Reutilization of discarded biomass for preparing functional polymer materials

A robust, stable, and scalable multifunctional composite foam utilizing full components of lignin and cellulose from lychee pruning waste

Foam materials hold great promise in construction and packaging applications. However, the non-biodegradability and poor thermal stability of petroleum-based foams present serious environmental and safety concerns. It is crucial to develop sustainable, eco-friendly foam fabrication methods that balance environmental responsibility with high performance. In this study, a novel high-strength, heat-resistant, and water-stable composite foam (FPLs) made from Lignin-based waterborne polyurethanes (LWPUs) and Cellulose fibers, derived from full-component utilization of lychee pruning waste, is introduced. A eco-friendly and simple method utilizing LWPUs crosslinking to fabricate composite foams has been developed, bypassing the need for special drying and ensuring scalability. The FPLs exhibits a high compressive modulus of 455.8 kPa and a yield strength of 191.2 kPa due to the interaction between the LWPUs adhesive and the cellulose fibers. In addition, it demonstrates natural water resistance (maximum contact angle of 122°), exceptional photothermal conversion performance (reaching a peak temperature of 199.7 °C under infrared laser irradiation), superior thermal stability (no deformation up to 250 °C), and insulation performance (thermal conductivity of 0.038 W/mK), while maintaining excellent degradability and recyclability. These materials hold promise as sustainable alternatives to conventional plastic-based foams, providing a viable solution to mitigate the pervasive issue of "white pollution."

Bacterial Cellulose-Based Materials: A Perspective on Cardiovascular Tissue Engineering Applications

Today, a wide variety of bio- and nanomaterials have been deployed for cardiovascular tissue engineering (TE), including polymers, metal oxides, graphene/its derivatives, organometallic complexes/composites based on inorganic-organic components, among others. Despite several advantages of these materials with unique mechanical, biological, and electrical properties, some challenges still remain pertaining to their biocompatibility, cytocompatibility, and possible risk factors (e.g., teratogenicity or carcinogenicity), restricting their future clinical applications. Natural polysaccharide- and protein-based (nano)structures with the benefits of biocompatibility, sustainability, biodegradability, and versatility have been exploited in the field of cardiovascular TE focusing on targeted drug delivery, vascular grafts, engineered cardiac muscle, etc. The usage of these natural biomaterials and their residues offers several advantages in terms of environmental aspects such as alleviating emission of greenhouse gases as well as the production of energy as a biomass consumption output. In TE, the development of biodegradable and biocompatible scaffolds with potentially three-dimensional structures, high porosity, and suitable cellular attachment/adhesion still needs to be comprehensively studied. In this context, bacterial cellulose (BC) with high purity, porosity, crystallinity, unique mechanical properties, biocompatibility, high water retention, and excellent elasticity can be considered as promising candidate for cardiovascular TE. However, several challenges/limitations regarding the absence of antimicrobial factors and degradability along with the low yield of production and extensive cultivation times (in large-scale production) still need to be resolved using suitable hybridization/modification strategies and optimization of conditions. The biocompatibility and bioactivity of BC-based materials along with their thermal, mechanical, and chemical stability are crucial aspects in designing TE scaffolds. Herein, cardiovascular TE applications of BC-based materials are deliberated, with a focus on the most recent advancements, important challenges, and future perspectives. Other biomaterials with cardiovascular TE applications and important roles of green nanotechnology in this field of science are covered to better compare and comprehensively review the subject. The application of BC-based materials and the collective roles of such biomaterials in the assembly of sustainable and natural-based scaffolds for cardiovascular TE are discussed.

Biomass composite with exogenous organic acid addition supports the growth of sweet sorghum (Sorghum bicolor 'Dochna') by reducing salinity and increasing nutrient levels in coastal saline-alkaline soil

Introduction

In coastal saline lands, organic matter is scarce and saline stress is high. Exploring the promotion effect of intervention with organic acid from biological materials on soil improvement and thus forage output and determining the related mechanism are beneficial to the potential cultivation and resourceful, high-value utilization of coastal mudflats as back-up arable land.

Method

Three exogenous organic acids [humic acid (H), fulvic acid (F), and citric acid (C)] were combined with four kinds of biomass materials [cottonseed hull (CH), cow manure (CM), grass charcoal (GC), and pine needle (PN)] and applied to about 0.3% of medium-salt mudflat soil. The salinity and nutrient dynamics of the soil and the growth and physiological differences of sweet sorghum at the seedling, elongation, and heading stages were observed under different treatments to screen for efficient combinations and analyze the intrinsic causes and influencing mechanisms.

