Formation and Transformation of Typical Pollutant from MSW by Hydrothermal Carbonization towards Biofuel Hydrochar Production

An unprecedented increase in municipal solid waste (MSW) is increasingly attractive in response to waste-to-energy. MSW pretreatment is an essential step due to the inherent properties of MSW. Hydrothermal carbonization (HTC) offers an efficient approach for converting MSW into carbonaceous hydrochars. In this chapter, the formation and transformation of heavy metals and polycyclic aromatic hydrocarbons (PAHs) during HTC of MSW were determined. The results indicated that HTC can homogenize the density and size of MSW and also increase carbon content. Moreover, the concentrations of heavy metals in the leachates of the hydrochars were lower than the United States Environmental Protection Agency (US EPA) maximum limits. Compared to MSW, the concentrations of Cr, Cd, Hg, and Zn in the hydrochars were low and the concentrations of Pb, As, Ni, and Cu were high. The concentrations of PAHs in the hydrochars increased with increasing temperature in the range of 1298.71–177698.20 μg/kg, which were much higher than that in MSW, except for H-160. The dominant PAH rings in MSW and the hydrochars were four-ring PAHs and three-ring PAHs, respectively. These findings suggest that 180°C is an appropriate hydrothermal temperature to reduce heavy metals and the toxicity PAHs of MSW

Data-driven assessment of immune evasion and dynamic Zero-COVID policy on fast-spreading Omicron in Changchun

Due to its immune evasion capability, the SARS-CoV-2 Omicron variant was declared a variant of concern by the World Health Organization. The spread of Omicron in Changchun (i.e., the capital of Jilin province in northeast of China) during the spring of 2022 was successfully curbed under the strategy of a dynamic Zero-COVID policy. To evaluate the impact of immune evasion on vaccination and other measures, and to understand how the dynamic Zero-COVID measure stopped the epidemics in Changchun, we establish a compartmental model over different stages and parameterized the model with actual reported data. The model simulation firstly shows a reasonably good fit between our model prediction and the data. Second, we estimate the testing rate in the early stage of the outbreak to reveal the real infection size. Third, numerical simulations show that the coverage of vaccine immunization in Changchun and the regular nucleic acid testing could not stop the epidemic, while the 'non-pharmaceutical' intervention measures utilized in the dynamic Zero-COVID policy could play significant roles in the containment of Omicron. Based on the parameterized model, numerical analysis demonstrates that if one wants to achieve epidemic control by fully utilizing the effect of 'dynamic Zero-COVID' measures, therefore social activities are restricted to the minimum level, and then the economic development may come to a halt. The insight analysis in this work could provide reference for infectious disease prevention and control measures in the future

Epigenetic Repression of RARRES1 Is Mediated by Methylation of a Proximal Promoter and a Loss of CTCF Binding

The cis-acting promoter element responsible for epigenetic silencing of retinoic acid receptor responder 1 (RARRES1) by methylation is unclear. Likewise, how aberrant methylation interplays effectors and thus affects breast neoplastic features remains largely unknown.We first compared methylation occurring at the sequences (-664~+420) flanking the RARRES1 promoter in primary breast carcinomas to that in adjacent benign tissues. Surprisingly, tumor cores displayed significantly elevated methylation occurring solely at the upstream region (-664~-86), while the downstream element (-85~+420) proximal to the transcriptional start site (+1) remained largely unchanged. Yet, hypermethylation at the former did not result in appreciable silencing effect. In contrast, the proximal sequence displayed full promoter activity and methylation of which remarkably silenced RARRES1 transcription. This phenomenon was recapitulated in breast cancer cell lines, in which methylation at the proximal region strikingly coincided with downregulation. We also discovered that CTCF occupancy was enriched at the unmethylayed promoter bound with transcription-active histone markings. Furthermore, knocking-down CTCF expression hampered RARRES1 expression, suggesting CTCF positively regulated RARRES1 transcription presumably by binding to unmethylated promoter poised at transcription-ready state. Moreover, RARRES1 restoration not only impeded cell invasion but also promoted death induced by chemotherapeutic agents, denoting its tumor suppressive effect. Its role of attenuating invasion agreed with data generated from clinical specimens revealing that RARRES1 was generally downregulated in metastatic lymph nodes compared to the tumor cores.This report delineated silencing of RARRES1 by hypermethylation is occurring at a proximal promoter element and is associated with a loss of binding to CTCF, an activator for RARRES1 expression. We also revealed the tumor suppressive roles exerted by RARRES1 in part by promoting breast epithelial cell death and by impeding cell invasion that is an important property for metastatic spread

The Surface Defects Detection of Citrus on Trees Based on a Support Vector Machine

Machine learning and image processing have been combined to identify and detect defects in mature citrus fruit at night, which has great research and development significance. First, a multi-light vision system was used to collect citrus UV images, and from these, 1500 samples were obtained, 80% of which were training and 20% were experimental sets. For a support vector machine (SVM) model with “2*Cb-Cr”, “4*a-b-l”, and “H” as the training features, the accuracy of the final training model in the experimental set is 99.67%. Then, the SVM model was used to identify mature citrus regions, detect defects, and output the defective citrus regions label. The average running time of the detection algorithm was 0.84097 s, the accuracy of citrus region detection was 95.32%, the accuracy of citrus defect detection was 96.32%, the precision was 95.24%, and the recall rate was 87.91%. The results show that the algorithm had suitable accuracy and real-time performance in recognition and defect detection in citrus in a natural environment at night

