Wet Residue Research Articles

Mechanism and kinetics of efficient removal of as from a high arsenic-bearing ZnSO4 solution using ultrasound enhanced oxygen

The traditional lime method for arsenic (As) removal from high arsenic-bearing ZnSO4 solution has disadvantages such as high cost, large amount of wet residue, significant secondary hazards, and long process flow. This study developed a new technology for efficient As removal using ultrasound enhanced oxygen. The effects of zinc roasting dust (ZRD) addition, reaction temperature, oxygen flow rate, and ultrasound power on As removal efficiency were investigated. Under the optimal conditions, the removal rate of As reached 97.90 %. The1O2, O2∙- and •OH radicals generated during the ultrasound-enhanced oxygen process significantly enhance the oxidation efficiency of As(III) and Fe2+. Ultrasound can also refine particle size and improve the removal efficiency of As. Compared with traditional lime method, the reaction time and wet residue amount have been reduced by 40 % and 70.37 %, respectively. Field emission scanning electron microscopy (FE-SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses indicate that As in ZnSO4 solution was primarily removed through by Fe(OH)3 colloidal adsorption and amorphous FeAsO4. Kinetic analysis revealed that the neutralization and As removal process using ZRD under ultrasound and oxygen action conforms to the internal diffusion control model. Ultrasound-enhanced oxygen As removal can reduce the reaction activation energy from 26.94 to 21.02 kJ/mol, effectively lowering the reaction barrier for As removal and demonstrating faster reaction rates under ultrasound conditions. Ultrasound-enhanced oxygen removal of As from high arsenic-bearing ZnSO4 solution provides an efficient and low-cost potential solution for enterprises.

Strip Tillage Improves Productivity of Direct-Seeded Oilseed Rape (Brassica napus) in Rice–Oilseed Rape Rotation Systems

Oilseed rape (Brassica napus) is a crucial global oil crop. It is generally cultivated in rotation with rice in southern China’s Yangtze River Basin, where the wet soil and residue retention after rice harvest significantly hinder its seedling establishment. Hence, this study developed a strip-tillage seeder for oilseed rape seeding following rice harvest. Additionally, seedling establishment, soil infiltration and evaporation post-seeding, soil moisture change, oilseed yield, and weed occurrence under strip tillage (ST) were compared with conventional shallow rotary-tillage (SR) and deep rotary-tillage (DR) seeding practices. Compared to SR and DR, the results demonstrated that ST had a higher seeding efficiency and 53.8% and 80.2% lower energy consumption, respectively. ST also enhanced seedling growth and oilseed yield formation more effectively than the competitor tillage treatments, with an oilseed yield increase exceeding 6%. Additionally, ST improved water infiltration and reduced soil water evaporation, resulting in higher topsoil (0–20 cm) moisture during the critical growth stages. Furthermore, ST reduced soil disturbance, significantly decreasing the density of the dominant weed, Polypogon fugax. Overall, ST seeding technology has the potential to improve the productivity of oilseed rape in rice–oilseed rape rotation systems, and its yield superiority is mainly due to seedling establishment improvement and soil moisture adjustment.

Anaerobic valorization of sewage sludge pretreated through hydrothermal carbonization: Volatile fatty acids and biomethane production

Hydrothermal carbonization (HTC) emerged as an effective technology for the treatment of various types of wet biomass and organic residues, including sewage sludge, offering the potential for sludge reduction and resource recovery. HTC pretreatment impact on downstream sludge fermentation is investigated. Results obtained at optimal conditions for HTC pretreatment (170 °C for 30 min) indicated that soluble carbon was significantly increased in the liquid fraction, enhancing feedstock availability for fermentation. Semi-continuous fermentation of HTC-treated sludge resulted in a stable process in which a mixed microbial community produced volatile fatty acids (VFAs) with longer chain acids content, acidification yield of 0.59 ± 0.05 g COD-VFA g−1 CODin and volumetric productivity of 1.6 ± 0.5 g COD-VFA L−1 d−1. Biomethane Potential tests evidenced high values for hydrochar. Overall, the HTC pretreatment enables improved conversion efficiencies, in the view of valorizing the liquid for VFA synthesis and the hydrochar for biomethane production.

