Phycoremediation of pollutants from coke-oven wastewater using Tetraspora sp. NITD 18 and estimation of macromolecules from spent biomass

Coke-oven wastewater contains an array of hazardous pollutants like cyanide, phenol, ammoniacal-N, etc. The main objective of the present study is to assess the effectiveness of phycoremediation technique as tertiary treatment for simultaneous removal of three model pollutants such as phenol, ammoniacal-N, and cyanide from secondary treated coke-oven wastewater. A green route was employed for the treatment of coke-oven wastewater via the use of Tetraspora sp. NITD 18, collected from a contaminated site. Strain susceptibility was tested for the growth in the simulated solution of phenol (10-300 mg/L), ammoniacal-N (100-800 mg/L), and cyanide (1-10 mg/L), and subsequently, optimum concentration was assessed as 100 mg/L, 400 mg/L, and 2 mg/L, respectively. pH 7 and inoculum concentration 10 % was found suitable for the removal of phenol (79.02 +/- 6.93 %), ammoniacal-N (74.7 +/- 5.07 %), and cyanide (80.4 +/- 0.015 %) from their individual solution at optimal initial concentrations after 14 days. For solutions of individual pollutants, preferred pollutants were examined on the basis of production of biomass with respect to time, and found the following order: ammoniacal-N > phenol > cyanide. The solution of mixed pollutants was prepared by mixing the said pollutants at their optimal level of initial concentrations at a suitable pH (7). Such a solution was termed as simulated coke-oven wastewater (SCOW). While the present investigation deals with co-current removal of pollutants from simulated coke-oven wastewater (SCOW) and real secondary treated coke-oven wastewater at laboratory scale, the continuous study on real wastewater at industrial scale with the isolated algal strain is the scope of the future work.

Automated summary

The study evaluated the effectiveness of phycoremediation technique in removing phenol, ammoniacal-N, and cyanide from coke-oven wastewater. Tetraspora sp. NITD 18 was used for the treatment, showing promising results for the removal of pollutants individually and in a mixed form.