation. Soil moisture content data confirmed the hydrological immobility of water in the blocks if not depleted by transpiration. The novel phenomena reported unveil the possible alteration of soil heterogeneity for optimization of the soil–water system in arid zone soils.Editor D. Koutsoyiannis; Associate editor F.F. HattermannCitation Al-Ismaily, S.S., Al-Maktoumi, A.K., Kacimov, A.R., Al-Saqri, S.M., Al-Busaidi, H.A., and Al-Haddabi, M.H., 2013. Morphed block-crack preferential sedimentation in a reservoir bed: a smart design and evolution in nature. Hydrological Sciences Journal, 58 (8), 1779–1788.

Elevated critical micelle concentration in soil–water system and its implication on PAH removal and surfactant selecting

Triton X-100 (TX100) and Brij 35 (B35) were used to investigate the elevated critical micelle concentration (CMC) induced by surfactant sorption and its influence on PAH removal in soil washing systems. The surface tension technique was applied to determine the CMC and the apparent CMC (CMCsoil) in soil–water systems. Surfactant sorption experiments were conducted by the batch equilibration technique. Surfactants sorbed on the soil at concentrations below the CMCsoil were quantified with data from the surface tension experiments for both an aqueous system and a soil–water system. Due to sorption, the CMCsoil values of the two surfactants are 2.75 and 6.31 times their corresponding CMC values in aqueous solutions, respectively. At concentrations below CMCsoil, the loss of B35 (92–99.7 %) was greater than that of TX100 (63–92 %). The PAH removal efficiencies are greatly dependent on the CMCsoil value. At surfactant concentrations below CMCsoil, the PAH removal is very low and remains almost invariable. Whereas, at concentrations above CMCsoil, the PAH removal increases greatly. B35 inhibited PAH desorption at concentrations below its CMCsoil. For TX100, some degree of PAH desorption enhancement was observed at concentrations below its CMCsoil. CMCsoil is a key parameter while selecting a surfactant for a specific soil washing system, only surfactant concentrations above their CMCsoil should be evaluated.

Treatment of Diesel-Contaminated Soil by Fenton and Persulfate Oxidation with Zero-Valent Iron

The objective of this research is to investigate Fenton and persulfate oxidation with zero-valent iron [Fe(0)] as a batch type ex-situ remediation technology for the treatment of diesel-contaminated soil. Results from batch experiments indicate that Fe(0) is a better catalyst for H2O2 and persulfate than Fe2+ for the enhancement of Fenton and persulfate oxidation in a batch system. Maximum removal was obtained after 12 h when 1 and 2 g of Fe(0) were added to hydrogen peroxide (250 mg/L) and persulfate (250 mg/L), respectively, in a soil-water system. As the amounts of Fe(0) and persulfate were increased three times at the optimal ratio, the removal of total petroleum hydrocarbon (TPH) was enhanced accordingly. More than 90% of the TPH was removed in 3 h, and the treated soil met the Korean regulation level (500 mg/kg) for TPH. Increased amounts of Fe(0) and hydrogen peroxide (up to 10 g and 1250 mg/L, respectively) also significantly enhanced degradation under the optimal conditions. The results of our study suggest that Fe(0)-assisted Fenton and persulfate oxidation in a batch reactor may be an alternative option to treat diesel-contaminated soil.

Environmental behavior of the fungicide metalaxyl in experimental tobacco field

The loss of metalaxyl, a systemic fungicide, was determined in runoff water from loamy soil plots of various surface slopes cultivated with tobacco, over a period of 170 days. Conditions were selected to simulate agricultural practices employed in the Mediterranean region. The surface slopes of plots were 0, 2.5, 5, 7.5, 10% and both cultivated and uncultivated (control) areas were simultaneously monitored. The cumulative losses of metalaxyl in surface runoff from tilled and untilled plots with a slope of 10% were estimated at 0.469% and 0.740% of the initial applied active ingredient respectively, while for the plots with a slope 0% they were 0.033% and 0.044%. The dissipation in topsoil was studied for a period of 110 days. The half-lives that were calculated using first-order kinetics ranged from 13.7 to 16.6 days in tobacco soil and from 13.8 to 17 days in non-cropped soil. The dissipation of metalaxyl from the topsoil in cultivation of tobacco was higher in comparison with the untilled plots (46–62% and 52–69% respectively, of the applied dose in 23 days after the second application). The slope of soil surface, the compound solubility and sorption capacities are the main parameters that influenced the transport of metalaxyl residues via surface water in soil-water systems.

