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Bio-based controlled release fertilizers (BCRFs) are cost-effective and renewable thus gradually replacing petroleum-based controlled release fertilizers (CRFs). However, most of the study mainly focused on modifying BCRFs to improve controlled-release performance. It is necessary to further increase the functionality of BCRF for expanding the application. A multifunctional double layered bio-based CRF (DCRF) was prepared. Urea was used as the core of fertilizer, bio-based polyurethane was used as the inner coating, and sodium alginate and copper ions formed the hydrogel as the outer coating. In addition, mesoporous silica nanoparticles loaded with sodium selenate was used to modify the sodium alginate hydrogel (MSN@Se hydrogel). The results showed that the nitrogen longevity of the DCRF was much better than that of urea and BCRF. The selenium nutrient longevity of the DCRF was 40 h, much longer than that of sodium selenate. The DCRF improved the yield and nutritive value of cherry radish (Raphanus sativus L. var.radculus pers) with the elevated contents of selenium, an essential trace element. Moreover, the DCRF showed inhibitory effect on Fusarium oxysporum Schltdl. and could resist soil-borne fungal diseases continuously. Overall, this multifunctional fertilizer has great potential for expanding the use of BCRFs for sustainable development of agriculture.

Bio-based polyurethanes are promising for the controlled release of nutrients and fertilizers, but their toughness and plasticity need to be improved. We developed a smooth, dense, elastic, and indestructible bio-based polyurethane (BPU) coating with a nutrient controlled release ∼150% superior, a tensile strength ∼300% higher, and a toughness ∼1200% higher than those for the original BPU coating. Through a one-step reaction of soybean oil polyols (accounting for more than 60%), isocyanate, and benzil dioxime, the dynamic covalent network based on oxime-carbamate replaces part of irreversible covalent cross-linking. The dynamic fracture-bonding reaction in the modified coating BPU can effectively promote the hydrogen bond recombination and oxime-carbamate chain migration in the coating process, which avoids the structural defects caused by coating tear and fertilizer collision. This work provides a simple and versatile strategy for building controlled-release fertilizer coatings.

This work provides an efficient UV-curing strategy for the manufacture of energy-saving, superior performance and biopolymer-coated large tablet controlled-release fertilizers.

Wastewater treatment is a severe environment issue, especially the discharge of excessive synthetic dyestuffs in the aquatic environment. In this study, a facile binary deep eutectic solvothermal process plus silica surface modification was successfully applied for preparation of porous nanosheet Ni2CO3(OH)2/SiO2 composites. The composites show powerful anionic dyes removal ability due to the high specific surface areas, hydrogen bond connection, coordination effect and strong electrostatic interactions with anionic dyes. A maximum adsorption capacity of 2637 mg g−1 at neutral pH (ca.7) and 303 K was achieved for Ni2CO3(OH)2/SiO2 composite to adsorb Congo red, a representative anionic dye. Moreover, the composite has an excellent specificity for anionic dyes and could maintain above 95% removal efficiency after 5 cycles. Therefore, the as-prepared nanocomposites could be qualified as candidates for industrial environmental remedy. Furthermore, the proposed material preparation strategy could be extended to fabricate various advanced energy and environmental materials.

Background: Aerobic glycolysis plays a key role in tumor metabolic reprogramming to reshape the immune microenvironment. The phosphoglycerate kinase 1 (PGK1) gene codes a glycolytic enzyme that converts 1,3-diphosphoglycerate to 3-phosphoglycerate. However, in lung adenocarcinoma (LUAD), the role of PGK1 in altering the tumor microenvironment (TME) has not yet been determined. Methods: Raw data, including bulk DNA and mRNA-seq data, methylation modification data, single-cell RNA-seq data, proteomics data, clinical case characteristics survival, immunotherapy data, and so on, were obtained from multiple independent public data sets. These data were reanalyzed to uncover the prognosis and immunological characteristics of PGK1 in LUAD. Results: We found that PGK1 mRNA and protein were considerably over-expressed in LUAD compared to normal tissue and that high PGK1 expression is associated with poorer prognostic outcomes in LUAD. The enrichment analysis of PGK1 co-expressed genes in lung adenocarcinoma revealed that PGK1 may be involved in hypoxia, metabolism, DNA synthesis, cell cycle, PI3K/AKT, and various immune and inflammatory signaling pathways. Furthermore, PGK1 is also linked to the recruitment of numerous immune cells, including aDC (dendritic cells), macrophages, and neutrophils. More importantly, PGK1 was highly expressed in immunosuppressive cells, including M2 macrophages, Tregs, and exhausted T cells, among others. Finally, higher PGK1 expression indicated significant correlations to immune checkpoints, TMB (tumor mutation burden), and high response to immunotherapy. Conclusions: The presented findings imply that PGK1, as a glycolysis core gene, may be important for the modification of the immune microenvironment by interacting with the tumor metabolism. The results of this study provide clues for a potential immunometabolic combination therapy strategy in LUAD, for which more experimental and clinical translational research is needed.

