[Study on the Chlorella pyrenoidosa cultivation technology based on the excess sludge utilization]

Area of Science:

• * Biotechnology and Environmental Science
• * Microalgae cultivation and biomass production

Background:

• * Wastewater and waste materials can be utilized for cost-effective microalgae production.
• * Sludge extracts present a potential low-cost medium for microalgae cultivation.

Purpose of the Study:

• * To develop a novel microalgae cultivation method using a mixture of sludge extracts and selenite enrichment (SE).
• * To evaluate the optimal ratio of sludge extracts to SE for cultivating Chlorella pyrenoidosa.

Main Methods:

• * Microalgae (Chlorella pyrenoidosa) cultivation in mixed media with varying ratios of sludge extracts and SE.
• * Measurement of microalgae growth via absorbance at 680 nm.
• * Quantification of chlorophyll, beta-carotene, and protein content.

Main Results:

• * Optimal microalgae growth observed at a 2:8 ratio of SE to sludge extracts (80% sludge extracts).
• * Significantly higher absorbance (0.845) at 680 nm compared to pure SE (0.571) or sludge extracts (0.247).
• * Maximal chlorophyll, beta-carotene, and protein content achieved with 80% sludge extracts.

Conclusions:

• * Sludge extracts are a viable and effective medium for Chlorella pyrenoidosa cultivation.
• * A mixed medium of 80% sludge extracts and 20% SE promotes superior microalgae growth and biomass quality.
• * This approach offers a sustainable and economical method for microalgae production.