Organic Content Research Articles

Synergistic biochar and Serratia marcescens tackle toxic metal contamination: A multifaceted machine learning approach

Metal contamination in soil poses environmental and health risks requiring effective remediation strategies. This study introduces an innovative approach of synergistically employing biochar and bacterial inoculum of Serratia marcescens to address toxic metal (TM) contamination. Physicochemical, enzymatic, and microbial analyses were conducted, employing integrated biomarker response (IBR) and machine-learning approaches for toxicity estimation. The combined application significantly reduced the Cd, Cr, and Pb concentrations by 71.6, 31.2, and 57.1%, respectively, while the Cu concentration increased by 85% in the individual Serratia marcescens treatment. Biochar enhanced microbial biomass by 33–44% after 25 days. Noteworthy physicochemical improvements included a 44.7% increase in organic content and a decrease in pH and electrical conductivity. The K⁺ and Ca2⁺ concentrations increased by 196.9 and 21.6%, respectively, while the Mg2⁺ content decreased by 86.4%. Network analysis revealed intricate relationships, displaying direct and indirect negative correlations between metals and soil physicochemical parameters. The IBR index values indicated effective mitigation of TM toxicity in Serratia marcescens and biochar with individual and combined treatments. Binary classification demonstrated high sensitivity (80.1%) and specificity (80.5%) in identifying TM-contaminated soil. These findings indicate significant biochar- and Serratia marcescens-induced impacts on toxic metal availability, physicochemical properties, and enzymatic activities in metal-contaminated soil, suggesting that blending soil with biochar and microorganisms is an effective remediation strategy.

Potential Utilization of Defective Fruit Juice Products for Black Soldier Fly Cultivation to Reduce Waste Generation in the Beverage Industry

The waste of fruit juice and tea defective products has organic content that conventionally has the potential to be utilized as a medium or place for maggot growth, but until now it has not been equipped with supporting scientific studies. Therefore, the objectives of the study are: 1) Assessing the characteristics of fruit juice and tea product waste, 2) Assessing the effectiveness of maggot in reducing fruit juice and tea product waste. This research is experimental in nature using variations in the composition of fruit juice and tea product waste as a source of nutrition for maggot which is carried out for 12 days. This variation uses the Complete Randomized Design method with 3 (three) treatments, namely variations in the composition of 60% tea + 40% fruit juice waste (S1), 50% tea + 50% fruit juice waste (S2), and 40% tea + 60% fruit juice waste (S3) in duplo. In addition, this study was completed with a control treatment. The results showed that the characteristics of fruit juice and tea waste containing protein (3.78-4.59%), fat (0.90-1.31%), carbohydrates (28.15-29.15%), crude fiber (2.42-3.12%) can be used as maggot cultivation media. The highest protein and crude fiber contents were found in the S3 composition waste at 4.59% and 3.12%. Maggot cultivation results that showed the highest fat and carbohydrate content were found in S1 composition waste at 1.31% and 29.15%. The recommended composition variation is S1 composition with the highest substrate consumption value and waste reduction index of 57.47% and 20.06%.

Accelerated removal of solvent residuals from PLGA microparticles by alcohol vapor-assisted fluidized bed drying

The removal of residual solvents from biodegradable poly(D,L-lactide-co-glycolide) (PLGA) microparticles by fluidized bed drying was investigated. Microparticles were prepared by the O/W solvent extraction/evaporation method and the influence of various process and formulation parameters on the secondary drying was studied. PLGA microparticles and films were characterized for residual organic solvent and water content, recrystallisation, surface morphology, drug loading and in-vitro release of the drugs dexamethasone and risperidone. While alcohol-free fluidized bed drying decreased the residual dichloromethane content only from about 7 % (w/w) to 6.4 % (w/w) (18 °C) or 3.2 % (w/w) (35 °C) within 24 h, 140 mg/L methanol vapor in purge gas facilitated almost complete removal of dichloromethane or ethyl acetate from microparticles (0–0.11 % (w/w) after 6 h). By controlling the alcohol concentration and temperature of the purge gas, the alcohol absorption and complete removal was controlled. Risperidone increased the methanol absorption enhancing the plasticization. A high initial residual water content was identified to promote aggregation and was eliminated by starting fluidized bed drying without alcohol. Alcohol vapor-assisted fluidized bed drying accelerated microparticle manufacturing without affecting the redispersibility, the drug loading and the in-vitro release of risperidone and dexamethasone.