The development of catalysts with relatively high current densities at low potentials for the electrooxidation of 5-hydroxymethylfurfural (HMF) is still challenging. In this study, an in situ deep eutectic solvent (DES) etching phosphorization strategy is developed to prepare nickel phosphides encapsulated in P,O-codoped carbon nanosheets (Ni-P@POC). The DES serves not only as an etchant to extract Ni

Iron (Fe) chelated by water-soluble humic substances can effectively overcome plant micronutrient deficiencies. However, the traditional synthesis methods are often complex, expensive, and thus not...

Electrochemical conversion is emerging as a powerful and promising method to produce a wide range of high-value chemicals on account of mild operation conditions, controllable selectivity, and scalability. 5-Hydroxymethylfurfural (HMF), with simple molecular structures including furan rings, –CO, and –OH groups, is considered one of the most versatile platform molecules. The electrooxidation of bio-based HMF to furandicarboxylic acid (FDCA), a crucial bio-based precursor of polyethylene furanoate (PEF), which would probably replace petroleum-based polyethylene terephthalate (PET), has recently attracted increasing attention. Here, we review the HMF electrochemical oxidation, from reaction pathway/mechanism to catalysts and coupling reactions. First, a pH-dependent reaction pathway is proposed, and the reaction mechanism (direct oxidation and indirect oxidation) is summarized systematically, which is also suitable for electrochemical oxidation of other small organic molecules containing aldehyde/alcohol groups (e.g., methanol, ethanol, glycerol, and glucose) to some extent. Then, the progress, advantages and disadvantages of HMF electrooxidation catalysts of noble metals, non-noble metals, and non-metals are reviewed, particularly on non-noble metal catalysts. Furthermore, for more efficient energy utilization, HMF electrooxidation coupled with H2 evolution, CO2 reduction, N2 reduction, and organic reduction are discussed. Finally, a few unique insights into reaction mechanism, an assessment about catalyst performance and an outlook for further development of this topic are provided. This review can offer a guideline for the in-depth understanding of electrochemical oxidation of small organic molecules as well as the design of advanced anodic electrocatalysts towards the utilization and production of renewable resources.

The vast increase in the use of post-consumer polyethylene terephthalate (PET) plastic brings with it the challenge of recycling the increase in waste bottles and materials. The degradation of waste PET to its monomers in an environmentally benign solvent is a desirable way to process waste PET. Analysis of solubility parameters has inspired the successful application of biomass-derived γ-valerolactone (GVL) for PET dissolution, and further accelerated the alkaline hydrolysis of waste PET to its monomers. Hydrogen-bonding interactions between PET chains and GVL play a major role in the dissolution. Swelling differential scanning calorimetry (DSC) has indicated that GVL processing PET proceeds through two steps: swelling and dissolving. The optimal dissolving process by swelling DSC showed that waste PET bottle pieces could fully swell at 120 °C in 1 h, then dissolve at 170 °C in 2 min. The maximum solubility of PET in GVL is around 0.25 g·g−1. Here, water was used as an anti-solvent to induce PET to reprecipitate from the hot solution. Due to the virtue of fully pre-swelling and the very fast dissolution, the degradation ratio of PET during the dissolving process was only 5.7%. GVL processing greatly increased the effective surface area of PET, which promoted the following complete alkaline hydrolysis of PET in around 8 min. This study provides an environmentally benign, very fast, and energy efficient pathway for recycling waste PET.

