Primary investigation of the antialgal activity of shrimp shell on Microcystis aeruginosa.

This study aimed to explore the application potential of an eco-friendly waste-shrimp shell in Microcystis aeruginosa (M. aeruginosa) control-for the first time. Four treatments with different doses (0.75, 1.5, 3.0, and 6.0 g/L) were built to investigate the effects of shrimp shell on the growth, cell viability, physiological changes, and microcystins (MCs) release of M. aeruginosa cells. The water quality after shrimp shell treatment was also detected. Results showed that the growth of M. aeruginosa was effectively inhibited by shrimp shell, and the inhibition rates were dose-dependent within 7 days. Though shrimp shells at high doses could inhibit the cell growth greatly, the MC release was accelerated as they led to the cells lysis. While with the low shrimp shell dose (0.75 g/L), both satisfied inhibition effect and low MC release could be achieved simultaneously. For the water quality, we found that the turbidity and TN was not affected obviously with low dosage of shrimp shell, but it resulted in the increasing of CODMn and TP contents. In summary, the shrimp shell can be used as an effective algicide to control algal blooms but its adverse effect on CODMn and TP of water should be further solved.