IR spectra simulations by anharmonic DFT and CDFT-saturated and unsaturated fatty acids of Siberian sturgeon (Acipenser baerii Brandt,1869)

The Siberian sturgeon is one of the most remarkable species in the field of aquatic biology which also has ecological importance, commercial significance, and nutritional characteristics. The purpose of this study is to determine the fatty acid content of different organs of Siberian sturgeon through both theoretical and experimental techniques to compare oxidative stability of the samples in terms of fatty acid profile. For this purpose, the fatty acid content of flesh, brain, caviar and liver of sturgeon was determined by gas chromatography and the middle infrared spectra of tissues were collected by an infrared spectrofotometer. The fatty acid content of samples was also computed by anharmonic DFT and CDFT calculations using IR spectra. Oleic acid was the most abundant fatty acid in all tissues. All tissues accumulated by docosahexanoic, eicosapentanoic and linolenic acids. The PCA model was able to classified the tissues with respect to fatty acid contents. Comprehensive anharmonic DFT calculations were performed to better understand the fatty acid of samples at the atomistic level and to predict the spectra of more complex food samples with varying fatty acid compositions. Oxidative stabilities of fatty acids were also investigated through Conceptual DFT based computations. Maximum Hardness and Minimum Electrophilicity Principles accurately predicted saturated and unsaturated fatty acids of sturgeon as the experimental data revealed.

Effects of organic richness, mineral composition, diagenesis, and thermal maturity on the viscoelastic properties of organic-rich Cretaceous mudstones in the Middle Magdalena Valley basin, Colombia

A major geological risk factor for engineering and energy-related applications, such as CO2 storage and unconventional hydrocarbon production, is the geomechanical integrity of mudrocks. The goal of this work is to better constrain the macroscopic mechanical properties resulting from microstructural components by investigating the effects of thermal maturity, mineral composition, diagenesis and organic richness on the mechanical properties of Cretaceous mudstones in two surface sections (San Vicente de Chucurí and La Cristalina Creek) and one well (La Luna-1) from the Middle Magdalena Valley Basin (MMVB), Colombia. The thermal maturity of 22 rock samples was evaluated via organic source-rock screening and determination of illite crystallinity (Reichweite). Both geothermometers placed the La Luna Formation rock samples from San Vicente de Chucurí and the La Luna-1 well within the oil generation window (80°C–120 °C). In contrast, the rock samples of the Guaguaquí Group from La Cristalina Creek in the southern part of the basin are within the gas window (>180 °C). The mineralogy of organic-rich mudstones in the MMVB is dominated by quartz and calcite. Moreover, mudstones from the MMVB have a wide range of organic richness and clay contents, with organic abundances comparable to and clay contents lower than those found in other source-rock reservoirs. The Young's modulus (EIT), Martens hardness (HM), and creep (CIT), as determined through microindentation experiments, highly varied, but overall, the findings suggest that the Cretaceous rocks of the MMVB present conditions favorable for hydraulic fracturing. Furthermore, the viscoelastic properties of Cretaceous rocks in the MMVB are influenced primarily by the concentrations of strong minerals (quartz and calcite) and weak components (clay and TOC). Specifically, an increase in the concentration of weak components compared with that of strong minerals leads to an increase in CIT and a decrease in HM and EIT, and vice versa. Unlike other source-rock reservoirs, there are no indications of a strong correlation between thermal maturity and mechanical properties, suggesting a decoupling of these parameters in rocks of the MMVB. A close scanning electron microscopy examination of the rocks indicated that the observed weak to moderate correlation between thermal maturity and mechanical properties appears to result from rock silicification and calcite cementation caused by the precipitation of these minerals at early stages of diagenesis. This observation implies that the impact of diagenesis on rock geomechanics of silica-rich and calcareous-rich mudstones may override or be more important than the effects of thermal maturity, which, along with clay and organic matter contents, are the greatest controls in the geomechanics of argillaceous source-rock reservoirs.

