The Experts below are selected from a list of 4215 Experts worldwide ranked by ideXlab platform

Yongjiong Ni - One of the best experts on this subject based on the ideXlab platform.

  • Effect of adding alum Sludge from water treatment plant on sewage Sludge Dewatering
    Journal of Environmental Chemical Engineering, 2016
    Co-Authors: Jun Li, Ailan Yan, Ting Ma, Liu Liu, Jun Liu, Yongjiong Ni
    Abstract:

    Alum Sludge from water treatment plant contained residual polyaluminum chloride (PACl) and large amount inorganic matters. Alum Sludge acted as chemical conditioner and physical conditioner improved the sewage Sludge Dewatering. It indicated that the addition of alum Sludge reduced the dosage of polyacrylamide (PAM) and decreased the moisture content of sewage Sludge. The moisture content was 64% when the blend ratio was 1 kg/kg (dry alum Sludge/dry sewage Sludge) with plate-and-frame filter press. The 3D-excitation-emission matrix (3D-EEM) was used to analyze the Sludge Dewatering process. A mechanism hypothesis of adding alum Sludge in sewage Sludge for improving the Sludge Dewatering was proposed. Alum Sludge implements the charge neutralization and adsorption bridging effect, provides friction and squeeze for crushing Sludge particles even cell, and acts as skeleton builders in the Sludge to improve the Sludge Dewatering.

Han-qing Yu - One of the best experts on this subject based on the ideXlab platform.

  • A Fenton-like process for the enhanced activated Sludge Dewatering
    Chemical Engineering Journal, 2015
    Co-Authors: Dong Qin He, Long Fei Wang, Hong Jiang, Han-qing Yu
    Abstract:

    The presence of high moisture content in sewage Sludge aggravates the disposal costs and restricts its application. Sewage Sludge is traditionally conditioned by dosing organic/inorganic chemicals. However, after the treatment, the moisture content and inorganic solid mass remain to be a high level. In this work, a Fenton-like Dewatering process, i.e., a combination of sulfuric acid, hydrogen peroxide and ferric sulfate, was developed. Uniform design was used to optimize the composite conditions, and the effects of Fenton-like treatment on Sludge Dewatering were examined. The results show that, after the treatment of the Fenton-like reaction, the moisture content of Sludge cake and the dry solid mass decreased from 80.0% to 66.1% and from 12.9 to 10.6. g/L, respectively. The mechanism for the enhanced Dewatering performance was explored, and the degradation of abundant extracellular polymeric substances, the lysis of the Sludge cells, and the release of bound water and typical metals within the Sludge flocs were found to be mainly responsible for the enhanced Dewatering performance. In addition, a surface thermodynamic analysis with the extended DLVO theory shows that the higher hydrophobicity and the less stable Sludge flocs also contributed to the decrease in moisture content. Our results confirm that such a Fenton-like treatment exhibited excellent performance in enhancing Sludge Dewatering and metal leaching and is a promising pretreatment approach for Sludge disposal.

Jiangxin Xiang - One of the best experts on this subject based on the ideXlab platform.

  • synthesis characterization and secondary Sludge Dewatering performance of a novel combined silicon aluminum iron starch flocculant
    Journal of Hazardous Materials, 2015
    Co-Authors: Qintie Lin, Huanlong Peng, Songxiong Zhong, Jiangxin Xiang
    Abstract:

    Flocculation is one of the most widely used cost-effective pretreatment method for Sludge Dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the Sludge Dewatering field. In this study, a novel combined silicon–aluminum–ferric–starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The Dewatering performance of secondary Sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good Dewatering efficiency over a wide pH range of 3.0–11.0, (2) superior Sludge Dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary Sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary Sludge Dewatering applications.

Wenwen Xue - One of the best experts on this subject based on the ideXlab platform.