Determination of Pesticide in Soil-Water System by Solid Phase Extraction and Gas Chromatography

A SPE-GC-FID method was developed for the analyzing the residues of prometryne and acetochlor in soil-water system. The sample solution was made up of the standard stock solution of prometryne-acetochlor and soil-water solution with a certain proportion.purified by C18solid-phase extraction (SPE) column, and then leached by acetone. The leached was filtrated with microporous membrane (d&lt;0.45 μm). The results showed that the standard curve was showed in the range of 1.5~30 μg/mL with a correlation coefficient of 0.9995 and 0.9980. The recoveries (n=5) were 98.9%~107.2%, with relative standard deviation ranged from 2.52% to 9.7%.The detection limits of prometryne was 0.22 μg/mL and acetochlor was 0.19 μg/mL. This method provides a dependable approach to examine and evaluate the residues of prometryne and acetochlor in the soil-water system.

Residue Determination of Prometryne and Acetochlor in Soil and Water by High Performance Liquid Chromatography

A new method has been developed to detect the residues of the binary mixed pesticides of prometryne-acetochlor in soil-water system by high performance liquid (HPLC). The study compared two pre-treatment ways: direct injection and solid-phase extraction. The results showed that the method of direct injection is better than that of solid-phase extraction. In the linear from 0.35 μg·mL-1 to 15 μg·mL-1 of prometryne-acetochlor, the correlation coefficients for prometryne and acetochlor were 0.9993 and 0.9999, and the limits of quantification were 0.011 μg·mL-1 and 0.106 μg·mL-1 respectively. The recoveries ranged from 91.2% to 109.7% with the relative standard deviations of 0.42% -0.78%. This method provides a dependable approach to determine the residues of prometryne and acetochlor in the soil-water system.

Analysis of residues of prometryne and acetochlor in soil–water system by solid-phase extraction and gas chromatography/mass spectrometry

A highly sensitive and simple analytical method was developed for analyzing the binary mixed pesticides of prometryne and acetochlor in soil–water system by gas chromatography/mass spectrometry (GC/MS). The sample solution was first purified by C18 solid-phase extraction column, which was leached by acetone. The leachate was enriched to 1.0 mL by pressure blowing concentrator and then analyzed by GC/MS. The linear calibration curves were showed in the range of 1–15 μg/mL with a correlation coefficient of 0.9991. The average recoveries (n = 5) were between 95.3 and 115.7%, with relative standard deviations ranged from 1.71 and 7.95%. The limits of detection of Prometryne/Acetochlor were up to 0.06 and 0.17 μg/mL, respectively. This method provides a reliable approach to examine and evaluate the residues of prometryne and acetochlor in the soil–water system.

Utilizing surfactants to control the sorption, desorption, and biodegradation of phenanthrene in soil-water system

An integrative technology including the surfactant enhanced sorption and subsequent desorption and biodegradation of phenanthrene in the soil-water system was introduced and tested. For slightly contaminated agricultural soils, cationic-nonionic mixed surfactant-enhanced sorption of organic contaminants onto soils could reduce their transfer to plants, therefore safe-guarding agricultural production. After planting, residual surfactants combined with added nonionic surfactant could also promote the desorption and biodegradation of residual phenanthrene, thus providing a cost-effective pollution remediation technology. Our results showed that the cationic-nonionic mixed surfactants dodecylpyridinium bromide (DDPB) and Triton X-100 (TX100) significantly enhanced soil retention of phenanthrene. The maximum sorption coefficient K*d of phenanthrene for contaminated soils treated by mixed surfactants was about 24.5 times that of soils without surfactant (Kd) and higher than the combined effects of DDPB and TX100 individually, which was about 16.7 and 1.5 times Kd, respectively. On the other hand, TX100 could effectively remove phenanthrene from contaminated soils treated by mixed surfactants, improving the bioavailability of organic pollutants. The desorption rates of phenanthrene from these treated soils were greater than 85% with TX100 concentration above 2000 mg/L and approached 100% with increasing TX100 concentration. The biodegradation rates of phenanthrene in the presence of surfactants reached over 95% in 30 days. The mixed surfactants promoted the biodegradation of phenanthrene to some extent in 10–22 days, and had no obvious impact on phenanthrene biodegradation at the end of the experiment. Results obtained from this study provide some insight for the production of safe agricultural products and a remediation scheme for soils slightly contaminated with organic pollutants.

