Importance of Biofilm Monitoring

What Standard Microbiological Tests Don’t Show

  • 17 novembre 2020
  • Author: John Bychkowski
  • Number of views: 2035
  • 0 Comments

Impact of Poor Microbiological Control
Uncontrolled microbiological growth in cooling and process water systems is a multi-billion dollar problem for businesses each year. The primary cause of this expensive problem is biofilm. Biofilms form when bacteria and other microorganisms found in the bulk water attach to exposed surfaces and begin to produce a mass of biopolymers known as extracellular polymeric substance (EPS). The EPS provides a sticky, protective barrier that allows complex communities of bacteria to thrive and exponentially grow. Bulky, biofouling deposits can quickly form as the EPS traps dirt, corrosion byproducts, and other debris suspended in the water, leading to blockages.

The protective barrier formed by biofilm is hard to penetrate with traditional biocide programs, making it very problematic in systems. Once established, biofilms can cause a multitude of problems including flow restrictions, reduced heat transfer, and microbiologically-influenced corrosion (MIC). These issues can lead to poor heat transfer efficiency, lost production, and even catastrophic equipment failures.

Current Monitoring Methods
Monitoring for microbiological control is an essential part of the water treatment program. Typical monitoring methods like dip slides or laboratory plate cultures only measure the planktonic (free floating) bacteria in the water sample from the system and not the bacteria growing within the biofilm, which can account for as much as 90% of all microbial activity in a system. The absence of bacteria using these methods does not necessarily indicate that a system does not have a biofouling problem.

Innovations in Microbiological Monitoring
To address the missing link in microbiological monitoring in the water treatment industry, Chem-Aqua developed a new biofilm monitor. The bioDART
® is an automatic, real-time monitor that measures a systems potential to form biofouling deposits. A systems biofouling index (BFI) reading provides a quantitative predictive indicator of its potential to form biofilm that can be used to gauge microbiological control. Sudden spikes or rapid increases in the BFI can be indicators of high levels of biofouling bacteria or changes in system operations. Examples include:

  • Offline chillers being brought online
  • Upsets in biocide feed
  • Mechanical upsets or process leaks (Glycol, process water, other contaminants)

Early warning signs allow Chem-Aqua to adjust and adapt the microbiological control program to changes in the system in order to optimize program costs and results.

Written by: John Bychkowski

Print
Tags:
Rate this article:
4.5

Please login or register to post comments.

Name:
Email:
Subject:
Message:
x

Tags

accumulators activated carbon aerobic bacteria air-cooled alkalinity amines anaerobic bacteria ASHRAE ASHRAE 188 ASHRAE 188-2018 atomizing A-type bacteria biocides biofilm biofouling blowdown blowdown control blowdown rate boiler boiler blowdown control boilers building water system calcium carbonate calculation capacity chapel tubes chilled chillers chlorides cleaning closed loop CMS directive compressor conductivity Control Ranges cooling Cooling System cooling systems cooling tower cooling towers cooling water corrosion Critical Parameters crystal growth modification polymers cycles of concentration dead legs Deaerator dealkalizer demand deposits disinfection dispersants dissolved gases dissolved solids downcomer D-type electric boilers EPS equipment extracellular polymeric substances filter sand filtration fire tube fire tube boilers firetube firetube boilers free halogen galvanic gases greensand halogen hard water hardness high heat flux steam generators hot water how do cooling towers work HVAC hybrid boilers ice ice machine inhibitor lead leak legionella legionella policy legionnaires legionnaire's disease magnesium silicate makeup water media microbial microbiological microorganisms molybdenum neutralizing amines non-oxidizing biocides oxidizing biocides Parameters phosphate phosphonate planktonic bacteria plastics plastics manufacturing preatreatment pretreatment preventative maintenance protozoa refrigeration residual retrograde solubility reverse osmosis risk risk management sanitizing scale sediment filtration sessile bacteria silica softener solids spray scrubber spray-type stagnant steam steam boiler steam boilers sterilization testing threshold inhibitors tray-type vapor compression venting vertical boilers volume volume estimation water loss water management water management plan water treatment water tube water tube boilers water-cooled watertube watertube boilers WMP