ENERGY
·
2024
·
IF 9
Xixi Lian,Shuxiao Wang,Rui Shan,Jing Gu,Che Zhao,Wei Zhao,Haoran Yuan,Yong Chen
Thermal conversion technology is an effective means to transform waste plastics into high-value-added products. This study explored the thermal decomposition characteristics and cracking mechanism of four different types of plastics (polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)) for thermal conversion technology. The findings revealed that PP exhibited the highest hydrogen yield, reaching 3.56 mmol/g at 510°C. PET's gas production was predominantly comprised of carbon monoxide and carbon dioxide. PVC gas products contained a significant amount of HCl, followed by hydrogen and methane. For solid products, the carbon yield followed the order PET > PVC > PS > PP, with the carbon content of PET accounting for 35.63% of the total products. PP and PS demonstrated higher oil yields for liquid products than PET and PVC. The oil yield of PP was 94.38%. Further analysis of the cracking mechanism found that during the thermal decomposition process, plastics underwent random fragmentation, leading to reactions such as β-scission, intramolecular and intermolecular hydrogen transfer, rearrangement, cyclization, etc., due to structural variations. This work provided foundational data for the thermal decomposition studies of different types of plastics.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2016
·
IF 5.991
Guilin He,Cong Li,Feilong Dong,Tuqiao Zhang,Long Chen,Leslie Cizmas,Virender K. Sharma
The degradation and transformation products of 17β-estradiol (E2) by chloramines in a pilot-scale water distribution system (WDS) were investigated using varying conditions including multiple mass ratios of chlorine to nitrogen (Cl/N), changing concentrations of chloramines, and different pH and pipe materials. The degradation of E2 was complete in ≤9 h in both deionized water (DW) and in the WDS under studied conditions. When the degradation rate of E2 was compared in WDS and DW, the degradation rate was appreciably greater in the WDS than in the DW at Cl/N mass ratios of 3, 4 and 6. However, at Cl/N mass ratios of 8 and 9, degradation was faster in the DW than in the WDS. The degradation rate of E2 was greatly affected by the initial total chloramine concentration, and the degradation of E2 in DW was consistent with second-order kinetics. The degradation rate of E2 in both the DW and the WDS increased with increasing pH. The order of degradation rate of E2in different pipes was: ductile iron loop (loop A) > polyethylene (PE) loop (loop B)> stainless steel loop (loop C). Ten specific degradation products of E2, produced by chloramination, were identified. Most of the degradation products of E2 chloramination were stable for more than 10 h. The degradation pathways of E2 in the WDS are proposed and briefly discussed. The concentrations of trihalomethanes (THMs), haloacetic acids (HAAs), and halogenated nitromethane (HNMs) during the degradation E2 in WDS were also determined.
研究领域:
环境科学
·
化学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 123
·101416-101426
·
IF 3.84
Lin-Lin Liu,Guo-Qiang He,Ying-Hong Wang,Song-Qi Hu
A facility was designed to collect the primary combustion products of boron-based fuel-rich propellants under different chamber pressures. The morphology and particle size of condensed-phase products were analyzed using a laser particle size analyzer and a scanning electron microscope (SEM), and chemical analysis of condensed-phase products was carried out by X-ray diffraction (XRD), laser Raman spectrometry, wet chemical analysis and elemental analysis. In addition, organics in condensed-phase products and gaseous products were analyzed by Fourier Transform Infrared Spectrometry (FTIR) and Gas Chromatography (GC), respectively. The results show that the condensed-phase products mainly consist of B, C, B4C (or B12C2), BN, Mg, MgO, MgAl2O4, Al, Al2O3, AlCl3, NH4[Mg(H2O)6]Cl3, NH4Cl and Fe3O4; there are large amounts of boron oxide and boron carbide in the condensed-phase products, which indicates that elemental boron is highly active during the primary combustion process; a higher chamber pressure may be disadvantageous to the secondary combustion efficiency because more inactive boron carbide, graphite and h-BN (especially boron carbide) are produced.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
