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Hydrothermal liquefaction (HTL) is a thermochemical conversion technology that produces bio-oil from wet biomass without drying. However, by-product gases will inevitably be produced, and their formation is unclear. Therefore, an automated machine learning (AutoML) approach, automatically training without human intervention, was used to aid in predicting gaseous production and interpreting the formation mechanisms of four gases (CO 2 , CH 4 , CO, and H 2 ). Specifically, four accurate optimal single-target models based on AutoML were developed with elemental compositions and HTL conditions as inputs for four gases. Herein, the gradient boosting machine (GBM) performed excellently with train R 2  ≥ 0.99 and test R 2  ≥ 0.80. Then, the screened GBM algorithm-based ML multi-target models (maximum average test R 2  = 0.89 and RMSE = 0.39) were built to predict four gases simultaneously. Results indicated that biomass carbon, solid content, pressure, and biomass hydrogen were the top four factors for gas production from HTL of biomass. This study proposed an AutoML-aided prediction and interpretation framework, which could provide new insight for rapid prediction and revelation of gaseous compositions from the HTL process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A series of hydrothermal liquefaction (HTL) experiments with two different samples of municipal sewage sludge (MSS) were conducted at 350 °C for 30 min residence time in a high pressure batch reactor. The main aim of the study was to explore the distribution and migration pathways of a broad range of metals and metalloids in the HTL products (bio-oil, char and aqueous phase) obtained in the presence of various homogeneous and heterogeneous catalysts (Na 2 CO 3 , Li 2 CO 3 , K 2 CO 3 , Ba(OH) 2 , Fe 2 O 3 , CeO 2 , NiMo/MoO 3 , MoS 2 , Ni/NiO, SnO 2 , FeS). The elements under study included 16 environmentally significant metals and metalloids (As, B, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Sn, Zn and Hg). The study showed that the quantitative migration of the tested metals and metalloids to the particular HTL products, relative to their initial content in the raw sludge, is different for the individual elements. Most metals exhibited a particularly strong affinity to the solid fraction (biochar). In the obtained HTL bio-oils, all tested elements were identified, except of Cd. It was also found that B and As have high affinity to the aqueous phase. A direct effect of catalysts on the contents of some elements in the products was also proved by the study, e.g. increased concentration of Cr in the biochar when Fe 2 O 3 was used as a process catalyst. Due to the wide scope of the tested elements and broad range of catalyst used, the results obtained represent a unique and comprehensive set of environmental data compared to similar HTL studies previously conducted for MSS., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Hydrothermal liquefaction (HTL) is an effective medium-temperature, high-pressure thermochemical process to dispose municipal sludge (MS), and biocrude (a crude bio-oil) is its main product. Many efforts are continued extensively to improve conversion efficiency and to promote industrial application of this technology. This work focuses on critical influencing factors (e.g., reaction temperature, residence time, atmosphere, solvent, catalyst, and pretreatment) and fundamental transformation mechanisms of main components (i.e., lipids, proteins, and carbohydrates) in MS HTL. It also analyzes migration behavior of heavy metals during MS HTL, which can provide a reference for subsequent recovery of nutrients from HTL products. Moreover, the applications of MS HTL products are systematically expounded, and potential challenges and opportunities are highlighted as well. It is necessary to develop advanced methods of catalyst recovery and innovative biocrude upgrading methods so as to reduce HTL investment and operating costs. Reusing aqueous phase and solid phase products as reaction medium and catalyst carrier separately after MS HTL is feasible to realize resource utilization of MS. This information can provide valuable guidance to promote MS HTL industrialization., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Nitrogen (N) in sewage sludge (SS) should be reduced if it is to be used to produce clean solid fuels. However, the N transformation during hydrothermal carbonization (HTC) of SS is not yet fully understood. Since the composition of SS is complex, it is wise to study a model compound, which should have typical functional groups of organic components. Hence, in this study, six model components (protein, lipid, cellulose, hemicellulose, humic acid, and lignin) representing the main organic components in SS were mixed with SS and treated at 150-270 °C for 1 h. The influence of the organic component and reaction temperature on hydrochar yield, hydrochar characterization, and N distribution in the products was investigated. Except for proteins and lipids, all the other components were found to contribute to the N content and aromatization of the hydrochar. Humus shows the best comprehensive performance in terms of both reducing the N content and increasing the aromaticity. The strongest effects of hemicellulose and cellulose on N retention in hydrochar are found to occur at 210 °C and 240 °C, respectively. The N retention caused by lignin is correlated with the Mannich reaction at 240 °C, while humus significantly promotes N transformation at 240 °C. For carbohydrates, lignin, and humus, the temperatures required for increasing the N content and aromaticity maintain a high degree of consistency. Although protein pulls down the energy recovery (ER) and yield of the hydrochar, observations indicate that it favors the carbonization process. This finding can be used for estimating the N content and quality of hydrochar and provides references for future research targeting the upgrading of hydrochar., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