Bio-based slow-release fertilizers (SRFs) have drawn significant attention because their applications for crop production can improve nutrient utilization efficiency as well as prevent environmental pollution. However, current commercial SRFs still exhibit uncontrollable release patterns, use a large quantity of synthetic coating materials, and are unable to adapt to complex soil conditions (e.g., arid soil). In this study, a double-layer SRF was formulated from a low-cost lignin–clay nanohybrid composite to not only achieve controllable and slow nitrogen fertilizer release but also improve the water-holding property. The low-cost and hydrophobic lignin–clay nanohybrid was cross-linked with bio-based alginate to prepare the core-layer material, followed by a coating process using a highly water-absorbent polymer poly(acrylic acid) (PAA) to achieve a double-layer SRF. We examined the chemical structures, urea release rates, and water-holding capacities of the double-layer PAA–lignin–clay nanohybrid composite coated SRF (PLC-SRF). The results showed that PLC-SRF released 13–40% less urea and absorbed 23% more water than SRFs coated with only alginate. Its urea release rate is slower than that of previously reported SRFs using other materials. This nanocomposite coating material has great potential for producing a new type of bio-based SRFs that are beneficial to sustainable crop production.

Here, a defect-engineered carbon nitride (DCN) electrocatalyst has been synthesized by directly annealing of a rationally designed urea precursor. The existence of defect sites was investigated by detailed characterizations. When loading a small amount of Ru nanoparticles, the obtained DCN catalyst offers excellent catalytic activity for electrochemical hydrogen evolution reaction.

Bio-organic–chemical fertilizer (BCF) has great potential to enhance agricultural production, protect environment, and improve sustainability. However, current BCFs are used only in a limited scope mainly due to the low activity of beneficial bacteria. It is significant to develop new BCFs with high beneficial bacteria activity for sustainable agricultural production. In this study, a novel slow-release bio-organic–chemical fertilizer (SBCF) was prepared from activated lignite, bacillus AMCC100153 (B153) (beneficial bacteria for tomato), and slow-release fertilizer (CSF) with suitable pH and low dissolubility salt content (to protect the bacterial activity). The pH and EC of different types of SBCFs with different compositions were determined and compared with those of BCFs derived from common chemical fertilizers (BCCF). The B153 activities were measured and compared with the optimum formula of SBCF. The bacillus colonization rules of SBCF and BCCF in tomato pot soil were explored by the Real-time qPCR. SBCF had higher bacillus activity than the corresponding BCCF. Pot experiments also showed that the bacillus formed colonization rapidly on tomato roots and secreted substances to promote root growth. The HPLC analysis found that the promoting substances were auxin and zeatin. Compared with no fertilizer control (CK) and the BCCF treatments, the SBCF treatment increased tomato yields by 73.08% and 29.04%, respectively. Findings of this work suggest that SBCF with high biological activity and growth promoting effect has great potential in agriculture production system in the future.

Crops grow poorly in saline-sodic soils, and the productivity of these soils can be dramatically improved with proper amendments. Current research mainly focuses on either organic or inorganic soil amendments, whereas few studies address options of combining organic and inorganic amendments. The objective of this study was to develop new organic and inorganic soil amendments which can lower the soil pH, replace sodium, and improve soil structure. Polyhalite (PL), microporous potassium-silicon-calcium mineral fertilizer (MF), furfural residue (FR), and fulvic acid (FA) were mixed with four different ratios to produce organic and inorganic soil amendments: PLFR, PLFA, MFFR, and MFFA. And their optimum mixing ratios were determined by comparing the potassium, calcium concentrations, and pH of filtrate after dissolution. Then, a leaching experiment was conducted by packing mixtures (mass ratio of soil to amendment = 219:1, equivalent to 13 t/hm2) of the saline-sodic soil with each one of these amendments plus two contrasts, gypsum (GP), and no amendment (CK). And the remediation effect was compared by pH, EC, ESP, texture, organic recombination degree of clay, saturated hydraulic conductivity, water-stable aggregates fraction, and enzyme (urease, alkaline phosphatase, and catalase) activities of soil. After four times leaching experiment, soil treated with PLFR had lower pH and 25.86% lower exchangeable sodium than untreated soils. The water-stable small macroaggregate fractions and saturated hydraulic conductivity of the MFFR-treated soils were significantly increased by 133% and 31%, respectively. Also, the total soil and heavy fraction organic carbons of the soils treated with MFFR in addition to its alkaline phosphatase activity were all significantly higher than the other treatments. The results revealed that MFFR has more potential as a soil amendment to improve soil structure and quality and thus help in the development and use of saline-sodic lands for agriculture.

