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The solar dryer can reduce production costs, energy consumption, waste (use fruits outside the quality standard for fresh consumption) and is an alternative for small and medium producers. The solar dryer can reduce costs and is an alternative for small and medium producers worldwide. The consumption of fresh and processed tomatoes is high in the world, but post-harvest losses is also and drying is an alternative to reduce these losses. The temperature maintenance and drying time corresponds 30% of the costs. The objective was evaluated the tomato physicochemical characteristics after drying in handmade solar dryer. ‘Carmen’ tomato fruits were bleached in water, 2.5% NaCl solution, 2.5% NaCl + 0.5% CaCl2 solution and unbleached. Tomato slices were placed in a handmade solar dryer from 7:00 to 17:00. The solar dryer prototype was wood made, comprising a collector and a drying chamber. The average cost of the camera was US$ 13.08 (1 Brazilian Real = 0.26 United States Dollar). Water loss, drying kinetics, mathematical models and physicochemical characteristics of fresh and dried tomatoes were evaluated. The average length of solar drying for the four treatments was 30 h and the Midilli and Kucuk mathematical model was the most adjusted. The acidity, reducing sugars and soluble solids were concentrated by drying, while ascorbic acid was reduced. The pH did not change. Tomatoes 'Carmen' can be dried in a handmade solar dryer for 30 h while maintaining product quality.

The aim of this study is to establish prediction models for the non-destructive evaluation of the carbonization characteristics of lignin-derived hydrochars as a carbon material in real time. Hydrochars are produced via the hydrothermal carbonization of kraft lignins for 1–5 h in the temperature range of 175–250 °C, and as the reaction severity of hydrothermal carbonization increases, the hydrochar is converted to a more carbon-intensive structure. Principal component analysis using near-infrared spectra suggests that the spectral regions at 2132 and 2267 nm assigned to lignins and 1449 nm assigned to phenolic groups of lignins are informative bands that indicate the carbonization degree. Partial least squares regression models trained with near-infrared spectra accurately predicts the carbon content, oxygen/carbon, and hydrogen/carbon ratios with high coefficients of determination and low root mean square errors. The established models demonstrate better prediction than ordinary least squares regression models.

Within the wood supply chain, the measurement of roundwood plays a key role due to its high economic impact. While wood industry mainly processes the solid wood, the bark mostly remains as an industrial by-product. In Central Europe, it is common that the wood is sold over bark but that the price is calculated on a timber volume under bark. However, logs are often measured as stacks and, thus, the volume includes not only the solid wood content but also the bark portion. Mostly, the deduction factors used to estimate the solid wood content are based on bark thickness. The aim of this study was to compare the estimation of bark volume from scaling formulae with the real bark volume, obtained by xylometric technique. Moreover, the measurements were performed using logs under practice conditions and using discs under laboratory conditions. The mean bark volume was 6.9 dm3 and 26.4 cm3 for the Norway spruce logs and the Scots pine discs respectively. Whereas the results showed good performances regarding the root mean square error, the coefficient of determination (R2) and the mean absolute error for the volume estimation of the total volume of discs and logs (over bark), the performances were much lower for the bark volume estimations only.

The objective of this study was to investigate the swelling potential of compacted lime-softening sludge for application in landfill liners. The study involved the assessment of the effect of compaction and moulding moisture content (30–40%), corresponding to the Proctor standard compaction test. One-dimensional oedometer swell tests were conducted using distilled water, tap water, and municipal landfill leachate, resulting in the determination of the expansion indices. Moreover, changes in the moisture content and dry density during the swelling process were investigated. The expansion index was significantly influenced by the initial moisture content and liquid chemistry. Subsequently, these factors also affected the sludge dry density decrease, and its moisture content increase, whereas the impact of the initial dry density on expansion was of low importance. An increase in the sludge moulding moisture content, limited swelling in all liquids used. The highest expansion, dry density, and moisture content changes due to swelling were identified for leachate at w wopt. It should be underlined that the effect of liquid on the swelling potential faded away along with a further increase in the moisture content w > wopt. The novelty of the work lies in identifying a significant plunge of the expansion index at w ≈ wopt for the leachate swelling test. The lime-softening sludge non-swelling moisture content was defined as wnon ≈ (wopt + 4.0%) − (wopt + 4.5%). For practical engineering implications, the moisture content between (wopt + 2.0%) and (wopt + 4.0%) was provided for the most suitable sludge application in landfill liners.

This study presented the fabrication of macro and micro-scale microbial fuel cells (MFCs) to generate bioelectricity from oxalate solution and monitor the biodegradation in a micro-scale MFC for the first time. The maximum generated power density of 44.16 W m−3 in the micro-scale MFC elucidated its application as a micro-sized power generator for implantable medical devices (IMDs). It is also worthwhile noting that for the macro-scale MFC, the significant amounts of open circuit voltage, oxalate removal, and coulombic efficiency were about 935 mV, 99%, and 44.2%, respectively. These values compared to previously published studies indicate successful oxalate biodegradation in the macro-scale MFC. Regarding critical challenges to determine the substrate concentration in microfluidic outlets, sample collection in a suitable time and online data reporting, an analogy was made between macro and micro-scale MFCs to elicit correlations defining the output current density as the inlet and the outlet oxalate concentration. Another use of the system as an IMD is to be a platform to identify urolithiasis and hyperoxaluria diseases. As a versatile device for power generation and oxalate biodegradation monitoring, the use of facile and cheap materials (

In the present study, reactive red 198 (RR198) dye removal from aqueous solutions by adsorption using municipal solid waste (MSW) compost ash was investigated in batch mode. SEM, XRF, XRD, and BET/BJH analyses were used to characterize MSW compost ash. CNHS and organic matter content analyses showed a low percentage of carbon and organic matter to be incorporated in MSW compost ash. The design of adsorption experiments was performed by Box–Behnken design (BBD), and process variables were modeled and optimized using Box–Behnken design-response surface methodology (BBD-RSM) and genetic algorithm-artificial neural network (GA-ANN). BBD-RSM approach disclosed that a quadratic polynomial model fitted well to the experimental data (F-value = 94.596 and R2 = 0.9436), and ANN suggested a three-layer model with test-R2 = 0.9832, the structure of 4-8-1, and learning algorithm type of Levenberg–Marquardt backpropagation. The same optimization results were suggested by BBD-RSM and GA-ANN approaches so that the optimum conditions for RR198 absorption was observed at pH = 3, operating time = 80 min, RR198 = 20 mg L−1 and MSW compost ash dosage = 2 g L−1. The adsorption behavior was appropriately described by Freundlich isotherm, pseudo-second-order kinetic model. Further, the data were found to be better described with the nonlinear when compared to the linear form of these equations. Also, the thermodynamic study revealed the spontaneous and exothermic nature of the adsorption process. In relation to the reuse, a 12.1% reduction in the adsorption efficiency was seen after five successive cycles. The present study showed that MSW compost ash as an economical, reusable, and efficient adsorbent would be desirable for application in the adsorption process to dye wastewater treatment, and both BBD-RSM and GA-ANN approaches are highly potential methods in adsorption modeling and optimization study of the adsorption process. The present work also provides preliminary information, which is helpful for developing the adsorption process on an industrial scale.

Wastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful at processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by its disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal communities of earthworm casts were mainly composed of microbial taxa not found in the sewage sludge; thus most of the bacterial (96%) and fungal (91%) taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Upon completion of GAP and during CAP, modified microbial communities undergo a succession process leading to more diverse microbiotas than those found in sewage sludge. Consequently, bacterial and fungal community composition changed significantly during vermicomposting. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices, if heavy metals or other pollutants are under legislation limits or adequately treated.

Lignocellulosic biomass is an attractive renewable resource to produce biofuel or platform chemicals. Efficient and cost-effective conversion systems of lignocellulosic biomass depend on their appropriate pretreatment processes. Alkali or dilute acid pretreatment of biomass requires a high temperature (> 150 °C) to remove xylan (hemicellulosic sugar) and lignin partially. In this study, peracetic acid was used to pretreat biomass feedstocks, including hardwood and softwood species. It was found that the thermally-assisted dilute acid pretreatment of biomass conducted under the mild temperature of 90 °C up to 5 h resulted in the effective removal of lignin from the biomass with a negligible loss of carbohydrates. This thermally-assisted pretreatment achieved 90% of delignification, and this result was compared with the microwave-assisted pretreatment method. In addition, the crystallinity index (CrI), surface morphology, and chemical structure were significantly changed after the acid pretreatment. The biomass digestibility increased significantly with increased reaction time, by 32% and 23% for hardwood and softwood, respectively. From this study, it is clear that peracetic acid pretreatment is an effective method to enrich glucan content in biomass by delignification.

This study investigated a novel agricultural low-cost bio-waste biochar derived from wood apple fruit shell waste via the pyrolysis method, which is modified by ball milling and utilized to remove toxic phenol and chlorophenols (4-CPh and 2,4-DCPh) from contaminated aqueous media. The ball-milled wood apple fruit shell waste biochar (WAS-BC) sorbent was systematically analyzed by BET, CHN, and FTIR as well as particle size, SEM–EDS, XPS and TGA studies. The sorption equilibrium and kinetic studies exhibit that the sorption capacity was greater than 75% within the first 45 min of agitation at pH 6.0. The uptake capacity of 2,4-DCPh onto WAS-BC was greater than those of 4-CPh and phenol. Equilibrium results were consistent with the Langmuir isotherm model, while the kinetic data were best represented by the Elovich and pseudo-second-order model. The maximum uptake of phenol, 4-CPh, and 2,4-DCPh was 102.71, 172.24, and 226.55 mg/g, respectively, at 30 ± 1 °C. Thus, this study demonstrates that WAS-BC is an efficient, low-cost sorbent that can be used for the elimination of phenol and chlorophenol compounds from polluted wastewater.

The present study was conducted to qualitatively and quantitatively elucidate dynamic changes of ginsenosides in ginseng pulp steamed under different temperatures (100 or 120 °C) for different durations (1–6 h) through UPLC-QTOF-MS/MS and HPLC with the aid of as numerous as 18 authentic standards of ginsenosides. Results show that levels of eight polar ginsenosides (i.e., Rg1, Re, Rb1, Rc, Rb2, Rb3, F1, and Rd) declined but those of 10 less-polar ginsenosides [i.e., Rf, Rg2, 20(S)-Rh1, 20(R)-Rg2, F4, 20(S)-Rg3, 20(R)-Rg3, PPT, Rg5, and 20(R)-Rh2] elevated with increases of both steaming temperature and duration; the optimum steaming conditions for achieving the highest total ginsenosides were 100 °C for 1 h. Particular, 20(R)-Rg3, a representative less-polar ginsenoside with high bioactivity such as potent anti-cancer effect, increased sharply but Re, the most abundant polar ginsenoside in fresh ginseng pulp, decreased dramatically. More importantly, ginsenoside species enhanced from 18 to 42 after steaming, mainly due to transformation of polar into less-polar ginsenosides. Furthermore, four malonyl-ginsenosides were detected in fresh ginseng pulps and ten acetyl-ginsenosides were formed during steaming, demonstrating that demalonylation and acetylation of ginsenosides were the dominant underling mechanisms for transformation of polar into less-polar ginsenosides.

Global warming has become a serious issue nowadays as the trend of CO2 emission is increasing by years. In Malaysia, the electricity and energy sector contributed a significant amount to the nation’s CO2 emission due to fossil fuel use. Many research works have been carried out to mitigate this issue, including carbon capture and utilization (CCUS) technology and biological carbon fixation by microalgae. This study makes a preliminary effort to screen native microalgae species in the Malaysian coal-fired power plant’s surrounding towards carbon fixation ability. Three dominant species, including Nannochloropsis sp., Tetraselmis sp., and Isochrysis sp. were identified and tested in the laboratory under ambient and pure CO2 condition to assess their growth and CO2 fixation ability. The results indicate Isochrysis sp. as the superior carbon fixer against other species. In continuation, the optimization study using Response Surface Methodology (RSM) was carried out to optimize the operating conditions of Isochrysis sp. using a customized lab-scale photobioreactor under simulated flue gas exposure. This species was further acclimatized and tested under actual flue gas generated by the power plant. Isochrysis sp. had shown its capability as a carbon fixer with CO2 fixation rate of 0.35 gCO2/L day under actual coal-fired flue gas exposure after cycles of acclimatization phase. This work is the first to demonstrate indigenous microalgae species' ability as a carbon fixer under Malaysian coal-fired flue gas exposure. Thus, the findings shall be useful in exploring the microalgae potential as a biological agent for carbon emission mitigation from power plants more sustainably.

Odors due to the emission of hydrogen sulfide (H2S) have been a concern in the sewage treatment plants over the last decades. H2S fate and emissions from extended aeration activated sludge (EAAS) system in Muharram Aisha-sewage treatment plant (MA-STP) were studied using TOXCHEM model. Sensitivity analysis at different aeration flowrate, H2S loading rate, wastewater pH, wastewater temperature and wind speed were studied. The predicted data were validated against actual results, where all the data were validated within the limits, and the statistical evaluation of normalized mean square error (NMSE), geometric variance (VG), and correlation coefficient (R) were close to the ideal fit. The results showed that the major processes occurring in the system were degradation and emission. During summer (27 °C) and winter (12 °C), about 25 and 23%, 1 and 2%, 2 and 2%, and 72 and 73% were fated as emitted to air, discharged with effluent, sorbed to sludge, and biodegraded, respectively. At summer and winter, the total emitted concentrations of H2S were 6.403 and 5.614 ppm, respectively. The sensitivity results indicated that aeration flowrate, H2S loading rate and wastewater pH highly influenced the emission and degradation of H2S processes compared to wastewater temperature and wind speed. To conclude, TOXCHEM model successfully predicted the H2S fate and emissions in EAAS system.

