Bioremediation of Tannery Effluents Using a Consortium of Blue–Green Algal Species

Abstract

Trivalent chromium in the form of basic chromium sulfate (BCS) is used for tanning hides/skins and is a strong pollutant of the soil and water bodies. Significant quantities of unutilized chemicals, such as sulfates, chlorides, are also discharged, contributing to high levels of total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), etc. Though many treatment techniques are being practiced, biotechnological methods are gaining importance. Biosorption is recognized as a costeffective technology worldwide; one potential sorbent being blue-green algae (BGA), for treating metal-bearing effluents. This work studies the feasibility of using a species each of Spirulina, Oscillatoria, and Synechocystis, individually and as a consortium, as sorbents to remove Cr 3þ from a segregated stream, viz. exhaust chrome liquor (ECL) and synthetic BCS solution. The species studied were found to be effective in removing Cr 3þ considerably at varying concentrations, besides reducing sulfates, BOD, COD, etc. The results of ECL experiments were more encouraging than those for BCS solution. The kinetic data on Cr 3þ sorption onto algal biomass fit well into the pseudo-second order model. The equilibrium data were analyzed using the classic Langmuir and Freundlich isotherm models, yielding good fits. The results of the experiments indicate that algal consortia could be good alternatives to the conventional treatment methods for leather and other industrial wastewaters containing chromium.

Physicochemical Characterization and Use of Heat Pretreated Commercial Instant Dry Baker's Yeast as a Potential Biosorbent for Cu(II) Removal

“…The use of eco‐friendly, low‐cost biomaterials, such as bacteria, fungi, yeast, marine algae, agricultural waste, plants, and/or animal origin by‐products as biosorbents for heavy metals ions offers a potentially inexpensive alternative compared to the conventional methods used for heavy metals decontamination from waters and wastewaters .…”

Phycoremediation of Hazardous Mixed Industrial Effluent by a Marine Strain of Phormidium sp

“…Therefore, effluent diluted to 30% was used for further studies, as it enabled good microalgal growth. This dilution of wastewater is far less than that in studies where <10% MIE was used . The microalgal culture grew very well, particularly under open terrace conditions, and reduced BOD, COD, nitrate, and nitrite concentrations within six to 15 days of inoculation; the phosphate level was not reduced.…”

“…BDL, below detectable level; IC, initial concentration (mg L À1 ); PR, percentage reduction. a El-Bestawy [21] ; b Fawzy and Issa [22] ; c Singh and Thomas [43] ; d Wu et al [42] ; e Shashirekha et al [34] ; f Dominic et al […”

“… a El‐Bestawy; b Fawzy and Issa; c Singh and Thomas; d Wu et al; e Shashirekha et al; f Dominic et al;…”

Environmental toxicity: Exposure and impact of chromium on cyanobacterial species

“…The effect of metals on algae has been studied by many workers. But there are comparatively fewer reports on prokaryotic organisms, cyanobacteria, in relation to metal toxicity which have low nutrient requirements and are also photosynthetic nitrogen fixers [3][4][5]. It has been found out that cyanobacteria contribute upto one half of annual nitrogen budget in some eutrophic lakes and are significantly important for rice fields.…”