The complex synthesis process, low utilization, and single function of fungicides have seriously hindered the development of fungicides in resistance to rice sheath blight. Here, an inexpensive and multifunctional Cu(II)-based water-dispersible humic acid (Cu-WH) fungicide with growth-promoting ability was developed with a simple method. A 3D molybdate carbon hierarchical nanosphere (MoO

To improve fertilizer use efficiency, reduce irrigation requirement, and minimize negative environmental impact, a novel large-grained-activated-lignite-slow-release fertilizer (LAF) with good water retention was developed by mechanical extrusion of activated lignite and conventional fertilizer. A 3D molybdate-sulfur hierarchical hollow nanosphere (3D-MoS2–HN) catalyst was successfully fabricated via a simple route, and the lignite was activated by 3D-MoS2–HN to increase its water-soluble humic acid content and nutrient adsorption ability. After activation, the amounts of small molecular active groups and water-soluble humic acid of activated lignite were significantly higher than those of raw lignite. The activation also increased adsorption ability of the activated lignite for nutrients. LAF prepared from the activated lignite had a preferable slow-release property and good water-holding capacity in soil. Moreover, a pot trial further demonstrated that LAF effectively improved the growth of an apple pla...

A novel bio-based elastic polyurethane coated urea fertilizer (ECU) was successfully developed using low-cost, biodegradable, and renewable waste palm oil. The process utilized acrylonitrile modification to grant the ECU with excellent swollen capacity. The modified green bio-based polyurethane (PU) coating efficiently delayed the nutrient release. Herein coating shell's swollen capacity and nutrient controlled-release behaviors of the normal bio-based PU-coated urea fertilizer (PCU) and ECU in water were investigated. The results showed acrylonitrile modified bio-based polyurethane successfully transformed it into coated controlled-release urea fertilizer with excellent agricultural properties. Nutrient released longevity of ECU reached more than 80 days while that of PCU was only about 50 days. The novel synthesis and innovative application of bio-based elastic material in this study will provide not only theoretical bases but also practical guidelines for research and development of high-efficiency and environmentally friendly controlled-release fertilizer.

Recently, superhydrophobic bio-based coating materials for sustainable and environmentally friendly controlled-release fertilizers (CRFs) have drawn much attention. The synthesis procedure of superhydrophobic nanomaterials have developed rapidly, but their applications in coating for superhydrophobic CRFs are still limited to small-scale uses because of the heavy environmental concerns and economic expenses. In this study, a novel one-step process was developed to synthesize nano lauric acid copper using ethyl alcohol and water as solvents. This nanomaterial was not only successfully used to modify bio-polyurethane, derived from castor oil for coating urea fertilizer to improve its release characteristic, but also was coated on different substrates including paper, metal, glass, and non-woven fabrics to make their surfaces superhydrophobic and superoleophilic. Non-woven fabrics and a 100 mesh nylon net coated with this nanomaterials effectively separated crude oil-in water emulsion with an ultrahigh efficiency and reusability. Furthermore, the nanomaterial exhibited excellent antibacterial properties and long-term stability. Overall, this novel nano lauric acid copper is a cost-effective and multifunctional coating material that has many promising applications, including controlled-release and oil/water separation in the future.

