Bioregeneration of GAC used in the Esfahan's Mobarakeh steel factory

Subject Areas : Water and Environment

Saeedreza Asemizavareh ¹ ( Department of Environmental Science, Damavand Branch , Islamic Azad University, Damavand, Iran )
Saeedeh Rafatnezhad ² ( Young Researchers Club, Damavand Branch , Islamic Azad University, Damavand, Iran )

Received: 2011-05-13 Accepted : 2011-12-15 Published : 2012-03-20

Keywords: Bioregeneration, Granular Activated Carbon (GAC, Mixed liquor suspended solids, Regeneration efficiency,

Abstract :

The objective of this study is to investigate the possibility of using a microbial mix to biodegrade the chemical wastewater (mainly phenol compounds) of the Mobarakeh steel factory (Esfahan-Iran) adsorbed on granular activated carbon (GAC) and to determine the adsorption capacity of the bioregenerated GAC. The apparatus consisted of a continuous reactor made of glass with the dimensions of 43 × 29 × 50 cm (L × W × H), with continuous airing supplied by a compressor and a 24-h feeding system. The microbes were acclimated for 3 months inside the reactor under these conditions: temperature of 30 ± 1 ºC, continuous feeding with a synthetic wastewater (C12H22O11 - CO (NH2)2 - Na2HPo4 at a daily loading rate of 1000 mg COD/L day) and continuous airing by the compressor. After the acclimation period (3 months), 300 g of the used GAC is introduced into the reactor, and a 2-month period of bioregeneration is started. At the beginning of this period, the COD of the feed solution was 500 mg L-1 as in the other studies and the amounts of mixed liquor suspended solids (MLSS) was 2420 (mg L-1). The regeneration efficiency (RE) increases from 6% on day 7 of the bioregeneration process to 28% on day 53, with the MLSS increasing from 3520 mg L-1 on day 7 to 13460 mg L-1 on day 53. The results indicate that the increase of MLSS affects the regeneration efficiency of GAC. The phenol adsorption capacities of the new GAC, used GAC (without bioregeneration), bioregenerated GAC (for 7 days) and the bioregenerated GAC (for 53 days) were 90.87, 0.00, 5.06 and 26.29 mg L-1, respectively. Therefore, the adsorption capacity of the 53-day bioregenerated GAC was higher than that of the used GAC without regeneration and of the GAC bioregenerated for shorter periods (7, 14, 23, 38, 45 days). This demonstrates that the bioregenerated GAC can be recycled and used for phenol adsorption for longer periods.

References:

1. Minister of public works and Government saervices Canadian, 2000. Priority substances list assessment report, phenol, Environmental protection act, Environment canad Health Canada, (accessed April 2005).


2. Abu Zeid N., Nakhla G., Farooq S., Osei-Twum E., 1995.  Activated carbon Adsorption in oxidizaing Environments. Water Research, Vol. 29, pp. 653-660


3. WHO., 1994. Phenol, Inter Rational programme on chemical safety, Environment health criteria 161, (accessed may 2005), http://www.inchem.org/documents/ehc/ehc 161.htm.


4. رجب زاده کهنمویی، سعید. بررسی آزمایشگاهی روش های مختلف احیاء کربن فعال آلوده به فنل، پایان نامه کارشناسی ارشد دانشکده شیمی دانشگاه علم و صنعت، 1381، صفحه 81


5. لطف اللهی، محمد نادر، احمد پناه، سید سعید- حقیقی اصل، علی، بازیابی کربن فعال اشباع از اتیل استات با دی اکسید کربن فوق بحرانی. یازدهمین کنگره ملی مهندسی شیمی ایران ، دانشگاه تربیت مدرس، 1385، 7- 9 آذر ، تهران، ایران


6. اطلاعات کاتالوگ شرکت شیمی پژوهان


7. Putz, A.R. H., Losh, D.E. and Speital Jr, G.E., 2005.  Removal of nonbiodegradable chemicals from mixtures during granular activated carbon bioregeneration¸ Journal of Envionmental Engineering, Vol. 131, pp. 196-205    


8. Caldeira¸ M., Heald¸ S.C., Carvalho¸ M.F., Vasconcelos¸ I., Bull A.T., and Castro¸ P.M.L., 1999.  4-Chlorophenol degradation by a bacterial consortium: development of granular activated carbon biofilm reactor¸ Applied Microbiology and Biotechnology, Vol. 25¸ pp. 722-729 

1. Goeddertz, J.G., Matsumonto M.R., and Weber, A.S., 1988. Offline Bioregeneration of granular activated carbon, Journal of Environmental Engineering, Vol. 114, pp. 1063-1076