Adhesion of bacterial pathogens to soil colloidal particles: Influences of cell type, natural organic matter, and solution chemistry

Fouling and subsequent chemical cleaning are two important issues for sustainable operation of nanofiltration (NF) membranes in water quality control applications. Because fouling strongly depends on the feed water quality, especially the ionic composition, chemical cleaning solutions should be chosen to target the solution chemistry that is most responsible for the formation of a compact, high resistance fouling layer. In this study, the effect of solution chemistry on natural organic matter (NOM) fouling of two NF membranes with different surface properties was investigated. Compared to monovalent cations, divalent cations were found to greatly enhance NOM fouling by complexation. Moreover, calcium ions caused a much greater fouling rate than magnesium ions, presumably due to the intermolecular bridging formed among NOM molecules through the calcium ions. Various chemical cleaning solutions were evaluated for water flux recovery efficiency. Although both deionized water and dilute NaOH solution were found effective in cleaning membranes fouled in the absence of calcium ions, efficient chemical cleaning in presence of calcium was achieved only when the calcium ion bridging was eliminated. The cleaning efficiency was shown to be highly dependent on solution pH and the concentration of the chemical cleaning agent.

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Electrostatic and (electro-)steric stabilization of colloidal particles by natural organic matter

10.7185/gold2021.6889 ◽

2021 ◽

Author(s):

Seniha Simale Su Uygan ◽

Stefan Schymura

Keyword(s):

Organic Matter ◽

Natural Organic Matter ◽

Colloidal Particles ◽

Steric Stabilization

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Influences of solution chemistry and polymeric natural organic matter on the removal of aquatic pharmaceutical residuals by nanofiltration

Water Research ◽

10.1016/j.watres.2009.04.038 ◽

2009 ◽

Vol 43 (13) ◽

pp. 3270-3280 ◽

Cited By ~ 75

Author(s):

Mohammad Ali Zazouli ◽

Heru Susanto ◽

Simin Nasseri ◽

Mathias Ulbricht

Keyword(s):

Organic Matter ◽

Natural Organic Matter ◽

Solution Chemistry

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Natural organic matter removal by nanofiltration: effects of solution chemistry on retention of low molar mass acids versus bulk organic matter

Journal of Membrane Science ◽

10.1016/j.memsci.2004.05.018 ◽

2004 ◽

Vol 242 (1-2) ◽

pp. 73-85 ◽

Cited By ~ 57

Author(s):

A.I. Schäfer ◽

A. Pihlajamäki ◽

A.G. Fane ◽

T.D. Waite ◽

M. Nyström

Keyword(s):

Organic Matter ◽

Natural Organic Matter ◽

Molar Mass ◽

Solution Chemistry ◽

Organic Matter Removal ◽

Bulk Organic Matter

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GPE 2007 - Utilization of the Coagulation Diagram in the Evaluation of the Natural Organic Matter (NOM) Removal for Obtaining Potable Water

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1441 ◽

2008 ◽

Vol 6 (1) ◽

Author(s):

Leila C Konradt Moraes ◽

Rosangela Bergamasco ◽

Célia Granhen Tavares ◽

Dillaine Hennig ◽

Milene Carvalho Bongiovani

Keyword(s):

Organic Matter ◽

Natural Organic Matter ◽

Colloidal Particles ◽

Potable Water ◽

Sodium Hydroxide Solution ◽

Degradation Process ◽

Process Efficiency ◽

Jar Test ◽

Soil Constituents ◽

Flocculation Time

The natural organic matter (NOM) is a mixture of many organic compounds that can be dispersed in superficial water. The NOM is due to the compounds formed in the biologic degradation process of the vegetable organic matter and its interaction with the clay and the other hydrographic basin soil constituents, besides algae and other microorganism activity. Many researchers have obtained results that indicate that the coagulation/flocculation process is an effective process in the NOM reduction without committing the non-stabilization colloidal particles. So, with the intuit to guarantee a better final water quality in the water treatment plants, different studies were evaluated based on the coagulation diagram for obtaining the best concentration of the chitosan coagulant as function of the pH for the NOM removal for obtaining potable water. The data for the coagulation diagram construction will be obtained by a series of tests in a jar-test apparatus. Different concentrations of the coagulant solution (0.1% w/v of chitosan) will be studied. The pH will be varied (4.0 8.5) with sodium hydroxide solution (NaOH) and hydrochloric acid (HCl) 25 and 50%. The rapid mixture gradient, the coagulation time, the slow mixture gradient and the flocculation time will be maintained constant during this experiment. The process efficiency will be evaluated by the color, turbidity and compounds with absorption in UV-254nm removal. The best results of removal were found for the chitosan in the concentration of 1.0mg/L and pH between 4.0-5.0, approximately.

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