Phosphates and organophosphorus cause environmental pollution, and excessive phosphate leads to water eutrophication. Glyphosate, an organophosphorus herbicide, harms the environment and human health. In this study, regenerable magnetic AL/Fe

Electrochemical oxidation of alcohol and aldehyde to carboxylic acids is one of the most important classes of catalytic reaction. The key point for such reactions lies in the fine tailoring the catalysts to improve the reaction and energy efficiency. For such a destination, identifying descriptors which are highly related to the catalytic efficiency is a prerequisite for designing electrocatalysts. In this work, taking 5-hydroxymethylfurfural (HMF), a biomass derived platform molecule containing alcohol and aldehyde, as the main research object, we revealed for the first time that the adsorption energy of substrate molecule is an activity descriptor for electrochemical alcohol and aldehyde oxidation. Too weak substrate adsorption is not favorable to C–H/O–H bond activation and dissociation, while too strong substrate adsorption hinders the formation of enough OHads (an important intermediate) due to the competitive adsorption of substrate molecules and OH– at limited reaction sites. The optimal catalytic activity can be achieved by adjusting the adsorption energy of substrate molecules to make them properly adsorbed on the catalyst surface. This work not only offers a guideline for the design of advanced catalysts towards the electrochemical alcohol and aldehyde oxidation (e.g., methanol, ethanol, benzyl alcohol, glycerol, glucose, furfural and HMF) for the utilization and production of renewable resources, but also benefits the design of other electrochemical catalysts.

Although solid-phase activation of lignite using a nanocatalyst has great potential in producing low-cost and sustainable humic acid, the large-scale application of this technology still faces challenges because of the high price and toxicity of the nanocatalyst. Additionally, the specific molecular components of humic acid in activated lignite remain unknown. In this work, a multifunctional molybdate-phosphorus hierarchical hollow nanosphere (Mo-P-HH) catalyst was successfully manufactured by a simple way followed by phosphorization. In comparison with a commercial Pd/C catalyst, the multifunctional Mo-P-HH catalyst was more effective in producing water-soluble humic acid with small molecular functional groups from lignite via solid-phase activation. Moreover, Fourier transform ion cyclotron resonance mass spectrometry revealed the molecular compositions of humic acid in activated lignite. Compared with that from raw lignite, the humic acid after Mo-P-HH activation had less aromatic structure but higher content of lipids, proteins, amino sugar, and carbohydrates. In addition, the activated humic acid simulated seed germination and seedling growth. Therefore, this study provided a high-performance hierarchical hollow nanocatalyst for activation of humic acid and also offered the theoretical basis for the application of humic acid in agriculture.

Self-healing materials have received increased attention because of their automatic detecting and repairing damage function. In this paper, a novel self-assembly and self-healing bionanocomposite was developed as a coating material for controlled release fertilizers. This nanotechnology-enabled coating is environmentally friendly and highly efficient and possesses a tunable nutrient-releasing characteristic. In the synthesis process, bio-based polyurethane coated urea (BPCU) was prepared by the reaction of bio-polyols with isocyanate. The BPCU was then modified by the layer-by-layer technology to prepare self-assembling modified BPCU (SBPCU). Last, hollow nano-silica (HNS) particles loaded with the sodium alginate (SA) were used to modify SBPCU to fabricate of self-assembling and self-healing BPCU (SSBPCU). The results show that the self-assembled materials were synthesized through electrostatic adsorption. The self-healing was observed through scanning electron microscopy and 3D-X-ray computed tomography, revealing the mechanism was that the repair agent released from HNS reacted with the curing agent to block the pore channels and cracks of the coating. As a result, the SSBPCU exhibited the highest hydrophobicity and surface roughness and thus the slowest release rate. For the first time, this work has designed a novel strategy to solve the bottleneck problem that restricts the development of a controlled-release fertilizer.

Sustainable bio-based coated fertilizers not only reduce nonpoint-source pollution, but also shift dependence away from petroleum-based materials. In this paper, a bio-based polyurethane (BPU) was derived from liquefied cotton straw (LCS) and was used to coat urea prills for a BPU-coated fertilizer (BPCF). Siloxane was incorporated into the BPU for the synthesis of a siloxane modified BPCF (SBPCF). In addition, both siloxane and polyether were used to modify the BPU to prepare a dual-modified BPCF (DBPCF). Various analytical and characterization tools were used to determine the properties (e.g., composition, structure, and morphology) of the BPU and the coating shells. Nutrient release experiments were also conducted to evaluate the nitrogen (N) release characteristics of the coated fertilizers. Structure and morphology analyses and measurements of the water contact angle and water adsorption revealed that the siloxane modification enhanced the hydrophobicity of the coatings of SBPCF and DBPCF to repel water entrance and thus improved the N release characteristics. As evidenced by the composition, structure and morphology analyses, further polyether modification created an interpenetrating polymer network (IPN) with the DBPCF coating to fix some of the inactive components that mitigated the rising of micropore number and size in the coating during nutrient release. As a result, the DBPCF showed the best properties and release characteristics. Findings of this work suggest that BPU-coated fertilizers, particularly DBPCF, present promising opportunities to the sustainable development of modern agriculture.