Results

The soil salinity, nutrient dynamics, and forage grass biological yield during sweet sorghum cultivation in saline soils differed significantly (p < 0.05) depending on the type of organic acid-biomass composite applied. Citric acid-pine needle composite substantially reduced the soil salinity and increased the soil nutrient content at the seedling stage and improved the root vigor and photosynthesis of sweet sorghum by increasing its stress tolerance, allowing plant morphological restructuring for a high biological yield. The improvement effect of fulvic acid-pine needle or fulvic acid-cow manure composite was manifested at the elongation and heading stages.

Discussion

Citric acid-pine needle composite promoted the growth of saline sweet sorghum seedlings, and the effect of fulvic acid-pine needle composite lasted until the middle and late stages.

Sustainable Secondary-Raw Materials, Natural Substances and Eco-Friendly Nanomaterial-Based Approaches for Improved Surface Performances: An Overview of What They Are and How They Work

To meet modern society’s requirements for sustainability and environmental protection, innovative and smart surface coatings are continually being developed to improve or impart surface functional qualities and protective features. These needs regard numerous different sectors, such as cultural heritage, building, naval, automotive, environmental remediation and textiles. In this regard, researchers and nanotechnology are therefore mostly devoted to the development of new and smart nanostructured finishings and coatings featuring different implemented properties, such as anti-vegetative or antibacterial, hydrophobic, anti-stain, fire retardant, controlled release of drugs, detection of molecules and mechanical resistance. A variety of chemical synthesis techniques are usually employed to obtain novel nanostructured materials based on the use of an appropriate polymeric matrix in combination with either functional doping molecules or blended polymers, as well as multicomponent functional precursors and nanofillers. Further efforts are being made, as described in this review, to carry out green and eco-friendly synthetic protocols, such as sol–gel synthesis, starting from bio-based, natural or waste substances, in order to produce more sustainable (multi)functional hybrid or nanocomposite coatings, with a focus on their life cycle in accordance with the circular economy principles.

The potential of degrading natural chitinous wastes to oligosaccharides by chitinolytic enzymes from two Talaromyces sp. isolated from rotten insects (Hermetia illucens) under solid state fermentation

It is difficult to produce chitin oligosaccharides by hydrolyzing untreated natural chitinous waste directly. In this study, two fungi Talaromyces allahabadensis Hi-4 and Talaromyces funiculosus Hi-5 from rotten black soldier fly were isolated and identified through multigene phylogenetic and morphological analyses. The chitinolytic enzymes were produced by solid state fermentation, and the growth conditions were optimized by combining single-factor and central composite design. The best carbon sources were powder of molting of mealworms (MMP) and there was no need for additional nitrogen sources in two fungi, then the maximum chitinolytic enzyme production of 46.80 ± 3.30 (Hi-4) and 55.07 ± 2.48 (Hi-5) U/gds were achieved after analyzing the 3D response surface plots. Pure chitin (colloidal chitin) and natural chitinous substrates (represented by MMP) were used to optimize degradation abilities by crude enzymes obtained from the two fungi. The optimum temperature for hydrolyzing MMP (40 °C both in two fungi) were lower and closer to room temperature than colloidal chitin (55 °C for Hi-4 and 45 °C for Hi-5). Then colloidal chitin, MMP and the powder of shrimp shells (SSP) were used for analyzing the products after 5-day degradation. The amounts of chitin oligosaccharides from SSP and MMP were about 1/6 (Hi-4), 1/17 (Hi-5) and 1/8 (Hi-4), 1/10 (Hi-5), respectively, in comparison to colloidal chitin. The main components of the products were GlcNAc for colloidal chitin, (GlcNAc)2 for MMP, and oligosaccharides with higher degree of polymerization (4-6) were obtained when hydrolyzing SSP, which is significant for applications in medicine and health products.