ACS ES&T Water
·
2025
·
IF 4.3
Yu Zhang,Yuan Zhuang,Yuhao Liu,Baoyou Shi
In the drinking water pipeline, PO43– and iron particles will inevitably coexist, but their effects on water quality are not fully clear. Here, PO43– was shown to inhibit the formation of disinfection byproducts (DBPs) in ductile cast iron pipe (decreases of 8.7%–29.8%). The inhibition effects were proved to be related to particle structure changes induced by PO43–. The PO43– influenced particles had lower roughness, smaller particle size, and a larger amount of negative charge. In the beaker without iron, the concentration of PO43– remained nearly consistent with the initial concentration, oscillating around 1.5 mg/L, whereas the PO43– concentration in the group containing Fe(II) exhibited a notable decline, reaching 1.28 mg/L. Thus, PO43– did not play a direct role in the formation of DBPs, but modulated the physicochemical behavior of water and the characteristics of particles. Therefore, when iron corrosion occurs in drinking water distribution systems (DWDSs), PO43– has the ability to inhibit the formation of DBPs, but other water quality issues should be considered at the same time. This study not only explains how PO43– affects the formation of DBPs in DWDSs, but also provides new thinking on how to control the risk of DBP exposure in DWDSs, which is worthy of further research.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Shunke Ding,Yang Deng,Hongwei Li,Chao Fang,Naiyun Gao,Wenhai Chu
Iodinated disinfection byproducts (I-DBPs) are of particular concern in drinking water due to the more cytotoxic and genotoxic properties than their chlorinated and brominated analogs. Formation of I-DBP primarily results from the oxidation of iodide-containing waters with various oxidants and the chlor(am)ination of iodinated organic compounds in drinking water. This study first reports that ferric chloride (FeCl3) can lead to the formation of iodinated coagulation byproducts (I-CBPs) from iodide-containing resorcinol solution or natural waters. The unwanted I-CBP formation involved the oxidation of iodide by ferric ions to generate various reactive iodine species, which further oxidize organic compounds. Although the oxidation rate of iodide by FeCl3 was several orders of magnitude slower than that by chlorine or chloramine, most of the converted iodide under the ferric/iodide system was transformed into iodine and iodinated organic compounds rather than iodate. Formation of four aliphatic I-CBPs was observed, and four aromatic I-CBPs were identified by gas chromatography mass-spectrometry and theoretical calculation. Coagulation of iodide-containing waters with FeCl3 also produced I-CBPs ranging from 12.5 ± 0.8 to 32.5 ± 0.2 μg/L as I. These findings call for careful consideration of the formation of I-CBPs from coagulation of iodide-containing waters with ferric salts.
研究领域:
环境科学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Yunpu Wang,Leilei Dai,Shaoqi Shan,Qin Zeng,Liangliang Fan,Yuhuan Liu,Roger Ruan,Yunfeng Zhao,Yue Zhou
This work is aimed to study the effect of unsaturation degree on microwave-assisted pyrolysis (MAP) of fatty acid salts. Sodium stearate, sodium oleate, and sodium linoleate were selected as model compounds. MAP of sodium oleate obtained the highest yield of liquid product. GC–MS analysis of liquid product revealed that MAP of unsaturated fatty acid salt could produce alkadienes, cycloalkanes, cycloalkenes, alkynes and aromatics, which could not appear in liquid product obtained from MAP of saturated fatty acid salt, and unsaturation degree had a great influence on liquid product composition. Analysis of the gas product indicated that MAP of sodium oleate produced more CO 2 and CO, while the MAP of sodium linoleate produced more gaseous hydrocarbons and H 2 . Analysis of the solid char showed that MAP of unsaturated fatty acid salts favors the cyclization and aromatization of pyrolysis vapours. The properties of liquid product were measured and analyzed, which confirmed that MAP of fatty acid salts is a feasible technology to produce high-quality renewable hydrocarbon fuels.