To improve nitrogen (N) use efficiency and minimize environmental pollution caused by fertilizer overuse, novel bio-based large tablet controlled-release urea (LTCRU) was prepared using bio-based coating materials to coat large tablet urea (LTU) derived from urea prills (U). Nano fumed silica (NFS) was added to the bio-based coating materials to improve the slow-release properties. The surface area of the LTU and U was measured by three-dimensional scanning. In comparison to U, LTU had a smaller surface area/weight ratio, which can reduce the coating materials. Scanning electron microscopy analysis showed that the addition of NFS in bio-based coating materials reduced the porosity of the coating shells of LTCRUs and, thus, enhanced the N release longevity of the controlled-released fertilizer. Dependent upon the pores on the coating shells of LTCRU, two N release patterns were revealed. Because of the good release characteristics, the novel LTCRU shows great potential to support sustainable agricultural production.

The development of biodegradable packing materials is a global priority due to the huge volumes of plastic refuse entering landfills and the environment. In this study, a series of biodegradable nanocomposite films based on poly(butylene adipate-co-terephthalate) (PBAT) and reinforced with an organophilic layered double hydroxide (OLDH) were scale-up fabricated. The OLDH nanosheets with a basal spacing of 4.07 nm were presynthesized on a large-scale by solvent-free high-energy ball milling. All of the PBAT/OLDH nanocomposite films (0.5–4 wt % OLDH) showed a uniform dispersion of OLDH nanosheets in the PBAT matrix. A PBAT/OLDH film containing 1 wt % OLDH (denoted herein as OLDH-1) demonstrated outstanding thermal, optical, mechanical, and water vapor barrier properties compared with a pure PBAT film (OLDH-0), including a 37% reduction in haze and a 41.9% increase in nominal tensile strain at break dramatically. Furthermore, the food packaging measurement revealed that the OLDH-1 film showed a better packaging effect than the pure PBAT film and commercial polyethylene packing materials. The feasibility of scale-up manufacture and the excellent processability, manufacturing scalability, mechanical performance, optical transparency, water vapor barrier properties, and food packaging performance of the PBAT/OLDH nanocomposite films encourage their future application as biodegradable packaging films.

Phosphates and organophosphorus cause environmental pollution, and excessive phosphate leads to water eutrophication. Glyphosate, an organophosphorus herbicide, harms the environment and human health. In this study, regenerable magnetic AL/Fe3O4/La(OH)3 adsorbents were developed by modifying Fe3O4 and La(OH)3 on aminated lignin (AL) for phosphate and glyphosate removal. The adsorption capacity for phosphate and glyphosate reached 60.36 mg g-1 and 83.87 mg g-1 when the initial concentrations were 150 mg L-1 and 250 mg L-1, respectively. The thermodynamic data showed that adsorption is a spontaneous and endothermic process. Adsorption can be applied at pH values ranging from 3 to 11 and is more suitable under acidic conditions. Fe3O4 and La(OH)3 both enhanced the adsorption capacities of phosphate and glyphosate. Phosphate and glyphosate compete slightly when coexisting in the adsorption process at low concentrations. Due to the magnetic properties of Fe3O4, the adsorbents can be separated rapidly and effectively with an external magnetic field. 89% adsorption capacity remained after four adsorption-desorption recycles. Thus, AL/Fe3O4/La(OH)3 shows potential for phosphate and glyphosate removal as an effective and reusable adsorbent.

