Ecolab USA Inc.

Nalco Chemical Company

Nalco Company

Alessandra Gerli

Michael J Murcia

Seong-Hoon Yoon

Geoff Townsend

Bruno C M Fernandes

Muhammad Tariq Khan

Jane B Wong Shing

Angela P Zagala

Laura M Sherman

Ana Urmenyi

Cathy C Doucette

Przem Pruszynski

Xavier S Cardoso

David I Weinstein

Biocide can be controllably added to a feed stream for a membrane. The membrane can separate the feed stream into a purified permeate stream and a concentrate stream containing contaminants from the feed stream. In some examples, a charge neutral biocide is introduced into the feed stream at a first addition rate. The concentration of the charge neutral biocide in the permeate stream is measured to provide a measured concentration of the charge neutral biocide in the permeate stream. The addition rate of the charge neutral biocide can be adjusted based on the measured concentration of the charge neutral biocide in the permeate stream to introduce charge neutral biocide into the feed stream at a second addition rate different than the first addition rate.

Charge neutral biocide dosing control for membrane biofouling control applications

Biocide can be controllably added to a feed stream for a membrane. In some examples, the feed stream is separated into a primary feed stream and a secondary feed stream, for example, with the secondary feed stream having a lower flow rate than the primary feed stream. The secondary feed stream may be used to monitor and control the addition of the biocide, which is then diluted when the secondary feed stream is combined with the primary feed stream to form a combined stream for delivery to the membrane.

Accurate biocide dosing for low concentration membrane biofouling control applications

A method of preparing a modified diallyl-N,N-disubstituted ammonium halide polymer and use of the polymer in combination with one or more high molecular weight, water soluble cationic, anionic, nonionic, zwitterionic or amphoteric polymers for increasing retention and drainage in a papermaking furnish.

Method of preparing modified diallyl-N,N-disubstituted ammonium halide polymers

An improved papermaking process comprising forming an aqueous coated broke papermaking slurry and adding a blend of a water-soluble dispersion polymer and a coagulant to the slurry to increase retention and/or drainage is disclosed. After addition of the polymers, the slurry is drained to form a sheet, and the sheet is dried.

Use of blends of dispersion polymers and coagulants for coated broke

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Leiden, Netherlands

Alessandra Gerli