Starch/polyvinyl alcohol blended materials used as solid carbon source for tertiary denitrification of secondary effluent.
Starch/polyvinyl alcohol (PVA) blended materials for using as a solid carbon source (SCS) were prepared by blending PVA and gelatinized starch in an aqueous solution system, in which PVA served as framework material and starch as carbon source. The optimization of starch content and temperature effects were investigated. It was indicated that higher denitrification efficiency could be achieved with more starch in the materials. The average specific denitrification rates were 0.93, 0.66, 0.37 and 0.36 mg/(g x day) corresponding to starch content of 70%, 60%, 40% and 30% respectively at 37 degrees C. The denitrification rates increased when operating temperature was raised from 23 degrees C to 30 degrees C and then 37 degrees C. The mechanism of carbon release was analyzed incorporating the experimental results of abiotic release in deionized water. The organic carbon was mainly hydrolyzed by microbes, and the biological release efficiencies were at the range of 89.2% to 96.0%. A long-term experiment with a continuous flow reactor with SCS material containing 70% starch was conducted to gain some experience for practical application. When the influent nitrate concentration was in the range of 35.2 to 39.1 mg/L, hydraulic retention time of 4 hr, and operating temperature of 30 degrees C, a nitrogen removal efficiency up to 94.6% and denitrification rate of 0.217 kg/(m3 x day) was achieved. The starch-based materials developed in this study can be used as a solid carbon source for tertiary nitrogen removal from secondary effluent.
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. l-p09@mails.tsinghua.edu.cn
Peng
P
Li
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Jiane
J
Zuo
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Wei
W
Xing
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Lei
L
Tang
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Xiangyang
X
Ye
School of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
Li
L
Zaixing
THUNIP Holdings Co., Ltd., Beijing 100020, China.
Lin
L
Yuan
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Kaijun
K
Wang
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Hongtao
H
Zhang
D002244:Carbon / Q000737:chemistry*; D058440:Denitrification; D009584:Nitrogen / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013213:Starch / Q000737:chemistry; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical; D018508:Water Purification
D014874:Water Pollutants, Chemical; D002244:Carbon; D011142:Polyvinyl Alcohol; D013213:Starch; D009584:Nitrogen