Reuse of refinery’s tertiary-treated wastewater in cooling towers: microbiological monitoring

Abstract

The study was planned to quantify the distribution of bacteria between bulk water and biofilm formed on different materials in an industrial scale cooling tower system of an oil refinery operating with clarified and chlorinated freshwater (CCW) or chlorinated tertiary effluent (TRW) as makeup water. The sessile and planktonic heterotrophic bacteria and Pseudomonas aeruginosa densities were significantly higher in the cooling tower supplied with clarified and chlorinated freshwater (CTCW) (p < 0.05). In the two towers, the biofilm density was higher on the surface of glass slides and stainless steel coupons than on the surface of carbon steel coupons. The average corrosion rates of carbon steel coupons (0.4-0.8 millimeters per year (mpy)) and densities of sessile (12-1.47 × 10(3) colony-forming unit (CFU) cm(-1)) and planktonic (0-2.36 × 10(3) CFU mL(-1)) microbiota remained below of the maximum values of reference used by water treatment companies as indicative of efficient microbial control. These data indicate that the strategies of the water treatment station (WTS) (free chlorine) and industrial wastewater treatment station (IWTS) followed by reverse electrodialysis system (RES) (free chlorine plus chloramine) were effective for the microbiological control of the two makeup water sources.

Wastewater reuse in a cascade based system of a petrochemical industry for the replacement of losses in cooling towers

“…Limpt and Wal (2014) treated the make up stream and achieved savings of up to 85% of chemical inputs, 28% of make up water and 48% of discharged effluent (van Limpt and van der Wal, 2014). Chien et al (2012) evaluated the use of treated municipal wastewater for losses reposition in cooling towers (Chien et al, 2012) and Santos et al (2015) used industrial treated wastewater to replenish losses in the cooling tower of a refinery in Brazil (Santos et al, 2015). Durante et al (2015) also used conventional treated effluent as make up water in a cooling tower in an agribusiness industry (Durante et al, 2015).…”

Comparative study of free and liposome-entrapped chloramphenicol against biofilms of potentially pathogenic bacteria isolated from cooling towers

“…They were obtained from the circulating water from industrial scale cooling towers (called towers 1 and 2) of a Brazilian industry. These isolates are part of the microbiota associated to corrosion of these towers, and were isolated as previously described by our group (Santos et al, 2015). All bacteria were identified by partial sequencing of the 16S rRNA (Dias-Souza et al, submitted to publication).…”

Assessing the factors affecting the water chemistry parameters in the auxiliary water system of a nuclear power plant

“…Response surface methodology is utilized in a wide spectrum of research activities to design and optimize the experimental runs [30][31][32][33]. This method is adopted to determine the critical values of make-up chloride and sodium content to prevent chemistry violations in the system.…”