Rehydrated corn grain silage with wet brewery residue and different inoculants

The objective was to evaluate the effects of including different proportions of Wet Brewery Residue (WBR) using inoculants on rehydrated ground corn silage quality. The experiment was conducted in a completely randomized design in a 4 x 3 factorial scheme with four replications. Four combinations of WBR and ground corn were evaluated to achieve 45 (DM45), 50 (DM50), 55 (DM55), and 65% (DM65) of dry matter (DM) in the homogenized material before siling, and three types of inoculation: without inoculant, with L. plantarum + P. acidylactici (Homo) and with L. buchneri (L. B). Ensiling was done in experimental PVC silos (±4.0kg) and stored for 180 days. The variables obtained were analyzed by the analysis of variance and regression procedures (P<0.05) using the R software. The percentage of real DM included in the treatments was 47%, 52%, 56%, and 66%. No impairment of the pH-reducing capacity of corn rehydrated with WBR was observed. Total dry matter losses were within the acceptable limit in silage with 52% DM (DM50), regardless of the type of inoculation. Gas losses were within the permissible limit only in the DM50 treatments with Homo inoculant and in the DM50 treatment without inoculation. Effluent losses were outside the tolerable limit in the treatment with 47% DM (DM45) in the presence of the inoculant LB. There was a significant interaction between the inoculant LB and the silages, with 47% (DM45) and 56% (DM55) DM for the Crude Protein (CP) levels. The ADF and NDF variables reduced linearly as a function of the increase in dry matter of the ensiled material, with a tendency for the lowest values to be found in treatments without inoculation. For all variables, an increase in energy levels (Non-Fibrous Carbohydrates, starch, Total Digestible Nutrients, and Net Energy gain) was observed with the increase in the DM content of the silage. It is concluded that silage with 52% DM (DM50) obtained the best results for fermentative losses. For bromatological and energetic characteristics, silage with 66% DM was the best, except for the CP variable, where 47% DM silage achieved superior results. In general, the addition of additives did not show any improvement in relation to treatments without inoculants.

PAU Smart Seeder: a novel way forward for rice residue management in North-west India

In winter, the paddy residues become wet during morning and late evening due to dew, which restricts the operation of sowing machines (Happy Seeder and Super Seeder) into paddy residues, as wet residues do not slide on furrow openers/tines. A PAU Smart Seeder (PSS) was developed and evaluated for a four-wheel tractor that can sow wheat with optimum crop establishment in combined harvested rice fields. The PSS were evaluated for its performance under varying straw load, forward speed, and rotor speed in terms of fuel consumption, field capacity, seed emergence, and grain yield. The crop establishment and wheat yield of PSS was also compared with the existing straw management machines Happy Seeder (HS) and Super Seeder (SS) under heavy paddy residue conditions. The effect of the straw load was more pronounced on dependent variables than the effect of the speed index. PSS performance was best at a forward speed of 2.6 km h−1, rotor speed of 127.5 rpm, and a straw load of 6 t ha−1. Average fuel consumption using PSS was lower than SS but higher than HS. Wheat emergence was higher by 15.6 and 25.7% on the PSS plots compared to HS and SS, respectively. Average wheat grain yield in PSS plots was significantly higher by 12.7 and 18.9% than SS and HS, respectively in one experiment, while the grain yield was similar for both PSS and HS in other experiments. PSS has a novel mechanism to manage paddy straw and simultaneously sow wheat into a heavy straw load (> 8 t ha−1) mixture of anchored and loose straw. In conclusion, PSS showed promise for in-situ management of rice straw as it eliminates most of the operational problems encountered by the existing seeders (HS and SS).

Environmental Assessment of Hydrothermal Treatment of Wet Bio-Residues from Forest-Based and Agro-Industries into Intermediate Bioenergy Carriers

