Collagen-Based Hydrogels Composites from Hide Waste to Produce Smart Fertilizers

Abstract

The study aims at reusing and recycling the protein hide waste from the leather industry in ecological conditions by elaborating an innovative procedure in order to obtain a collagen matrix functionalized with nitrogen, phosphorus, and potassium (NPK) nutrients to be used for preparing smart fertilizers. This is an interdisciplinary approach, as it starts from hide waste raw material as a critical industrial waste, which is then subjected to several technological steps by selection of optimal processing parameters, followed by product fabrication at the laboratory, and next scales to the industrial pilot plant to obtain novel agro-hydrogels. In this context, the technology scheme for collagen hydrolysate with encapsulated nutrients was proposed and the process parameters were optimized by functionalization of agro-hydrogels with various natural and synthetic polymers, such as polyacrylamide, poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate) copolymer, starch or dolomite. Based on the laboratory experiments, a pilot plant was constructed and tested. Taking as reference the collagen hydrolysate with encapsulated nutrients, the new fertilizers were adequately characterized by chemical analysis, determination of biodegradability and the degree of release of oxidable compounds in water. Based on the biodegradation mechanism and kinetic analysis of oxidable compounds release, adequate arguments are evidenced to demonstrate that these fertilizers can be applied for amendment of poor agricultural soils.

Advanced Collagen-Based Composites as Fertilizers Obtained by Recycling Lime Pelts Waste Resulted during Leather Manufacture

“…The values of pH and electrical conductivity were determined in aqueous suspensions of various concentrations ranging between 0.5% and 10%. The results are collected in Table 2 , and the methods used are in accordance with European Commission Regulation 2003/2003, adjusted due to the organic matrix of these fertilizers, and also in accordance with procedure described in [ 22 ].…”

“…Our previous works [ 21 , 22 , 23 ] reported on the synthesis and physical–chemical characterization of novel collagen-based hydrogels by recycling the protein hide waste from the leather industry in ecological conditions and obtaining advanced collagen-based composites with N, P, and K nutrients encapsulated and functionalized with two synthetic polymers, namely poly-acrylamide and poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate) (P(SSNa-co-GMAx), and two natural compounds, namely starch and dolomite, in order to be used as fertilizers for poor soil amendment. The reason why the last two natural compounds were selected for collagen functionalization was to test their efficacy on improving fertilizer quality by using starch as an organic and dolomite as a mineral amendment, as they are both available in high amounts and as waste to be recycled.…”

A Systematic Review of the Potential of a Dynamic Hydrogel as a Substrate for Sustainable Agriculture

“…The potential of hydrogels as insecticide carriers, as demonstrated by alginate hydrogels, could aid against pests [99]. For instance, the application was beneficial against plant root-feeding insects [67], reduced Phytophthora capsici infestation in capsicum [56], and controlled ant population in trees within 48 h of application [99]. Nonetheless, incorporating active insecticidal ingredients into hydrogel requires further discussion as it has a different mode of action against pests [1,67].…”

Innovative Collagen Based Biopolymers Tested as Fertilizers for Poor Soils Amendment

“…Our previous research [26,27] developed new collagen composites produced by the incorporation of both mineral (phosphorus and potassium) nutrients and various synthetic and natural polymers into the collagen hydrogel matrix that was extracted with pelt waste processing in order to be proposed as fertilizers for the treatment of poor soils.…”