Impact of industrial salt effluent and seaweed liquid fertilizers on three microalgae

Three marine microalgae Chaetoceros muelleri Lemmerman, Dunaliella salina (Dunal) Teod., and Arthrospira platensis (Gomont) Geitler were grown in their respective medium under laboratory conditions. Harvested biomass of all the three algae was grown in salt refinery effluent, to reduce or eliminate the hazardous chemicals for a period of 21, 18, and 20 days, respectively. The initial and final levels of hazardous chemicals (Cu, Zn, P, K, Na, Cl, Fe, F, Mg, SO4 and BOD, COD) in the effluents were analyzed according to APHA and their results were recorded. Heavy metals such as barium, aluminum, silver, strontium, and cadmium were identified by Inductively coupled plasma atomic emission spectroscopy. Among three microalgae, A. platensis was unable to survive after 3 days due to the presence of harmful chemicals in the effluent. The effect of Seaweed liquid fertilizers (SLF) extracted from Kappaphycus alvarezii (Doty) Doty ex P. C. Silva var. tambalang (Doty) and Turbinaria conoides (J. Agardh) Kutzing were examined on the two microalgal species except A. platensis. Extracts were added in four different percentages such as 0.4, 0.9, 1.3, and 1.7 % to C. muelleri and D. salina. The changes in the microalgal cells and SLFs were analyzed under confocal microscopy.