Effectiveness of combined activated allophane and effective microorganisms attached bioball to reduce phenol concentration in water

Phenol is a hazardous substance and should be reduced to 1 ppm to meet the quality standard of the Indonesia Ministry of Environment No 5 of 2014. This study aims to design an effective, acceptable to community and low cost technique for phenol reduction. The model design combines two techniques consisting of adsorption by activated allophane and biosorption by commercial type 4 Effective Microorganisms (EM4) on bioball media. The natural allophane clay is abundantly and freely available in Lawu volcano soils, Central Java, Indonesia. Allophane is activated using NaOH to increase adsorption capacity and molded to a tube form. The EM4 is capable of biodegrading phenol as containing photosynthesis bacteria, Lactobacillus sp., Actinomycetes sp., Streptomycetes sp., fermentation fungus and yeast. The EM4 is seeded and attached to bioball media and contained into the allophane tube. This combination is supposed to be effective in reducing phenol level. Four kinds of model solutions were prepared, each consisted of 3 ppm, 4 ppm, 5 ppm and 6 ppm phenol in aquadest. Each of 10 liter model solution was contained into a different bioreactor and operated in an aerobic environment using batch method. All bioreactors are set for 0, 6, 12, 18, 24 hours at 28°C, 32°C, 37°C and 46°C. The examination of phenol levels were done according to Indonesia National Standard Procedure (SNI) No. 06-6989.21-2004. The optimum result showed a decrease of 80.6% from 3.993 ppm to 0.772 ppm phenol at 28°C and 24 hour contact time. To understand the overall combination process, analysis of Langmuir and Freundlich isotherms was consulted. As Langmuir isotherm with determination coefficient (R2) of 0.9845 and constant (c) of 1,7199 was more compatible than Freundlich isotherm, the chemical reaction of the combination technique was dominant over physical process.