Total Chemical Components, Biological Activity and Chromatographic Analyzes of Styrax officinalis Fruit Extract

This study aims to investigate the total chemical component, biological activity and chromatographic analysis of the fruit extract of Styrax officinalis, obtained from local markets trading local products in the Gaziantep region. Methanol was used to extract the pericarp and seed samples that make up the fruit. Fruit pericarp extract with high phenolic content showed a significant capacity in all antioxidant activity analyses. No antibacterial activity of the extracts was observed against the standard strains used. Regarding phenolic acid content, the most abundant phenolic acid in the fruit pericarp extract was chrysin and t-cinnamic acid. In contrast, in the seed extract, it was t-cinnamic acid and quercetin. HPLC results revealed that succinic acid was the main component of organic acid contents in all extracts. The fact that the main components determined from all analyses have various strong pharmacological activities reveals the importance of the widespread use of S. officinalis.

Effect of the main components in gasification wastewater on the surface properties of coal water slurry

AbstractCoal water slurry is an advanced and efficient clean coal technology; using gasification wastewater to prepare coal water slurry can recycle wastewater and improve energy utilization efficiency. As the complex substances in wastewater have a great influence on the slurry properties, the effects of organic matter, metal ions, and ammonia nitrogen in gasification wastewater on the surface properties of coal water slurry are studied in this paper in order to provide new ideas for slurry mechanism of coal water slurry prepared from wastewater. Results show the following: (a) Compared with ordinary coal water slurry, the concentration of coal water slurry prepared from wastewater with high organic content increased by 2.9%, while the concentration of coal water slurry prepared from wastewater with high ammonia nitrogen content decreased by 2.1%. (b) The contact angles of coal water slurry prepared with phenols, alcohols, and urethane are reduced by 2.8°, 6.3°, and 1.5°, respectively, so organic matter can change the hydrophilicity of coal particles and affect slurryability. (c) Mg2+ and Ca2+ have basically no effect on slurry. Fe3+ reduces the absolute value of Zeta potential by 33.1, and Cu3+ increases that by 22.8, as they affect the slurryability by changing the surface potential of coal particles and the absorption of additives. (d) Ammonia nitrogen influences the slurryability by changing the pH value of the slurry. The conclusion of the influence mechanism of organic matter, metal ions, and ammonia nitrogen in wastewater on slurryability can provide a technical reference for the selection of suitable wastewater to prepare coal water slurry.

Organic Capillary Barriers for Soil Water Accumulation in Agriculture: Design, Efficiency and Stability

Acute shortage of water resources and high unproductive water losses are the key problems of irrigated agriculture in arid regions. One of the possible solutions is to optimize soil water retention using natural and synthetic polymer water absorbers. Our approach uses the HYDRUS-1D design to optimize the placement of organic water absorbents such as peat and composite hydrogels in the soil profile in the form of water-storing capillary barriers. Field testing of the approach used a water balance greenhouse experiment with the cultivation of butternut squash (butternut squash (Cucurbita moschata (Duchesne, 1786)) under sprinkler irrigation with measurement of the soil moisture profile and unproductive water losses in the form of lysimetric water outflow. In addition, the biodegradation rate of organic water absorbents was studied at the soil surface and at a depth of 20 cm. Organic capillary barriers reduced unproductive water losses by 40–70%, retaining water in the topsoil and increasing evapotranspiration by 70–130% with a corresponding increase in plant biomass and fruit yield. The deepening of organic soil modifiers to the calculated depth not only allowed capillary barriers to form, but also prevented their biodegradation. The best results in soil water retention, plant growth and yield according to the “dose-effect” criterion were obtained for a composite superabsorbent with peat filling of an acrylic polymer matrix. The study showed good compliance between the HYDRUS design and the actual efficiency of capillary barriers as an innovative technology for irrigated agriculture using natural and synthetic water absorbents.