The continuously increasing plastic wastes and diminishing fossil resources have attracted global attention into research and development of biodegradable packaging materials. In the present study, organophilic layered double hydroxides (OLDH) intercalated with aliphatic long-chain molecules as reinforcing agents were incorporated into biodegradable poly(vinyl alcohol) (PVA) matrix by a solution casting method. FTIR, XRD and SEM were performed to analyze the structure of PVA/OLDH films. The OLDH nanosheets were well-dispersed in PVA matrix and formed strong interfacial interactions with the PVA chains, leading to remarkable improvements of optical property, mechanical performance, water vapor barrier property and thermal stability. At a loading of only 2% OLDH in PVA, we observed ~67% decrease in haze and ~66% increment in tensile strength in the composite film compared with pure PVA film. Furthermore, a 24.22% decrease in water vapor permeability (enhancement in water vapor barrier property) due to the addition of 0.5 wt% OLDH and enhanced thermal stability could be observed. These results revealed that the overall performance could be improved by introducing OLDH at very low loadings and that the PVA nanocomposite films have potential for future application in packaging films. Therefore, the use of high-performance PVA/OLDH nanocomposite films can evidently promote the application of biodegradable PVA materials in packaging industry.

Soil, air, and water pollution caused by lignite is considered a serious environmental problem. Activation methods thus have been developed to extract humic acid from lignite to support the agricultural production as the soil amendment or fertilizer synergist. The traditional activation methods of humic acid from lignite, however, are not environmentally friendly. As the first study, this work developed a novel solid-phase activation method with a Pd/CeO2 nanocatalyst for lignite-derived humic acid. This study analyzed the morphology and structures of the as-synthesized Pd/CeO2 nanocatalyst with various characterization tools. The mechanisms of the Pd/CeO2 nanocatalyst for lignite activation were determined. The Pd/CeO2 catalyst effectively promoted the production of water-soluble humic acids from lignite via KOH solid-phase activation at room temperature. It increased the amount of small molecular active groups and the corresponding small molecules of humic acid. The existence of a strong synergistic eff...

Novel biobased polyurethane (PU) was synthesized by using waste frying oil-based polyol (WFOP) and isocyanate for slow-release fertilizers (SRFs). Epoxy resin (EP) was used to modify PU to synthesize the interpenetrating network (IPN) for improving the properties of the coating film. Nine polymer-coated nitrogen (N) fertilizers were prepared from these composite coating materials. The N release characteristics of the PU-coated urea (PCU) in water and soil were determined. Degradation behavior of coatings in the soil was evaluated. Results showed that 20% EP in the coating increased the cross-linking density by 77.9%, reduced the coating porosity by 28%, and thus slowed the nutrient release from the PCU significantly. Because of its compact structure, the water absorption rate of the EP-modified PCU shell was slower than that of the unmodified ones. All the PCUs, especially the EP-modified ones, showed excellent slow N release behaviors. In addition, the biopolymers derived from waste frying oil also displ...

The economic benefits of using controlled-release urea (CRU) on wheat and maize depend on costs and grain yields. Delays in the release of nitrogen (N) from CRUs can limit the availability of early season N and crop growth. Because of its high cost, the use of CRUs for wheat and maize production by commercial growers is very limited. We investigated the effects of a mixture of CRU and uncoated urea (N ratios 7:3, respectively) on crop yields, economic benefits, N budgets, and soil fertility in a wheat-maize rotation system over an 8-year period in Shandong Province, China. Annually, the mixture was applied at 270 kg N ha−1 (Mix 1), 540 kg N ha−1 (Mix 2), and 810 kg N ha−1 (Mix 3). Uncoated urea treatments were simultaneously applied at 540 kg N ha−1 (Urea 2) and 810 kg N ha−1 (Urea 3). The N release characteristics of these mixtures under field condition were synchronized with N requirements of the wheat and maize crops during their entire growth periods. Applying the mixture increased grain yields of wheat and maize by 8.2–11.9% and 6.8-9.8%, respectively, compared with treatments of monotypic, uncoated urea. Mean N use efficiencies were increased by 35.7–37.6% and 13.2–14.3% for wheat and maize, respectively, and annual net profits increased 15.4–21.8%, compared with uncoated urea treatments at the same rates of N application. Considering the N budget, apparent N losses were increased with higher N application rates, and applying the mixture significantly reduced N losses compared with monotypic urea. Regardless of application rate, the mixed urea treatments reduced the leaching of N in the soil profile by augmenting NO3−-N and NH4+-N contents at the 0–40 cm soil depth and reduced the leaching of NO3−-N into deeper soil layers. The pH of the surface soil was also lowered and exchangeable Ca2+ and Mg2+ were reduced by the long-term application of monotypic urea. In conclusion, applying the mixture of CRU and uncoated urea is recommended for sustainable increases in crops yields, maintaining soil fertility, reduction of N leaching, and increased net profits.