Effect of exopolymeric substances on the kinetics of sorption and desorption of trivalent chromium in soil

AbstractLaboratory batch sorption-desorption and column experiments were performed to better understand the effects of microbial exopolymeric substances (EPS) on Cr(III) sorption/desorption rates in the soil-water system. The experiments were carried out in two different modes: one mode (sorption) in which Cr(III) and EPS were applied simultaneously, and the other (desorption) included the sequential application of Cr(III) and EPS to the soil-water system. The batch sorption and desorption experiments showed that, while chromium(III) desorption was significantly enhanced in the presence of EPS relative to non-EPS-containing systems, the desorption rates were much smaller than the sorption rates, and the fraction dissolved by EPS accounted for only a small portion of the total chromium initially sorbed onto soil minerals. Similarly, the column experiments suggested that, while the microbial EPS led to an increase in Cr dissolution relative to non-EPS-containing systems, only a small portion of the total chromium initially added to the soil was mobilised. The differences observed in Cr sorption and desorption rates can be explained through the very low solubility and strong interactions of chromium species with soil minerals as well as the mass transfer effects associated with low diffusion rates. The overall results suggest that, while microbial EPS may play an important role in microbial Cr(VI) treatment in sub-surface systems due to the formation of soluble Cr-EPS complexes, the extent and degree of Cr mobilisation are highly dependent on the type of initial Cr sorption.

Anion exchange of organic carboxylate by soils responsible for positive Km–fc relationship from methanol mixture

The cosolvency model was not applicable for predicting the sorption of organic carboxylic acids. The reason of inapplicability was investigated by analyzing the solubility (Sm) and sorption (Km) of benzoic acid, 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,6-trichlorophenol (2,4,6-TCP). The Sm and Km by two iron-rich soils was measured as a function of methanol volume fraction (fc), electrolyte compositions, and pHapp. For 2,4,6-TCP, the Km of both neutral and anion species was well-explainable by the cosolvency model, exemplifying the knowledge of cosolvency power (σ) being sufficient to describe its sorption. However, for benzoic acid and 2,4-D, the Km of organic anions increased with fc, illustrating the organic carboxylate to be responsible for the deviation. The Sm of organic anions was not affected by the ionic valence (Ca2+ vs. K+) of liquid phase. Among hydrophilic quantities of the 2,4-D sorption, the fraction of anion exchange increased with fc while the fraction of Ca-bridge decreased in the same range. Adding solvent in soil–water system is likely to render soil surface charge more positive, fortifying the anion exchange, but opposing the formation of Ca-bridging. Therefore, it can be concluded that the positive Km–fc relationship is due to the anion exchange of organic carboxylate with positively charged soil surface, whose contribution is >50% of overall sorption at solvent-free system and becomes greater with fc up to 82%.

Environmental behavior and toxicity of herbicides atrazine and simazine

Este artigo mostra alguns aspectos ambientais e toxicológicos sobre os herbicidas triazínicos atrazina e simazina. Esses compostos são usados no controle de ervas-daninhas em plantações de cana-de-açúcar e milho. Apesar de serem parcialmente solúveis, podem ser detectados em água subterrânea e superficial. Suas mobilidade e biodegradação no sistema água-solo podem variar dependendo das características intrínsecas de cada matriz como teor de matéria orgânica. Embora sejam considerados pouco tóxicos, esses herbicidas possuem alta capacidade de interferência nos sistemas nervoso e endócrino humano e da biota selvagem. Os mecanismos de sua detoxificação são semelhantes à de outros xenobióticos; no entanto, existem poucos dados sobre os efeitos à saúde humana causada pela simazina. Portanto, o uso desses compostos deve ser revisto devido ao seu comportamento ambiental e os efeitos toxicológicos.