Combustion behavior and kinetics of low-lipid microalgae via thermogravimetric analysis

10.1016/j.biortech.2015.01.045Bioresource Technology181148-15

Emission, distribution and toxicity of polycyclic aromatic hydrocarbons (PAHs) during municipal solid waste (MSW) and coal co-combustion

Emission and distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) were investigated during municipal solid waste (MSW) and coal combustion alone and MSW/coal blend (MSW weight fraction of 25%) co-combustion within a temperature range of 500 degrees C-900 degrees C. The results showed that for all combustion experiments, flue gas occupied the highest proportion of total PAHs and fly ash contained more high-ring PAHs. Moreover, the 3- and 4-ring PAHs accounted for the majority of total PAHs and Ant or Phe had the highest concentrations. Compared to coal, MSW combustion generated high levels of total PAHs with the range of 111.28 mu g/g-10,047.22 mu g/g and had high toxicity equivalent value (TEQ). MSW/coal co-combustion generated the smallest amounts of total PAHs and had the lowest TEQ than MSW and coal combustion alone. Significant synergistic interactions occurred between MSW and coal during co-combustion and the interactions suppressed the formation of PAHs, especially hazardous high-ring PAHs and decreased the TEQ. The present study indicated that the reduction of the yield and toxicity of PAHs can be achieved by co-combustion of MSWand coal. (C) 2016 Elsevier B.V. All rights reserved

Co-liquefaction of microalgae and lignocellulosic biomass in subcritical water

This study investigated co-liquefaction of microalgae (Chlorella pyrenoidosa, CP) and lignocellulosic biomass (Rice husk, RH) in subcritical water for bio-oil production. The effects of liquefaction temperature (200-350 degrees C), residence time (10-90 min), solid concentration (10-30 wt.%) and mass ratio of CP/RH on product distribution were investigated. The results showed that the highest yield of bio-crude oils at the combination of 50% CP with 50% RH was obtained at 300 degrees C temperature, 60 min residence time and 20 wt.% solid concentration. The oil yields increased gradually with the increased mass ratio of CP/RH. The major compounds identified in bio-crude oils from hydrothermal liquefaction (HTL) of RH were cyclic oxygenates (20.62%), followed by esters, ketones and alcohols (17.19%). As for CP, the main components were straight & branched amides (28.38%). A synergistic interaction was observed between CP and RH during co-liquefaction, resulting in decreased acidity and nitrogen content of bio-crude oils. (C) 2015 Elsevier Ltd. All rights reserved

Quantitative trait loci controlling amino acid contents in wheat (Triticum aestivum L.)

Abstract Quantitative trait locus/loci (QTL) for amino acid content (AAC), 17 individual amino acid and total amino acid (TAA) contents of wheat were studied using a doubled haploid (DH) population containing 168 progeny lines derived from a cross between 'Huapei 3' and 'Yumai 57', Chinese bread wheat cultivars. The inclusive composite interval mapping (ICIM) was applied on wheat meals from 2008 and 2009 in Shandong province, China using QTL IciMapping 2.2. The results indicated that total 32 QTL were detected in wheat meals from 2008, contributing to 4.86-30.95% of total phenotypic variation. Total 53 QTL, accounting for 4.39-23.87% of total phenotypic variance, were detected in wheat meals from 2009. Most QTL were co-localized, forming 13 QTL clusters in two cropping seasons, whereas 4 QTL clusters were coincident in two years. Especially, the loci near marker Xbarc86 on chromosome 3A detected in both years influenced 13 amino acids, and also controlled protein and wet gluten contents, which could be used for marker for protein and amino acids contents

Polycyclic Aromatic Hydrocarbons and Toxic Heavy Metals in Municipal Solid Waste and Corresponding Hydrochars

Hydrothermal carbonization (HTC) is an effective pretreatment technology for converting municipal solid waste (MSW) into homogenized, energy-dense, and carbon-rich hydrochars with low energy consumption. In this study, heavy metals and free polycyclic aromatic hydrocarbons (PAHs) in MSW and corresponding hydrochars were investigated. The results showed that the hydrochar yield decreased with an increasing temperature from 160 to 260 degrees C. Heavy metal contents, including Cr, Cd, Hg, and Zn, in the hydrochars were lower than those in MSW, while Pb, As, Ni, and Cu showed an accumulation in the hydrochars at most temperatures. In addition, the Toxicity Characteristic Leaching Procedure test showed that the contents of heavy metals in leachates were all lower than the United States Environmental Protection Agency (U.S. EPA) limits. With regard to PAHs, total free PAH contents in the hydrochars were higher than those of MSW, except for the hydrochar obtained at 160 degrees C. The total PAHs in the hydrochar increased with the increase of the temperature from 160 to 240 degrees C and then significantly decreased with further increasing the temperature. The three-ring PAHs were dominant in the hydrochars, while for MSW, PAHs were mainly up to four-ring PAHs. The toxic equivalent quantity values of the hydrochars were higher than those Of MSW, except for the hydrochars obtained at 160 and 180 degrees C. The present study indicated that the significant reduction of heavy metals and PAHs in MSW could be achieved by HTC of MSW.</p