Consortium of Microalgae for Tannery Effluent Treatment

Abstract

Wastewater generated in tanneries have essential elements for microalgae growth, but it has also some toxic compounds that may hinder or restrain the growth of microalgae in this environment. This work tested microalgae consortium growth originating from a deactivated effluent treatment decanter of a complete tannery (beamhouse to finished leather) for the treatment of wastewater of a tannery processing wet-blue leather to finished leather. It was initially evaluated the growth of the microalgae consortium in the three effluents diluted in 50% distilled water: raw effluent (50RE50W), effluent after primary coagulation/flocculation (50PE50W), and effluent after primary and secondary biological treatment (50BE50W). After 16 days of cultivation, the 50PE50W presented the highest HIGHLIGHTS • The microalgae consortium was able to grow in tannery effluents.• The culture achieved higher growth in the diluted raw effluent.

Influence of period light on cultivation of microalgae consortium for the treatment of tannery wastewaters from leather finishing stage

“…In the authors previous study, wastewater from the finishing stage (raw wastewater, after primary and secondary treatment) was treated with a microalgae consortium. In this study it was noticed that there were removals close to P-PO 4 , NTK (Total Kjeldahl Nitrogen), NeNH 3 , and COD among the compared wastewater and a higher growth of microalgae in the raw wastewater (Pena et al, 2019). In another study from authors, Pena et al (2018) used the microalgae Tetraselmis sp.…”

Advanced Oxidation Processes and Biotechnological Alternatives for the Treatment of Tannery Wastewater

“…Microalgae are autotrophic and photosynthetic aquatic microorganisms capable of synthesizing various high-value compounds, such as lipids, proteins, carbohydrates and pigments, which, together with a rapid growth rate and the ability to adapt to extreme environments, make them a viable option in the wastewater treatment [ 7 , 16 , 169 , 170 ]. This adaptive capacity allows them to grow under various conditions of acidic pH, high temperatures or excess of some compounds [ 171 ], allowing them to generate a greater amount of biomass and products of commercial interest [ 172 , 173 ].…”

“…It has been shown that this tolerant mechanism in Chlorella and Scenedesmus strains is due to the activation of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) as a biological response to oxidative damage induced by the presence of metals [ 182 ]. However, it is not yet possible to use the crude tannery effluent as a culture medium, which can be attributed to high toxic loads and the dark color of the crude effluent, which prevents the entry of light into the medium and limits the growth of microalgae, which suggests the application of wastewater dilutions to allow better adaptation [ 16 , 183 ] and determination of the appropriate photoperiod [ 7 ].…”

“…Some of these technologies are chemical coagulation, photodegradation, biodegradation, adsorption, ozonation, electrocoagulation and reverse osmosis [ 13 ]; however, the difficulty of implementing them is related to high energy consumption, use of large areas of land, high operation and maintenance costs [ 14 ]; in the same way, in some processes, other polluting byproducts are generated [ 15 ]. The foregoing has launched various biotechnological processes, including the use of microalgae, bacteria and fungi, as sustainable and economically affordable alternatives [ 16 ].…”

“…In India, one of the three largest leather producers after China and Italy, high concentrations of Pb, Cr, Zn and Cu were found, and an efficiency of 60–98% of removal of these metals under different conditions was demonstrated, specifically with microalgae [ 30 ]. In Brazil, progress has been made regarding the growth of microalgae consortia under different concentrations of tannery wastewater [ 16 ].…”