Integrated chemical and biochemical technology to produce biogas with a reduced ammonia content from municipal biowaste. Validating lab-scale research in a real operational environment

Abstract

The current paper reports the scientific, technical, environmental, economic and social impacts of two integrated chemical and biochemical processes that employed a novel virtuous biowaste under the real operational conditions...

The Autocatalytic Chemical Reaction of a Soluble Biopolymer Derived from Municipal Biowaste

“…For example, for the chemical hydrolysis of a wide variety of municipal biowaste composts, the following Equation (3) has been proposed [ 1 ]: C/N =1.81 + 2.60 Z where Z is the ratio of the measured total aliphatic, aromatic, carboxylic, phenol, phenoxide, methoxy, amine, amide and ketonic carbon over the sum of amine, amide and carboxylate functional groups. A similar significant linear relationship has been confirmed between the C/N values of different composts with the C/N values of the derived SBP products [ 27 ]. The relationship allows one to predict the chemical composition of SBPs obtained from different composts.…”

“…The polymeric molecules in the crude soluble products, through their basic and acidic functional groups, may establish intermolecular H-bonds. Depending on their concentration in water, these molecules form aggregates [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] of different sizes trough the H-bond network established between macromolecules of different compositions. In dilute solutions, the size of these aggregates [ 37 ] is likely to decrease, and therefore the composition of retentates through a membrane with a specific cutoff may change depending on the concentration of the solution fed to the membrane.…”

“…Also, depending on the concentration in water, SBPs have been found to promote their auto-oxidation [ 26 ]. The same products have been shown to catalyse the oxidation of ammonia to nitrogen [ 27 ], even in the absence of irradiation. These findings suggest that, in addition to their photosensitising properties, the SBPs could perform also as catalysts for their mild auto-oxidation under proper experimental conditions.…”

“…The valorisation of fermented MBW materials as feedstock for the production of other value-added products than soil amendments/composts is highly worthwhile. On one hand, the use of MBW anaerobic digestates as soil amendments is restricted due to their ammonia content and disadvantaged by the high cost of the secondary treatment to make the digestate comply with the current legislation [ 27 ]. On the other hand, the market value of the compost is very low [ 1 , 10 ] and does not cover the compost production cost.…”

Effect of municipal biowaste derived biostimulant on nitrogen fate in the plant-soil system during lettuce cultivation

“…The value of these products does not cover the processing costs. As collection and treatment costs are paid off by citizens’ taxes, MBW and its digestate and compost represent negative cost feedstocks 3 . Converting MBW, digestate and compost to value-added chemicals is potentially the way to improve current MBW treatment plants and turn them into eco-friendly biorefineries producing fuel and new multifunctional value-added biobased products (BPs) for use in the chemical industry, agriculture and waste treatment sectors 4 .…”