Effect of nutrients on Chlorella pyrenoidosa for treatment of phenolic effluent of coal gasification plant

Abstract

The ability of Chlorella pyrenoidosa, a freshwater microalga, to degrade phenolic effluent of coal-based producer gas plant under ambient conditions was investigated. C. pyrenoidosa was able to grow in high-strength phenolic effluent. Major contaminant present in the effluent was phenol (CHOH). The effluent has 1475.3 ± 68 mg/L of initial total phenolic concentration. The effect of nutrients used for algal cultivation in phenol degradation was analyzed by inoculating four different concentrations, viz.,1, 2, 3, and 4 g of wet biomass/L of raw effluent of C. pyrenoidosa mixed with effluent into two batches (with and without nutrients). C. pyrenoidosa was able to degrade more than 95% of the phenol (CHOH) concentration with the algal concentrations of 3 and 4 g/L when supplemented with nutrients. With effluent devoid of nutrients, the average percent reduction in total phenolic compounds was observed to a maximum of 46%. No physical changes in the C. pyrenoidosa were observed during degradation. C. pyrenoidosa was able to consume the organic carbon present in the phenolic compounds as carbon source for its growth despite the inorganic carbon supplemented externally.

Influence of photodegradation on the removal of color and phenolic compounds from palm oil mill effluent by Arthrospira platensis

“…7 Response surface plot (3D) of (a) final biomass expressed as dry weight (mg L −1 ) and (b) growth rate as a function of initial light intensity and initial total phenolic compounds exposed to the medium, thereby enhancing dye removal. Furthermore, Stephen and Ayalur (2017) found that Chlorella pyrenoidosa at an initial inoculum of around 3-4 g L −1 could remove phenol up to 95% when supplemented with nutrients. CCD RSM revealed that increasing initial phenolic compounds and light intensity significantly enhanced the phenol removal efficiency by photodegradation.…”

Phycoremediation of phenol‐polluted petro‐industrial effluents and its techno‐economic values as a win‐win process for a green environment, sustainable energy and bioproducts

“…2020). However, Chlorella pyrenoidosa has been reported for heterotrophic (Stephen and Ayalur 2017a) and mixotrophic (Stephen and Ayalur 2017b) degradation of phenol with a capacity reaching 91–95% of 295 mg phenol l −1 . Nevertheless, the phycoremediation of phenol by Scenedesmus sp.…”

“…Nevertheless, it should be taken into account the green house gas (GHG) emission reduction, the decline in sludge formation, low‐energy requirement, simple operation and maintenance and the disinfection effect of algal photosynthesis on most pathogenic bacteria (e.g. Escherichia coli ) and viruses, via the pH increment with the assimilation of CO 2 , H + ions and bicarbonate by algae, which collectively add to the advantage of wastewater treatment via microalgae (Stephen and Ayalur 2017b). …”