Hydrothermal carbonization (HTC) of low quality, wet biogenic residues into intermediate bioenergy carriers can potentially contribute to a more flexible and stable renewable energy system and reduce environmental impacts compared to current residue disposal practices. This study quantifies the environmental impacts via life cycle assessment (LCA) of a novel hydrothermal process for the treatment on an industrial scale of application of three wet biogenic residues (paper bio-sludge, olive pomace, and orange peel) into bioenergy carriers, i.e., solid pellets and biogas. A comprehensive attributional cradle-to-gate life cycle assessment (LCA) was conducted; the life cycle impact assessment (LCIA) utilised the ReCiPe impact assessment method. A selection of 10 significant impact categories was prioritised. Reliability of this categorization was also ensured through a sensitivity analysis carried out using Monte Carlo simulation. Climate change, particulate matter formation and terrestrial acidification impact categories showed the highest reliability, while for freshwater ecotoxicity and freshwater eutrophication impact categories in the study suggest the need for more robust data and further investigation. The climate change impact category presents the following values, as kg CO2eq/tresidue: pulp and paper bio-sludge (PPB), 17.9; olive pomace (OP), −1290; orange peel (ORP), −1301. The LCA study compared electricity yields of the hydrothermal treatment process with conventional treatment processes for each of the target residue streams. The environmental performance of the proposed hydrothermal treatment benefits significantly from the combination of intermediate bioenergy carriers (pellets) from the solid fraction with biogas production from the liquid fraction. Avoided emissions due to the heat recovery provide further environmental benefits. The LCIA results show that the carbon footprint of the F-CUBED production system, as kgCO2eq/kWhe, accounts for –4.56, −0.63, and −0.25 for paper bio-sludge, olive pomace and orange peel, respectively.

Thermochemical Co-Liquefaction of Fruit Pomace’s Blends in a Binary Solvent System Toward Value-Added Bioproducts

Abstract Poland belongs to the most meaningful producers of fresh food products in the European Union, e.g., apples, cherries, carrots, as well as currants. A significant part of these products are subjected to further processing, which results in the generation of an abundant amount of wet residues, such as pomace. The present paper aims to investigate the possibility of co-processing various industrial residues in the form of fruit pomaces through thermochemical liquefaction toward high-energy-density biocrude and biochar. More specifically, industrial wastes received from commercial juice production, i.e., blackcurrant, apple, and cherry pomaces, were converted under subcritical conditions of the water-isopropyl alcohol solvent system at fixed conditions. Particular focus was put on testing binary and ternary mixture feedstock systems and the possibility of predicting the bioproduct yield. Furthermore, the quality of the resultant biocrudes was analyzed by means of FTIR, GC-MS, and elemental analysis. For all separately studied raw materials and their binary and ternary mixtures, the dominant group fraction was biocrude with its yield ranging between 45.8 and 54.5 wt%. Produced liquids exhibit high energy density (HHV between 30.1 and 32.4 MJ/kg); thus, all of them pose perspective alternative fuels for generating heat and electricity. Also, the solid biochars presented a high energy density (HHV around 24–26 MJ/kg) and can be considered as an alternative energy carrier. The postulated approach aims to increase the flexibility and profitability of future technology of processing useless waste toward value-added bioproducts for the chemical and energy sectors.

Process evaluation of mild hydrothermal carbonization to convert wet biomass residue streams into intermediate bioenergy carriers

Hydrothermal carbonization (HTC) is a promising process for the upgrading of wet biomass residues. Models of HTC processes, in particular at continuous pilot-scale, are needed to move HTC from lab-scale to industrial scale. This study presents a process model for mild HTC, dewatering and conversion to intermediate energy carriers (bio-pellets and biogas for power and/or heat production) of three wet biomass residue streams: paper sludge, olive pomace and orange peels, based on lab- and pilot-scale experiments. In addition, the process energy efficiency and feedstock utilization of the HTC process is calculated and compared with conventional treatment options for the chosen residues, i.e., direct anaerobic digestion (olive pomace, orange peels) or combustion after conventional dewatering (paper sludge). The process model indicates that the HTC pilot-scale process is much more efficient in terms of feedstock utilization to produce heat and/or power than the reference scenarios. The process energy efficiency of the HTC process (pilot-scale) was calculated to be 26 %, 63 % and 40 % for paper sludge, olive pomace and orange peel feedstocks, respectively. For all feedstocks, both the solid and liquid-generated products are equally important for improving the overall process energy efficiency. This study demonstrates the potential benefits of HTC processes for upgrading wet biomass waste streams based on continuous pilot-scale data.

