Residual Phenol Concentration Research Articles

Removal and degradation of phenol in a saturated flow by in-situ electrokinetic remediation and Fenton-like process

In this laboratory study, a sandy loam soil saturated with phenol solution was treated by in-situ electrokinetics-Fenton process incorporated with a permeable reactive wall of scrap iron powder (SIP). The soil was contaminated and saturated with aqueous phenol solution of 90–115 mg/kg in concentration. It was then placed in a soil cell. The soil cell was assembled with an anode reservoir and a cathode reservoir at its ends. A bed of SIP (1.05–32.69 g) was inserted in the soil cell at a distance of 5 cm from the anode reservoir compartment. For the test runs, 0.3% H 2O 2 was used as the anode reservoir fluid, whereas de-ionized water was used as the cathode reservoir fluid. An electric gradient of 1 V/cm was applied to enhance the saturated flow in the soil cell for a period of 10 days. Experimental results have shown that the electroosmotic (EO) flow quantity decreased as the amount of SIP increased. This phenomenon was in good agreement with the results showing the value of EO permeability increased with a decreasing amount of SIP. Results also showed that throughout the test period the cumulative, consumed mass of H 2O 2 in the anode reservoir increased as the amount of SIP decreased. On the other hand, the cumulative, increased mass of phenol in the cathode reservoir was found to increase with a decreasing amount of SIP. Meanwhile, the residual phenol concentration in the soil cell was found to decrease with a decreasing amount of SIP. When 1.05 g scrap iron powder was used, an overall removal and destruction efficiency of phenol of 99.7% was obtained. Therefore, it is evident that an in-situ combined technology of electrokinetic remediation and Fenton-like process is capable of simultaneously removing and degrading the phenol in a saturated flow.

Fate of organic bases during Biooxidation of coal carbonization wastewater

Low temperature and high temperature coal carbonization processes generate wastewaters containing ammonia, phenols, organic bases, viz. pyridine, alpha picolines, beta picolines, lutidine, quinoline and aniline. Most of the biological treatment processes employed for the treatment of the coal carbonization wastewater are evaluated and monitored for the removal of ammonia and phenols. The organic bases being pollutants of environmental concern, their status in the treatment units should be monitored. In the present investigation the fate of the organic bases has been evaluated in two stage activated sludge process employed for the treatment of coal carbonization wastewater. In the first stages of activated sludge process, the bases, viz. pyridine, picolines, and lutidine do not get removed effectively even at high sludge retention time (SRT) of 10.9 days. The poor removal of bases in the first stage of activated sludge process unit may be attributed to the residual phenol concentration of more than 5 mg/L in the first stage of bioreactor and preferential utilization of phenols over organic bases. In the second stage of the activated sludge process most of the bases get removed efficiently at SRT of 12 days. On employing a two stage activated sludge process, the bases from coal carbonization wastewaters could be removed effectively by operating first stage at SRT of 2.18 days and the second stage of the process at 12 days SRT respectively.

Process development for remediation of phenolic waste lagoons

Aqueous phenolic wastes from a phenolic resin production process were disposed in lagoons on the production site. Groundwater contamination in the area has exceeded state limits and thus mandated remedial action. Representative core samples from within and around the highly contaminated soil regions were collected. These samples were physically and chemically characterized to better determine the extent and nature of contamina- tion. Both in situ and on-site remediation scenarios were considered. The most promising scenario was in situ forced leaching with above- ground aerobic microbial treatment of the leachate. The treatment could be carried out with six months operation at a cost of approximately $170 per ton of treated soil, with the capability of reaching a final residual soil phenol concentration less than 20 mg/kg dry soil.