Liquid fertilizer products from anaerobic digestion of food waste: mass, nutrient and energy balance of four digestate liquid treatment systems

Abstract

This study compared four different digestate liquid treatment systems of a theoretical anaerobic digestion plant in order to facilitate the utilization of municipal food waste nutrients in agriculture. The mass, nutrient and energy balances of a theoretical plant digesting 60 kt/y of food waste were used to evaluate the feasibility of the treatments to concentrate nutrients into liquid fertilizer products. The studied technologies for digestate liquid treatment were ammonia stripping, ammonia stripping combined with reverse osmosis (RO), evaporation combined with RO, and stripping combined with both evaporation and RO. As a result, processing of digestate into concentrated fertilizer products consumed less than 10% of the produced energy from food wastes and was also sufficient for the heat-demanding digestate liquid treatments, evaporation and stripping. The digestate liquid treatment systems were considered as nitrogen and potassium concentration methods which were able to concentrate up to

Cleaner energy for cleaner production: Modeling and optimization of biogas generation from Carica papayas (Pawpaw) fruit peels

“…This trend was recorded for elements such as nitrogen, phosphorus, potassium, magnesium, manganese, iron, zinc, aluminium and copper. Therefore, these digestates can be said to be rich in nutrient and has great potentials to increase both the microbial and nutrient status of soil when applied through the rhizosphere as fertilizers especially in nutrient-depleted soils (Tampio et al, 2016a). Plant growth and general wellbeing could also be enhanced via the use of such digestate as biofertiliser especially in Sub-Saharan Africa and other regions faced with soil nutrient depletion and erosion of top soil.…”

“…Anaerobic digestion is a biochemical process that is widely used for the treatment and energy recovery from many kinds of biomasses, especially agricultural products and agro-industrial wastes (He et al, 2016;Othman et al, 2017). It is an efficient method which employs diverse microbial groups for the conversion of biomasses and wastes into biogas (which serves to mitigate the energy challenges currently faced in several parts of the world) (Ismail and Talib, 2016;Chuichulcherm et al, 2017) and digestate biofertilizer which can be used to improve soil nutrients and plant growth when applied either in solid or liquid form (Shane and Gheewala, 2017;Tampio et al, 2016a).…”

Effect of flocculation pre-treatment on membrane nutrient recovery of digested chicken slurry: Mitigating suspended solids and retaining nutrients

“…Therefore, a feasible utilization method ought to be adopted to enrich nutrient concentrations and reduce the volume of digested slurry so that the pre-treated digested slurry could be easily transported and applied as a fertilizer in regions of high demand [9]. This nutrient enrichment and mitigation strategy might also help reduce the environmental pollution risk of nutrient run-off and leaching by the surplus application of digested slurry [10].…”

Synergy between anaerobic digestion and a post‐treatment based on Thermophilic Aerobic Membrane Reactor (TAMR)

“…The physical‐chemical methods include struvite formation , ammonia stripping , evaporation , membrane separation , adsorption processes with activated carbons, ion exchange resins, zeolites , and biochar , as well as various combination of these processes. In particular, Tampio et al have shown that the system based on evaporation combined with reverse osmosis is an efficient nutrient technology for the production of transportable fertilizer products for agricultural application due to the highest concentration of nutrients, nutrient availability, the low mass of the product and low energy consumption of the treatment. Stripping is an efficient technology for nitrogen recovery; however, the high mass of the residue containing the remaining K and P should be further managed sustainably.…”