PH Affects the Spontaneous Formation of H2O2 at the Air-Water Interfaces.

Recent studies have shown that the air-water interface of aqueous microdroplets is a source of OH radicals and hydrogen peroxide in the atmosphere. Several parameters such as droplet size, salt, and organic content have been suggested to play key roles in the formation of these oxidants. In this study, we focus on the effect of acidity on the spontaneous interfacial hydrogen peroxide formation of salt-containing droplets. Na2SO4, NaCl, and NaBr bulk solutions, at the range of pH 4 to 9.5, were nebulized, using ultra high-purity N2/O2 (80%/20%), and H2O2 was measured in the collected droplets. All of the experiments were performed in T = 292 ± 1 K and humidity levels of 90 ± 2%. For Na2SO4 and NaCl, the H2O2 concentration was increased by ∼40% under alkaline conditions, suggesting that OH- enriched environments promote its production. When CO2 was added in the ultrapure air, H2O2 was observed to be lower at higher pH. This suggests that dissolved CO2 can initiate reactions with OH radicals and electrons, impacting the interfacial H2O2 production. H2O2 formation in NaBr droplets did not display any dependence on the pH or the bath gas, showing that secondary reactions occur at the interface in the presence of Br-, which acts as an efficient interfacial source of electrons.

Variation of magnesium drives plant adaption to heterogeneous environments by regulating efficiency in photosynthesis on a large scale

Abstract Magnesium (Mg) is a vital nutrient for plants, and its role in photosynthesis, enzyme regulation and resistance to environmental stress is becoming increasingly evident. However, there is a paucity of knowledge regarding the characteristics of Mg (content, density and stock) on a large scale, particularly at the community level, which is essential for linking to ecosystem functions. A leaf‐branch‐trunk‐root‐matched database of the Mg content (mg g−1) and biomass density (g m−2) of plant organs across 1972 sampling sites in China was constructed based on field surveys and data compilation. Using machine learning algorithms, we comprehensively explored the spatial patterns and main influencing factors of plant Mg content and density (g m−2). Furthermore, a new index, leaf Mg productivity (LMP), was developed to determine the Mg use efficiency, defined as the ratio of gross primary productivity to leaf Mg density. The Mg contents in the leaves, branches, trunks and roots were 2.80, 0.87, 0.23 and 1.66 mg g−1, respectively. Deserts exhibited higher Mg content, with the primary influencing factors being high temperatures and soil Mg supply. Higher LMP values observed in grasslands and deserts indicate that Mg use is more efficient in these relatively stressful environments, whereas forests require more Mg for unit biomass productivity. This change was driven by the minimum temperature, aridity and soil Mg content. Synthesis. We systematically explored spatial variation in plant community Mg and its correlation with the photosynthetic capacity of plant communities. The aridity and soil Mg content have negative effects on LMP. This suggests that Mg is used more efficiently in photosynthesis under conditions of resource scarcity, indicating that resources become more valuable when they are limited. Photosynthesis in forests is more sensitive to Mg and more Mg is required for biomass production; therefore, Mg is not just a nutrient but a potential bottleneck in optimizing photosynthetic efficiency. Our findings highlight the pivotal role of Mg in photosynthesis and offer a foundation for optimizing ecosystem management through Mg regulation.

Degradation of enestroburin in the water-sediment system: kinetics, transformation products identification and toxicity assessment to aquatic organisms

ABSTRACT Pesticides inevitably enter the water environment in the process of use. However, the degradation and its transformation products (TPs) of enestroburin in water-sediment systems are not yet known. This study systematically investigated the degradation behaviour of enestroburin through indoor simulation experiments. The study demonstrated that the different organic content of sediments and oxygen conditions had a little effect on the degradation. The study also analysed transformation products by UPLC-QTOF-MS and MetabolitePilot software. A total of 3 TPs of enestroburin were identified, and one product (M-381) was confirmed and quantified. Based on these transformation products, the pathways of enestroburin were supposed, namely hydrolysis of chlorobenzene, hydrolysis of ester group and electrophilic substitution of benzene ring. Finally, ECOSAR software was utilised to predict the potential toxicity of the proposed TPs towards fish, daphnids, and green algae. The toxicity of TPs to aquatic organisms is lower than the parent compound, but they are still toxic. The study results provide data to support the safe use of enestroburin and provide a reference for the degradation and transformation of other strobilurin fungicides.