The research progress, hotspots, challenges and outlooks of solid-phase denitrification process

Nitrogen pollution is one of the main reasons for water eutrophication. The difficulty of nitrogen removal in low-carbon wastewater poses a huge potential threat to the ecological environment and human health. As a clean biological nitrogen removal process, solid-phase denitrification (SPD) was proposed for long-term operation of low-carbon wastewater. In this paper, the progress, hotspots, and challenges of the SPD process based on different solid carbon sources (SCSs) are reviewed. Compared with synthetic SCS and natural SCS, blended SCSs have more application potential and have achieved pilot-scale application. Differences in SCSs will lead to changes in the enrichment of hydrolytic microorganisms and hydrolytic genes, which indirectly affect denitrification performance. Moreover, the denitrification performance of the SPD process is also affected by the physical and chemical properties of SCSs, pH of wastewater, hydraulic retention time, filling ratio, and temperature. In addition, the strengthening of the SPD process is an inevitable trend. The strengthening measures including SCSs modification and coupled electrochemical technology are regarded as the current research hotspots. It is worth noting that the outbreak of the COVID-19 epidemic has led to the increase of disinfection by-products and antibiotics in wastewater, which makes the SPD process face challenges. Finally, this review proposes prospects to provide a theoretical basis for promoting the efficient application of the SPD process and coping with the challenge of the COVID-19 epidemic.

Surveying the elimination of hazardous heavy metal from the multi-component systems using various sorbents: a review

In this review, several adsorbents were studied for the elimination of heavy metal ions from multi-component wastewaters. These utilized sorbents are mineral materials, microbes, waste materials, and polymers. It was attempted to probe the structure and chemistry characteristics such as surface morphology, main functional groups, participated elements, surface area, and the adsorbent charges by SEM, FTIR, EDX, and BET tests. The uptake efficiency for metal ions, reusability studies, isotherm models, and kinetic relations for recognizing the adsorbent potentials. Besides, the influential factors such as acidity, initial concentration, time, and heat degree were investigated for selecting the optimum operating conditions in each of the adsorbents. According to the results, polymers especially chitosan, have displayed a higher adsorption capacity relative to the other common adsorbents owing to the excellent surface area and more functional groups such as amine, hydroxyl, and carboxyl species. The high surface area generates the possible active sites for trapping the particles, and the more effective functional groups can complex more metal ions from the polluted water. Also, it was observed that the uptake capacity of each metal ion in the multi-component solutions was different because the ionic radii of each metal ion were different, which influence the competition of metal ions for filling the active sites. Finally, the reusability of the polymers was suitable, because they can use several cycles which proves the economic aspect of the polymers as the adsorbent.

Waste Reutilization in Polymeric Membrane Fabrication: A New Direction in Membranes for Separation

In parallel to the rapid growth in economic and social activities, there has been an undesirable increase in environmental degradation due to the massively produced and disposed waste. The need to manage waste in a more innovative manner has become an urgent matter. In response to the call for circular economy, some solid wastes can offer plenty of opportunities to be reutilized as raw materials for the fabrication of functional, high-value products. In the context of solid waste-derived polymeric membrane development, this strategy can pave a way to reduce the consumption of conventional feedstock for the production of synthetic polymers and simultaneously to dampen the negative environmental impacts resulting from the improper management of these solid wastes. The review aims to offer a platform for overviewing the potentials of reutilizing solid waste in liquid separation membrane fabrication by covering the important aspects, including waste pretreatment and raw material extraction, membrane fabrication and characterizations, as well as the separation performance evaluation of the resultant membranes. Three major types of waste-derived polymeric raw materials, namely keratin, cellulose, and plastics, are discussed based on the waste origins, limitations in the waste processing, and their conversion into polymeric membranes. With the promising material properties and viability of processing facilities, recycling and reutilization of waste resources for membrane fabrication are deemed to be a promising strategy that can bring about huge benefits in multiple ways, especially to make a step closer to sustainable and green membrane production.

Synthesis of a novel superabsorbent with slow-release urea fertilizer using modified cellulose as a grafting agent and flexible copolymer

In this work, a number of glucose unites in polymeric structure of cellulose was converted to 2,4-dihydroxy-3-(1-hydroxy-2-oxoethoxy)butanal (cellulose containing di aldehyde units (CCDAUs)) by oxidation with sodium periodate, followed by condensation with acetone to produce 5,7-dihydroxy-6-((1-hydroxy-4-oxopent-2-en-1-yl)oxy)hept-3-en-2-one unites (cellulose containing di ene units (CCDEUs)). This modified cellulose was characterized by different methods and applied as a copolymer and grafting agent to synthesize an eco-friendly (CCDEUs-g-poly(AA)/urea) superabsorbent with slow-release urea fertilizer. The created double bonds in C₂ and C₃ positions of β-d-glucose units increased the linkage between cellulose and acrylic acid, leading to the formation of a strong network for slow-release urea fertilizer. Also, this modification created an expanded network for storage a high amount of water by increasing the cellulose flexibility. The reaction conditions for modification and synthesis of the superabsorbent, the oxidation degree value of glucose units, kinetics models, the effect of different saline solutions, various pH and reswelling time on the water absorbency, water retention capacity, reusability, biodegradability, and slow-release property were investigated. Also, the effect of synthesized CCDEUs-g-poly(AA)/urea on plant growth was tested and excellent results were obtained.