The two types of cellulose nanofiber (CNF) surface characteristics were evaluated by oil contact angle under ethanol–water solution at several concentrations as well as in air. Wood pulp-based 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-oxidized cellulose nanofiber (TOCNF) sheets and bamboo-derived mechanical counter collision cellulose nanofiber (ACC-CNF) sheets were fabricated by casting followed by drying. The CNF shows underwater superoleophobic mimicking fish skin properties and slippery surface mimicking Nepenthes pitcher. The underwater superoleophobic properties of CNF was evaluated theoretically and experimentally. The theoretical calculation and experimental results of contact angle showed a large deviation. The roughness, zeta potential, and water absorption at different concentrations were key factors that determine the deviation. Antifouling investigation revealed that CNF was a good candidate for antifouling material.

Polyphenols based bioactive compounds from vegetables and fruits are known for impressive antioxidant activity. Ingestion of these antioxidants may promote human health against cardiovascular diseases and cancer. Mango is a popular tropical fruit with special taste, high nutritional value and health-enhancing metabolites. The aim was to investigate the diversity of phytochemicals between two mango cultivars of china at three stages of fruit maturity. We used ESI-QTRAP-MS/MS approach to characterize comprehensively the metabolome of two mango cultivars named Hongguifei (HGF) and Tainong (TN). HPLC was used to quantify selected catechin based phenolic compounds. Moreover, real-time qPCR was used to study the expression profiles of two key genes (ANR and LAR) involved in proanthocyanidin biosynthesis from catechins and derivatives. A total of 651 metabolites were identified, which include at least 257 phenolic compounds. Higher number of metabolites were differentially modulated in peel as compared to pulp. Overall, the relative quantities of amino acids, carbohydrates, organic acids, and other metabolites were increased in the pulp of TN cultivar. While the contents of phenolic compounds were relatively higher in HGF cultivar. Moreover, HPLC based quantification of catechin and derivatives exhibited cultivar specific variations. The ANR and LAR genes exhibited an opposite expression profile in both cultivars. Current study is the first report of numerous metabolites including catechin-based derivatives in mango fruit. These findings open novel possibilities for the use of mango as a source of bioactive compounds.

Made available in DSpace on 2021-06-25T10:15:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 The adoption of dicamba-tolerant soybean varieties has increased the concern and demand for new drift and volatility reduction technologies. Potential spray nozzles and adjuvants should be studied to determine its effects on drift and volatility of dicamba tank-mixtures. The objective of this study was to evaluate physicochemical characteristics of spray solutions containing dicamba; to analyze droplet size effect with air induction nozzles; and to assess dicamba volatilization on soybean plants with a proposed methodology. Treatments included dicamba only and mixtures with herbicides and adjuvants. Dicamba mixed with lecithin + methyl soybean oil + ethoxylated alcohol adjuvant had the greatest efficacy potential among treatments considering tank-mixture pH, surface tension, contact angle and droplet size. The MUG11003 nozzle produced the coarsest droplet size and was better suited for drift management among nozzle types. The proposed volatilization methodology successfully indicated dicamba volatilization in exposed soybean plants and among the evaluated treatments, it showed greater volatilization for dicamba with glyphosate + lecithin + propionic acid adjuvant. Departamento de Ciências da Produção Agrícola UNESP Jaboticabal Campus Departamento de Ciências da Produção Agrícola UNESP Jaboticabal Campus

Residues from the wine industry constitute an abundant feedstock for biodiesel production in wine-producing countries. The use of grapeseed oil, together with bioethanol obtained from distillation of wine surplus or grape skins and stalks and wine lees, as reagents in the transesterification reaction, results in a mixture of fatty acid ethyl esters (FAEE), which is a fully renewable, autochthonous, and waste-derived biofuel. In this work, a blend of FAEE produced from grape seed oil with diesel fuel was selected based on a study of fuel properties, and the optimal blend, with 30% v/v of FAEE, was tested in a Euro 6 engine following the Worldwide harmonized Light-duty Test Cycle (WLTC) and a Real Driving Emissions Cycle (RDE), as required in the new certification procedures. Engine performance and emissions from this blend and a commercial diesel fuel were compared. The FAEE blend showed a significant potential to reduce particle emissions, both in mass and number (from 23% in number to 46.5% in mass for WLTC, and from 56% in number to 61% in mass for RDE), and CO (25.5% for WLTC and 39% for RDE) but penalized NOx (32% higher in WLTC and 26.4% higher in RDE).

Fuels and their components accumulate in soil, and many soil organisms are exposed to this pollution. Compared to intensive research on the effect of conventional fuel on soil, very few studies have been conducted on soil ecotoxicity of biofuels. Considering the limited information available, the present study evaluated the changes caused by the presence of biodiesel and diesel fuel in soil. The reaction of higher plants and soil organisms (microbial communities and invertebrates) was analysed. Conventional diesel oil and two types of biodiesel (commercial and laboratory-made) were introduced into the soil. Two levels of contamination were applied—5 and 15% (w/w per dry matter of soil). The plate method was used to enumerate microorganisms from soil contaminated with biodiesel and diesel fuel. Phytotoxicity tests were conducted by a 3-day bioassay based on the seed germination and root growth of higher plant species (Sorghum saccharatum and Sinapis alba). Fourteen-day ecotoxicity tests on earthworm were performed using Eisenia fetida. Based on the results of the conducted tests it was found out that the organisms reacted to the presence of fuels in a diverse manner. As to the microorganisms, both the growth and reduction of their number were noted. The reaction depended on the group of microorganisms, type of fuel and dose of contamination. The lipolytic and amylolytic microorganisms as well as Pseudomonas fluorescens bacteria were particularly sensitive to the presence of fuels, especially biodiesel. Fuels, even at a high dose, stimulated the growth of fungi. Monocotyledonous sugar sorghum plants were more sensitive to the presence of fuels than dicotyledonous white mustard. There was also a significant negative impact of contamination level on plant growth and development. Biodiesel, to a greater extent than conventional fuel, adversely affected the survival and volume of earthworms.

Accumulation of the Municipal Sewage Sludge (MSS) is considered as one of the most harmful renewable ecological and human health problems. MSS is a renewable resource that could be used as a soil organic amendment. This study aims to reduce the Heavy Metals (HMs) from the sludge content and sludge compost. Furthermore, this study is considered the first to assess the mycotoxins content in sludge and sludge compost via a new biological treatment using the fungus Serendipita indica or a mixture of lactic acid bacteria, thus providing safer nutrients for the soil amendment for a longer time and preserving human health. The HMs and mycotoxins were determined. The results exhibited that the biotic remediation of bio-solid waste and sewage sludge compost succeeded; a new bio-treated compost with a very low content of heavy metals and almost mycotoxins-free contents was availed. Also, the results indicated that the Lactobacilli mixture realized the best results in reducing heavy metals contents and mycotoxins. Afterward, S. indica. biotic remediation of bio-solid waste and sewage sludge compost minimized the health risk hazards affecting the human food chain, allowing for the different uses of sludge to be safer for the environment.