Consumo, desempenho e comportamento ingestivo de cordeiros terminados em confinamento com resíduo úmido de cervejaria como volumoso

ABSTRACT: The present study evaluated the effect of increasing levels of wet brewery residue (WBR) as a source of roughage on nutrient intake, performance and ingestive behaviour in lambs finished in confinement. Thirty-two uncastrated male lambs were used, weaned at 50 days of age. The treatments comprised increasing levels of WBR as roughage in the diet: 31, 44, 57 and 70%, on a dry-matter. The concentrate consisted of disintegrated corn, soybean meal, calcitic limestone and mineral salt. There was a quadratic effect (P ≤ 0.05) from the increasing levels of WBR on the intake of DM, OM, CP and TCH. The intake of EE, NDF and ADF increased linearly (P ≤ 0.01), while TDN intake showed a linear reduction (P < .0001) for increases in the level of WBR. There was a quadratic effect (P ≤ 0.010) on the average daily weight gain (ADG) from the addition of WBR to the diet. The time spent on feeding and rumination (P ≤ 0.05), expressed in minutes, showed a linear increase. Feeding rate for DM showed decreasing linear behaviour (P ≤ 0.006), while NDF rumination rate showed increasing linear behaviour (P ≤ 0.013) due to the increased levels of WBR in the diet. There was a linear increase in the time spent on each feeding activity (P ≤ 0.007) with the increase in WBR in the diet. Maximum weight gain is achieved when 46.9% WBR is used as a source of roughage in the diet, and this level can be recommended for terminating lambs in confinement.

Phase Equilibrium and Crystallization Process of the Ternary System KCl-(NH2)2CO-H2O at Different Temperatures

The phase equilibriums of the ternary system KCl-(NH2)2CO-H2O at 303.15 K, 323.15 K, 333.15 K, and 343.15 K were studied using the isothermal dissolution equilibrium method, in which the composition of equilibrium solid phase was determined by Schreinemaker’s wet residue method and X-ray diffraction (XRD) method. It was found that the ternary system is a simple cosaturated system, without the formation of neither double salt nor solid solution. Wilson and NRTL models were employed to correlate in the solubility data of the system at experimental temperatures. The maximum values of RAD and RMSD of the Wilson model were 2.18 × 10−2 and 0.83 and those of the NRTL model were 1.69 × 10−2 and 0.40, respectively. The two models were utilized to forecast solubility data at various temperatures, and the obtained outcomes were in line with the literature data. Based on the experimental solubility data at 343.15 K, the cooling crystallization process of the system was monitored online by focused beam reflectance measurement (FBRM) and particle video microscope (PVM). The crystal products were characterized by XRD, scanning electron microscope (SEM), and energy dispersive spectrometry (EDS). The results showed that the precipitation of (NH2)2CO occurred during the crystallization process, and this was followed by KCl. KCl was formed on the surface of (NH2)2CO crystal. The crystal was a simple mixture containing KCl and (NH2)2CO.

Comparative Effectiveness and Persistence of Antimicrobial Durability in Dry and Wet States of a Novel Antimicrobial Surface Disinfectant

Aims: We evaluated a novel disinfectant (VR) and seven comparators (disinfectants A–G) against resistant pathogens common in healthcare settings. Methods and Results: VR at different dilutions, along with commercial disinfectants A–G, was tested against surrogate viruses, and resistant bacterial and fungal pathogens. Surrogate viruses had an initial concentration of ~1 × 108 mL−1, and bacterial and fungal isolates had an initial concentration of ~1 × 106 mL−1 on Siliconee surfaces. After the application of VR or a comparator disinfectant, surfaces were tested for the reduction in microbial loads after 30 s and 5 min wet exposures, and after a 24 h dry residue exposure. Sterile deionized water was used as a control. The VR at a concentration of 4.68% was superior to all comparator disinfectants against most pathogens in wet and dry testing. The VR at 7.8% concentration showed the highest pathogen-reduction rate among all comparator disinfectants when tested against all pathogens. Conclusions: Overall, the novel VR disinfectant was the most effective disinfectant in both wet and dry residue states against the range of tested pathogens. Significance and Impact of the Study: VR is a broadly effective disinfectant combination for use in high-risk settings, particularly those in which intervals between applications of disinfectant can be lengthy or inconsistent.