研究领域:
能源化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Jun Hu,Chen Wang,Bijuan Shao,Lingxiao Fu,Jianming Yu,Zhimin Qiang,Jianmeng Chen
Biofilm formation is ubiquitous on the corroded inner surface of water distribution pipes. Extracellular polymeric substances (EPS) secreted by biofilm microorganisms are nonnegligible precursors of disinfection byproducts (DBPs). The aim was to study the catalysis of copper corrosion products (CCPs, CuO and Cu 2+ ) on the formation of carbonaceous and nitrogenous DBPs (C-DBPs and N-DBPs) with EPS as a precursor. Results indicate that CCPs had a remarkable enhancement on the formation of DBPs, especially N-DBPs. The enhancement by Cu 2+ was mainly via homogeneous catalysis initiating from its complexation with EPS, while that by CuO was primarily through heterogeneous catalysis initiating from the polarization of Cl atom in HOCl/OCl − . The enhancement was more evident as pH increased because an alkaline condition favored the electrostatic interactions of CCPs with EPS and HOCl/OCl − . The presence of Br − weakened the enhancement, which may be attributed to that HOBr/OBr − had a much higher reaction rate than HOCl/OCl − towards the low reactive moieties in EPS. Due to more phenolic or unsaturated/conjugated groups, EPS proteins had a higher catalytic formation of DBPs than EPS polysaccharides. Among the major amino acids in EPS proteins for DBPs formation, tyrosine had the highest enhancement on the formation of trihalomethanes, while histidine had the highest catalytic formation of halogenated acetic acids, acetonitriles and acetamides. The study helps to understand the formation of DBPs by the joint actions of EPS and CCPs in drinking water distribution systems.
研究领域:
环境科学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Wenliang Wang,Zhenhao Ma,Xingjin Zhao,Shiwei Liu,Liping Cai,Sheldon Q. Shi,Yonghao Ni
Microwave absorbents play a vital role in governing the monomeric products from lignin during the microwave-assisted depolymerization (MAD) process. The influence of various microwave absorbents on the conversion efficiency and lignin monomeric products in a dynamic vapor flow reaction system was investigated. Results showed that the selected microwave absorbents could linearly and rapidly heat lignin from 200 to 500 °C within 8 min under a microwave power of 1000 W. The yields of liquid products, guaiacols, and phenols were increased linearly with the heating rate (°C/min). The high microwave absorptivity of absorbents promoted the formation of liquid products and phenolic compounds. To offer further support, the use of MoS2 with a very high microwave absorptivity (185.0 °C/min) showed very high yields of liquid products (34.1 wt %) and phenolics (32.1 wt %). This work provided an effective methodology to enhance the lignin conversion efficiency to monomeric products using microwave absorbents.
研究领域:
化学工程
·
生物质能
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2019
·
IF 7.913
Chao Fang,Shunke Ding,Shibo Gai,Rong Xiao,Yinan Wu,Bing Geng,Wenhai Chu
The present study investigated the effect of oxoanions on catalytic behaviour of copper corrosion products (CCPs) during chlorination of bromide-containing waters. Three types of oxoanions (carbonate, sulphate, and phosphate) and four types of CCPs (Cu 2+ , Cu(OH) 2 , Cu 2 O, and CuO) were involved in investigation and the effect of oxoanions concentration was also examined. The result indicated that carbonate and sulphate slightly inhibited oxidant decay in the presence of CCPs, but the formation of brominated disinfection by-products (Br-DBPs) remained largely unchanged. In contrast, the presence of phosphate (0.2–1 mM) almost eliminated the catalytic effect of Cu 2+ . For CCP solids (i.e. Cu(OH) 2 , Cu 2 O, and CuO), phosphate preferentially inhibited the formation of bromate rather than Br-DBPs. Despite the catalysis by CCP solids was reduced to some extent, the oxidant decay rate and bromate and Br-DBP formation were still significantly higher than blank groups, even at high phosphate concentration. By testing different addition scheme (simultaneous/sequential addition), it was proposed that phosphate was a strong competitor for hypohalites, rapidly destroying CCPs-hypohalites complexes on some adsorption sites. However, there were some specific sites that can only be adsorbed by hypohalites, leading to the incomplete inhibition of phosphate. Finally, the inhibition effect of phosphate on CCPs catalysis was tested in real water matrix. For Cu 2+ , higher reduction of bromate and Br-DBPs was found in raw water rather than filtered water, while converse pattern was true for Cu(OH) 2 and Cu 2 O, and this discrepancy can be ascribed to the difference in catalytic mechanism between Cu 2+ and CCP solids.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Marine Drugs