The behaviour of ash of fuel affects its thermal efficiency when in use. The ash analyses of bio-coal briquettes developed from lean grade coal and torrefied woody biomass have received limited intensive study. Therefore, the present study aims at analysing the ashes of briquette made from lean grade coal and torrefied woody biomass using blended coal tar pitch and molasses as the binder. Bio-coal briquettes were produced from coal and torrefied biomass in various hybrid ratios. Ashing of various briquettes was done in a muffle furnace at 850 °C for 3 h. Mineral phases of the ash were identified using an X-ray Diffractometer (XRD), while the mineral oxides were obtained using an X-ray Fluorescence Spectrometer. The AFT700 Furnace was used with its AFT700 software to evaluate the ash fusion temperatures of the ashes. The XRD patterns look similar, and quartz was found to be the dominant mineral phase present in the raw coal and bio-coal briquettes. The SiO2 (57–58%), Al2O3 (19–21%), and Fe2O3 (8–9%) were the major oxides observed in the ashes. The final fusion temperatures of the ashes range from 1300–1350 °C. The compositions of the ashes of the bio-coal briquettes are classified as detrital minerals. It was concluded that the addition of torrefied biomass (≤ $$10\%)$$ 10 % ) and blended binder ($$\le $$ ≤ 15%) to coal gave a negligible impact on the ashes of the resultant bio-coal briquettes.

Sensor data can be wirelessly transmitted from simple, battery-less tags using Radio Frequency Identification (RFID). RFID sensor tags consist of an antenna, a radio frequency integrated circuit chip (RFIC), and at least one sensor. An ideal tag can communicate over a long distance and be seamlessly integrated onto everyday objects. However, miniaturized antenna designs often have lower performance. Here we demonstrate compact, flexible sensor tags with read range comparable to that of conventional rigid tags. We compare fabrication techniques for flexible antennas and demonstrate that screen and stencil printing are both suitable for fabricating antennas; these different techniques are most useful at different points in the design cycle. We characterize two versions of flexible, screen printed folded dipoles and a meandered monopole operating in the 915 MHz band. Finally, we use these antennas to create passive sensor tags and demonstrate over the air communication of sensor data. These tags could be used to form a network of printed, flexible, passive, interactive sensor tags.

Agricultural wastes, such as wheat bran and swine wastewater, were used for bioremediation of oil-contaminated soil. Two optimised strains that could degrade oil efficiently were selected. The result showed that the best ratio of strain A to strain B was 7:3. Swine wastewater could be a replacement for nitrogen source and process water for bioremediation. Next, the Box-Behnken design was used to optimise the culture medium, and the optimal medium was as follows: microbial dosage of 97 mL/kg, wheat bran of 158 g/kg and swine wastewater of 232 mL/kg. Under the optimal medium, the oil degradation rate reached 68.27 ± 0.71% after 40 d. The urease, catalase, and dehydrogenase activities in oil-contaminated soil all increased, and the microbe quantity increased significantly with manual composting. These investigations might lay a foundation for reducing the pollution of agricultural wastes, exploring a late model for bioremediation of oil-contaminated soil.

Two-stage anaerobic digestion of palm oil mill effluent (POME) is a promising method for converting the waste from the largest agricultural industry in Southeast Asia into a clean and sustainable energy. This study investigates the degradation of acid-rich effluent from the dark fermentation stage for the production of biomethane (BioCH4) in a 30-L continuous stirred-tank reactor (CSTR). The continuous methanogenic process was operated with varied HRTs (10 - 1 day) and OLRs (4.6–40.6 gCOD/L.d−1) under thermophilic conditions. Methanothermobacter sp. was the dominant thermophilic archaea that was responsible for the production rate of 4.3 LCH4/LPOME.d−1 and methane yield of 256.77 LCH4kgCOD at HRT of 2 d, which is the lowest HRT reported in the literature. The process was able to digest 85% and 64% of the initial POME’s COD and TSS, respectively. The formation of methane producing granules (MPG) played a pivotal role in sustaining the efficient and productive anaerobic system. We report herein that the anaerobic digestion was not only beneficial in reducing the contaminants in the liquid effluent, but generating BioCH4 gas with a positive net energy gain of 7.6 kJ/gCOD.

The methods of separation of microalgae has a significant impact in the economic aspects of their cultivation. In this study, pine bark was used as a substrate for immobilization of microalgal biomass cultivated in raw municipal sewage. The experiment was conducted in cylindrical photobioreactors (PBRs) with circulation of wastewater. Biomass was cultivated for 42 days. After that time, abundant growth of the biofilm with microalgae on the surface of pine bark as well as improvement of the quality of treated sewage were observed. The efficiency of removal of nutrients from wastewater was 64–81% for total nitrogen and 97–99% for total phosphorus. Moreover, the concentration of suspended solids in sewage was reduced, which resulted in a decrease in turbidity by more than 90%. Colorimetric analysis and Volatile Matter (VM) content in the substrate showed a decrease in the Higher Heating Value (HHV) and concentration of VM due to the proliferation of biofilm.

The industrial wastewater disposal has been growing attention for environmental protection and resource substitution, current decades. Similarly, the durability enhancement of concrete has increased attention by microbial induced CaCO3 precipitation (MICP) process (biocalcification). However, ecofriendly utilization of industrial wastewater in concrete formation is unstudied so far. The present study was carried out to evaluate the effect of industrial wastewater on the formation of cement mortar, compressive strength and water absorption. The biocement mortar strength (y) increased (y = 0.5295×2 + 1.6019×+251.05; R2 = 0.9825) with increasing percentage of organic wastewater (x) (BM0 – BM100) by MICP, where highest strength (280.75 kgf/cm2) was observed on BM100 (100% wastewater), compared to control (252.05 kgf/cm2). The water absorption (y) of biocement mortar decreases (y = −0.0251×2–0.103× + 15.965; R2 = 0.9594) with increment of wastewater (x) (%) (BM0 – BM100), where a minimum-water-absorption (14.42%) observed on BM100, compared to control (15.89%). SEM micrograph and XRD shows the formation of most-distinctive CaCO3 crystallization (aragonite/calcite) (acicular, brick shape, massive and stacked structure) inside biocement mortar (BM100), which fills the pores within cement mortar to form a denser structure, by microbial organic wastewater. Thus, present findings implied a cost-effective of MICP technology to improve the concrete properties along with the mitigation of industrial wastewater pollution, which goes some way towards solving the problem of industrial wastewater pollution.

Phytoremediation is one of the environmental-friendly and cost-effective systems for the treatment of wastewater, including industrial wastewater such as palm oil mill effluent final discharge (POME FD). However, the effects of the wastewater on the phytoremediator plants, in term of growth performance, lignocellulosic composition, and the presence of nutrients and heavy metals in the plants are not yet well studied. In the present work, we demonstrated that POME FD increased the growth of P. purpureum. The height increment of P. purpureum supplied with POME FD (treatment) was 61.72% as compared to those supplied with rain water (control) which was 14.42%. For lignocellulosic composition, the cellulose percentages were 38.77 ± 0.29% (treatment) and 34.16 ± 1.01% (control), and the difference was significant. These results indicated that POME FD could be a source of plant nutrients, which P. purpureum can absorb for growth. It was also found that the heavy metals (Al, As, Cd, Co, Cr, Ni and Pb) inside the plant were below the standard limit of the World Health Organization (WHO). Since POME FD was shown to have no adverse effects on P. purpureum, further research regarding the potential application of P. purpureum following phytoremediation of POME FD such as biofuel production is warranted to evaluate its potential use to fit into the waste-to-wealth agenda.

