Search

Your search keyword '"Zheng, Guanyu"' showing total 239 results
Start Over Author "Zheng, Guanyu"
239 results on '"Zheng, Guanyu"'

20. Enhancing sludge dewaterability in sequential bioleaching: Degradation of dissolved organic matter (DOM) by filamentous fungus Mucor sp. ZG-3 and the influence of energy source.

Author

Wang, Zhenyu, Feng, Wen, Tang, Shigang, Zhao, Jing, Zheng, Guanyu, and Zhou, Lixiang

Subjects
BACTERIAL leaching, DISSOLVED organic matter, FILAMENTOUS fungi, MUCOR, ZETA potential, THIOBACILLUS ferrooxidans, ORGANIC acids
Abstract

This study aimed to enhance sludge dewatering through sequential bioleaching, employing the filamentous fungus Mucor sp. ZG-3 and the iron-oxidizing bacterium Acidithiobacillus ferrooxidans LX5. The mechanism by which Mucor sp. ZG-3 alleviates sludge dissolved organic matter (DOM) inhibition of A. ferrooxidans LX5 was investigated, and the optimal addition of energy source for enhanced sludge dewaterability during sequential bioleaching was determined. Sludge dissolved organic carbon (DOC) decreased to 272 mg/L with a 65.2% reduction by Mucor sp. ZG-3 in 3 days, and the degraded fraction of sludge DOM was mainly low-molecular-weight DOM (L-DOM) which inhibited the oxidization of Fe2+ by A. ferrooxidans LX5. By degrading significant inhibitory low-molecular-weight organic acids, Mucor sp. ZG-3 alleviated DOM inhibition of A. ferrooxidans LX5. In the sequential bioleaching process, the optimal concentration of FeSO4·7H2O for A. ferrooxidans LX5 was 4 g/L, resulting in the minimum specific resistance to filtration (SRF) of 2.60×1011 m/kg, 40.0% lower than that in the conventional bioleaching process with 10 g/L energy source. Moreover, the sequential bioleaching process increased the sludge zeta potential (from -31.8 to -9.47 mV) and median particle size (d50) of the sludge particle (from 17.90 to 27.44 μm), contributing to enhanced sludge dewaterability. Inoculation of Mucor sp. ZG-3 during the bioleaching process reduced the demand for energy sources by A. ferrooxidans LX5 while improving sludge dewaterability performance. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

42. Benchmarking New Zealand's frontier firms

Author

Zheng, Guanyu, Duy, Hoang Minh, and Pacheco, Gail

Subjects
L25, O33, ddc:330, resource allocation, labour productivity, productivity convergence, O47
Abstract

New Zealand has experienced poor productivity performance over the last two decades. Factors often cited as reasons behind this are the small size of the domestic market and distance to international partners and markets. While the distance reason is one that is fairly insurmountable, there are a number of other small advanced economies that also face similar domestic market constraints. This study compares the relative performance of New Zealand's firms to those economies using novel cross-country microdata from CompNet. We present stylised facts for New Zealand relative to the economies of Belgium, Denmark, Finland, Netherlands and Sweden based on average productivity levels, as well as benchmarking laggard, median and frontier firms. This research also employs an analytical framework of technology diffusion to evaluate the extent of productivity convergence, and the impact of the productivity frontier on non-frontier firm performance. Additionally, both labour and capital resource allocation are compared between New Zealand and the other small advanced economies. Results show that New Zealand's firms have comparatively low productivity levels and that its frontier firms are not benefiting from the diffusion of best technologies outside the nation. Furthermore, there is evidence of labour misallocation in New Zealand based on less labour-productive firms having disproportionally larger employment shares than their more productive counterparts. Counter-factual analysis illustrates that improving both technology diffusion from abroad toward New Zealand's frontier firms, and labour allocation across firms within New Zealand will see sizable productivity gains in New Zealand.

Published
2021

Catalog

Books, media, physical & digital resources
See catalog results