Sequential shape-selective adsorption and photocatalytic transformation of acrylonitrile production wastewater.
Acrylonitrile production wastewater has been widely recognized as one type of refractory organic wastewater because of its complicated composition and low bioavailability. It usually contains plenty of micromolecular nitrile and pyridine, resulting in high chemical oxygen demand (CODCr), total organic carbon (TOC) and total nitrogen (TN) concentrations. In this study, a novel microporous zeolite, CS-Z1, was developed as an adsorbent for rapidly shape-selective adsorption of the micromolecular pollutants from the acrylonitrile production wastewater, and a visible light-driven Ti-β-Bi2O3 photocatalysis was introduced to sequentially treat the residual macromolecular pollutants for complete purification. The adsorption processes by CS-Z1 were mostly achieved within the first 5 min, and the equilibrium was reached quickly after 30 min, where the CODCr, TOC and TN removal efficiencies of the wastewater were as high as 93.5%, 92.2% and 96.8%, respectively, much higher than those by other adsorbents. Furthermore, the adsorption efficiencies of CS-Z1 were barely affected by the variation of pH value and temperature, which was mainly attributed to the shape-selective adsorption mechanism of the CS-Z1 zeolite. The Ti-β-Bi2O3 photocatalysis could remove more than 95% of the residual macromolecular pollutants in the wastewater, where a synergistic mechanism of reduction-oxidation/polymerization was proposed. In a 108 h of CS-Z1 adsorption and Ti-β-Bi2O3 photocatalysis sequential process, the CODCr, TOC and TN concentrations was reduced to below 20, 7 and 5 mg L(-1), respectively, demonstrating the excellent practical potential of the sequential treatment system for acrylonitrile production wastewater.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China. Electronic address: daiyr@craes.org.cn.
Yunrong
Y
Dai
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China. Electronic address: songyh@craes.org.cn.
Yonghui
Y
Song
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China; Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China. Electronic address: tu_xiang@creas.org.cn.
Xiang
X
Tu
Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China. Electronic address: jiangyp@gmail.com.
Yanpeng
Y
Jiang
Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, 100012, Beijing, PR China. Electronic address: yhzmlyy90311@126.com.
Yu
Y
Yuan
D000181:Acrylonitrile / Q000737:chemistry*; D000327:Adsorption; D007220:Industrial Waste / Q000032:analysis*; D010782:Photolysis; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
D000181:Acrylonitrile; D007220:Industrial Waste; D062065:Wastewater; D014874:Water Pollutants, Chemical; D017641:Zeolites
Acrylonitrile production wastewater; Photocatalysis; Sequential treatment; Shape-selective adsorption; Zeolite