Effect of oxidizing and non-oxidizing biocides on biofilm at different substrate levels in the model recirculating cooling water system

Abstract

With the reducing of water resources, using advanced treated refinery wastewater as recirculating cooling water is an effective method to save water and to reduce the pollution of petroleum and petrochemical industry. However, the control of biofilm is a bottleneck in the application of this technology. To resolve the problem of biofilm formation and development, antimicrobial characteristics of chlorine dioxide and benzyldimethyldodecyl-ammonium chloride on biofilm at different substrate levels were investigated. Biofilm detachment ratio and TTC-dehydrogenase activity (DHA) were two indexes to discuss the antimicrobial effects. The results showed that at the high substrate level, the biofilms characteristics (biomass, the content of protein, polysaccharide and EPS) were the higher than those at the medium and low substrate levels, however biofilm's DHA at the medium substrate level (12.97 lgTF/(g h)) was higher than those at the medium substrate level (7.64 lgTF/(g h)) and low substrate level (1.94 lgTF/(g h). The difference of substrate level in the media resulted in different biofilm structure. By contrast with the control experiment, biofilm detachment ratios were all increased in three media with ClO 2 and BDMDAC addition. After ClO 2 addition, MITs were 30, 120 and 240 min and MIC was 1, 4 and 6 mg/L, respectively, at the low, medium and high substrate level. After BDMDAC addition, MITs in three media were all longer than those after ClO 2 addition, MIC was 200, 300 and 400 mg/L, respectively, at the low, medium and high substrate level.

Effect of six kinds of scale inhibitors on calcium carbonate precipitation in high salinity wastewater at high temperatures

“…In recent years, more attention has been paid to the reuse of refinery wastewater in the petroleum industry after advanced treatment (Liu et al, 2011a(Liu et al, , 2011b. Compared with natural water, there are a considerable number of inorganic ions and organic substrates in refinery wastewater, which would lead to easier scale formation in circulating cooling water systems (Liu et al, 2013).…”

The application of non-oxidizing biocides to prevent biofouling in reverse osmosis polyamide membrane systems: a review

“…Benzyldimethyldodecyl ammonium chloride (BDMDAC) is a quaternary ammonium salt agent and cationic biocide, routinely used as a disinfectant in swimming pools and industrial cooling water systems (Ferreira et al 2009;Liu et al 2011). BDMDAC forms an electrostatic bond with the negatively charged sites on microbial cell walls, causing cell lysis, disruption of cell-wall permeability, and reduced intake of nutrients to the cell (Liu et al 2011). BDMDAC has very good inactivation potential, but Gomes et al (2014) concluded that it was unsuccessful at removing biofilms.…”

Antimicrobial and Anticorrosion Activity of a Novel Composite Biocide against Mixed Bacterial Strains in Taiwanese Marine Environments

“…To control biocorrosion, various techniques have been employed, including protective coatings [ 20 ], corrosion inhibitors [ 21 ], cathodic production [ 22 , 23 ], biological approaches [ 24 ], and biocides [ 25 , 26 ]. Among these methods, all of which are based on the inhibition of bacterial growth and excessive biofilm formation, biocides are the most commonly used.…”