Study Regarding the Potential Use of a Spent Microbial Biomass in Fertilizer Manufacturing

Abstract

A spent biomass, which results from the biopharma industry, is stabilized and functionalized by biosorption with microelements. The efficiency of this new biomaterial was tested in two experiments: 1) In a mixture with soil to determine its effects of the germination capacity of cereals and vegetables, and 2) in a formulation of mixed fertilizers to determine its influence on the development and production of the two types of vegetables. The results obtained during germination experiments performed in pots showed that at a biomass concentration less than 20%, the germination output was greater than 95% and the germination index was almost 1. The experiments performed in land on vegetables (including Solanum lycopersicum and Capsicum annuum) featured six types of fertilizers formulated with new biomaterials. The obtained results indicated that two types of fertilizers (N 10:0:0 and NP 5:5:0), which were formulated with functionalized biomass and featured the microelements Co, Cu, Fe, Mn, and Zn, exhibited significant effects when compared with vegetables cultivated on unfertilized soil surfaces (the untreated variant). The studies regarding the effect of the new fertilizers obtained based on spent biomass from biopharma industry indicate the following: a) This material, even if it is stabilized and functionalized, cannot be used as such as a germination substrate for vegetables; in addition, it cannot be introduced into soil together with cereals seeds (during the autumn work), because the germination can be affected negatively; b) the functionalized biomass can be used in the formulation of different types of fertilizers; if these fertilizers are introduced into soil with the autumn plowing, then they may have a positive influence on the yield of some species of vegetable, such as Solanum lycopersicum and Capsicum annum. The new fertilizers have a major environmental impact due to: 1) Removal of waste, which results from pharmaceutical biosyntheses, with significant impact on soil pollution, due to its storage in the form of waste dumps, on the soil; 2) recovery and reinsertion into the natural circuit of nutrients like C, N, P, K, Mg, and Ca contained in spent biomass, by their reuse in agriculture; and 3) high content of compounds with C from spent biomass can improve in time the content of fulvic and humic acids in soil, with a positive effect on soil characteristics from an agronomic point of view.