Title : Phycoremediation of tannery waste using cyanobacteria as bioreagent with special reference to Nano Chromium formation
Tannery wastewater carries heavy pollution load due to high organic and inorganic contents, highly colored compounds and toxic metallic substances. Characterization of this water from inlet point showed high level of BOD (1234.33 mg/L), COD (1706.64 mg/L), Total Chromium (56.85 mg/L), TDS (6984mg/L), sulfide (140.8 mg/L) and ammonium (134.5 mg/L). These values were several folds above the standard limits set by ISI (2000). From the present investigation, it was found that Cyanoprokaryotes efficiently removed toxic metals on one hand and nutrients on the other hand from tannery wastewater. In this investigation, marine Cyanoprokaryote Phormidium valderianum was grown in various dilutions including raw tannery wastewater of leather complex, Eastern India in open tank (4.0 L with a depth of 15 cm and the breadth of 25 cm). The cyanoprokaryote was found to be efficient in removing nitrate and phosphate by 90% and 76% respectively from raw wastewater. Dissolved oxygen increased by 10 folds in all dilutions of Tannery Wastewater. The efficiency of ammonia removal (84%) was found to be maximum in case of 50% dilution. The growth performance of exposed biomass was measured in terms of dry weight and Chlorophyll content. Surface topography and distribution of elements adsorbed in algal biomass was analyzed with SEM and EDAX study. The functional groups of the algal biomass before and after treatment were investigated through FTIR spectroscopic study. Atomic Absorption Spectroscopic analysis of treated algal biomass showed a significant amount of chromium removal from wastewater and formation of nano chromium was determined using UV-VIS spectra in an in-vitro exposure of algal biomass to potassium dichromate solution. The Scanning and Transmission Electron Microscopy study revealed the cluster of rod-shaped nano chromium formed by the cyanobacterial biomass. Detail characteristic features of nano chromium would be discussed.
Take Away Notes:
• Efficiency of marine Cyanoprokaryote in removing toxic compounds from tannery wastewater.
• Nano chromium formation by Cyanoprokaryote.
• Characteristics of nano chromium formed by marine cyanoprokaryote.
• Chromium removal capacity of Phormidium.
• Type of functional groups of Phormidium biomass involved in chromium removal.
• Algae based treatment of tannery wastewater in large scale could be a future prospect.
• Chromium nanoparticles can be used in various electronic applications.