• Energy Research

Kitchen waste could be processed and recycled into safe fertilizers/soil improvers for sustainable agriculture through different methods: (1) Dried pellets from model kitchen waste treated with anaerobic effective microorganisms; and (2) Anaerobically digested kitchen waste. For comparison, a commercial mineral fertilizer was used. These methods were applied in two separate glasshouse experiments: one under cool (mainly winter) conditions (X–IV) and one under warm (mainly summer) conditions (VI–X) consisting of 3–4 subsequent harvests in northern Poland. Comparing the food waste agronomic performance after anaerobic digestion and effective microorganism treatments, especially under different climatic conditions, is a novel approach. Kitchen waste served as a much better fertilizer than mineral fertilizer, but only during the cool season. In addition, it provided 20–40% more plant yields for dosages >120 kg N/ha and a similar N uptake. In the warm season, in comparison to effective microorganism-incubated kitchen waste, its anaerobic digestion improved the relative agronomic effectiveness twice after 30 days of growth (82% versus 43%). However, the total effectiveness for anaerobically digested kitchen waste versus pelleted and effective microorganism-incubated kitchen waste was 32% versus 27% (N utilization-wise) and 36% versus 21% (plant biomass yield-wise). The Monod kinetic model was applied for the internal efficiency of N utilization; for the best fitting procedure, R2 > 0.96 for the cool season and R2 > 0.92 for the warm season. Kitchen waste introduced to the soil provided better soil properties than mineral fertilizer. The study contributes to the biological systems for waste recycling in agriculture, bioproduction processes, and the global food chain.

Surface characterization and metal ion adsorption properties ofSpirulinasp. andSpirulina maximawere verified by various instrumental techniques. FTIR spectroscopy and potentiometric titration were used for qualitative and quantitative determination of metal ion-binding groups. Comparative FTIR spectra of natural and Cu(II)-treated biomass proved involvement of both phosphoryl and sulfone groups in metal ions sorption. The potentiometric titration data analysis provided the best fit with the model assuming the presence of three types of surface functional groups and the carboxyl group as the major binding site. The mechanism of metal ions biosorption was investigated by comparing the results from multielemental analyses by ICP-OES and SEM-EDX. Biosorption of Cu(II), Mn(II), Zn(II), and Co(II) ions by lyophilizedSpirulinasp. was performed to determine the metal affinity relationships for single- and multicomponent systems. Obtained results showed the replacement of naturally bound ions: Na(I), K(I), or Ca(II) with sorbed metal ions in a descending order of Mn(II) > Cu(II) > Zn(II) > Co(II) for single- and Cu(II) > Mn(II) > Co(II) > Zn(II) for multicomponent systems, respectively. Surface elemental composition of natural and metal-loaded material was determined both by ICP-OES and SEM-EDX analysis, showing relatively high value of correlation coefficient between the concentration of Na(I) ions in algal biomass.

The ability of commercial Spirulina species to remove chromium(III) [Cr(III)] from an aqueous environment was studied under photoautotrophic conditions. Biomass displayed high adsorptive capacity, with recorded sorption rates up to 99% at a concentration range of 0.02 to 0.18 mg chromium ions/mL of medium. Using isolated cell wall preparations, it was shown that Cr(III) is mainly sorbed onto the surface of cell walls and that the sorption capacity of the walls is enormously high. Living cells of cyanobacteria show the tendency to form multilayer sorption systems, as indicated electron microscopy.

The increasing amount of bio-waste creates the need to develop a method for efficient management based on processes that are more environmentally friendly than incineration and composting. This research aimed to utilize the waste of raspberry seeds after supercritical CO2 extraction. The biomass was enriched with micronutrients by the biosorption process to prepare micronutrient fertilizers for organic farming and biofortification of raspberries fruits. It was observed that at 100% dose of micronutrients, raspberry crop yield increased by 3%, and transfer of micronutrients to fruit biomass increased by 4.7%, 6.4%, and 8.8% (Cu, Mn, Zn, respectively) compared to commercial fertilizer. The supply of micronutrients at a dose of 150% led to a significant increase in micronutrient content of 3%, 41%, and 8% (Cu, Mn, and Zn, respectively) compared to commercial fertilizer. Research shows that the application of higher doses of micronutrients leads to the enrichment of edible parts of fruits, and fertilizers ensure environmental safety. The fruits contained on average 11.5% more microelements compared to the groups fertilized with the commercial product. The fruit yield (9.09-10.4 Mg per hectare) and the sugar content (9.82-10.2%) were also the highest. The micronutrients released from fertilizers and available to plants throughout the vegetation period affect the increase in yield, especially in the case of plants fruiting several times a year.