Hydrothermal carbonization of waste biomass: An experimental comparison between process layouts

This paper contributes to the knowledge on waste biomass conversion processes occurring in the presence of hot compressed water. The experimental procedure detailed herein assesses different process schemes based on the low-temperature reaction known as hydrothermal carbonization. The performances of two lab-scale reactor configurations, with and without a downstream flash expansion step, were evaluated and compared. Each setup was tested with six different types of waste biomass. Fir, beech, and olive prunings are representative of lignocellulosic raw materials, while potato, pea, and carrot are representative of non-lignocellulosic wastes from processing in the local agro-food industry. The batch reactions (200 °C, water/solid = 7/1) were carried out for up to 120 min. The hydrochars were characterized by elemental composition, humidity, heating value, and mass and energy yields. The extent of difference between the results obtained for the two procedures varied significantly with the material treated. At a residence time of 30 min, the solid yields increased due to expansion, ranging from 10 to 36% for lignocellulosic material and 50 to 220% for agro-food industry scraps. The downstream flash expansion step causes an increase of the solid yields, especially for hydrochars from lignocellulosic materials, leading to higher energy recovered compared to the configuration without expansion. Lignocellulosic and agro-food wastes behaved dissimilarly, likely because of different hydrothermal reaction pathways. The additional expansion step can considerably increase the efficiency of energy recovery in full-scale plants, the extent of which depends on the biomass waste substrate used.

Evaluation of new environmental friendly particulate soil fertilizers based on agroindustry wastes biopolymers and sugarcane vinasse

This study evaluated the physicochemical and morphological properties of pectin and chitosan particles combined with sugarcane vinasse for soil fertilization applications. Particles were obtained by adding the biopolymeric solutions (pectin or chitosan solution) dropwise into the crosslinking solutions (calcium chloride 1% in ethanolic solution or tripolyphosphate 5% aqueous solution) followed by drying. Vinasse enhanced pectin gel stability improving pectin/vinasse particle properties. Physicochemical characterization indicated that vinasse nutrients were properly incorporated in both pectin and chitosan matrices. Particles showed spherical shape, with an average diameter of 3 and 2 mm for the pectin and chitosan particles with vinasse, respectively. Chitosan particles, compared to pectin, showed lower swelling capacity and solubility and higher mechanical resistance indicating a denser and more compact polymer network. Both particles were able to hinder water evaporation rates from sandy soil under water stress conditions. Biobased particles with vinasse added show potential to be applied as soil fertilizer representing an alternative to use and disposal of this expressive wastewater from sugar and alcohol industries.

Design, Preparation, and Evaluation of a Novel Elastomer with Bio-Based Diethyl Itaconate Aiming at High-Temperature Oil Resistance

A novel elastomer poly(diethyl itaconate-co-butyl acrylate-co-ethyl acrylate-co-glycidyl methacrylate) (PDEBEG) was designed and synthesized by redox emulsion polymerization based on bio-based diethyl itaconate, butyl acrylate, ethyl acrylate, and glycidyl methacrylate. The PDEBEG has a number average molecular weight of more than 200,000 and the yield is up to 96%. It is easy to control the glass transition temperature of the PDEBEG, which is ranged from −25.2 to −0.8 °C, by adjusting the monomer ratio. We prepared PDEBEG/CB composites by mixing PDEBEG with carbon black N330 and studied the oil resistance of the composites. The results show that the tensile strength and the elongation at break of the composites with 10 wt% diethyl itaconate can reach up to 14.5 MPa and 305%, respectively. The mechanical properties and high-temperature oil resistance of the composites are superior to that of the commercially available acrylate rubber AR72LS.