Respiratory protection is key in infection prevention of airborne diseases, as highlighted by the COVID-19 pandemic for instance. Conventional technologies have several drawbacks (i.e., cross-infection risk, filtration efficiency improvements limited by difficulty in breathing, and no safe reusability), which have yet to be addressed in a single device. Here, we report the development of a filter overcoming the major technical challenges of respiratory protective devices. Large-pore membranes, offering high breathability but low bacteria capture, were functionalized to have a uniform salt layer on the fibers. The salt-functionalized membranes achieved high filtration efficiency as opposed to the bare membrane, with differences of up to 48%, while maintaining high breathability (> 60% increase compared to commercial surgical masks even for the thickest salt filters tested). The salt-functionalized filters quickly killed Gram-positive and Gram-negative bacteria aerosols in vitro, with CFU reductions observed as early as within 5 min, and in vivo by causing structural damage due to salt recrystallization. The salt coatings retained the pathogen inactivation capability at harsh environmental conditions (37 °C and a relative humidity of 70%, 80% and 90%). Combination of these properties in one filter will lead to the production of an effective device, comprehensibly mitigating infection transmission globally.

Mining is an essential human activity, but results in several environmental impacts, notably the contamination of ground and surface water through the presence of toxic substances such as metals and sulfates in mine drainage. Permeable reactive barriers (PRB) have been applied to remediate this environmental impact, but the high costs associated with the maintenance of this system are still a challenge. The main objective of this study was to evaluate the use of kraft pulp mill alkaline residues, known as dregs and grits, as material for PRB, and to determine their capacity for retaining copper and sulfate. The work was carried out in laboratory adsorption kinetics assays, batch assays and column tests. Tests for elemental characterization, point of zero charge, acid neutralization capacity, total porosity, bulk density and moisture of the dregs and grits were conducted. The results showed high retention of Cu due to a chemical precipitation mechanism, notably for dregs (99%) at 5 min in adsorption kinetics. The grits presented similar results after 180 min for the same assay. Sulfate retention was effective at pH below 5, with an efficiency of 79% and 89% for dregs and grits, respectively. Dregs presented the best results for acid drainage remediation, notably with a solid:liquid (S:L) ratio of 1:10.

Vegetable Market have become major sources of organic waste. Some of such waste when being diverted to landfills not only increase the landfill loading but also contribute to increase greenhouse gas emission. Of the many technologies available in handling such hugely generated waste, composting has proven very effective for decades. Enzyme and non-enzyme mediated aerobic composting of vegetable market complex waste (VMCW) have been investigated. Conventional composting technique though being capable of handling large quantum of waste are found to consume more time. Proven to be disadvantages factor. In the present investigation, the pre-cultured seed inoculums used for vegetable market complex waste, shortened the typical composting period from 45 to 9 days for the first time. Also, rapid size and volume reduction of VMCW was witnessed. The organic degradation of VMCW was observed as 42% (82 ± 2.83% to 40.82 ± 0.61%), with a volume reduction from 0.012m3 to 0.003 m3 within 9 days. An enriched nutrients NPK level of compost bio-fertilizer was recorded as 0.91% w/w, 0.5% w/w and 1.029% w/w respectively. Compost maturity observed through the X-ray diffraction (XRD) analysis of the manure confirmed the conversion of the crystal structure of the compost particle to amorphous form and the mineralization of organic matter during the composting. Thus, the fermented pre-cultured seed inoculums favored an enhanced nutrients level with shortened composting time.

Cannabidiol (CBD) has become a buzzword in many products that have bloomed on the market. The scientific community and some authorities have recently raised concerns on the quality of these products. In particular, the discrepancy between the labelled and the real content of cannabidiol in liquids for e-cigarettes seems to be emerging as a major issue. Furthermore, to-date no studies have been carried out on the chemical stability upon storage of these type of products. The aim of this work was to investigate the accuracy in labelling of thirteen commercially e-liquids containing CBD and the effects of different storage conditions on their quality. The results showed that only 38% of samples were labelled within a ±10% variance from their labels. Stability tests showed a maximum degradation of CBD when samples were stored at 37 °C for 30 days with average values up to 20%. The effect of light was lower but still significant with averages values up to 15% degradation after 30 days. In conclusion, we believe that health authorities should regulate and control this market more stringently to protect customers and their health. Furthermore, our stability tests have shown that if clear indications are provided on the best storage conditions, the quality of these products can be mostly preserved.

Ineffectiveness of the chemicals applied so far for waterlogged wood conservation created the need to develop new more, efficient and reliable agents. As an alternative, a new method with the use of organosilicon compounds differing in chemical composition and molecular weight has been investigated. The results obtained show the potential of organosilicons as consolidants in waterlogged wood conservation able to effectively stabilise wood dimensions upon drying. The best wood stabilisers were low-molecular organosilicons enable to penetrate the cell wall as well as chemicals with functional groups capable of interacting with wood polymers and forming stabilising coatings on the cell wall surface. The best anti-shrink efficiency values were obtained for (3-Mercaptopropyl)trimethoxysilane, (3-Aminopropyl)triethoxysilane, 1,3-Bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, reaching 98, 91 and 91%, respectively. Most of the applied organosilicons reduced wood hygroscopicity, which limits the risk of further dimensional changes of wood exposed to a variable air moisture content and potentially reduces wood biodegradation. In the light of our studies, the proposed method of waterlogged wood conservation with organosilicons is potentially reversible in the case of siloxanes and amino-silanes as well as retreatable, which complies with the requirements of the conservation ethics.

The enhancement of composting technology to stabilize sludge pretreated by ozonation and ultrasonic was tested for 35 days. Secondary sludge produced by biological process are characterized with endogenous residue and inert solid matter which inhibit fully degrade bacterial cell walls. The composting process was performed with sludge pretreated with ozonatian and ultrasonics and green waste in a ratio of 2:1. The composting characteristics was evaluated for different physico-chemical and microbiological parameters in five different reactors. A high degree of composting quality was achieved with respect to significant reduction in volatile solids (VS) (32%), total organic carbon (TOC) (35.0%), C/N ratio (23.74), total coliform (TC) (168) along with the substantial increase in availability of nutrients like N (1.2%) and P (8.77%). High removal efficiency of TC and Fecal Coliform (FC) were observed in composting results, where simultaneous ultrasonic and ozonation were considered as primary-stabilization process. Therefore, applying integrated ultrasonic/ozonation with composting system for sludge stabilization is potentially useful technology in sustainable land restoration practices to meet standards and produce soil conditioner.

