done in collaboration with the sample collection every hour, it consists of: pH, density, E:A ratio, chemical volume, extractant depth, and mixer tip speeds. Once the data has been collected it will immediately be place inside of the lab notebook. The samples are then sent off for Inductive Coupled Plasma (ICP) and Inductive Coupled Plasma Mass Spectrometry (ICP-MS) analysis. 

At the end of this test 3 7 .2 gallons of acid mine drainage feed had been used over the course of approximately 40 hours. 

This example determined the effect of sulfate extraction efficiency using extractant phase formulation. The apparatus of FIG. 13 was constructed. The extractant phase was prepared by selecting components from Table 3, and certain components of these were selected and blended in propor› tions given in Table 5. The test conditions used are given in Table 5. 

The experiment used extractant solution from Table 5 to extract sulfate from 2000 ppm Na$_{2}$SO$_{4 }$ solution. Since the extraction of sulfate anions in a Na$_{2}$ SO$_{4 }$ solution rely mainly on a concentration gradient, this set-up served as "worst case" in sulfate anion removal of water purification process. The extractant solution was treated with 15% Na$_{2}$CO$_{3 }$ to load up the extractant with carbonate anion, and then the extractant and Na$_{2}$ SO$_{4 }$ solution were tested under different E/A ratio. The aqueous phase was analyzed using ion chromatography to determine the remaining sulfate concen› tration. The ion chromatography results determined the amount of sulfate removed at different E/A ratio. And those results were also plotted via McCabe-Thiele plot, which lead to the discovery of the stages needed for sufficient sulfate loading and stripping of the water treatment process. The experiment also determined the range of extractant needed for effective sulfate extraction, which preferred by the invention is about 5-15%, most preferably 8-12%. The McCabe-Thiele result is shown in FIG. 9 to FIG. 12. 

To validate the results, a sulfate extraction process was set up with the apparatus of FIG. 13. This process was designed to extract sulfate anion from a 2000 ppm Na$_{2}$ SO$_{4 }$ solution via a continuous circuit. The result from this process vali› dated the proposed design and the same sulfate process apparatus was implemented into the overall process flow scheme. This also established a baseline test condition, which includes E/A ratio between 1/4-1/6 for sufficient sulfate extraction and stripping in three to four stages. 

This example determined the effect of metal and sulfate extraction efficiency in a less contaminated stream using extractant phase formulation. The apparatus of FIG. 14 was constructed. The extractant phase was prepared by selecting components from Table 3 blended in proportions giving in Table 5. The test conditions used are given in Table 5. 

This experiment used extractant solution from Table 5 with process apparatus of FIG. 14 to perform water purifi› cation process with an acid mine drainage stream containing low contaminant levels. The process was set up with the same number of extracting and stripping stages. The com› bination of high extraction efficiency of metal cation and sulfate anion and the low contaminant concentration in the acid mine drainage stream caused secondary emulsion at the third extraction stage. The emulsion also stopped phase disengagement between extractant solution and the raffinate. 

## Example IA (Stages Determination) 

## Example 2 (Run #2) 

The extractant solution and raffinate emulsion created from the process behaved similarly to an emulsion of an extract› ant solution and deionized water. The emulsified raffinate from this process was left in the tank for 24 hours to prolong the settling time in an attempt to achieve better phase disengagement. However, there was no visible phase sepa› ration after 24+ hours of settling time, and the emulsion was not able to break until pH adjustment was made by addition of sulfuric acid. It appears that mixing was excessive thus forming a stable microemulsion. Stable in that the disen› gagement from the emulsion was too slow. When mixer speed was controlled this problem did not return. 

This example determined the effect of acid mine drainage liquid-liquid extraction (LLX) system efficiency with shorter mixing residence time using extractant phase for› mulation. The apparatus of FIG. 14 was constructed. The extractant phase was prepared by selecting components from Table 3 blended in ranges given in Table 4. The test conditions used are given in Table 5. 

This experiment also used extractant solution from Table 5 with process apparatus of FIG. 14 to evaluate acid mine drainage water purification process performance under shorter mixing residence time. The two-part experiment tested different process conditions; the first part of the experiment tested the treatment process with E/Aratio of 1/6 and mixing residence time of 60 seconds, and the second part tested the treatment process with E/ A ratio of 1/8 and mixing residence time of 35 seconds. 

The 60 seconds mixing residence time trial was behaving well on its own, and the consumption rates of Na$_{2}$CO$_{3 }$ and H$_{2}$SO4 were determined in this experiment. The raffinate from individual stream was sent to ion chromatography and Inductively Coupled Plasma Mass Spectrometry (ICP/MS) to determine the final metal and sulfate concentration. These results and measurements helped to determine the final mass/molar balance of the overall process. The 35 seconds mixing residence time trial also had a smooth operation. However, the raffinate’s ion chromatography and ICP/MS results from this trial turned out not fulfilling the perfor› mance requirement. This allowed the determination of the mixing residence time and E/ A ratio limitation for the treatment system. The analytical results from these trials are shown in Table 6. 

The result from the two-part experiment not only showed the limitation of E/ A ratio and mixing residence time needed for sufficient process treatment, but also determined the extractant solution input rate with respect to the mixer size. If too much extractant solution pushed into strippers, the mixer section would be overwhelmed and started plugging up because of the excess extractant solution in the mixer. The excess extractant solution in the mixer had gel-like behavior and caused the mixer to lose hydraulic suction. This would severely cripple the process because it was essentially equal to shutting down the process at midpoint while more acid mine drainage water and extractant were being pushed through the front end of the process. The discovery of this particular limitation allowed the determi- nation of the maximum extractant solution flow rate into the strippers, thus provided the boundary condition needed for the process. 

This example determined the effect of water entrainment from extractant phase formulation, especially the contribu- 

## Example 3 (Run #6) 

## Example 4 

