Biodegradation of phenol in wastewater by immobilised mutant strain of Pseudomonas pictorum

Abstract

Immobilisation of bacteria in carrier materials provides the bacterial cells, the capacity to resist fluctuating dissolved organic load during its removal from wastewater. In this study, mutant strain of Pseudomonas pictorum (MU 174) was immobilised in ricebran based activated carbon at a rate of 22.4×10⁴ cells per gram under the conditions of temperature and pH of 30°C and 7.0 respectively. Percentage degradation of phenol in nutrient medium and sewage medium by free MU 174 was 99% in 12 hours, for phenol concentration of 500 mg/l under batch conditions. In the above media the percentage degradation of immobilised MU 174 was found to be 99.9% in 12 hours and 6 hours respectively for phenol concentration of 500 mg/l. A study on continuous treatment of phenol in sewage medium by ricebran based activated carbon containing immobilised MU 174 packed in a column indicated that the percentage removal of phenol was greater than 99% at a Hydraulic Retention Time (HRT) of 24 hours. The percentage removal of pollutional parameters like BOD, COD, suspended solids and volatile solids during the treatment of phenol laden wastewater was also determined.

Key words:

• Biodegradation
• Immobilistation
• Mutant of P. pictorum
• Phenol removal