Formaldehyde, biocidal action

Formaldehyde, biocidal action, 34 (1997) 149 Free energy, biological action and linear, 10 (1974) 205... 

The release of formaldehyde during the generation of the biocidally active phosphine is responsible for the reduction in hydrogen sulfide concentrations that have been observed during its use (Larsen et al, 2000). The release of formaldehyde probably is not responsible for any appreciable amount of biocidal action. In oilfield systems that have insoluble iron sulfide present, the use of THPS has been seen to help dissolve and remediate the problems associated with iron sulfide fouling (Walker, 1991 Diaz, 1998 Nasr-El-Din and Al-Humaidan, 2001 Jeffery et al, 2000 Gilbert et al, 2002). The species that is responsible for this reaction is actually the THP (trihydroxymethyl phosphine). 

Summary. This paper supports the use of formaldehyde at economically feasible concentrations as a biocide for EOR processes that use xanthan biopolymer. Its biocidal action against anaerobic sessile xanthan-degrading field organisms was clearly superior to three other biocides tested when 100% kill was used as the criterion for effectiveness. 

The results reported here indicate the potential for Bronopol (Myacide AS) as a preservative in mineral slurry systems. In particular, its ability to control organisms that are tolerant or resistant to other biocide chemistries is a valuable feature. Sondossi et alf" have reported on the activity of Bronopol against organisms that are resistant to formaldehyde. The results presented here indicate that this ability also covers BIT resistant organisms. The explanation for this may be related to some unique facet of Bronopol s mode of action and this fact is supported by published work. Overall, it suggests that Bronopol could be used in clean-up regimes to recover contaminated product. 

As far as the biocide properties are concerned, 0-Mannich bases containing extended hydrocarbon chains and used for their combined detcrgent/gcrmicidc action are worth mentioning. A good preserving function is also performed by plywood adhesives, based on urea, melamine, and formaldehyde, which are fixed by suitable iodo-derivatives presumably by amino- and amidomethylation reactions. 

Rossmore HW, Sondossi M. Applications and mode of action of formaldehyde condensate biocides. Adv Appl Microbiol 1988 33 223-273. 

Environmental concerns and local regulations often dictate the use of specific sanitizers in a particular geographic location. Owing to safety concerns, the use of formaldehyde in USA has declined, in contrast to Europe, where formaldehyde and glyoxal are widely used in formulations for hard surface care products and hospital instrument disinfection. Alcohol sanitizers are primarily used in waterless hand wipes, and hand sanitizers and disinfectants. The antimicrobial action wears off when the volatile alcohol evaporates from hands or substrates. Alcohol sanitizers are not strong biocides. The most commonly used alcohol as a disinfectant is pine oil that is obtained from pitch soaking of pinewoodby steam distillation or solvent extraction. It consists mainly of isomeric tertiary and secondary, cyclic terpene alcohol, and has a turpentine-like odor. Pine sol is predominantly used in household consumer products. 

Mechanism of action. QACs have surfactant properties and therefore help to solubilize the cell membrane of microbial cells (Merianos, 1991). This leads to cell damage and ultimately cell death. QACs are especially effective when used in combination with other biocides that attaek the cell wall. The surfactant action exhibited by the QAC helps to make the cell wall of microbial cells more aeeessible to other biocides. The QACs facilitate penetration of biocides such as glutaraldehyde, formaldehyde, and THPS and leads to enhanced biocidal activity of these biocides. 

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