Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Water Res ; 257: 121743, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38728775

ABSTRACT

Effective deep-dewatering is crucial for wastewater sludge management. Currently, the dominant methods focus on promoting cell lysis to release intracellular water, but these techniques often lead to secondary pollution and require stringent conditions, limiting their practical use. This study explores an innovative method using a commercially available complex quaternary ammonium salt surfactant, known as G-agent. This agent remarkably reduces the sludge water content from 98.6 % to 56.8 % with a low dosage (50 mg/g DS) and under neutral pH conditions. This approach surpasses Fenton oxidation in terms of dewatering efficiency and avoids the necessity for cell lysis and bound water release, thereby reducing the risk of secondary pollution in the filtrate, including heavy metals, nitrogen, phosphorus, and other contaminants. The G-agent plays a significant role in destabilizing flocs and enhancing flocculation during the conditioning and initial dewatering stages, effectively reducing the solid-liquid interfacial affinity of the sludge. In the compression filtration stage, the agent's solidification effect is crucial in forming a robust skeleton that improves pore connectivity within the filter cake, leading to increased water permeability, drainage performance and water flow-out efficiency. This facilitates deep dewatering of sludge without cell lysis. The study reveals that the G-agent primarily improves water flow-out efficiency rather than water flowability, indicating that cell lysis and bound water release are not indispensable prerequisites for sludge deep-dewatering. Furthermore, it presents an encouraging prospect for overcoming the limitations associated with conventional sludge deep-dewatering processes.


Subject(s)
Flocculation , Sewage , Waste Disposal, Fluid , Waste Disposal, Fluid/methods , Filtration , Water/chemistry , Surface-Active Agents/chemistry
2.
Environ Res ; 250: 118554, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38417657

ABSTRACT

Accurate prediction and measurement of yield stress are crucial for optimizing sludge treatment and disposal. However, the differences and applicability of various methods for measuring yield stress are subjects of ongoing debate. Meanwhile, literature on measuring sludge yield stress is limited to low solid concentrations (TS <10%), understanding and studying the yield stress of medium to high solid concentration sludge is crucial due to increasingly stringent standards for sludge treatment and disposal. So, this study employed a rotational rheometer to measure sludge yield stress across a wide range of TS (4-50%) using steady shear, dynamic oscillatory shear, and transient shear. The study derived significant conclusions by comparing and summarizing the applicability and limitations of each testing method: Dynamic oscillatory shear methods, including G'-σ curve method, γ-σ curve method, and G**γc method can measure sludge yield stress ranging from 4% to 40% TS, while other methods are restricted to low or limited solid concentrations; The G' = G″ method, utilizing the intersection of G' and G″ curves, consistently yields the highest value for yield stress when 4%≤ TS ≤ 12%; The rotational rheometer cannot measure sludge yield stress when the solid concentration exceeds 40% TS; The relationship between sludge yield stress and solid concentration is stronger as a power-law for TS ≤ 25%, transitioning to linear for higher concentrations (28%≤ TS <40%). This study systematically explores the applicability and limitations of various measurement methods for characterizing sludge yield stress across a wide range of solid concentrations, providing valuable guidance for scientific measurement and highlighting challenging research issues.


Subject(s)
Sewage , Rheology/methods , Waste Disposal, Fluid/methods
3.
J Environ Manage ; 346: 119017, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37738720

ABSTRACT

Exploring moisture distribution, especially bound water content, is vital for studying and applying sludge dewatering. The differential scanning calorimetry (DSC) method has been extensively utilized for the quantitative characterization of moisture distribution in sludge. However, this method has certain limitations, such as low reproducibility of results, leading to controversial parameter values in different papers and hindering result comparison. In this study, we investigated the influence of key sample attributes on measuring sludge bound water using the DSC method.The findings demonstrated that the moisture content and mass of sludge samples substantially influenced the reproducibility and stability of DSC test results. To ensure data reliability, the moisture content of the sludge sample should be minimized and kept below 84%, with the mass not exceeding 10 mg. Compared to the influence of sludge moisture content and sample mass, the heating rate (1⁓5 °C/min) minimally affected DSC test results. This study offers a comprehensive insight into how sample attributes and test parameters affect the quantitative characterization of bound water in sludge using the DSC method. Furthermore, practical strategies are presented to enhance the method's applicability in sludge bound water characterization.