Although bio-materials for controlled-release fertilizers (CRFs) have been developed rapidly because of their low-cost and green and sustainable properties, the release characteristics of these CRFs still face problems because the coating is often hydrophilic with many micro-holes. In this paper, a novel coating material was developed to coat fertilizers using bio-based polyurethane (BPU) derived from liquefied wheat straw (LWS). Organosilicon (OS) and nano-silica (NS) were also used to modify the BPU to increase the nanoscale surface roughness and reduce the surface energy, and thus to make it superhydrophobic. The nutrient release characteristics of the superhydrophobic BPU coated fertilizer (SBPCF) were greatly enhanced, compared with the unmodified BPU coated fertilizer (BPCF). This was because the nanoscale surface roughness of the SBPCF prevented water from contacting the coating material. In addition, the nanoparticles on the SBPCF surface also block the micro-holes on the coating and thus reduced the entrance of water. The results suggest that the new coating technology can create a superhydrophobic surface on CRFs and thus improve their controlled-release characteristics.

The treatment of spent cooking liquor is critical for clean production of pulp and paper industry. There is a compelling need to develop a cost-effective and green technology for reuse of organic matter in spent cooking liquor to mitigate the negative impacts on the environment. The objective of this study is to examine the chemical structure of fulvic acid-like substances extracted from spent cooking liquor (PFA) and their relationship with bioactivity in plant growth. Compared with the benchmark Pahokee peat fulvic acid (PPFA), PFA has less aromatic structure, but higher content of lignin, carbohydrates, and amino acid. After fractionation, protein/amino proportion decreased with increasing molecular weight, but the aromaticity increased. Under salt stress, rice seedling growth was promoted by PFA with low molecular weight (5 kDa), but inhibited by fraction with high molecular weight (10 kDa). Principal component analysis suggested that promoted growth was more related with chemical structure (O- and N-alkyl moieties) than with molecular weight. This study provided the theoretical basis for development of an innovative green technology of sustainable reuse of spent cooking liquor in agriculture.

Controlled-release fertilizers (CRFs) are an effective approach in providing essential nutrients for plant growth while minimizing the loss of nutrients in water and air, reducing contamination risks. However, commercial CRFs often release nutrients either too quickly or slowly due to the properties of their coating materials (polymer or sulfur). In this work, a novel CRF technology was developed using chitosan (CS) and graphene oxide (GO) nanocomposites as coating materials. CS and GO solutions were applied at varying ratios in preparing different nanocomposites. CS and GO formed homogeneous nanocomposite films through their interactions with each other. Fertilizer beads were successfully encapsulated by the CS-GO films using the simple dipping method. Resulting CRFs showed controlled-release behaviors, with nutrient release lasting for about a week. Although additional investigations are required for further evaluation and optimization, this method presents a promising concept for an alternative fertilizer-coating technology.

Although commercialized slow-release fertilizers coated with petrochemical polymers have revolutionarily promoted agricultural production, more research should be devoted to developing superhydrophobic biopolymer coatings with superb slow-release ability from sustainable and ecofriendly biomaterials. To inform the development of the superhydrophobic biopolymer-coated slow-release fertilizers (SBSF), the slow-release mechanism of SBSF needs to be clarified. Here, the SBSF with superior slow-release performance, water tolerance, and good feasibility for large-scale production was self-assembly fabricated using a simple, solvent-free process. The superhydrophobic surfaces of SBSF with uniformly dispersed Fe3O4 superhydrophobic magnetic-sensitive nanoparticles (SMNs) were self-assembly constructed with the spontaneous migration of Fe3O4 SMNs toward the outermost surface of the liquid coating materials (i.e., pig fat based polyol and polymethylene polyphenylene isocyanate in a mass ratio 1.2:1) in a magnetic f...