Remediation of dense non-aqueous phase liquids (DNAPLs) represents a challenging issue because of their persistent behaviour in the environment. This pilot-scale study investigates, by means of in situ experiments and numerical modelling, the feasibility of the pulsed pumping process of a large amount of a DNAPL in an alluvial aquifer. The main compound of the DNAPL is hexachlorobutadiene (HCBD), added in 2015 to the persistent organic pollutants list (POP). A low-permeability keyed enclosure was built at the location of the DNAPL source zone in order to isolate a finite volume of soil and a 3-month pulsed pumping process was applied inside the enclosure to exclusively extract the DNAPL. The water/DNAPL interface elevation at both the pumping well and an observation well was recorded. The cumulated pumped volume of DNAPL was also monitored. A total volume of about 20 m of pure DNAPL was recovered since no water was extracted during the process. The three-dimensional and multiphase flow simulator TMVOC was used and a conceptual model was elaborated and generated with the pre/post-processing tool mView. Numerical simulations reproduce the pulsed pumping process and show an excellent match between simulated and field data of DNAPL cumulated pumped volume and a reasonable agreement between modelled and observed data for the evolution of the water/DNAPL interface elevations at the two wells. This study offers a new perspective in remediation since DNAPL pumping system optimisation may be performed where a large amount of DNAPL is encountered.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jconhyd.2018.05.005DOI Listing

Publication Analysis

Top Keywords

pulsed pumping
16
pumping process
16
dnapl
10
numerical modelling
8
process large
8
keyed enclosure
8
large amount
8
amount dnapl
8
water/dnapl interface
8
cumulated pumped
8

Similar Publications

Clonal Spread and Genetic Mechanisms Underpinning Ciprofloxacin Resistance in .

Foods

January 2025

MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, China.

is a major cause of foodborne illness worldwide, and the emergence of ciprofloxacin-resistant strains poses a significant threat to food safety and public health. This study aimed to investigate the prevalence, spread, and mechanisms of ciprofloxacin resistance in isolates from food and patient samples in Shanghai, China. A total of 1625 isolates were screened, and 34 (2.

View Article and Find Full Text PDF

The Pre-Polarization and Concentration of Cells near Micro-Electrodes Using AC Electric Fields Enhances the Electrical Cell Lysis in a Sessile Drop.

Biosensors (Basel)

January 2025

Biomedical Engineering Program, Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23508, USA.

Cell lysis is the starting step of many biomedical assays. Electric field-based cell lysis is widely used in many applications, including point-of-care (POC) applications, because it provides an easy one-step solution. Many electric field-based lysis methods utilize micro-electrodes to apply short electric pulses across cells.

View Article and Find Full Text PDF

Background: The purpose of this study was to investigate the myocardial protective effect of Xuebijing (XBJ) injection in isolated donor heart preservation based on autophagy and NLRP3 inflammatory pathway, and to provide clues for improving the quality of donor heart preservation in the clinic.

Methods: Fourteen Guangxi Bama miniature pigs were randomly divided into two groups to establish the isolated heart perfusion model of extracorporeal membrane oxygenation (ECMO): (1) normal saline group (NS group): 50 mL normal saline was added to the perfusion solution; and (2) Xuebijing injection group (XBJ group): 10 mL of XBJ was added to the perfusate. Both groups were continuously pumped with 5 mL/h for 8 hours.

View Article and Find Full Text PDF

Low-threshold anisotropic polychromatic emission from monodisperse quantum dots.

Natl Sci Rev

February 2025

Institute of Nanoscience and Applications, Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.

Colloidal quantum dots (QDs) are solution-processable semiconductor nanocrystals with favorable optoelectronic characteristics, one of which is their multi-excitonic behavior that enables broadband polychromatic light generation and amplification from monodisperse QDs. However, the practicality of this has been limited by the difficulty in achieving spatial separation and patterning of different colors as well as the high pumping intensity required to excite the multi-excitonic states. Here, we have addressed these issues by integrating monodisperse QDs in multi-excitonic states into a specially designed cavity, in which the QDs exhibit an anisotropic polychromatic emission (APE) characteristic that allows for tuning the emission from green to red by shifting the observation direction from perpendicular to lateral.

View Article and Find Full Text PDF

Schlieren texture and topography induced confinement in an organic exciton-polariton laser.

Nat Commun

January 2025

Humboldt Centre for Nano- and Biophotonics, Institute for Light and Matter, Department of Chemistry and Biochemistry, University of Cologne, Köln, Germany.

Non-linearities in organic exciton-polariton microcavities represent an attractive platform for quantum devices. However, progress in this area hinges on the development of material platforms for high-performance polariton lasing, scalable and sustainable fabrication, and ultimately strategies for electrical pumping. Here, we show how introducing Schlieren texturing and a rough intra-cavity topography in a liquid crystalline conjugated polymer enables strong in-plane confinement of polaritons and drastic enhancement of the lasing properties.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!