The main goal of this paper was to elaborate the possibility of industrial application of biosorption properties of Enteromorpha prolifera (production of mineral feed additives for livestock). In this study, biosorption process was used in the binding of chromium(III) ions from aqueous solution by the green macroalga. The kinetics of biosorption process was studied in a batch system with respect to the initial pH, temperature, initial metal ion concentration, and initial biomass concentration. E. prolifera demonstrated good biosorption properties. The equilibrium biosorption capacity increased with pH and with initial concentration of metal ions. The uptake of chromium(III) ions by the dried alga was affected by the temperature, but in small extent. With increase of the biomass concentration, the decrease of biosorption capacity at equilibrium was observed. The best biosorption conditions were determined as the initial pH 5, temperature 25 degrees Celsius, the initial chromium(III) ions concentration 400 mg/L, and biosorbent concentration 1.0 g/L. Biosorption capacity at equilibrium reached at these conditions was 100 mg/g. The mechanism of the biosorption of chromium(III) ions by E. prolifera was analyzed in equilibrium experiments. Equilibrium data were fitted to Langmuir, Dubinin-Radushkevich, and Freundlich adsorption isotherms. The most suitable model for describing the obtained data was Langmuir model. The experimental results and the analysis of the solution before and after biosorption process suggested ion-exchange mechanism.

Problem statement: Recently a particular attention was paid to the issue of microelement hunger, also termed hidden hunger. The problem was of global significance, since was related with the public health and concerns over 2 billion people. Approach: The study discusses the state of the art in the research on food biofortification as the sustainable solution to cope with micronutrient deficiencies. Enrichment of food with microelements seems to be the rational method of preventive, not interventionist character. Consuming such food should reduce the intake of mineral supplements containing inorganic salts, whereby microelements posses low bioavailability. Different methods of increasing the density of microelements in food of plant and animal origin (agronomic and biotechnological) are discussed. Results and Conclusion: Using microelements introduced with either fertilizers or feeds in the form which is highly bioavailable should yield plant and animal products containing higher levels of these constituents. Introducing microelements bound to a biomass which serves as a biological carrier is possible by means of the process of biosorption. The method is widely discussed in the literature as wastewater treatment process in which metal cations are removed from effluents and bound with the biomass by postulated ion exchange mechanism. The same process can be used to enrich the biomass with metal cations of nutritional significance. Studies on laying hens fed with new feed additives produced by biosorption yielded higher densities of Fe, Zn, Mn and Cu in eggs content, as compared with the control group which was fed with diet containing inorganic form of microelements.

Abstract In circular economy an effective strategy with regard to material valorization for fertilizers is expected to substantially improve sustainability, save resources and offer significant environmental, social and economic benefits. Wastes – especially biomass – are a large reservoir of materials which can be recovered via different technologies and used for manufacturing various fertilizers. Increasing re-use of nutrients from waste biomass is very difficult and requires taking additional steps to effectively use the potential of waste. It is necessary to introduce selective waste collection, increase the efficiency of nutrient recovery, obtain a more concentrated form with good bioavailability. Biomass waste streams carry huge potential, the content of fertilizer components is estimated at approx. 22 million Mg/year for nitrogen and 1.3 million Mg/year for phosphorus. Waste streams with the highest potential are waste from the food chain, manure and sewage, which are further processed and can be used for the production of fertilizers. Further research and experiments should be done to develop technologies that will enable exploitation of materials of high added value from biomass. Careful consideration should be given to energy routes. There is an urgent need for new technologies with which stable market dynamics via new business models could be safeguarded.

In the present paper, new environmental-friendly fertilizer components were produced in biosorption process by the enrichment of the biomass with zinc, essential in plant cultivation. The obtained new preparations can be used as controlled release micronutrient fertilizers because microelements are bound to the functional groups present in the cell wall structures of the biomass. It is assumed that new fertilizing materials will be characterized by higher bioavailability, gradual release of micronutrients required by plants, and lower leaching to groundwater. The biological origin of the material used in plant fertilization results in the elimination of toxic effect towards plants and groundwater mainly caused by low biodegradability of fertilizers. Utilitarian properties of new formulations enable to reduce negative implications of fertilizers for environmental quality and influence ecological health. In this work, the utilitarian properties of materials such as peat, bark, seaweeds, seaweed post-extraction residues, and spent mushroom substrate enriched via biosorption with Zn(II) ions were examined in germination tests on Lepidium sativum. Obtained results were compared with conventional fertilizers-inorganic salt and chelate. It was shown that zinc fertilization led to biofortification of plant in these micronutrients. Moreover, the mass of plants fertilized with zinc was higher than in the control group.