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language
eng
Author
Xin Chen
Wakatsuki, Toshiyuki
Description
Multi-soil-layering systems composed of soil mixture blocks (SMB) arranged in a brick-like pattern and surrounded by permeable zeolite layers (PL) were designed for domestic wastewater and polluted river water treatment. To investigate the efficiency of MSL systems in relation to structural differences, five MSL systems with different sizes and layers of SMB and PL were constructed in five 50 cm × 10 cm × 60 cm acrylic boxes. The SMB comprised sandy soil, charcoal, sawdust and iron on a dry weight ratio of 7:1:1:1. Diluted domestic wastewater with an average suspended solids (SS), biological oxygen demand (BOD5), total phosphorus (T-P) and total nitrogen (T-N) concentration of 73, 34, 1.3 and 15 mg L−1, respectively, was applied at a hydraulic loading rate (HLR) ranging from 1,000 to 3,000 L m−2 day−1. At HLR of 1,000 and 2,000 L m−2 day−1, systems with larger SMB surface area had higher removal rates for SS, BOD5, chemical oxygen demand (COD) and T-P because of the enhanced contact efficiency between wastewater and SMB. The structural difference was greatest at a HLR of 2,000 L m−2 day−1, especially for COD and T-P removal. An increase in the top surface area of SMB was found to affect the efficiency of MSL systems more than an increase in side surface area. When the HLR was increased to 3,000 L m−2 day−1, the effect of structural differences on MSL systems was not as great, probably because of preferential water flow into PL as well as the oxidation–reduction potential ORP change caused by the accumulation of SS at high HLR. For T-N removal, no structural difference was found at a low HLR of 1,000 L m−2 day−1 and when HLR increased to more than 2,000 L m−2 day−1, a secondary effect of SS accumulation and ORP change appeared to influence the systems’ performance more than the expansion of SMB surface area.
Subject
hydraulic loading rate
multi-soil-layering system
soil mixture block
structure
water permeable layer
Journal Title
Soil science and plant nutrition
Volume
53
Issue
2
Start Page
206
End Page
214
sort
206
ISSN
0038-0768
Published Date
2007-04
DOI
NII Type
Journal Article
Content Type
9001
Format
PDF
Text Version
出版社版
Gyoseki ID
e8333
OAI-PMH Set
Faculty of Life and Environmental Science
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