·
2014
·Vol. 12
·期 4
·1788-1814
·
IF 3.512
Shi-Ming Fang,Chang-Jing Wu,Chang-Wei Li,Cheng-Bin Cui
Many fungal biosynthetic pathways are silent in standard culture conditions, and activation of the silent pathways may enable access to new metabolites with antitumor activities. The aim of the present study was to develop a practical strategy for microbial chemists to access silent metabolites in fungi. We demonstrated this strategy using a marine-derived fungusPenicillium purpurogenumG59 and a modified diethyl sulphate mutagenesis procedure. Using this strategy, we discovered four new antitumor compounds named penicimutanolone (1), penicimutanin A (2), penicimutanin B (3), and penicimutatin (4). Structures of the new compounds were elucidated by spectroscopic methods, especially extensive 2D NMR analysis. Antitumor activities were assayed by the MTT method using human cancer cell lines. Bioassays and HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses were used to estimate the activated secondary metabolite production. Compounds2and3had novel structures, and1was a new compound belonging to a class of very rare natural products from which only four members are so far known. Compounds1–3inhibited several human cancer cell lines with IC50values lower than 20 μM, and4inhibited the cell lines to some extent. These results demonstrated the effectiveness of this strategy to discover new compounds by activating silent fungal metabolic pathways. These discoveries provide rationale for the increased use of chemical mutagenesis strategies in silent fungal metabolite studies.Keywords:natural products;alkaloids;structure elucidation;DES mutagenesis;silent fungal metabolite production
研究领域:
药理学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2021
·Vol. 44
·期 24
·4368-4375
·
IF 3.645
Denglang Zou,Yunbin Cui,Si Li,Duocheng Sang,Weimeng Liu,Tianshu Zhao,Xueli Gu,Tao Chen,Yulin Li
Biosynthesis is a promising way to manufacture desired products, however, the purification of its final products is a tough work due to the huge amount of reaction matrix. Liquid stationary phase of high-speed counter-current chromatography could easily avoid the commonly disadvantages that occurred in traditional column chromatography in the field of biosynthesized products purification. This characteristic makes high-speed counter-current chromatography particularly applicable for final products separation in biosynthesis. In this study, the glycosylation products of Silybin B by one-pot glycosylation were successfully purified by high-speed counter-current chromatography to show the applicability of high-speed counter-current chromatography for preparative separation of biosynthesis products. An optimized n -hexane/ethyl acetate/methanol/water (2:5:2:3, v/v/v/v ) system was applied in this study. As a result, four Silybin B glycosylation products, including 7 mg of Silybin B-5-O- β -D-glucoside ( SG-1 ), 12 mg of Silybin B-3-O- β -D-glucoside ( SG-2 ), 10 mg of Silybin B-7-O- β -D-glucoside ( SG-3 ), and 24 mg of Silybin B-20-O- β -D-glucoside ( SG-4 ), were simultaneously separated from 200 mg of glycosylation crude products, with the purity of 89.3, 95.2, 96.4, and 97.5%, respectively. Their structures were identified by spectroscopic analysis.
研究领域:
分析化学
·
生物化学
·
制药工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Xu Gao,Juan Yan,Chunyu Wang,Peizeng Yang,Junhe Lu,Yuefei Ji
Brominated and nitrated byproducts generated from bromide (Br - ) and nitrite (NO 2 - ), respectively, by sulfate radical (SO 4 •- ) oxidation have raised increasing concern. However, little is known about the concurrent generation of brominated and nitrated byproducts in the unactivated peroxymonosulfate (PMS) oxidation process. This study revealed that Br - can facilitate the transformation of NO 2 - to nitrated byproducts during unactivated PMS oxidation of phenol . In the co-existence of 0.1 mM Br - and 0.5 mM NO 2 - , the total yield of identified nitrated byproducts reached 2.316 μM in 20 min, while none was found with NO 2 - alone. Nitryl bromide (BrNO 2 ) as the primary nitrating agent was formed via the reaction of NO 2 - with free bromine in situ generated through the oxidation of Br - by PMS. BrNO 2 rapidly reacted with phenol or bromophenols , generating highly toxic nitrophenols or nitrated bromophenols, respectively. Increasing NO 2 - concentration led to more nitrated byproducts but less brominated byproducts. This study advances our understanding of the transformation of Br - and NO 2 - in the unactivated PMS oxidation process. It also provides important insights into the potentially underestimated environmental risks when PMS is applied to degrade organic contaminants under realistic environments, particularly when Br - and NO 2 - co-exist.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）