Colloidal fouling of nanofiltration membranes: A novel transient electrokinetic model and experimental study

Colloidal fouling is one of the main reasons for the reduced efficiency of membrane based water desalination processes. The synchrony of several resistance mechanisms like hydraulic, osmotic, and electro-kinetic as well as numerous coupling effects complicate the analysis of their individual contributions to the fouling extent. An new measuring approach using a dead-end filtration test-cell allows exactly this, irrespectively of any simultaneously occurring concentration polarization phenomena. First results show that the hydraulic resistance of a fully developed colloidal layer is not exclusively determined by the physicochemical properties of its constituents but seems to be strongly depending on the specific way of its formation (e.g. ionic strength prevailing during layer build up or filtration sequence of different particle sizes). This time-dependent effect is largely irreversible and therefore most likely due to persistent changes in the fouling layer structure. A minor reversible ionic strength effect could also be demonstrated. The extent of this effect is identical irrespectively if the ionic strength is increased or decreased. Results further indicate that commonly applied models like the Kozeny-Carman equation are lacking a size dependent parameter that causes a disproportional decrease of colloidal fouling layer resistance with decreasing foulant particle size.

/pdf/measuring-hydraulic-layer-resistance-and-correlated-effects-4pv8e6gkjq.pdf

Measuring hydraulic layer resistance and correlated effects in colloidal fouling of salt-retaining membranes

Physicochemical influences on electrohydrodynamic transport in compressible packed beds of colloidal boehmite particles

Production and processing of colloidal particles require a deeper understanding of surface charge of particles and interaction of mass and charge transport in packed beds. The assessment of fundamental parameters is rather complex due to the additional influence of the particle charge on the structure of a packed bed. The combination of different measurement techniques (streaming potential and electroosmosis) allows for separating the effects, based on the postulation of a new method to quantify the ratio of surface conductance to liquid conductance. The purpose of this paper is to investigate the influence of the pH value and compression on the electrohydrodynamic transport parameters.

Electrohydrodynamic transport in nanoporous packed beds

Electrostatic and electroviscous effects can significantly decrease the permeability of packed beds which consist of colloidal particles. This results in poor filterability of colloidal suspensions. Electrostatic effects refer to the dependency of the structure of the packed bed on the particles' tendency to agglomerate or disagglomerate. This tendency is influenced by the particle charge, and thus the pH and the ionic strength of the suspension. Electroviscous effects relate to the increased flow resistance of the pores due to a streaming potential being established when the electrochemical double layer of the particles is sheared off. It is difficult to distinguish electrostatic and electroviscous effects because they are interrelated. The comparison of permeability measurements of both TiO 2 and Al 2 O 3 with a classical permeability model demonstrates the influence of the two different effects on permeability.

Distinction between Electrostatic and Electrokinetic Effects on the Permeability of Colloidal Packed Beds

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

B. Schäfer

Author Tools

Chat about Author

Papers

Distinction between Electrostatic and Electrokinetic Effects on the Permeability of Colloidal Packed Beds