Mechanism of removal of toxic arsenic (As) from zinc sulfate solution by ultrasonic enhanced neutralization with zinc roasting dust

Arsenic in zinc sulfate solution greatly hinders the zinc hydrometallurgy process, and the treatment of arsenic residue with lime also generates large cost due to the large amount of residue. Herein, a new process of neutralization by zinc roasting dust (ZRD) and ultrasound (US) field enhancement of arsenic removal was proposed. The process includes the following steps:one-stage neutralization, KMnO4 oxidation and two-stage neutralization to remove arsenic. The process has the advantages of a good arsenic removal effect, no introduction of new impurities, and less residue. The effects of the ZRD dosage, temperature and US power on arsenic removal were investigated. The optimal conditions were 12 g/L, 70 ℃ and 300 W, respectively, and the arsenic removal rate reached 99.3%. The X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FE-SEM-EDS) were utilized to analyze the raw materials and residue. The results showed that, compared with conventional conditions, US strengthening treatment led to more complete reaction of ZRD. The arsenic removal residue after US treatment mainly existed in the form of ZnFe2O4, Fe3O4 and ZnS, which exhibited low reactivity. Ultrasound could effectively destroy the wrapper on the surface of ZRD, and enhance the liquid–solid reaction, which reduced the amount of residue and improved the arsenic removal efficiency. Interestingly, we found that ultrasound could enhance arsenic removal by increasing the ligand exchange between arsenate and sulfate. Compared with the lime and conventional ZRD neutralization, the wet residue weight after US treatment was reduced by 46.8% and 16.3%, respectively.

Solid–Liquid Phase Equilibria in the Ternary MgCl2–NiCl2–H2O System at 303–323 K

For efficient nickel recovery from laterite nickel ore, an improved understanding of the solubility in ternary MgCl2–NiCl2–H2O systems is required. Herein, the stable phase equilibria in a ternary MgCl2–NiCl2–H2O system at 303, 313, and 323 K were studied using an isothermal dissolution equilibrium method. For this ternary system, the solubility and density were measured at different temperatures. The equilibrium solid phases were identified using X-ray diffraction, combined with the Schreinemakers’ method for wet residues. Based on the solubility data, the phase diagrams of the MgCl2–NiCl2–H2O system at 303, 313, and 323 K were plotted. At all investigated temperatures, the phase diagrams of this ternary system presented an invariant point, two isothermal dissolution curves, and three crystallization regions. Neither double salt nor solid solution was produced. The Mixed Solvent Electrolyte (MSE) model was applied to calculate the solubility for this ternary system. According to the comparison of phase diagram, the calculated data were in good agreement with the experimental values.

Production of value-added peptides from agro-industrial residues by solid-state fermentation with a new thermophilic protease-producing strain

This work aimed to explore an effective way for converting agro-industrial residues into value-added products. A thermophilic protease-producing strain was isolated from soybean meal (SBM) and identified as Bacillus licheniformis by 16S rDNA sequencing. After incubating Bacillus licheniformis CPB2 in casein medium for 24 h, the protease activity, peptide yield, and protein conversion rate of the culture could reach 8.87 ± 0.33 U/mL, 68.58%, and 82.27%, respectively. Brewer's spent grain (BSG) and SBM were used as co-substrates to produce value-added peptides through thermophilic solid-state fermentation (TSSF) with Bacillus licheniformis CPB2. The peptide content of the co-substrates increased from 25.71 mg/g to 112.72 mg/g under the optimal TSSF conditions. The fermented products showed an increased crude protein and free amino acids contents and a decreased crude fat and ash contents as well as trypsin inhibitor activity compared with the unfermented co-substrates. TSSF could degrade macromolecular proteins into peptides, unfold the protein aggregates, and reduce the particle size. Industrial relevanceThis work proposed an effective way for the rational and efficient utilization of wet and dry agro-industrial residues to produce value-added products, which showed a broad potential for reducing production costs, saving water resources and energy, and preserving the ecological environment.

Оцінка біоенергетичного потенціалу АПК для забезпечення енергетичної незалежності галузі

