# Effect of the height of the culture column Experimental

2.6. Statistical analysis

Mean and standard deviation values for the recovery efficiency were calculated for each test three times. Kruskal–Wallis test for the resulting differences were calculated (electrode separation, height of the culture column, volts and runs) and the Mann–Whitney test for the natural sedimentation differences. Statistical analysis was performed using SPSS Statistics v19 (SPSS, Inc., and IBM Company1989, 2010).

3. Results and discussion

3.1. Effect of electrodes

Fig. 4. Mean absorbance values of different BD 1008 electrode (3 replicates in each test).Figure optionsDownload full-size imageDownload as PowerPoint slide

Table 1.

Ilhan et al. (2008) concluded that Al electrodes showed a higher treatment efficiency than Fe ones, with a rate of removals of 56% and 35% respectively. In addition, Cerqueira et al., (2009) concluded that the distance between the aluminum electrodes did not cause a significant increase in the removal efficiency of contaminants, while the distance between iron electrodes influenced the EF process. Although the most advantageous results of the aluminum, in polymerase chain reaction (PCR) investigation iron electrodes were used instead of the first ones because aluminum has been associated with alterations in biological systems, especially fish, and its implications in the development of neurodegenerative diseases (Rondon-Barragán et al., 2007).