Search results for "Filtration"
showing 8 items of 908 documents
Modelling urban stormwater impact mitigation by using bmps and storage tanks
2005
The continuous growth of urban areas and the increasing public awareness about environmental impact of stormwater raised high interest on quality impact on the receiving water bodies. Indeed, in the last decades, large efforts have been provided for improving urban drainage systems in order to mitigate environmental impacts. In the present paper, a simplified modelling approach has been developed in order to evaluate the mitigation efficiency of different BMP schemes including infiltration and storage facilities and both considering possible distributed controls and centralised structures. The main goals of the research are the simulation of BMP efficiency in different operational condition…
Hydro-mechanical modelling of MX-80 bentonite: one dimensional study
2016
As a first step towards modelling the coupled Thermo-Hydro-Mechanical-Chemical (THMC) behaviour of bentonite, the Barcelona Basic Model (BBM) has been implemented into Numerrin finite element code. This model has been fully coupled with the single phase flow equation for unsaturated soils which models liquid water transport. Suction obtained from solving the flow equation is used as an input for the BBM model and the volumetric deformations from the mechanical analysis are used to update the pore water pressure field. As an alternative, BBM is used alongside the Kröhn’s model which assumes that bentonite re-saturation is mainly driven by water vapour diffusion. The paper simulates one dimen…
The effects of different combinations of fixed and moving bed bioreactors on rainbow trout (Oncorhynchus mykiss) growth and health, water quality and…
2019
The effect of bioreactor design on nitrification efficiency has been well studied, but less is known about the overall impacts on water quality. Besides nitrification, submerged fixed bed bioreactors (FBBR) trap fine solid particles, whereas moving bed bioreactors (MBBR) grind solids, possibly increasing solids and particle accumulation in the system. In this experiment, the effects of different combinations of fixed bed and moving bed bioreactors on water quality, solids removal, particle size distribution, fish health based on histopathological changes and nitrification efficiency were studied in laboratory scale recirculating aquaculture systems (RAS) with rainbow trout (Oncorhynchus myk…
Microstructural evaluation and recommendations for face masks in community use to reduce the transmission of respiratory infectious diseases
2022
Funding Information: A.K., H.Y. and R.J. also acknowledges the funding through Academy of Finland BESIMAL (Decision No. 334197) and Aalto University, Department of Communications and Networking. This work has also received funding in part from the EPSRC UK (grant number EP/R012091/1). A.K. would also like to thank Mr. Volkan Kaplan for the fruitful discussions in the early concept generation. Publisher Copyright: © 2022 The Author(s) Background and Objective: Recommendations for the use of face masks to prevent and protect against the aerosols (≤5µm) and respiratory droplet particles (≥5µm), which can carry and transmit respiratory infections including severe acute respiratory syndrome coro…
Modelling the removal and reversible immobilization of murine noroviruses in a Phaeozem under various contamination and rinsing conditions
2018
International audience; Enteric viruses entering the soil with contaminated irrigation water can reach groundwater or be internalized in plants through their roots without being inactivated. Their fate in the soil depends on the virus, the soil and the soil solution. In order to write a mathematical model suitable for a Calcaric Phaeozem, we investigated the removal of murine norovirus and reversible immobilization in aggregate columns according to a saturation procedure, conditions between contamination and rinsing time, temperature and soil solution. Viruses were quantified before and after 0.45‐μm filtration with an RT‐qPCR (real‐time polymerase chain reaction). Experimental results supp…
Alternative analysis of transient infiltration experiment to estimate soil water repellency
2019
The repellency index (RI) defined as the adjusted ratio between soil‐ethanol, Se, and soil‐water, Sw, sorptivities estimated from minidisk infiltrometer experiments has been used instead of the widely used water drop penetration time and molarity of ethanol drop tests to assess soil water repellency. However, sorptivity calculated by the usual early‐time infiltration equation may be overestimated as the effects of gravity and lateral capillary are neglected. With the aim to establish the best applicative procedure to assess RI, different approaches to estimate Se and Sw were compared that make use of both the early‐time infiltration equation (namely, the 1 min, S1, and the short‐time linear…
Diallyldimethylammonium Chloride (DADMAC) in Water Treated with Poly-Diallyldimethylammonium Chloride (PDADMAC) by Reversed-Phase Ion-Pair Chromatogr…
2023
Poly-diallyldimethylammonium (PDADMAC) chloride is a flocculant agent extensively used in water clarification treatments. Commercial polyelectrolyte formulations often contain residual monomer (DADMAC), reaction by-products and other reactants as contaminants that could potentially affect human health. In the present study, we optimized an analytical method based on reversed-phase ion-pair chromatography coupled with mass spectrometry for quantifying ultra-trace levels of DADMAC, without preliminary treatments, in drinking water distributed by the Palermo aqueduct. The method was validated in terms of accuracy (recovery between 80 to 120%), precision (RSD < 10%), linearity range (from 0.…