The objective of the study was to investigate the effect of dietary supplementation with nettle or fenugreek on folliculogenesis and steroidogenesis in the juvenile rabbit ovary. To gain insight into the mechanism of action of these herbs, we examined follicle formation, ovarian cell proliferation and apoptosis, steroidogenic enzyme abundance and steroid concentrations in ovarian tissue and plasma. Animals were fed with control, 1% nettle- or 1% fenugreek-supplemented pellets from 5 to 12 weeks of age (n = 10 per each group), when animals were slaughtered for ovary and blood collection. The addition of nettle decreased the numbers of primordial (P = 0.015) and early antral (P = 0.02) follicles and increased the number of primary (P = 0.04) ones when compared with the control group. Following fenugreek supplementation, the numbers of primary (P = 0.008) and antral (P = 0.027) follicles were greater, while the number of early antral (P = 0.003) follicles was lower in comparison with the control group. Nettle revealed apoptotic activity through activation of caspases 9 (P = 0.047), 8 (P = 0.022) and 3 (P = 0.004), whereas fenugreek increased (P = 0.042) follicular cell proliferation marked by PCNA protein abundance. Furthermore, only fenugreek targeted steroidogenic enzymes, decreasing CYP17A1 (P = 0.043) and increasing CYP19A1 (P = 0.048) protein abundances that resulted in enhanced estradiol biosynthesis and its elevated (P = 0.006) plasma concentration. In conclusion, both herbs affected follicle development in the rabbit ovary in a stage specific manner. Additionally, fenugreek altered ovarian steroidogenesis in a way that might affect sexual maturation in rabbits., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

The aim of the study was to investigate the sorption interactions between phenol and materials obtained from four different underground coal gasification (UCG) ex-situ simulations. These interactions are significant in terms of the impact of the UCG on the groundwater environment. Sorption parameters were determined for two sample types: raw coal mined from the coal-bed and then subjected to the gasification process; and char residue acquired from the cavity formed as a result of the UCG processes. Laboratory-scale tests were carried out using deionized water and aqueous solutions with increasing concentrations of phenol (from 50 mg/dm 3 to 2000 mg/dm 3 ) at 298 K. On the assumption of physical interactions (non-specific physisorption) and due to a nonlinear mass distribution of adsorbed substances as a function of equilibrium concentration, the Freundlich isotherm model was applied to describe adsorption phenomena. The isotherms have good fitting (R 2 from 0.5716 to 0.9811). Relatively high percentage phenol removal efficiency was observed for all tested chars (from 17.0% to 99.8% for the 1.0-2.5 mm fraction and from 6.9% to 99.6% for the 10.0-12.5 mm fraction). Additionally, the sorption characteristics was used to evaluate the retardation coefficients. The largest delay in the organic pollutant migration in the environment around a UCG reactor occurs for phenol transport in the layer of the post-process char from 'Wesoła' after 40 bar pressure experiment., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

