Journal of Environmental Biology

Removal of nutrients in denitrification system using coconut coir

fibre for the biological treatment of aquaculture wastewater

Author Details

Valsa Remony Manoj

(Corresponding author)

Centre for Environmental Studies, Anna University, Chennai - 600 025, India

e-mail: talktovrmanoj@gmail.com

Namasivayam Vasudevan

Centre for Environmental Studies, Anna University, Chennai - 600 025, India

Publication Data

Paper received:

15 May 2010

Revised received:

10 October 2010

Re-revised received:

05 January 2011

Accepted:

05 February 2011

Abstract

Ideal bacterial support medium for fixed film denitrification processes/bioreactors must be inexpensive, durable and possess large surface area with sufficient porosity. The present study has been focussed on removing nitrate nitrogen at two different nitrate nitrogen loading rates (60 (NLR I) and 120 (NLR II) mg l^-1) from simulated aquaculture wastewater. Coconut coir fibre and a commercially available synthetic reticulated plastic media (Fujino Spirals) were used as packing medium in two independent upflow anaerobic packed bed column reactors. Removal of nitrate nitrogen was studied in correlation with other nutrients (COD, TKN, dissolved orthophosphate). Maximum removal of 97% at NLR-I and 99% at NLR – II of nitrate nitrogen was observed in with either media. Greater consistency in the case of COD removal of upto 81% was observed at NLR II where coconut coir was used as support medium compared to 72% COD removal by Fujino Spirals. The results observed indicate that the organic support medium is just as efficient in nitrate nitrogen removal as conventionally used synthetic support medium. The study is important as it specifically focuses on denitrification of aquaculture wastewater using cheaper organic support medium in anoxic bioreactors for the removal of nitrate nitrogen; which is seldom addressed as a significant problem.

Key words

Aquaculture, Biological treatment, Coconut coir fibre, Denitrification 

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