4.
Br J Nutr ; 126(12): 1852-1860, 2021 12 28.
Article in English | MEDLINE | ID: mdl-33597052

ABSTRACT

Epidemiological studies have focused on the effects of iodine intake on the risk of thyroid cancer. However, their relationship is still obscure. The objective of the present study was to examine the association in the Chinese population. A new ecological study which combined the Data of Annual Report of Cancer, the Survey of Iodine Deficiency Disorders (IDD) surveillance and the Water Iodine Survey was conducted to analyse the relationship between iodine intake and the thyroid cancer incidence in China. In total, 281 counties were included. Thyroid cancer incidence was negatively correlated with the consumption rate of qualified iodised salt (CRQIS) and positively correlated with goiter prevalence (GP) of children aged 8-10 years, residents' annual income and coastal status. Areas with a low CRQIS and areas with a high GP had a relatively high incidence of thyroid cancer. Regression models showed that a low CRQIS and a high GP in children aged 8-10 years (both reflecting iodine deficiency status) play a substantial role in thyroid cancer incidence in both males and females. Additionally, living in coastal areas and having a high annual income may also increase the risk of thyroid cancer. These findings suggest that mild iodine deficiency may contribute to the exceptionally high incidence of thyroid cancer in some areas in China. Maintaining appropriate iodine nutrition not only helps to eliminate IDD but also may help to reduce the occurrence of thyroid cancer.


Subject(s)
Goiter , Iodine , Thyroid Neoplasms , Child , China/epidemiology , Female , Goiter/epidemiology , Humans , Incidence , Male , Prevalence , Sodium Chloride, Dietary/adverse effects , Sodium Chloride, Dietary/analysis , Thyroid Neoplasms/epidemiology , Thyroid Neoplasms/etiology
5.
Sci Rep ; 10(1): 6992, 2020 04 24.
Article in English | MEDLINE | ID: mdl-32332761

ABSTRACT

The aim of the research is to explore the relationship between hyperthyroidism, iodine, antithyroid drugs (propylthiouracil) and vascular endothelial injury. In total, 136 SD rats were randomly allocated into the control group, the hyperthyroidism group, the hyperthyroidism propylthiouracil group, the hyperthyroidism low iodine group, the high iodine group, and the endothelial injury group. Rats were raised for 60 days. Afterward, indicators concerning endothelial damage were determined, including the von Willebrand Factor (vWF), thrombomodulin (TM), nitric oxide (NO), endothelin 1 (ET-1), and P-selectin, as well as the plant hemagglutinin sample type oxidized low-density lipoprotein receptor 1 (LOX-1) from the aorta and the number of endothelial progenitor cells (EPCs) in whole blood. The hyperthyroidism group had significantly higher values for vWF, TM, NO, ET-1, and P-selectin in serum and a higher number of EPCs in whole blood compared with the control group, similar to the LOX-1 expression in abdominal aorta. The hyperthyroidism low iodine group had significantly higher values for vWF, ET-1, and P-selectin in serum and a higher number of EPCs in whole blood compared with those of the control group, as was the case for LOX-1 expression in the abdominal aorta. The hyperthyroidism propylthiouracil group had significantly higher values for FT4 in the serum compared with those in the control group. The electron microscope showed that hyperthyroidism caused a certain degree of endothelial injury to the abdominal aorta in rats. Hyperthyroidism can damage the vascular endothelium and is a high-risk factor for cardio-cerebrovascular disease. Propylthiouracil could be used in the treatment of hyperthyroidism, thus protecting endothelial cells from damage.


Subject(s)
Endothelial Cells/metabolism , Hyperthyroidism/blood , Hyperthyroidism/pathology , Thyroid Diseases/blood , Thyroid Diseases/pathology , Animals , Endothelial Progenitor Cells/metabolism , Endothelin-1/metabolism , Female , Hyperthyroidism/metabolism , Male , Nitric Oxide/metabolism , P-Selectin/metabolism , Rats , Rats, Sprague-Dawley , Rats, Wistar , Risk Factors , Scavenger Receptors, Class E/metabolism , Thrombomodulin/metabolism , Thyroid Diseases/metabolism , von Willebrand Factor/metabolism
6.
Talanta ; 178: 663-669, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-29136878

