Biological factors influencing the degradation of water-soluble metal working fluids
- 10 Downloads
The present investigation focuses on the biological studies that determine the optimum usability of metal working fluids well before the disposal. The parameters including pH, concentration, and microbial contamination under different usage conditions were investigated. The testing conditions were limited to CNC turning centre for machining mild steel specimens. The experimental results showed a clear increase in the coolant concentration up to 21% from 3 to 5% and pH variation from the value of 7 to 10.6 due to the microbial contamination and desertion of water during weekends. Plating by serial dilution method test revealed the presence of 220 bacterial colonies with a dilution factor of 105, which was eventually reduced to 54 bacterial colonies with an implementation of stirrer and oxygenator system. Polymerase chain reaction indicated the presence of pathogenic bacteria including Arthrobacter subterraneus and Bacillus megaterium by amplifying the DNA strands and bio-informatics tools. MWF samples were further analysed for antibiotics by antibiotic susceptibility test using filter paper discs which showed bacterial growth inhibitors such as erythromycin, penicillin solution and thromycin which eliminate the bacterial contaminations.
KeywordsMetal working fluids (MWFs) Contamination pH Concentration Serial dilution method
- Cakir O, Yardimeden A, Ozben T, Kilickap E (2007) Selection of cutting fluids in machining processes. J Achiev Mater Manuf Eng 25(2):99–102Google Scholar
- Kucharikova E, Peterka J et al (2009) Cutting fluids management. J Mater Sci Technol 26:33–38Google Scholar
- Taylor GT (1999) Bio-degradation of used machine tool cutting fluids. In: Waste Management Conference, Arizona, USAGoogle Scholar