The kinetics on the growth of T. fenturx/dans in the presence of Cu ( H ) was studied using d series piezoeleclrie quartz crystal (SP~). Arsenic ion inhibits the growth of T.ferroox/dans, which is consistem with the previous results by other measuring methods. This further demonstrates that the SPQC can monitor the chemical activity of T.ferroox4Ams growth. Cupric ion accelerates the growth of T.ferrotrx4.dam. The mechanism was discussed, i. e., copper lXOn~tes the protein enzyme of T. ferwox/dans, msticyanin, to form over the range of cupric ion concentration studied. The reaction order of cupric ion in accelerating the bacterial growth is 0.067. The growth of T.~ is dependent on temperature, the apparent reaction activation energy decreases from 25.56 kJ/mol to 18.32 kJ/mol because of the addition of 10 mg/L Cu( I1 ) to the bacterial growth solution of pH 2.0 at initial inocuhm of 10%. Kay words: series piezoelectric quartz crystal; T.ferroaddam ; growth kinetics; sigmoid curve; cupric ion Document code: A In biohydrometallurgy, T.ferroox/&z~ is one of the most important microorganisms hI for the extraction of base metals including coppe rE2-43 , nickel [s'6] , zinc [73 , lead [s3 etc, and the pretreatment of arsenic refractory gold oresE9-t21.The studies on the growth of T. ferroox/dans have been conducted by many researchers E13"Lsl , and corresponding mechanisms were put forward [16ml . The major obstacles ~lsJ encountered in commercially bioleaching sulfide ores are long periodical time of T. femu~/dans growth, and that it is difficult to obtain sufficient cell populations. Thus, the kinetics of bioleaching sulfide ores by T. ferroox/dans has been gradually paid attention to. Silver ion was considered to catalyze the biooxidation of pyrite or arsenical refractory gold Om [19~21] , by which, however, the bacterial growth is inhibited and the increase in the biomass is limited. From a biological standpoint, two main controlling factors affecting the oxidation rates are the activity as well as the biomass of the bacteria. In order to increase the biomass, electrochemical means [='233 were applied. For example, T. ferroox/dans grown in an electrolytic reactor under applied current conditions were found to be more efficient as attested to by a 3.7 -fold increase in protein concentration and an increase in the ferrous oxidation rate by 1.5 times ~ . However, electrochemical equipment is complicated and the production cost is risen. Therefore, in order to accelerate the bacterial growth and shorten the periodical time, it is of great importance to study the kinetics on the growth of T. ferroox~ using of new approaches. The resistance of T.J~rroox'/dxms to cupric ions was widely studied to the process for bioleaching coppe rE~'~] , but little information on the role of cupric ion in accelerating the bacterial growth has been reported. Furthermore, a rapid method for monitoring the growth of T. ferrooxlkhms continuously by using a series piezoelectric quartz crystal was presented in our previous work [~3 . The SPQC...