ABSTRACT

This work reports a facile strategy for the synthesis of water-soluble fluorescent probes Pyr1 and Pyr2, which have carboxyl and hydroxyl group in the side chain of thioacetal moiety, respectively. Pyr1-2 exhibit exclusively selective turn-on fluorescence response towards Hg2+ over other cations, based on intramolecular charge transfer (ICT) mechanism. Upon addition of Hg2+, the thioacetal moiety in Pyr1-2 can be converted to aldehyde group, which is confirmed by 1H NMR titrations. The detection limits for Pyr1-2 are less than 1.80nM in aqueous media, lower than the maximum allowable level of Hg2+ in drinking water by EPA. Moreover, Pyr2 have been successfully used for fluorescence imaging of Hg2+ in living cells, demonstrating potential application in biological science.


Subject(s)
Fluorescent Dyes/chemistry , Limit of Detection , Mercury/analysis , Pyrenes/chemistry , Spectrometry, Fluorescence/instrumentation , Sulfhydryl Compounds/chemistry , Cell Line, Tumor , Humans , Hydrogen-Ion Concentration , Intracellular Space/chemistry , Mercury/chemistry , Optical Imaging , Water/chemistry
7.
J Inorg Biochem ; 166: 126-134, 2017 01.
Article in English | MEDLINE | ID: mdl-27852004

ABSTRACT

The interactions between alkynylplatinum(II) terpyridine complexes 1-3 and the G-quadruplex DNA, including c-myc and telomeric quadruplex DNA, are investigated both in dilute solution and under molecular crowding conditions. The UV-vis absorption spectroscopy, circular dichroism and molecular docking studies suggest that 1-3 associate with telomeric and c-myc G-quadruplexes via groove binding, and electrostatic interactions. Experimental studies indicate that under molecular crowding conditions (in the presence of 40wt% PEG 200), 1-2 show weak affinity for c-myc, while 3 still displays high affinity and selectivity for c-myc. On the other hand, 1-3 act as efficient and selective ligand for telomeric quadruplex DNA under molecular crowding conditions. The complex 3 exhibits excellent cytotoxicity against A549, K562 and SGC-7901, with IC50 values that are 35.0-fold, 10.0-fold, and 12.1-fold lower than the values of cisplatin under the same conditions, respectively.


Subject(s)
G-Quadruplexes , Organoplatinum Compounds , Proto-Oncogene Proteins c-myc/metabolism , Telomere/metabolism , A549 Cells , Cisplatin/chemistry , Cisplatin/pharmacology , Humans , K562 Cells , Molecular Docking Simulation , Organoplatinum Compounds/chemistry , Organoplatinum Compounds/pharmacology , Proto-Oncogene Proteins c-myc/chemistry , Pyridines/chemistry , Pyridines/pharmacology , Telomere/chemistry
8.
Photochem Photobiol Sci ; 13(11): 1529-40, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25162985

ABSTRACT

The yttrium coordination polymer of pyrene modified hypocrellin A (Y(3+)-PyrHA) is synthesized and characterized. The methoxydiglycol malonate modified fullerene can be included in the cavity of Y(3+)-PyrHA in organic solution and buffer solution containing amphiphilic polymers, such as polyvinyl pyrrolidone (PVP), pluronic F127 and P123. The interaction between an amphiphilic polymer and Y(3+)-PyrHA plays an important role in controlling the size and morphology of Y(3+)-PyrHA/fullerene. TEM images of Y(3+)-PyrHA/fullerene in 1% F127 and P123 show nanoparticles in the size range 10-60 nm, while TEM images of Y(3+)-PyrHA/fullerene in 1% PVP display large-scale aggregation. Singlet oxygen is generated by irradiation of the polymer solution of Y(3+)-PyrHA/fullerene in the presence of oxygen. The electron paramagnetic resonance (EPR) spin trapping and 9,10-dimethoxyanthracene-2-sulfonic acid sodium salt (MAS) photooxidation results suggest that in 1% P123 solution Y(3+)-PyrHA/fullerene exhibits a higher singlet oxygen quantum yield than Y(3+)-PyrHA and the corresponding fullerene.