Identification of Pops Organic Compounds in Sediment in the Cisangkuy Watershed Using GC-MS Analysis Method

The Cisangkuy Watershed is a tributary of the Upper Citarum River located in the Bandung Basin, West Java. Based one previous research, one organic pollution in the Cisangkuy Watershed is the presence of POPs (Persistent Organic Pollutants) compounds. POPs are organic compounds that can last a very long time in the environment (persistent) and have toxic properties for organisms. This study aims to identify and analyse the organic content of POPs and sediments in the Cisangkuy Watershed, as well as to analyse the source of pollutants and categorise them based on the Stockholm Convention on Persistent Organic Pollutants. Identification of POPs compounds using gas chromatography-mass spectrometry (GC-MS) technique. Sediment sampling was conducted by grab sampling that involved 20 sampling points from upstream to downstream of the Cisangkuy Watershed (CS-1 to CS-20). Samples were collected from 9 sub-districts. The research location shows that the land activities at the sampling point include asphalt hot mix, pharmaceutical, textile, and manufacturing industries. The results showed the presence of 1,2-Benzenedicarboxylic acid, mono (2-ethylhexyl) ester, 4,8,12-Tetradecatrienenitrile, 5,9,13-trimethyl-, and 2-Hexyl-1-octanol compounds at sampling points from upstream to downstream. These compounds were derived from chemical industry effluents, fossil fuel combustion, and agricultural activities. The compounds are classified as ‘industrial waste’ and ‘industrial waste with antibiotic properties’ by the Stockholm Convention on Organic Waste Management.

Shale Oil Generation Conditions and Exploration Prospects of the Cretaceous Nenjiang Formation in the Changling Depression, Songliao Basin, China

Low-maturity shale oil predominates in shale oil resources. China’s onshore shale oil, particularly the Cretaceous Nenjiang Formation in the Songliao Basin, holds significant potential for low-maturity shale oil, presenting promising exploration and development prospects. This study delves into the hydrocarbon generation conditions, reservoir characteristics, and oil-bearing property analysis of the mud shale from the Nen-1 and Nen-2 sub-formations of the Nenjiang Formation to pinpoint favorable intervals for shale oil exploration. Through the integration of lithology, pressure, and fracture distribution data in the study area, favorable zones were delineated. The Nen-1 sub-formation is widely distributed in the Changling Depression, with mud shale thickness ranging from 30 to 100 m and a total organic content exceeding 2.0%. Type I kerogen predominated as the source rock, while some samples contained type II kerogen. Organic microcomponents primarily comprised algal bodies, with vitrinite reflectance (Ro) ranging from 0.5% to 0.8%. Compared to Nen-1 shale, Nen-2 shale exhibited less total organic content, kerogen type, and thermal evolution degree, albeit both are conducive to low-maturity shale oil generation. The Nen-1 and Nen-2 sub-formations predominantly consist of clay, quartz, feldspar, calcite, and pyrite minerals, with minor dolomite, siderite, and anhydrite. Hydrocarbons primarily reside in microfractures and micropores, including interlayer micropores, organic matter micropores, intra-cuticle micropores, and intercrystalline microporosity, with interlayer and intra-cuticle micropores being dominant. The free oil content (S1) in Nen-1 shale ranged from 0.01 mg/g to 5.04 mg/g (average: 1.13 mg/g), while in Nen-2 shale, it ranged from 0.01 mg/g to 3.28 mg/g (average: 0.75 mg/g). The Nen-1 and Nen-2 sub-formations are identified as potential intervals for shale oil exploration. Considering total organic content, oil saturation, vitrinite reflectance, and shale formation thickness in the study area, the favorable zone for low-maturity shale oil generation is primarily situated in the Heidimiao Sub-Depression and its vicinity. The Nen-2 shale-oil-enriched zone is concentrated in the northwest part of the Heidimiao Sub-Depression, while the Nen-1 shale-oil-enriched zone lies in the northeast part.

