Taguchi approach significantly increases bioremediation process efficiency: a case study with Hg (II) removal by Pseudomonas aeruginosa.
OBJECTIVE
Optimization of process parameters for mercury removal by an Hg (II)-reducing Pseudomonas aeruginosa strain.


RESULTS
A strain of Ps. aeruginosa was found to reduce 10 mg l(-1) Hg (II) to Hg0 with 70% efficiency in 24 h. To optimize process performance, a statistical tool--Taguchi design of experiments (DOE)--was used to carry out 18 well-defined experiments (L18 Orthogonal array) with eight variable parameters (viz. agitation, temperature, pH, carbon source, medium volume: flask volume ratio and concentrations of Hg (II), ammonium sulfate and yeast extract). When data obtained were analyzed using specialized software for Taguchi design, Qualitek-4 (Nutek Inc., MI, USA), Hg (II) reduction efficiency was predicted to be 95% in 24 h under the optimized process parameters (also suggested by the software). In the validation experiment, Hg (II) removal of 99.29% in 24 h was indeed obtained.


CONCLUSIONS
Using Taguchi DOE, Hg (II) reduction (and hence its removal) using Ps. aeruginosa could be improved by 29.3%.


CONCLUSIONS
Taguchi approach could be employed as an efficient and time-saving strategy for parameter optimization in bioremediation processes.
Tupe
S G
SG
Agharkar Research Institute, Pune, India.
Rajwade
J M
JM
Paknikar
K M
KM
D018533:Biomass; D019149:Bioreactors; D003198:Computer Simulation; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D008627:Mercuric Chloride / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology; D012984:Software; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
D003470:Culture Media; D012722:Sewage; D014874:Water Pollutants, Chemical; D008627:Mercuric Chloride