Biogas and biofertilizer production of marine macroalgae: An effective anaerobic digestion of Ulva sp.

Abstract

Abstract Nowadays the increasing prices of petroleum-based fuels have persistently focused on the development of alternative energy sources, whereas the solid residue can be used as an organic fertilizer which can be one of the solutions from depending on conventional synthetic fertilizer. The research work mainly focused on biomethanation and development of biofertilizer from the seaweed Ulva sp. The Ulva sp. mixed with organic matter (cow dung) has been used in different concentrations for biogas production and the methane was theoretically computed that 1.528 kg/m3 volatile solids (VS). The ratio 3:1 proportion obtained was 574 ± 26 ml-g VS biogas production than the control and 1:1, 2:1 ratio. The cumulative biogas was quantitatively analyzed by gas chromatography for the proportion of methane (CH4) and ranged from 72% in Ulva sp.: cow dung 3:1. The solid residue was used as an organic fertilizer for the growth of Vigna radiata. The results revealed that the physicochemical parameters, pigments and nitrogen, phosphorus and potassium (NPK) analysis were increased in the 3:1 ratio when compared to the others. The Ulva sp. was used in eco-friendly and zero waste management process. From the seaweed Ulva sp. to reduce the sustainable and clean environment; to improve the agricultural crop production and also enhances the soil fertility.