The effect of coal rank on the composition and toxicity of water effluents resulting from two underground coal gasification experiments with distinct coal samples (lignite and hard coal) was investigated. A broad range of organic and inorganic parameters was determined in the sampled condensates. The physicochemical tests were supplemented by toxicity bioassays based on the luminescent bacteria Vibrio fischeri as the test organism. The principal component analysis and Pearson correlation analysis were adopted to assist in the interpretation of the raw experimental data, and the multiple regression statistical method was subsequently employed to enable predictions of the toxicity based on the values of the selected parameters. Significant differences in the qualitative and quantitative description of the contamination profiles were identified for both types of coal under study. Independent of the coal rank, the most characteristic organic components of the studied condensates were phenols, naphthalene and benzene. In the inorganic array, ammonia, sulphates and selected heavy metals and metalloids were identified as the dominant constituents. Except for benzene with its alkyl homologues (BTEX), selected polycyclic aromatic hydrocarbons (PAHs), zinc and selenium, the values of the remaining parameters were considerably greater for the hard coal condensates. The studies revealed that all of the tested UCG condensates were extremely toxic to V. fischeri; however, the average toxicity level for the hard coal condensates was approximately 56% higher than that obtained for the lignite. The statistical analysis provided results supporting that the toxicity of the condensates was most positively correlated with the concentrations of free ammonia, phenols and certain heavy metals., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Concentrations of cadmium and lead were measured in liver and kidneys of Mallard (n=60) and Coot (n=50). Free living birds were collected by hunters in years 2006-2008 in the area of fishponds near Zator in southern Poland. Age group was determined according to the appearance of the plumage (Mallards) and iris color (Coot). Concentrations of metals were measured with ET-AA spectrometer. Among all birds specimens with negligible (n=5) and high concentrations (Mallards n=18 and Coots n=17) of cadmium and lead were chosen for further analysis. Histopathological alterations were observed, ranging from circulatory disturbances, retrogressive changes, inflammations to leukocytic infiltration in liver and kidney. They dominated among birds with the highest concentrations of metals. The control group of birds was characterized by a very small number of mentioned lesions. Probably the higher cadmium and lead concentrations in tissues are co-factors in the development of lesions., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Bank voles were trapped in the neighborhood of the Sendzimir steelworks in Krakow and the ZGH Boleslaw zinc smelter in Bukowno. The Borecka forest in the north of Poland served as a control area. Lead, cadmium, zinc, and iron concentrations were analyzed in the liver, kidneys, testes, and femur bones of the bank voles. Typically, high levels of lead and cadmium were found in the bones and kidneys, respectively. In the femurs of the rodents from Bukowno, 109.26 microg g(-1) dry weight of lead was detected. The kidneys of these animals had accumulated 32.98 microg g(-1) cadmium. Concentrations of zinc and iron in the tissues were at physiological levels. No damage was found in the tissues of the bank voles from the Borecka forest or in the testes of animals from other areas. Histopathological changes in the kidneys of the rodents from Krakow as well as changes to the liver and kidneys of the animals from Bukowno were demonstrated.

The influence of the steelworks in Warsaw and Krakow as well as the zinc smelters in Bukowno and Miasteczko Slaskie on lead, cadmium, zinc and iron concentrations and the structure of selected tissues of yellow-necked mice were analysed. The Borecka Forest was chosen as a control area. The highest concentrations of lead, 172.36 g/g dry weight, and cadmium, 23.58 g/g, were detected in the femurs and kidneys, respectively, of rodents caught in Bukowno. Zinc and iron concentrations ranged over physiological values. No histopathological changes were observed in analysed tissues of all rodents in the control area. Damage occurred in the liver and kidneys of animals from all other sites and in the testes of rodents from Bukowno. Decreased glycogen content, interstitial fibrosis, and increased number of pyknotic nuclei as well as necrosis were seen in hepatocytes. In the kidneys hyperplasia of the tubules, atrophy of glomeruli, interstitial fibrosis and necrosis were observed. Degenerate cells were present in the lumen of seminiferous tubules of animals from the Bukowno area. Even relatively low concentrations of lead and cadmium, like those found in the liver and kidneys of rodents from the neighbourhood of the steelworks, caused histopathological changes.

Cadmium is one of many metals that are not physiologically or biochemically essential to organisms. This element is extremely dangerous as it is easily absorbed and remains in tissues for a long time. Long exposure to high doses of cadmium may cause biochemical and functional changes in some critical organs. In this study, wheat grains contaminated with cadmium chloride were used to test the influence of cadmium on male bank voles (Clethrionomys glareolus). Doses used in the experiment were environmentally realistic: 0.25 microg g-1 (control), 15 microg g-1, and 40 microg g-1 cadmium (dry weight). The animals were given cadmium-contaminated food and clean water ad libitum for 3 and 6 months. After these exposures, the animals were killed and the kidneys, liver, and testes from each vole were collected for analyses. The concentrations of Cd, Cu, Zn, and Fe in the tissues were determined with an atomic absorption spectrophotometer. The formalin-fixed testes, kidneys, and part of the liver were embedded in paraffin and then stained with hematoxylin and eosin. Cadmium accumulation in the tissues was directly proportional to dose. The highest cadmium concentrations were found in the kidneys of animals fed the highest dose of cadmium. Histological examination of the tissues revealed some pathological changes in the structure of kidneys, liver, and testes., (Copyright 1998 Academic Press.)