Diuron herbicide degradation catalyzed by low molecular weight humic acid-like compounds

Phenylureas such as diuron are major herbicides used worldwide to control undesirable weeds. The environmental fate of phenylureas is of great interest because massive amounts of those herbicides are used. It is known that abiotic degradation of phenylureas in soil–water systems is catalyzed by humic acids. However, due to the chemical heterogeneity and large molecular sizes of humic acids, the specific effects of functional groups during catalysis have not been elucidated. Therefore, we studied here for the first time the kinetics of diuron degradation in the presence of low molecular weight humic acid-like compounds such as benzoic acid derivatives. Experiments were carried out at various pH and temperature, and monitored by high-performance liquid chromatography. Results show that all benzoic acid derivatives efficiently catalyzed diuron hydrolysis. The catalytic efficiency decreased in the following order: 0.88 M−1 day−1 for 3,4-dihydroxybenzoic acid, 0.72 M−1 day−1 for 4-hydroxybenzoic acid, 0.23 M−1 day−1 for phthalic acid, 0.11 M−1 day−1 for 2-hydroxybenzoic acid, and 0.09 M−1 day−1 for 2,4-dihydroxybenzoic acid. These differences in the catalytic efficiency are explained by steric hindrance affecting the accessibility of reactive sites and hence influencing the rate of the overall process. Steric factors are therefore expected to control the catalytic activity of humic acids because of the chemical similarities between humic acids and low molecular weight humic acid-like compound. Our results should help predict more accurately the fate and abiotic degradation mechanism of phenylureas in the environment.

Biogeochemistry of stable Ca and radiogenic Sr isotopes in a larch-covered permafrost-dominated watershed of Central Siberia

Stable Ca and radiogenic Sr isotope compositions were measured in different compartments (stream water, soil solutions, rocks, soils and soil leachates and vegetation) of a small permafrost-dominated watershed in the Central Siberian Plateau. The Sr and Ca in the area are supplied by basalt weathering and atmospheric depositions, which significantly impact the Sr isotopic compositions. Only vegetation significantly fractionates the calcium isotopes within the watershed. These fractionations occur during Ca uptake by roots and along the transpiration stream within the larch trees and are hypothesised to be the result of chromatographic processes and Ca oxalate crystallisations during Ca circulation or storage within plant organs. Biomass degradation significantly influences the Ca isotopic compositions of soil solutions and soil leachates via the release of light Ca, and organic and organo-mineral colloids are thought to affect the Ca isotopic compositions of soil solutions by preferential scavenging of 40Ca. The imprint of organic matter degradation on the δ44/40Ca of soil solutions is much more significant for the warmer south-facing slope of the watershed than for the shallow and cold soil active layer of the north-facing slope. As a result, the available stock of biomass and the decomposition rates appear to be critical parameters that regulate the impact of vegetation on the soil–water system in permafrost areas. Finally, the obtained δ44/40Ca patterns contrast with those described for permafrost-free environments with a much lower δ44/40Ca fractionation factor between soils and plants, suggesting specific features of organic matter decomposition in permafrost environments. The biologically induced Ca isotopic fractionation observed at the soil profile scale is not pronounced at the scale of the streams and large rivers in which the δ44/40Ca signature may be controlled by the heterogeneity of lithological sources.

Effect of hydroxypropyl-β-cyclodextrin on diuron desorption and mineralisation in soils

Purpose The herbicide diuron has the unfortunate property of being strongly adsorbed onto soil organic matter particles, and hence, is slowly degraded in the environment because of its reduced bioavailability. The aim of this work was to gain insight into the fate and behaviour of diuron in the soil–water system, and develop and test an environmentally friendly soil decontamination technique that could give rise to an enhancement of diuron mineralisation by sensitive soil endogenous microorganisms, by means of increasing the bioavailability of the pollutant employing cyclodextrin (CD) solutions what would represent an improvement from both economic and environmental standpoints.