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Difference between revisions of "Flocculation"
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{{Infobox technology|Name=Flocculation|Category=Separation technologies}} | {{Infobox technology|Name=Flocculation|Category=Separation technologies}} | ||
<onlyinclude>Flocculation refers to the "reversible aggregation of colloidal particles to larger particles that can be filtered"<ref>{{Cite book|author=Peter W. Atkins, Loretta Jones|year=2006|book_title=Chemie - einfach alles|publisher=Wiley-VCH|place=Weinheim|ISBN=978-3-527-31579-6}}</ref>. Flocculation can be induced by adding "flocculants". The IUPAC Gold Book uses coagulation and flocculation as synonyms of agglomeration and defines agglomeration as a "process of contact and adhesion whereby dispersed particles are held together by weak physical interactions ultimately leading to phase separation by the formation of precipitates of larger than colloidal size."<ref>{{Cite web|Author=The International Union of Pure and Applied Chemistry (IUPAC)|title=IUPAC - agglomeration (except in polymer science) (A00182)|url=https://goldbook.iupac.org/terms/view/A00182|year=|e-pub date=|date accessed=January 31, 2022}}</ref></onlyinclude> | <onlyinclude>'''Flocculation''' refers to the "reversible aggregation of colloidal particles to larger particles that can be filtered"<ref>{{Cite book|author=Peter W. Atkins, Loretta Jones|year=2006|book_title=Chemie - einfach alles|publisher=Wiley-VCH|place=Weinheim|ISBN=978-3-527-31579-6}}</ref>. Flocculation can be induced by adding "flocculants". The IUPAC Gold Book uses coagulation and flocculation as synonyms of agglomeration and defines agglomeration as a "process of contact and adhesion whereby dispersed particles are held together by weak physical interactions ultimately leading to phase separation by the formation of precipitates of larger than colloidal size."<ref>{{Cite web|Author=The International Union of Pure and Applied Chemistry (IUPAC)|title=IUPAC - agglomeration (except in polymer science) (A00182)|url=https://goldbook.iupac.org/terms/view/A00182|year=|e-pub date=|date accessed=January 31, 2022}}</ref></onlyinclude> | ||
==Feedstock== | ==Feedstock== | ||
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==Process and technologies== | ==Process and technologies== | ||
Exemplary applications: | Exemplary applications: Flocculation is used in biotechnology applications in conjunction with microfiltration to improve the efficiency of biological feeds. The addition of synthetic flocculants to the bioreactor can increase the average particle size making microfiltration more efficient. When flocculants are not added, cakes can form and accumulate causing low cell viability. Positively charged flocculants work better than negatively charged ones since the cells are generally negatively charged. | ||
In the brewing industry flocculation is a very important process in fermentation during the production of beer where cells form macroscopic flocs. These flocs cause the yeast to sediment or rise to the top of a fermentation at the end of the fermentation. Subsequently, the yeast can be collected (cropped) from the top (ale fermentation) or the bottom (lager fermentation) of the fermenter in order to be reused for the next fermentation. | In the brewing industry flocculation is a very important process in fermentation during the production of beer where cells form macroscopic flocs. These flocs cause the yeast to sediment or rise to the top of a fermentation at the end of the fermentation. Subsequently, the yeast can be collected (cropped) from the top (ale fermentation) or the bottom (lager fermentation) of the fermenter in order to be reused for the next fermentation. | ||