The present work investigates biomass wastes and their ashes for re-use in combination with mineralised CO2 in cement-bound construction products. A range of biomass residues (e.g., wood-derived, nut shells, fibres, and fruit peels) sourced in India, Africa and the UK were ashed and exposed to CO2 gas. These CO2-reactive ashes could mineralise CO2 gas and be used to cement ‘raw’ biomass in solid carbonated monolithic composites. The CO2 sequestered in ashes (125–414 g CO2/kg) and that emitted after incineration (400–500 g CO2/kg) was within the same range (w/w). The CO2-reactive ashes embodied significant amounts of CO2 (147–424 g equivalent CO2/kg ash). Selected ashes were combined with raw biomass and Portland Cement, CEM 1 and exposed to CO2. The use of CEM 1 in the carbonated products was offset by the CO2 mineralised (i.e. samples were ‘carbon negative’, even when 10% w/w CEM 1 was used); furthermore, biomass ashes were a suitable substitute for CEM 1 up to 50% w/w. The approach is conceptually simple, scalable, and can be applicable to a wide range of biomass ashes in a closed ‘emission-capture’ process ‘loop’. An extrapolation of potential for CO2 offset in Europe provides an estimate of CO2 sequestration potential to 2030.

The nanoformulations of pesticides have shown great interest from many parties due to their slow release capability and site-specific delivery. Hence, in this work, a new nanoformulation of a fungicide, namely chitosan-hexaconazole nanoparticles with a mean diameter size of 18 nm was subjected to the residual analysis on oil palm tissue, leaf and palm oil (crude palm oil and crude palm kernel oil) using a quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with the gas chromatography–micro electron capture detector (GC–µECD). The chitosan-hexaconazole nanoparticles were applied using the trunk injection method at 4.5 g a.i./palm (standard single dose) and 9.0 g a.i./palm (double dose). The fungicide residue was analyzed at 0 (6 h after application), 1, 3, 7, 14, 30, 60, 90, and 120 days after treatment. The palm oil matrices; the crude palm oil (CPO) and crude palm kernel oil (CPKO) were found to be residue-free. However, it was observed that high accumulation of the fungicide in the stem tissue and leaf after the treatment using the chitosan-hexaconazole nanoparticles, which is good for better bioavailability for the treatment of the fungi, Ganoderma boninense. The dissipation kinetic at double dose treatment in the tissue and leaf was found to govern by the second-order kinetic with half-lives (t1/2) of 383 and 515 days, respectively.

In paper industry, xylanases are used to increase the pulp properties in bleaching process as its eco-friendly nature. The xylanases activity is hindered by high temperature and alkaline conditions with high enzyme production cost in the paper industry. Here, XynHB, an alkaline stable xylanase from Bacillus pumilus HBP8 was mutated at N188A to XynHBN188A. Expressed mutant in E. coli showed 1.5-fold higher xylanase activity than XynHB at 60 °C. The mutant expressed in Pichia pastoris was glycosylated, remained stable for 30 min at 60 °C. XynHBN188A optimized based on codon usage bias for P. pastoris (xynHBN188As) showed an increase of 39.5% enzyme activity. The strain Y16 forming the largest hydrolysis halo in the xylan plate was used in shake flask experiments produced an enzyme activity of 6,403 U/ml. The Y16 strain had 9 copies of the recombinant xynHBN188As gene in the genome revealed by qPCR. The enzymatic activity increased to 48,241 U/ml in a 5 L fermentor. Supplement of 15 U/g xylanase enhanced the brightness of paper products by 2% in bleaching experiment, and thereby improved the tensile strength and burst factor by 13% and 6.5%, respectively. XynHBN188As has a great potential in paper industries.

Efficient, fast and new micro-analytical methods for characterization of ultrastructures of fungal spores with electron microscopy are very much required and essential. SEM analysis of biological materials, especially fungi, requires optimal preparation of the specimen and often requires the usage of dried samples which demands a challenging sample preparation. In the present investigation, we described a fast and improved method for the preparation of fungal specimen for scanning electron microscopy (SEM). The fungus, Curvularia lunata was grown on the surface of sterile Whatman No.1 filter paper which was overlaid on Potato Dextrose Agar (PDA) medium, gold coated immediately after removal from the growth medium and subjected to imaging. Generally, SEM imaging is done with samples that were fixed with chemical fixatives, dehydrated and gold coated specimens, but here we describe an easy and more efficient sample preparation for SEM which enabled enhanced image quality and precision visualization of fungal cells, especially the spores. The developed method has enabled the analysis of even the robust samples like fungal spores that to eliminating special temperature requirement. The ultimate goal was to develop an improved protocol/method applied to analysis of fungal spores with greater coverage about fungal specimen preparation. This method permits the use of rapid sample preparation and will allow us to imaging of individual spore or conidia structures in the context of fungal cell architecture which clarifies our understanding in fungal taxonomy/biology.

Reduction of CO2 emissions associated with cement production is challenging in view of the increasing cement demand and the fact that major part of the emissions originates from the main raw material used - limestone - which can be only to extremely low amount substituted. A Carbon Capture and Utilization (CCU) approach based on mineralization of fines derived from concrete appears to be a viable alternative to reduce these emissions. The CO2 sequestration and the reactivity of the obtained carbonated recycled fines is experimentally demonstrated for lab as well as industrial materials for different mineralization conditions. It is shown that all CO2 originally released by limestone calcination during clinker production can be sequestered by the full carbonation of the fines within a short time. Upon full carbonation, gels with pozzolanic properties form in the fines irrespective of the conditions tested. The carbonated fines have specific CO2 savings more than 30% higher than the simple clinker replacement by limestone.

Halving the proportion of the people without sustainable access to safe drinking water and basic sanitation is among the Sustainable Development Goals (SDG). Lack of access to safe drinking water has been associated with the prevalence of waterborne diseases. Due to this reported association, the development of household water treatment devices has been an alternative to improve the quality supply of domestic water. In this study, we aimed to evaluate the performance of a ceramic silver-impregnated pot filter (CSF) system coupled with an adsorption process, composed of silver-impregnated granular activated carbon and zeolite (CSF + GAC-Z), to remove waterborne bacteria Escherichia coli and Salmonella spp. from spiked water. The performance of this system was compared with the conventional CSF system. In this respect, we evaluated six CSF and six CSF + GAC-Z using spiked water with 103 and 102 CFU/mL of E. coli and Salmonella spp. The mean percentage of removals ranged between 98% and 99.98%. The highest bacterial removal efficiency was recorded by the CSF + GAC-Z (99%) and CSF (99.98%) for E. coli and Salmonella spp., respectively, but no significant statistical differences were found between filtration systems. Our findings suggest that the CSF + GAC-Z system was effective in the removal of waterborne bacteria from spiked water.