  • uv initiated polymerization of hydrophobically associating cationic polyacrylamide modified by a surface active monomer a comparative study of synthesis characterization and Sludge Dewatering performance
    Industrial & Engineering Chemistry Research, 2014
    Co-Authors: Yi Liao, Huaili Zheng, Li Qian, Yongjun Sun, Li Dai, Wenwen Xue
    Abstract:

    Two cationic polyacrylamides, PAA and PAD, were synthesized for Sludge Dewatering. The advanced instruments such as 1H NMR, FTIR, and SEM were used to characterize the two copolymers. Their hydrophobic association properties in water were investigated by viscosimetry as well as the Dewatering performance studied by the Sludge Dewatering experiment. The results showed that the optimum conditions for preparation of PAA were that the initiator concentration, urea concentration, molar ratio of AODBAC to AM, and irradiation time were 0.3‰, 1.0%, 10:90, and 60 min, respectively. Also, it was found that PAA had a stronger hydrophobic interaction with a lower intrinsic viscosity and longer dissolution time as well as a better Dewatering performance. Furthermore, the charge neutralization and bridging effects were found to contribute much to the Sludge Dewatering by PAA in which the Dewatering performance was able to be enhanced further by the hydrophobic interaction.

Raymond J. Zeng - One of the best experts on this subject based on the ideXlab platform.

  • Impact of dosing order of the coagulant and flocculant on Sludge Dewatering performance during the conditioning process.
    Science of The Total Environment, 2018
    Co-Authors: Hou-feng Wang, Hua-jie Wang, Raymond J. Zeng
    Abstract:

    Abstract The combined use of coagulant and flocculant can achieve excellent Dewatering performance. In this study, we investigated the impact of dosing order of the coagulant and flocculant on Sludge Dewatering performance. The results showed that capillary suction time (CST) values during the coagulation-flocculation process decreased 20–25% compared to those during the flocculation-coagulation process using the same doses of additives. Moisture content of the Sludge during the coagulation-flocculation process was lower. The dosing order of coagulants and flocculants during the conditioning process was clearly important for Sludge Dewatering, and the coagulant should be dosed before the flocculant. Furthermore, a mechanism for the different Dewatering performance was proposed: larger agglomerated and destabilized colloid particles formed, and more bound water was released into the Sludge bulk solution during the coagulation-flocculation process, compared with the flocculation-coagulation process, which resulted in better Dewatering performance, as reflected in the CST value and moisture content of the Sludge cake. These results enable a better understanding of combined conditioning with coagulants and flocculants on Sludge Dewatering.

  • Applying rheological analysis to understand the mechanism of polyacrylamide (PAM) conditioning for sewage Sludge Dewatering
    RSC Advances, 2017
    Co-Authors: Hou-feng Wang, Hua-jie Wang, Raymond J. Zeng
    Abstract:

    Nowadays, polyacrylamide (PAM) is widely used for Sludge conditioning, while the interactions between PAM and Sludge particles influencing the Dewatering process remain to be clarified. This study focused on applying rheological analysis to understand the mechanism of PAM conditioning for sewage Sludge Dewatering. Effective solid–liquid separation was achieved mostly due to the changes of physical properties instead of biochemical properties for conditioned Sludge. PAM addition enhanced the non-Newtonian properties and strengthened the solid-like character of Sludge in the linear region, allowing initial enhancement of the network strength of Sludge flocs. Due to these changes in rheological behavior and more free water being available to flow, the breakdown of the colloidal network of Sludge in the non-linear viscoelastic regime allowed high-performance separation between water and solid-phase. These findings show that rheological analysis can serve as a useful indicator of the activated Sludge Dewatering process.

  • Applying rheological analysis to better understand the mechanism of acid conditioning on activated Sludge Dewatering.
    Water Research, 2017
    Co-Authors: Hou-feng Wang, Hua-jie Wang, Hai-yang Yang, Raymond J. Zeng
    Abstract:

    The pH value is a key parameter and affects Sludge Dewatering. Comprehensive understanding of the effects and mechanism of pH is important for Sludge treatment process and Sludge Dewatering. The goal of this study was to evaluate the proposed mechanism of acid conditioning on Sludge Dewatering based on rheological analysis. At lower Sludge pH, changes in floc structure, surface properties, and flocculation improved the performance of Dewatering. Additionally, lower Sludge pH caused the hydrolysis of EPS and intracellular materials, which released greater amounts of bound water. These changes resulted in altered rheological properties, weakening network strength and shrinking the linear viscoelastic regime, making the Sludge system sensitive to shear. Thus, both the Sludge Dewatering rate and moisture reduction efficiency were improved by lowering the pH. These factors demonstrate that rheological analysis can understand the mechanism of acid conditioning on activated Sludge Dewatering better.