A bench case study was performed on oil refinery waste from a Northeastern Company near Lima, OH. The client supplied approximately ten (10) gallons of Selenium bearing waste to LES’ facility on March 28, 1995. The waste sample was clear with no apparent color or detectable odor. The initial feed of pH sample was 9.7. Effluent samples were collected and analyzed for total selenium and pH; spot tests were performed for Phenol.
The balance of the Selenium waste was processed through the ENVIRO-CLEAN PROCESS pilot carbon unit. The system consisted of a feed pump, pH controller and two (2) carbon columns. Each column contained about 180 grams of Filtrasorb 400 granular activated carbon, manufactured by Calgon Carbon. Effluent samples were collected and analyzed for total selenium. This validation study was conducted to verify the system’s capability to remove iron to acceptable levels. The effluent selenium results are presented in Table 2.0, with the time periods marked in parenthesis, designating when the sample was collected during the test run.
TABLE 2.0 ENVIRO-CLEAN EFFLUENT ANALYSIS
|Sample||Selenium (mg/l)||Phenol (mg/l)|
|Sample #1 (4 hrs)||0.048||<0.001|
|Sample #2 (18 hrs)||0.173||<0.001|
|Sample #3 (22 hrs)||0.153||<0.001|
|Sample #4 (24 hrs)||0.203||<0.001|
|Sample #5 (26 hrs)||0.210||<0.001|
|Sample #6 (28 hrs)||0.283||<0.001|
|Sample #7 (32 hrs)||0,070||<0.001|
The processing of the selenium waste sample was completed without any mechanical or process difficulties. The effluent was crystal clear with no visible trace of solids or color.
The ENVIRO-CLEAN PROCESS produced an feed effluent well below the client’s current selenium discharge levels (3 mg/l). The activated carbon system’s capability to remove Selenium from the mining waste stream was demonstrated with removal levels of 95.5%. The average total selenium concentration in the pilot unit’s effluent was