The purpose of the study is to assess the bioenergy potential of the agro-industrial complex of Ukraine to ensure the energy independence of the industry. The article analyzes the structure of the world-wide supply of primary energy and determines the share of renewable energy sources (hereinafter – RES) in this structure. The expediency of using biomass for the development of bioenergy in Ukraine is substantiated. The classification of the main sources of biomass for energy production is characterized, which, first of all, include primary wood, agricultural waste (dry and wet residues), energy plants, food and industrial waste. The formation of primary agricultural waste in Ukraine is studied, starting from the gross harvest of the main crops and waste coefficients. The theoretical bioenergy potential of primary crop waste in Ukraine in terms of equivalent fuel based on the heat of combustion of waste from the corresponding crops is calculated. The technical bioenergy potential of crop waste has been determined using the coefficients of technical accessibility, the basis of which is the existing technologies for the collection and processing of agricultural waste into energy. An assessment of the economic potential of crop waste for energy production is carried out, the computed technical potential of crop waste and the coefficient of energy use of waste have been taken as the basis for the calculation. According to the results of the study, it is concluded that in Ukraine, the primary waste of such crops as corn for grain, sunflower, wheat, rapeseed and soybeans has the greatest potential for use for energy purposes. The main barriers that hinder the development of bioenergy in Ukraine and slow down the pace of achieving energy independence of the agro-industrial complex are identified. The main ways to overcome the identified barriers are proposed, which should stimulate the use of the bioenergy potential of the agro-industrial complex of Ukraine.

Morphological aspects of rumen papillae of lambs fed agro-industrial wastes.

Sheep meet production systems require roughage feed of good nutritional quality. However, the production of sorghum or corn silage, besides expensive, also depends on large cultivable areas and favorable weather conditions. Thus, agro-industrial residues have stood out as a feed alternative that contribute to the reduction of production costs and to the conservation of the environment. Fragments of the ruminal mucosa of 30 healthy lambs fed with agro-industrial residues and slaughtered with a final weight of 36 kg were analyzed by light and scanning electron microscopy. We observed that the coproducts grape residue and wet brewery residue affected the shape, dimensions, and cytoarchitecture of the rumen epithelium in contrast to traditional sorghum silage. The rumen papillae of lambs fed grape waste were larger, and their epithelium was thinner when compared to the papillae of lambs fed wet brewery waste and sorghum silage. It can be assumed that the increased mucosal surface area of the rumen contributed to greater weight gain and reduced time to slaughter. The use of a greater variety of agro-industrial residues as a substitute for traditional feedstuffs contributes to the increase in animal protein production in many countries, making the confinement of sheep more viable and sustainable.

Holistic exploitation of pulsed electric field (PEF)-treated and lipid extracted microalgae Auxenochlorella protothecoides, utilizing anaerobic digestion (AD)

This study proposes a cascade processing of the lipid-rich microalgae Auxenochlorella protothecoides. Freshly harvested biomass is pre-concentrated to 100 g/kgsusp and then pretreated using pulsed electric fields (PEF). PEF-treatment, which affects permeability of cells membrane, induces a spontaneous release of microalgal ingredients into the surrounding medium, mostly carbohydrates and micronutrients, which can be recovered. After separation of this aqueous fraction, lipid extraction is performed on the remaining wet pellet using an ethanol-hexane blend. After recovery of those different valuables, it was considered, to convert the rest biomass (cell envelope and most of the other remaining hard- or non-extractable components), to storable energy. Anaerobic digestion (AD) of the remains to biogas was considered to be a promising solution. AD-processes have the charm that unprocessed wet microalgal biomass, as well as wet organic biomass residues from previous extraction steps can be utilized directly without further purification or drying steps. The obtained biogas can then be upgraded to methane for an energetic use.PEF-treated algal biomass showed a 10 % increased methane outcome (467 mLnorm/gVS) compared to the untreated sample. PEF-treated microalgae, subjected to extraction of the aqueous fraction, demonstrated a 23 % increase in methane yield (558 mLnorm/gVS), compared to control. Finally, the biomass, PEF-treated and subjected to extraction of water fraction and lipids, still achieved 41 % of methane potential (205 mLnorm/gVS) during the AD process, compared to the untreated control.Our study demonstrates the feasibility of cascade processing using PEF-treatment. Moreover, all the study was developed keeping in mind industrial requirements. In particular, our downstream approach did not require any drying, the pretreatment required low amount of energy, i.e. 1.5 MJ/kgCDW and the majority of the biomass was valorized. Since all techniques used, especially PEF-pretreatment, can be up-scaled, we believe this approach has great potential for implementation in industry.