Potato and dairy industry side streams as feedstock for fungal and plant cell cultures

Utilization of industrial side streams as nutrient source for cellular agriculture is a promising option to improve the sustainability of the production processes. The aim of the study was to evaluate usability of two liquid food industry side streams, potato cell fluid and acid whey, as nutrient source for production of food ingredients with plant cell cultures (arctic bramble (Rubus arcticus L.) and tobacco BY-2 (Nicotiana tabacum L.)) and filamentous fungi (Paecilomyces variotii, Rhizopus oligosporus and Trichoderma reesei). The side streams were found to contain various sugars and other potential nutrients suitable for the studied organisms. The side streams were used as a sole nutrient source (fungi) or as a replacement of selected nutrients in the growth media (fungi and plant cells) in flask scale cultivations. Acid whey was successfully used as a growth medium for filamentous fungi, but it inhibited plant cell growth presumably due to high organic acid content (14 g/l). Potato side stream was found suitable as a fungal and plant cell growth media supplement, and it was used together with glucose for filamentous fungi, or as a partial replacer of macronutrients for plant cells, in bioreactor cultivations yielding high fungal (up to 36 g/l dry weight) and good plant cell (9.5 g/l dry weight) biomass production. Analyses of the produced biomasses revealed good nutritional value in terms of amino acid (17–27 % of dry matter) and dietary fiber (23–30 % of dry matter) contents, giving good premises for utilization in human nutrition.

Retention factor variation on wide range of mobile phase compositions in reversed-phase high-performance liquid chromatography; a short tutorial

Mobile phase composition remains the major experimental parameter influencing the separation process in reversed-phase high-performance liquid chromatography (RP-HPLC). Its influence on the retention of solutes is explained by the Hildebrand solubility parameter and solvophobic theory, which also considers molecular characteristics of the participants in a separation process. The main empirical dependences (linear and polynomial) between the retention factor and the composition of mobile phase (retention function) are discussed taking into consideration a wide range of mobile phase compositions. Two direct chromatographic indices are resulting from these equations: the extrapolated value of retention factor for zero organic content in mobile phase composition (log kw) and the solvent strength parameter (S), which for a linear retention function is its slope being constant over the entire mobile phase compositions. Another chromatographic index could result from the retention function for zero content of water in mobile phase, but this situation can be applied only for very hydrophobic solutes. For large domains of mobile phase composition, the retention function cannot be described by a single type of dependence. This explains the paradox of generating by extrapolation different logkwvalues for different organic components. For the mobile phase close to pure water the retention function is different from that at average water concentration.

Investigation of antimicrobial and antioxidant properties of postbiotics produced by lactobacillus rhamnosus and limosilactobacillus reuteri and their potential application in surface decontamination of red meat

This study investigated the antimicrobial properties of postbiotics produced by lactobacillus rhamnosus and limosilactobacillus reuteri in surface decontamination of red meat against pathogenic bacteria (Escherichia coli and Staphylococcus aureus). The study evaluated postbiotic activity using agar well diffusion, minimum inhibitory concentration (MIC mg/mL), minimum bactericidal concentration (MBC mg/mL), antioxidant properties, total phenolic content (TPC), and organic acid content. Among 18 meat samples, the mixed postbiotic (L. rhamnosus and L. reuteri, 100 mL/mg) displayed the strongest effect against E. coli, achieving a 5.54 log CFU/g reduction after 48 h with a well diffusion diameter of 23 mm, MIC of 20, and MBC of 25. A similar trend was observed for S. aureus, with the mixed postbiotic showing a reduction of 6.9 log CFU/g after 48 h, MIC of 25, and MBC of 50. Interestingly, the mixed postbiotic also exhibited the highest TPC (250.8 mL/mg). L. reuteri postbiotic displayed the strongest antioxidant activity (52.3 mL/mg) and highest organic acid content (18.9 mL/mg). These results suggest the potential of Lactobacilli-derived postbiotics as natural antimicrobials for controlling surface pathogens on meat products. Additionally, the observed link between TPC and antimicrobial activity warrants further investigation into the potential role of antioxidants in enhancing biopreservation efficacy.