Preparation and Performance of Silica/ESBR Nanocomposites Modified by Bio-Based Dibutyl Itaconate

Ester-functionalized styrene-butadiene rubber (dibutyl itaconate-styrene-butadiene rubber) (D-ESBR) was synthesized by low-temperature emulsion polymerization using dibutyl itaconate (DBI) as a modified monomer containing ester groups. Nonpetroleum-based silica with hydroxy groups was used as a filler to enhance the D-ESBR, which can provide excellent mechanical properties, low rolling resistance, and high wet skid resistance. During the preparation of the silica/D-ESBR nanocomposites, a hydrogen-bonding interface was formed between the hydroxy groups on the surface of silica and the ester groups in the D-ESBR macromolecules. As the content of ester groups in the D-ESBR increases, the dispersion of silica in the nanocomposites is gradually improved, which was verified by rubber process analyzer (RPA) and scanning electron microscopy (SEM). Overall mechanical properties of the silica/D-ESBR modified with 5 wt % DBI were improved and became superior to that of the non-modified nanocomposite. Compared with the non-modified silica/D-ESBR, the DBI modified silica/D-ESBR exhibited a lower tan δ value at 60 °C and comparable tan δ value at 0 °C, indicating that the DBI modified silica/D-ESBR had lower rolling resistance without sacrificing wet skid resistance.

Adsorption of cadmium and lead ions by phosphoric acid-modified biochar generated from chicken feather: Selective adsorption and influence of dissolved organic matter

To improve the adsorption efficiency, a H₃PO₄-modified biochar (CFCP) was prepared using chicken feather and applied to Cd²⁺ and Pb²⁺ adsorption. The pseudo-second-order model could explain the Cd²⁺ and Pb²⁺ adsorption behavior. CFCP had faster adsorption rate than non-modified biochar (CFC2). The Langmuir and Freundlich isotherm could better describe the Cd²⁺ and Pb²⁺ adsorption, respectively. The value of q_m for Cd²⁺ adsorption and K_F for Pb²⁺ adsorption by CFCP was 7.84 mg·g^-1 and 24.41 mg^1-(1/n)·L^1/n·g^-1, which was 1.38 and 5.41 times of the corresponding results of CFC2. Relative to Cd²⁺, Pb²⁺ was selectively adsorbed by biochars in the binary metal system. Phosphate precipitation explained in part the selective adsorption of Pb²⁺. Proline, glucose, and pH (4-6) had little influence on Cd²⁺ and Pb²⁺ adsorption. Electrostatic interaction, precipitation, and O-H bonds were the primary adsorption mechanisms. The increased N-containing heterocycles of CFCP accounted for the increased Cd²⁺ and Pb²⁺ adsorption.

Preparation of hydroxyapatite-based porous materials for absorption of lead ions

In this paper, soybean protein isolate (SPI) was used as template, hydroxyapatite was crystallized on protein chains of SPI by in-situ synthesis, then the obtained inorganic HA/biopolymer SPI composite (HA@SPI) was calcined at suitable temperature, which afforded a novel hydroxyapatite-based porous materials (HApM). The results indicated that the product showed a porous morphology structure and excellent absorption performance for Pb²⁺. HApM maximum removal of lead was attained (96.25%) at an initial pH value of 7.4, temperature of 25 °C and contact time of 30 min with an initial metal concentration of 60 mg/L. In order to identify composition, structure and functional groups involved in the uptake of Pb²⁺, Fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TG), X-ray diffraction (XRD) scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) analysis were carried out. Therefore, the hydroxyapatite-based porous materials (HApM) is a promising candidate for the treatment of liquid wastes containing toxic Pb²⁺ metal ion, heavy metal ion antidotes and other related fields.

Modified mussel shell powder for microalgae immobilization to remove N and P from eutrophic wastewater

In this work, calcined mussel shell powder (CMSP) was activated by K₂CO₃ (K-CMSP), and this porous K-CMSP surface was modified by L-arginine (L-ARG) to render porous biomass a positively charged surface, which was innovatively utilized as a carrier to immobilize microalgae by adsorption via electrostatic interactions. The pore and the surface structures of CMSP and K-CMSP were characterized by XRD, FTIR, BET and SEM. The surface morphology of immobilized microalgae was visualized via using inverted optical microscope and SEM. It was found that microalgae could survive for 60 days, and the loss rate of chlorophyll-a preserved at -24 °C was the lowest, 44.73%. The microalgae could revive to normal growth level within 10 days and the cell content of microalgae was the highest at 25 °C, 2.8022 × 10⁶ cell/mL. At 25 °C, the highest removal rate of N and P was obtained about 95.0% and 88.63%, respectively.

