Quantitative laboratory study of pesticide sorption and degradation during transport can provide insight into the basic processes affecting pesticide fate in field soils. Accordingly, we demonstrate the application of analytical solutions of two-site/two-region transport models useful in studying simultaneous pesticide sorption and degradation. Soil-column displacement experiments involving H2O...

Highway runoff from IP 4, a mountain road in the north-east of Portugal, has been monitored using a system integrating a raingauge, a flowmeter and an automatic water sampler. Average daily traffic (ADT) is 6000 and the study catchment has 5970 m2 of total area and 2500 m2 of road pavement. A single stormwater outlet discharges into an infiltration pond with overflow to a creek. Sampling was ca...

Bioavailability of pesticides sorbed to soils is an important determinant of their environmental fate and impact. Mineralization of sorbed atrazine was studied in soil and clay slurries, and a desorption-biodegradation-mineralization (DBM) model was developed to quantitatively evaluate the bioavailability of sorbed atrazine. Three atrazine-degrading bacteria that utilized atrazine as a sole N s...

BACKGROUND Physico-chemical sorption onto soil minerals is one of the major processes of dissolved organic carbon (OC) stabilization in deeper soils. The interaction of DOC on soil solids is related to the reactivity of soil minerals, the chemistry of sorbate functional groups, and the stability of sorbate to microbial degradation. This study was conducted to examine the sorption of diverse OC ...

Microbial volatilization of selenium as dimethylselenide (DMSe) and dimethyldiselenide (DMDSe) from soil is an important part of the Se cycle in nature, but little is known about the stability and transformations of these gases during residence in the soil environment before dissipation to the atmosphere. Experiments monitored by gas chromatography and atomic absorption spectroscopy were made w...

Intensive agricultural practices and use of pesticides, essential to achieve high crop yields, present particular risks to soil and water resources which sustain life. Degradation and sorption of pesticides in soils are both spatially variable and also among the most sensitive factors determining losses to surface water and groundwater. Currently, no general guidance is available on suitable ap...

In aqueous suspension, the affinity of many pesticides for smectites is influenced by the clay properties such as surface area, surface charge density and location, exchangeable cations, and hydration status of exchangeable cations in clay interlayers. The amount and the type of salts present in the aqueous phase influence clay quasicrystal structures and hydration status, which we hypothesize ...

Laboratory and field experiments were conducted to evaluate the effect of olive-mill waste (OMW) addition to a Mediterranean olive grove soil on sorption, persistence, and mobility of two herbicides which are simultaneously applied for weed control in olive groves: terbuthylazine (TA) and fluometuron (FM). Laboratory batch sorption experiments showed that OMW addition to the soil at rates of 5 ...

Prion sorption to soil is thought to play an important role in the transmission of scrapie and chronic wasting disease (CWD) via the environment. Sorption of PrP to soil and soil minerals is influenced by the strain and species of PrP(Sc) and by soil characteristics. However, the ability of soil-bound prions to convert PrP(c) to PrP(Sc) under these wide-ranging conditions remains poorly underst...