Effect of fragmentation on the transport of polyvinyl chloride and low-density polyethylene in saturated quartz sand.

Microplastics are an obstinate pollutant in terrestrial environments, posing a risk to the subsurface soil matrix and potentially to groundwater. In this study, the transport and retention behaviour of two major plastic polymers, 125-300 μm Polyvinyl chloride (PVC) plastic fragments and 300 μm Low-density polyethylene (LDPE) spherical particles, were explored in saturated quartz sand (1.6-2.

Transport-based source tracking of contaminants in a karst aquifer: Model implementation, proof of concept, and application to event-based field data.

Identification and location of contamination sources is crucial for water resource protection - especially in karst aquifers which provide 25% of the world´s population with water but are highly vulnerable to contamination. Transport-based source tracking is proposed and verified here as a complementary approach to microbial and chemical source tracking in karst aquifers for identifying and locating such sources of contamination and for avoiding ambiguities that might arise from using one method alone. The transport distance is inversely modelled from contaminant breakthrough curves (BTC), based on analytical solutions of the 1D two-region non-equilibrium advection dispersion equation using GNU Octave.

Transport behavior of the pharmaceutical compounds carbamazepine, sulfamethoxazole, gemfibrozil, ibuprofen, and naproxen, and the lifestyle drug caffeine, in saturated laboratory columns.

Despite the large number of pharmaceutically active compounds found in natural environments little is known about their transport behavior in groundwater, which is complicated by their wide range of physical and chemical properties. The transport behavior of five widely used and often detected pharmaceutical compounds and one lifestyle drug has therefore been investigated, using a set of three column experiments. The investigated compounds were the anticonvulsant carbamazepine, the lifestyle drug caffeine, the antibiotic sulfamethoxazole, the lipid regulator gemfibrozil, and the nonsteroidal anti-inflammatories ibuprofen and naproxen.

Transport and Attenuation of Particles of Different Density and Surface Charge: A Karst Aquifer Field Study.

Although karst aquifers are far more susceptible to contamination than porous aquifers, with the transport of particulate matter being an important factor, little is known about the attenuation of solutes within karst aquifers and even less about the attenuation of particulate matter. These in situ investigations have therefore aimed to systematically identify the processes that influence the transport and attenuation of particles within a karst aquifer through multitracer testing, using four different types of 1 μm fluorescent particles and the fluorescent dye uranine. Each of the types of particles used were detected at the observed spring, which drains the investigated aquifer.

Use of two artificial sweeteners, cyclamate and acesulfame, to identify and quantify wastewater contributions in a karst spring.

The identification and differentiation of different sources of contamination are crucial aspects of risk assessment in water resource protection. This is especially challenging in karst environments due to their highly heterogeneous flow fields. We have investigated the use of two artificial sweeteners, cyclamate and acesulfame, as an indicator set for contamination by wastewater within the rural catchment of a karst spring.

Relationship between organic micropollutants and hydro-sedimentary processes at a karst spring in south-west Germany.

Karst aquifers are known to be highly vulnerable to contamination due to their particular hydraulic characteristics. A number of parameters (such as turbidity, dissolved organic matter concentration, particle size distribution) have been proposed as proxies that can be used to detect changes in water quality or contamination of karst springs. However, most of these are not very specific concerning the source of any contamination.

Impact of materials used in lab and field experiments on the recovery of organic micropollutants.

Organic micropollutants are frequently detected in the aquatic environment. Therefore, a large number of field and laboratory studies have been conducted in order to study their fate in the environment. Due to the diversity of chemical properties among these compounds some of them may interact with materials commonly used in field and laboratory studies like tubes, filters, or sample bottles.

Potential of zerovalent iron nanoparticles for remediation of environmental organic contaminants in water: a review.

Zerovalent iron (ZVI) has the potential to degrade different organic contaminants. Nanoscale zerovalent iron (NZVI) can reduce the contaminants even more rapidly due to its small size and large specific surface area (SSA), compared to granular ZVI. The main objective of this paper is to assess and compare the potential of NZVI for degradation of different contaminants in water under specific environmental conditions.

Laboratory-scale experiments and numerical modeling of cosolvent flushing of multi-component NAPLs in saturated porous media.

This study examines the mechanistic processes governing multiphase flow of a water-cosolvent-NAPL system in saturated porous media. Laboratory batch and column flushing experiments were conducted to determine the equilibrium properties of pure NAPL and synthetically prepared NAPL mixtures as well as NAPL recovery mechanisms for different water-ethanol contents. The effect of contact time was investigated by considering different steady and intermittent flow velocities.

Redox-sensitivity and mobility of selected pharmaceutical compounds in a low flow column experiment.

In this study a laboratory column experiment under water saturated conditions was conducted to investigate the transport behaviour of the pharmaceutical compounds sulfamethoxazole, carbamazepine, diclofenac, and ibuprofen under varying nitrate concentrations. Organic rich sediment (f(OC)=0.01) and surface water from a formerly investigated field site were used.

Activated soil filters for removal of biocides from contaminated run-off and waste-waters.

Building facades can be equipped with biocides to prevent formation of algal, fungal and bacterial films. Thus run-off waters may contain these highly active compounds. In this study, the removal of several groups of biocides from contaminated waters by means of an activated soil filter was studied.

Vertical flow soil filter for the elimination of micro pollutants from storm and waste water.

A technical scale activated soil filter has been used to study the elimination rates of diverse environmentally relevant micro pollutants from storm and waste water. The filter was made of layers of peat, sand and gravel. The upper (organic) layer was planted with reed (phragmites australis) to prevent clogging and was spiked with activated sludge to enhance microbial biomass and biodegradation potential.

Mobility of pharmaceuticals carbamazepine, diclofenac, ibuprofen, and propyphenazone in miscible-displacement experiments.

Many pharmaceuticals pass the unsaturated zone before reaching an aquifer. Therefore, laboratory sand column transport experiments were conducted to study the transport behavior of carbamazepine, diclofenac, ibuprofen, and propyphenazone under unsaturated conditions. The test water was artificial sewage effluent to simulate the infiltration of reused wastewater.

Determination of sorption coefficients of pharmaceutically active substances carbamazepine, diclofenac, and ibuprofen, in sandy sediments.

Laboratory batch studies were conducted to characterize the sorption behavior of three pharmaceutically active substances (carbamazepine, diclofenac, and ibuprofen) in different sediment types. The sediments were natural sandy sediments from the water saturated zone and the unsaturated zone in the Berlin (Germany) area. They are characterized as medium and fine-grained sands, both with low organic carbon content.

Transport of pharmaceutically active compounds in saturated laboratory columns.

Occurrences of pharmaceutically active compounds in surface water and sewage water have been widely reported. Investigations show the presence of several classes of pharmaceuticals such as antirheumatics (e.g.