9.
J Phys Chem B ; 116(7): 2048-58, 2012 Feb 23.
Article in English | MEDLINE | ID: mdl-22257146

ABSTRACT

The metal coordination polymer of hypocrellin A bearing tryptamine motif (M-DTrpHA) can include fullerene via a two-point interaction, involving π-π stacking and electron donor-acceptor interaction. The 1:1 host-guest system M-DTrpHA/fullerene exhibits a moderate association constant K(a) (6.62 × 10(4) to 6.46 × 10(5) M(-1)). Both of the metal ions in M-DTrpHA and the substituents connected to the fullerene core play important roles in stabilizing the M-DTrpHA/fullerene complex. Transient absorption spectral and NIR absorption spectral results demonstrate that, in the M-DTrpHA/fullerene system, efficient photoinduced electron transfer from the tryptamine group in M-DTrpHA to fullerene may occur, resulting in a long-lived fullerene anion radical. The observed order of quantum yield (Φ(ET)(T)) and rate constants (K(ET)(T)) for electron transfer via (3)C(60)(*) is Y(3+)-DTrpHA > La(3+)-DTrpHA > DTrpHA, consistent with their binding ability to C(60). The nanostructure of M-DTrpHA is rearranged to form an interpenetrating network after interaction with fullerene.


Subject(s)
Coordination Complexes/chemistry , Fullerenes/chemistry , Perylene/analogs & derivatives , Quinones/chemistry , Tryptamines/chemistry , Coordination Complexes/chemical synthesis , Electrochemical Techniques , Perylene/chemical synthesis , Perylene/chemistry , Phenol , Quinones/chemical synthesis , Spectroscopy, Near-Infrared , Tryptamines/chemical synthesis
10.
Chirality ; 17 Suppl: S19-23, 2005.
Article in English | MEDLINE | ID: mdl-15736172

ABSTRACT

By using homochiral mesoporous POST-1 (Scheme 1) as an inherently chiral sensitizing host, supramolecular enantiodifferentiating photoisomerizations of (Z)-cyclooctene (1Z) were performed for the first time to examine the sensitizing ability of the chiral nanopores, walls of which are decorated with pyridine chromophore. The homochiral nanopores of POST-1 crystals were demonstrated to function as an effective chiral-sensitizing cavity to give the optically active (E)-isomer 1E in up to 5% enantiomeric excess (ee), thus expanding the scope of porous material-mediated chirogenesis to both ground and excited electronic states.

11.
Phys Chem Chem Phys ; 7(5): 1036-42, 2005 Mar 07.
Article in English | MEDLINE | ID: mdl-19791396

ABSTRACT

Fourier-transform ion cyclotron resonance (FTICR) mass spectrometric studies have been performed on donor-acceptor and donor-bridge acceptor fullerene-based systems. Matrix-assisted laser desorption/ionization (MALDI) was used for ion production; both the positive and negative ion modes were utilized. In addition, collision-induced dissociation (CID) experiments were carried out to study the movement of the charge (electron or hole) upon fragmentation. The experiments are complemented by ab initio theoretical calculations yielding both molecular orbital energies and electron density distributions. It was found that the theoretical electron density map predicted the experimentally observed fragmentation correctly in every case. Both the calculations and the MS experiments may be useful in studying these and related donor-acceptor systems in view of their use for charge separation and eventually, solar energy production.


Subject(s)
Computer Simulation , Fullerenes/chemistry , Models, Chemical , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
12.
Zhongguo Zhong Yao Za Zhi ; 27(3): 209-10, 2002 Mar.
Article in Chinese | MEDLINE | ID: mdl-12774404

ABSTRACT

OBJECTIVE: To study the chemical constituents in the root of Cichorium intybus. METHOD: The compounds were isolated and identified by column chromatography and NMR, IR, MS data. RESULT: Twelve compounds were isolated and identified. CONCLUSION: 2,3,4,9-tetrahydro-1H-pyrido-(3,4-b)indole-3-carboxylic acid was isolated from the Cichorium genus for the first time, azelaic acid and daucosterol were isolated from the the plant for the first time.


Subject(s)
Cichorium intybus/chemistry , Dicarboxylic Acids/isolation & purification , Indoles/isolation & purification , Plants, Medicinal/chemistry , Sitosterols/isolation & purification , Dicarboxylic Acids/chemistry , Indoles/chemistry , Plant Roots/chemistry , Sitosterols/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL
...