India produces huge quantities of agricultural residues and stubbles and mainly disposed by burning on site causing air pollution. The organic matter present in the residues and stubble may be utilized by anaerobic digestion as a source of renewable energy subsequently reducing emission of greenhouse gases caused by burning. In the present study, solid state anaerobic digestion (SSAD) of pearl millet straw was investigated at mesophilic and thermophilic temperature with four different total solid (TS) content (15, 20, 25 and 30%). Results showed that 20 and 25% TS generated maximum methane (124.1 ± 7 and 162.4 ± 9L/kg VS) at mesophilic and thermophilic temperature respectively. However, increasing TS content beyond 25% did not show significant increment on methane yield. Analytical analysis showed correlation between the reduction of volatile solids and methane yield as well as VFA (volatile fatty acid) accumulation at high TS content. Also, VlseKriterijuska Optimizacija Komoromisno Resenje (VIKOR) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods as MultiCriteria Decision Making modelling (MCDM) applied to select best possible alternative for SSAD of pearl millet. MCDM analysis showed that VIKOR method endorsed the experimental results.

The acute problem of eutrophication increasing in the environment is due to the increase of industrial wastewater, synthetic nitrogen, urine, and urea. This pollutes groundwater, soil and creates a danger to aquatic life. Therefore, it is advantageous to use these waste materials in the form of urea as fuel to generate power using Microbial Fuel Cell (MFC). In this work, we studied the compost soil MFC(CSMFC) unlike typical MFC with urea from the compost as fuel and graphite as a functional electrode. The electrochemical techniques such as Cyclic Voltammetry, Chronoamperometry are used to characterise CSMFC. It is observed that the CSMFC in which the compost consists of urea concertation of 0.5 g/ml produces maximum power. Moreover, IV measurement is carried out using polarization curves in order to study its sustainability and scalability. Bacterial studies were also playing a significant role in power generation. The sustainability study revealed that urea is consumed in CSMFC to generate power. This study confirmed that urea has a profound effect on the power generation from the CSMFC. Our focus is to get power from the soil processes in future by using waste like urine, industrial wastewater, which contains much amount of urea.

Shake-flask cultures of microorganisms involve flame sterilization during sampling, which produces combustion gas with high CO2 concentrations. The gaseous destination has not been deeply analyzed. Our aim was to investigate the effect of flame sterilization on the headspace of the flask and on the shake-flask culture. In this study, the headspace CO2 concentration was found to increase during flame sterilization ~0.5–2.0% over 5–20 s empirically using the Circulation Direct Monitoring and Sampling System. This CO2 accumulation was confirmed theoretically using Computational Fluid Dynamics; it was 9% topically. To evaluate the influence of CO2 accumulation without interference from other sampling factors, the flask gas phase formed by flame sterilization was reproduced by aseptically supplying 99.8% CO2 into the headspace, without sampling. We developed a unit that can be sampled in situ without interruption of shaking, movement to a clean bench, opening of the culture-plug, and flame sterilization. We observed that the growth behaviour of Escherichia coli, Pelomonas saccharophila, Acetobacter pasteurianus, and Saccharomyces cerevisiae was different depending on the CO2 aeration conditions. These results are expected to contribute to improving microbial cell culture systems.

Simultaneous saccharification and fermentation (SSF) with delayed yeast extract feeding (DYEF) was conducted in a 2-L bioreactor equipped with in-situ recovery using a gas stripping in order to enhance biobutanol production from lignocellulosic biomass of oil palm empty fruit bunch (OPEFB). This study showed that 2.88 g/L of biobutanol has been produced from SSF with a similar yield of 0.23 g/g as compared to separate hydrolysis and fermentation (SHF). An increase of 42% of biobutanol concentration was observed when DYEF was introduced in the SSF at 39 h of fermentation operation. Biobutanol production was further enhanced up to 11% with a total improvement of 72% when in-situ recovery using a gas stripping was implemented to reduce the solvents inhibition in the bioreactor. In overall, DYEF and in-situ recovery were able to enhance biobutanol production in SSF.

The current study analyzed and optimized the concentration of NaOH for alkaline pretreatment of kitchen refuse for biogas production. Also, the benefits of microwave assistance in enhanced biogasification of kitchen refuse were evaluated. The TS, VS and structural changes were compared using standard experimental techniques. Molecular dynamics was investigated for the molecular level changes leading to higher biogasification in NaOHmicrowave combined pretreatment. The methane and biogas yields were calculated to validate the benefits of microwave assistance in efficient biogasification. The NaOH-microwave combined pretreatment showed higher VS production. Microwave treatment degraded and removed lignin more efficiently. Molecular dynamics studies revealed the induction of configurational instability in lignin and cellulose molecules with variable temperatures. The methane and biogas production increased with 6% NaOH concentration, and decreased at higher NaOH concentration till 10%. Microwave assistance declined the required NaOH concentration further to 4%. Thus, as compared to 6% NaOH concentration required for an efficient pretreatment, the kitchen refuse was efficiently pretreated with 4% NaOH concentration when combined with a 30 min duration microwaving. The experimental and computational data provided a detailed analysis proposing an optimized, novel and promising method to pretreat kitchen refuse for efficient and enhanced biogas production.

Recently, historical and conservation studies have attached an increasing importance to investigating the materials used in historic documents. In particular, the identification of the animal species from which parchments are made is of high importance and is currently performed by either genetic or proteomic methods. Here, we introduce an innovative, non-invasive optical method for identifying animal species based on light-parchment interaction. The method relies on conservation of light energy through reflection, transmission and absorption from the sample, as well as on statistical processing of the collected optical data. Measurements are performed from ultraviolet (UV) to near-infrared (NIR) spectral ranges by a standard spectrophotometer and data are processed by Principal Component Analysis (PCA). PCA data from modern parchments, made of sheep, calf and goat skins, are used as a database for PCA analysis of historical parchments. Using only the first two principal components (PCs), the method confirmed visual diagnostics about parchment appearance and aging, and was able to recognise the origin species of historical parchment of among database clusters. Furthermore, taking into account the whole set of PCs, species identification was achieved, with all results matching perfectly their proteomic counterparts used for method assessment. The validated method compares favourably with genetic and proteomic methods used for the same purpose. In addition to animals’ proteomic and genetic signatures, a unique “optical fingerprint” of the parchments’ origin species is revealed here. This new method is non-invasive, straightforward to implement, potentially cheap and accessible to scholars and conservators, with minimal training. In the context of cultural heritage, the method could help solving questions related to parchment production and, more generally, medieval writing production.

The preservation of cultural heritage is one of the major challenges of today’s society. Parchments, a semi-solid matrix of collagen produced from animal skin, are a significant part of the cultural heritage, being used as writing material since ancient times. Due to their animal origin, parchments easily undergo biodeterioration: the most common biological damage is characterized by isolated or coalescent purple spots, that often lead to the detachment of the superficial layer and the consequent loss of written content. Although many parchments with purple spot biodegradative features were studied, no common causative agent had been identified so far. In a previous study a successional model has been proposed, basing on the multidisciplinary analysis of damaged versus undamaged samples from a moderately damaged document. Although no specific sequences were observed, the results pointed to Halobacterium salinarum as the starting actor of the succession. In this study, to further investigate this topic, three dramatically damaged parchments were analysed; belonging to a collection archived as Faldone Patrizi A 19, and dated back XVI-XVII century A.D. With the same multidisciplinary approach, the Next Generation Sequencing (NGS, Illumina platform) revealed DNA sequences belonging to Halobacterium salinarum; the RAMAN spectroscopy identified the pigment within the purple spots as haloarchaeal bacterioruberin and bacteriorhodopsine, and the LTA technique quantified the extremely damaged collagen structures through the entire parchments, due to the biological attack to the parchment frame structures. These results allowed to propose a model of the progressive degradation pattern of the parchment collagen. Overall, these data validate a multi-phase microbial succession model. This demonstration is pivotal to possible new restoration strategies, important for a huge number of ancient documents.