Trace elements effect on hydrolytic stage towards biogas production of model lignocellulosic substrates

The effect and the response of several trace elements (TE) addition to the anaerobic degradation of key compounds of lignocellulosic biomass were evaluated. Lignin, cellulose and xylose were selected as principal compounds of lignocellulosic biomass. Lignin degradation was only improved by the addition of 1000 mg Fe/L, which allowed an improvement on the methane yield coefficient of 28% compared to control. SEM images from an abiotic assay showed that this effect is more likely related with a chemical effect induced by the Fe solution, instead of an enzymatic response. Pre-treatments focused on breaking the recalcitrant structure of the lignin could be more promising than TE addition for rich lignin-content substrates. Unlike to the response observed with lignin, cellulose showed a clear effect of the TE addition on methane production rate, indicating a higher preponderance of the enzymatic activity compared to the lignin biomethanization. Experiments with xylose resulted in a strong accumulation of volatile fatty acids. TE addition should be adapted to the substrate composition given the different response of each lignocellulosic compound to the different TE addition.

Sustainability Assessment of Bioenergy from a Global Perspective: A Review

Bioenergy, as a renewable energy resource, is expected to see significant development in the future. However, a key issue that will affect this trend is sustainability of bioenergy. There have been many studies on this topic but mainly focusing on only one or two-dimensions of the issue and also with much of the literature directed at studies of European regions. To help understand the wider scope of bioenergy sustainability, this paper reviews a broad range of current research on the topic and places the literature into a multi-dimensional framework covering the economic, environmental and ecological, social and land-related aspects of bioenergy sustainability, as well as a geographical analysis of the areas for which the studies have been carried out. The review indicates that it is hard to draw an overall conclusion on the sustainability of bioenergy because of limited studies or contradictory results in some respects. In addition, this review shows that crop-based bioenergy and forest bioenergy are seen as the main sources of bioenergy and that most studies discuss the final utilization of bioenergy as being for electricity generation. Finally, research directions for future study are suggested, based on the literature reviewed here.

Preparation of Keratin-Glycine Metal Complexes and Their Scavenging Activity for Superoxide Anion Radicals

To address the problem of limited application of natural SOD, the development of SOD mimic enzymes is of great importance for bioantioxidation. Herein, we report on a new type of biopolymer antioxidant with excellent scavenging activity for O2•-, keratin-glycine metal complexes (FK-GlyM, M = Zn, Cu, Mn, Ni). They are prepared by feather keratin firstly combined with glycine and then metal ions. Using FT-IR, TG, CD, and SEM, the performance of the obtained complexes (FK-GlyM) for scavenging O2•- is analysed and investigated. Importantly, the scavenging activity of FK-GlyCu is excellent in all FK-GlyM, and FK-GlyCu60 has the most excellent anti-O2•- activity in all FK-GlyCux, of which EC50 and degree of simulation were, respectively, up to 4.5×10-3±0.0012 μmol/L and 911.1% compared with nature Cu, Zn-SOD. Finally, its mechanism was also discussed. In summary, this method about the simulation strategies will provide a novel idea for exploiting new-type biocompatible and highly reactive antioxidants.

Acidogenic fermentation of the organic fraction of municipal solid waste and cheese whey for bio-plastic precursors recovery - Effects of process conditions during batch tests

The problem of fossil fuels dependency is being addressed through sustainable bio-fuels and bio-products production worldwide. At the base of this bio-based economy there is the efficient use of biomass as non-virgin feedstock. Through acidogenic fermentation, organic waste can be valorised in order to obtain several precursors to be used for bio-plastic production. Some investigations have been done but there is still a lack of knowledge that must be filled before moving to effective full scale plants. Acidogenic fermentation batch tests were performed using food waste (FW) and cheese whey (CW) as substrates. Effects of nine different combinations of substrate to inoculum (S/I) ratio (2, 4, and 6) and initial pH (5, 7, and 9) were investigated for metabolites (acetate, butyrate, propionate, valerate, lactate, and ethanol) productions. Results showed that the most abundant metabolites deriving from FW fermentation were butyrate and acetate, mainly influenced by the S/I ratio (acetate and butyrate maximum productions of 21.4 and 34.5g/L, respectively, at S/I=6). Instead, when dealing with CW, lactate was the dominant metabolite significantly correlated with pH (lactate maximum production of 15.7g/L at pH = 9).

Starch-based and multi-purpose nanofibrous membrane for high efficiency nanofiltration

The objective of the present work is to develop nanofibrous membranes from rice-flour based nanofibers containing PVA for high efficiency filtration.