Effects of hydrogen peroxide and sodium nitrate on microwave-assisted polyethylene oxidative degradation in the presence of nitric acid

Polyethylene (PE) upcycling has been challenging due to the chemical robustness of non-activated C-C and C-H bonds. One promising strategy is oxidative degradation, in which a strong oxidizing agent, usually nitric acid, oxidizes PE to produce a mixture of organic acids (C4 to C7 diacids and acetic acid). However, current research focuses on how to utilize the obtained organic acids as feedstock (e.g. for plasticizer and gaseous hydrocarbon synthesis) rather than improving the process itself. In this study, we evaluated the effects of adding hydrogen peroxide and sodium nitrate at 200 °C, considering possible PE oxidation mechanisms in the presence of nitric acid. Hydrogen peroxide can partially replace nitric acid, thereby reducing the required amount of nitric acid in the process. This is because, at sufficient nitric acid concentrations, hydrogen peroxide accelerates PE oxidation, while nitric acid simultaneously prevents the overoxidation of the resulting organic acids by hydrogen peroxide. When a nitric acid/hydrogen peroxide solution (1:1 mol/L) was employed for 3 h, the carbon efficiency and total organic acid concentration were 35.6 % and 14.0 g/L, respectively. Furthermore, the addition of sodium nitrate improved overall reaction efficiency through the Baeyer-Villiger type oxidation, which involves a nucleophilic attack on the protonated carbonyls by the nitrate ions. When a nitric acid/sodium nitrate solution (1.5:0.5 mol/L) was employed for 1.5 h, the carbon efficiency and the organic acid yield increased to 39.0 % and 15.3 g/L, respectively. Finally, the potential for upcycling waste PE was also demonstrated using both HNO3/H2O2 and HNO3/NaNO3 conditions, producing organic acids from waste linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE). This study comfirms the potential to reduce the amount of nitric acid used in the microwave-assisted upcycling of waste PE, an aspect that had been previously overlooked. This reduction can contribute to a more environmentally friendly transformation of the proposed process, facilitating the conversion of waste PE into valuable chemicals.

Comparing occurrence of per- and polyfluoroalkyl substances (PFAS) in municipal biosolids and industrial wastewater sludge: A City of Los Angeles study

Biosolids and sludge are what remain after the liquid fraction of wastewater is separated during wastewater treatment. These high organic content matrices are known to contain organic contaminants, a few of which are the hazardous and environmentally persistent per- and polyfluoroalkyl substances (PFAS). The current study investigates whether sludge from a treatment facility serving mostly industrial establishments and biosolids from a facility serving mostly domestic dwellings retain these ‘forever chemicals’ similarly. Using 31 markers covering different classes of PFAS, the sludge was found to contain higher levels of PFAS (869 ± 791 ng/g; 21 of 31) than biosolids (31 ± 7 ng/g, 11 of 31). The most abundant overall was perfluorooctane sulfonic acid (PFOS), mostly in sludge (range: 71–1300 ng/g versus 0–18 ng/g in biosolids). The large PFAS concentration variability in sludge was seasonal and sinusoidal. Sludge, additionally, contained all long chain PFAS, precursors (mostly surfactant ingredients and their transformation byproducts) and short chain PFAS (perhaps because of higher moisture content). By regression, the sludge is shown to consistently contain twice as much PFAS as biosolids when the same amounts are exposed to increasing levels of PFAS. Factors observed to cause differential PFAS retention between sludge and biosolids were moisture (98.6 % and 72.1 %, respectively), chain length, input quality (industrial versus residential) and functional group. Sulfonic acids for instance are one C atom shorter than carboxylates with similar occurrence in sludge and biosolids. More studies are needed to define the roles that organic carbon of sludge/biosolids, water chemistry, temperature and factors not considered here play in partitioning PFAS between the two matrices with respect to inputs. Existing Koc values could not help in explaining observed trends, but the ratio of biosolids-to-influent concentrations was found to correlate positively with PFAS size. Using influent in the ratio, and not effluent, is novel. SynopsisSludge and biosolids are soil amendments; they contain hazardous and persistent PFAS. Methods of decoupling PFAS from these matrices start with understanding matrix-driven PFAS partitioning as shown here.