Activated sludge from wastewater treatment plants was seeded into a sequencing batch reactor (SBR) in which synthetic wastewater was used as the influent. The sludge was bulked by decreasing the concentration of dissolved oxygen (DO). By adding a 30 min step of anaerobic stirring after the water inflow, the sludge bulking was rapidly inhibited after 10 running cycles, and the sludge volume index (SVI) decreased from 222 to 74 mL·g−1. The results of high-throughput sequencing showed that the relative abundance of bacteria Thiothrix, bacteria norank_o_Sphingobacteriales and fungi Trichosporon was increased by 6.3, 4.3 and 81.2%, after initial SBR stages, but these bacteria were inhibited by the addition of an anaerobic step, as their relative abundances decreased by 0.7, 0.8 and 14.7%, respectively. The proliferation of Thiothrix, norank_o_Sphingobacteriales and Trichosporon was the primary reason for the observed sludge bulking in the reactor. After the anaerobic step was added, the sludge extracellular polymeric substances (EPS) concentration was increased from 84.4 to 104.0 mg·(gMLSS)−1 (grams of mixed liquor suspended solids). Thus, the addition of an anaerobic step can inhibit the growth of filamentous bacteria, increasing the sludge EPS concentration and promoting the precipitation of activated sludge.

Microplastic pollution caused by washing processes of synthetic textiles has recently been assessed as the main source of primary microplastics in the oceans. Therefore, understanding the effective contribution of the washing process of synthetic clothes to this environmental problem, is of great importance. In this study, wash trials at real scale were performed on commercial clothes by using a household washing machine in order to gain reliable data about the release of microplastics, and to identify possible influences of textile characteristics on the release. The wastewater was collected and filtered through subsequent filters with decreasing porosity, and the amount and dimensions of microfibres were determined. Microfibre release was analysed in relation to the nature and characteristics of the washed clothes. Results showed that microfibres released during washing range from 124 to 308 mg for kg of washed fabric depending from the type of washed garment that corresponds to a number of microfibres ranging from 640,000 to 1,500,000. Some textile characteristics, such as the type of fibres constituting the yarns and their twist, influenced the release of microfibres during washing. A great amount of microfibres of cellulosic nature was also released during washing of clothes made with a blend of polyester/cellulose. Finally the most abundant fraction of microfibres shed was retained by filters with pore size of 60 µm, presenting an average length of 360–660 μm and an average diameter of 12–16 μm, indicating dimensions that could pass through wastewater treatment plants and pose a threat for marine organisms.

A rapid Fenton treatment at second-scale intervals was investigated for further removal of organic compounds in the effluent of bio-treated dyeing and finishing wastewater (BDFW). The decolorization kinetics was studied using a stopped-flow spectrophotometer (SFS) at second-scale intervals. A combined first-order model was found to fit well for the decrease of both methylene blue and rhodamine B in SFS as well as SCOD (soluble chemical oxygen demand) and DOC (dissolved organic carbon) in real BDFW in batch test during Fenton oxidation. A full-scale plant with treatment capacity of 400,000 m3·d−1 was designed and has been run continuously based on the results of the stopped-flow study to treat the effluent of BDFW using Fenton oxidation in 16 pipeline reactors, each with a volume of 6.9 m3 and 24 s of reaction time since 2014. The COD, SCOD and DOC decreased from 140, 110 and 35 mg·L−1 to 77, 71 and 26 mg·L−1 respectively, which can meet the latest strict discharge limitations. The natural fluorescent substances detected in the BDFW were completely removed. The main organic pollutants in the BDFW can be significantly reduced using both gas chromatography-mass spectrometry and ultrahigh-performance liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry. The rapid Fenton reaction applied in pipeline reactors at second intervals has several advantages over the conventional Fenton’s process such as much shorter reaction time at second scale intervals, no need to build extra pH adjustment or reaction tanks, simple operation, low capital cost, etc.

A sustainable bioprocess was developed for the valorization of a no/low value substrate, i.e. waste frying oils (WFOs) with high content of free fatty acids (FFAs), otherwise unsuitable for biodiesel production. The bioprocess was verified using both recombinant (Escherichia coli) and native (Pseudomonas resinovorans) polyhydroxyalkanoates (PHAs) producing cell factories. Microbial fermentation of WFOs provided a 2-fold advantage: i) the reduction of FFAs content resulting into an upgrading of the “exhausted waste oils” and ii) the production of a bio-based microbial polymer. Proper strain designing and process optimization allowed to achieve up to 1.5 g L−1 of medium chain length, mcl-PHAs, together with an efficient conversion (80% yield) of the treated WFO into biodiesel.

In this work, we studied a novel algae cultivation strategy, mixotrophic microalgae biofilm, to improve the productivity and cost-efficiency of algal biofuel production. In contrast to previous methods, this improved approach can achieve high productivity at low cost by harnessing the benefits of mixotrophic growth’s high efficiency, i.e., capable of subsisting on inorganic and organic carbons thus unaffected by limited light, and microalgae biofilm’s low harvesting cost. Our results, as one of the first studies of this type, proved that microalgae biofilms under mixotrophic condition exhibited significantly higher productivity and quality of biofuel feedstock: 2–3 times higher of biomass yield, 2–10 times higher of lipid accumulation, and 40–60% lower of ash content when compared to microalgae biofilms under autotrophic condition. In addition, we investigated the impact of cell-surface properties (hydrophobicity and roughness) on the growth activities of microalgae biofilms and found that the productivity of mixotrophic biofilms was significantly correlated with the surface hydrophobicity. Finally, our work demonstrated the applicability of integrating this novel cultivation method with wastewater for maximum efficiency. This study opens a new possibility to solve the long-lasting challenges of algal biofuel feedstock production, i.e., low productivity and high cost of algal cultivation.

Biohydrogen produced from the electrolysis of biomass is promising because the onset voltages are less than 1.0 V and comparable to those of water and alcohol-water electrolysis. The present study focuses on Miscanthus sinensis as a model grass because of its abundance and ease of cultivation in Japan. The electrochemical performance and hydrogen formation properties of electrolysis cells using grass as a biohydrogen source were evaluated at intermediate temperature to achieve electrolysis. The components, such as holocellulose, cellulose, lignin, and extractives, were separated from Miscanthus sinensis to understand the reactions of Miscanthus sinensis in the electrolysis cell. The relatively high resistivity and low current-voltage performance of an electrolysis cell using lignin were responsible for degradation of the electrolysis properties compared to those with pure cellulose or holocellulose as biohydrogen resources. Biohydrogen was formed according to Faraday’s law and evolved continuously at 0.1 A cm−2 for 3,000 seconds.