One-step natural pyrite-assisted mechanochemical detoxification of Cr(VI) in soda ash Chromite Ore Processing Residue: Effectiveness, mechanisms, and life cycle analysis

Traditional wet and dry Chromite Ore Processing Residue (COPR) detoxification methods consume acid for pH adjustment and produce greenhouse gasses (CO2), yielding potential secondary pollution. It is imperative to develop an environmentally-friendly, efficient, and effective method for COPR treatment. This study reported the one-step natural pyrite-assisted mechanochemical detoxification of Cr(VI) in COPR. Under optimal conditions (i.e., the pyrite/COPR mass ratio of 5% and mechanochemical treatment at 600 rev./min for 2.5 h), Cr(VI) in COPR was efficiently reduced and immobilized, and the leaching concentration of total Cr met the regulatory limit of 5 mg/L. The X-ray absorption near-edge structure (XANES) analysis further verified that the Cr(VI) in treated COPR was 100% reduced to Cr(III). Potential mechanism could be that the enclosed non-exchangeable Cr(VI) in the chromite matrix was exposed to the COPR particle surface under the mechanical action; then, the redox reaction between pyrite and Cr(VI) were induced and enhanced through accumulated crystal defects and generated new surfaces with dangling bonds under mechanical forces. Life cycle assessment (LCA) results highlight that the high energy input is the major contributor eliciting environmental impacts for this current technology. More efficient and cleaner energy supplies should be sought alternatively to overcome the overall sustainability.

Phase equilibria in the ternary systems LiCl–LiBr–H2O and LiCl–LiBr–CH3OH at 298 K

Oil gas field brine is a dominant liquid mineral resource in Sichuan Basin, and its rational development and utilization is of great significance to the national economy. In order to explore the physicochemical properties of brine and provide theoretical guidance for the comprehensive utilization of brine, the isothermal solubilities of the ternary systems LiCl − LiBr − H2O and LiCl − LiBr − CH3OH at 298 K were determined by employing the isothermal dissolution equilibrium method. Based on the measured composition of the liquid phase, wet solid phase and equilibrium solid phase, isothermal phase diagrams of the two systems at 298 K were drawn. The results show that according to the phase diagram of the ternary system LiCl − LiBr − H2O at 298 K, there is no single salt and double salt formation, but the crystalline region precipitated by the solid solution occupies all the crystalline space. The phase region is divided by a solubility boundary line into two parts, namely the liquid phase unsaturated region located below the isotherm and the completely mutually soluble solid solution crystallization region above it. Therefore, the two single salts LiCl and LiBr could not be successfully separated with the guidance of this phase diagram. The ternary system LiCl − LiBr − CH3OH at 298 K has single salt and solid solution formed, but no double salt determined. The phase diagram of the ternary system LiCl − LiBr − CH3OH consists of an invariant point, two isothermal solubility lines, and two crystallization regions precipitated with Li(Cl, Br) and LiCl, respectively. Using the phase diagram as a guiding tool for phase separation, LiCl can be acquired by crystallization and filtration operations, but it cannot be achieved for LiBr. In this work, a combination of wet residue method and XRD is used to identify the equilibrium solid phase. Selecting the particle swarm optimization algorithm, the solubility predictions of the ternary systems LiCl − LiBr − H2O and LiCl − LiBr − CH3OH at 298 K were achieved through the well-established Pitzer model. The solubility simulation results satisfactorily matched with the experimental values, indicating that the parameters selected for the simulation have strong applicability.

Techno-Economic Analysis for Direct Processing of Wet Solid Residues Originated from Grain and Inedible Plant Wastes.

Large number of solid wastes is produced from ethanol and wine plants sourcing from grain and inedible plant wastes, for example, WDGS (wet distiller’s grain with soluble) and DDGS (dry distiller’s grain with soluble) produced from ethanol plants using corn. This study investigates alternative methods for using these co-products through combustion and anaerobic digestion. Process simulation and economic analysis were conducted using current market prices to evaluate the viability of the processes. Products in the form of energy are produced. Optimization of the corn ethanol plant was also explored for re-using the heat and electricity produced in those processes. These processes will supply more viable options to utilisation of those wastes. The anaerobic digestion of WDGS to produce electricity scenario was found to have the biggest profit among the four scenarios which can bring the annual income of 14.1 million Australian dollar to the ethanol plant. An environmental analysis of the CO2 emissions was also conducted. Using the Australian state emission factor, the amount of CO2 offset through both combustion and anaerobic digestion can be seen. The anaerobic digestion of WDGS to supply heat to the plant was proved having the largest CO2 abatement with the value of 0.58 kg-CO2e/L-EtOH.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12155-022-10501-6.