Predictive models for estimating the sugar content and organic acids in processed mangoes based on the initial content

SummaryThe quality of processed products can be adversely affected by uncontrollable batches of mangoes, which exhibit heterogeneous characteristics. This study aimed to establish predictive models for sugar and organic acid contents (dependent variables) in processed products using the initial compositions of fresh mangoes. Three mango cultivars (cv. ‘Kent’, cv. ‘Keo Romeat’, and cv. ‘Keo Chen’) were classified as low‐density and high‐density groups. Each group of mangoes at the green‐mature, mid‐ripe, and ripe stages was processed into pasteurised purees, dried slices, and mango chips. Prediction models were established using a mix of simple linear regression (SLR) based on the initial content and Analysis of Variance (ANOVA) to identify the impact of qualitative variables (ripening stage, cultivar‐density, and processing technique). In processed mangoes, 13% sucrose content was estimated to accumulate with the three qualitative variables, whereas glucose and fructose contents decreased from their initial levels by 10% and 7%, respectively. Processing techniques can predict the ratio of sugars/acids (S/A) in processed products, regardless of the ripening stage or cultivar‐density. Similar to S/A, citric acid and malic acid contents in mango products were significantly increased by processing techniques. The initial content and processes were insufficient to predict the final contents of the same parameters in processed mangoes; therefore, some models need to include the effects of ripening stage and cultivar‐density to improve the prediction. These relevant explanatory variables contributed significantly to the development of the models, resulting the accuracy of predictive models with normalised root mean square errors (NRMSEs) lower than 10%, except for malic acid (14.04%). In conclusion, it is feasible to estimate the sugar and acidity levels in processed mangoes, offering promising possibilities for ensuring consistent quality of mango‐based products.

Effect of postharvest cold storage and subsequent shelf-life on fruit quality and endogenous phytohormones in nectarine fruit

Cold storage is the main approach to extend the postharvest storage period of nectarines. The objective of this study was to investigate fruit quality (flavor and nutrition) and endogenous phytohormone changes and their related transcriptional changes in nectarine fruit after cold storage and subsequent shelf-life, which was performed metabolome, transcriptome and physiological analysis. Cold storage led to irreversible flavor loss due to the inhibition of aroma biosynthesis genes at low temperature. Sugar and organic acid content was affected, with an increase in glucose, fructose and malic acid, and a decrease in sorbitol and citric acid after cold storage or shelf-life. For fruit nutritional quality, total flavonoids or total carotenoids was not significantly affected by cold storage, whereas shelf-life process enhanced their accumulation. The activities of key enzymes for flavonoid biosynthesis, PAL and C4H, were enhanced during the shelf-life process, resulting in a significant increase in flavonoids and enhanced free radicals scavenging capacity. Meanwhile, shelf-life process increased carotenoids content by improving the expression of carotenoid biosynthesis genes PSY, ZDS and ZISO. Additionally, cold storage significantly increased the IAA content and ethylene production, thereby inducing the up-regulation of related signaling transduction genes. The shelf-life process further increased ethylene production, as well as salicylic acid and jasmonic acid content. This study unravels these crucial physiological and associated transcriptional changes of nectarines after cold storage, and may provide a theoretical foundation for improving fruit quality of peaches after cold storage.