title: Pretreatment of ultra-high concentrated wastewater from phthalonitrile resin manufacturing by chemical precipitation, reduction and oxidation.
abstract: To remove the toxic and refractory pollutants in the phthalonitrile resin wastewater and improve its biodegradability, a combined process (i.e., CaCl2+AA+Fe/Cu/air) was developed to pretreat this wastewater obtained from a phthalonitrile resin manufacturing plant in southwestern China. First, CO3(2-) was precipitated and removed by adding CaCl2. Furthermore, its ultra-high concentrated NO2(-) (22.7±0.1 g/L) was reduced into N2 by adding amidosulphonic acid (AA). Meanwhile, two control experiments were setup to confirm the superiority of the combined process (i.e., CaCl2+AA). Subsequently, the wastewater was further treated by Fe/Cu/air process after the removal of CO3(2-) and NO2(-). The results suggest that the developed method not only could effectively remove the ultra-high concentrated CO3(2-) (>99%) and NO2(-) (>99%), but also could obtain high COD (58.8%) and colority (95.2%) removal efficiencies. Meanwhile, B/C ratio of this wastewater increased from 0.19 to 0.45, which suggests the biodegradability also was improved significantly. Finally, the high treatment efficiency was mainly attributed to the synergistic effects of CaCl2, AA and Fe/Cu/air. Therefore, the combined process is a promising pretreatment process for the ultra-high concentrated wastewater from phthalonitrile resin manufacturing.
authors: Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors: Qingqing
authors: Q
authors: Ji
authors: Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors: Yue
authors: Y
authors: Yuan
authors: Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065, China. Electronic address: laibo@scu.edu.cn.
authors: Bo
authors: B
authors: Lai
authors: Department of Environmental Science and Engineering, School of Architecture and Environment, Sichuan University, Chengdu 610065, China.
authors: Ping
authors: P
authors: Yang
authors: Research Center of Water Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors: Yuexi
authors: Y
authors: Zhou
mesh_terms: D000388:Air; D057919:Biological Oxygen Demand Analysis; D002122:Calcium Chloride / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry*; D011232:Chemical Precipitation; D003300:Copper / Q000737:chemistry; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry; D009570:Nitriles; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D011108:Polymers; D013451:Sulfonic Acids / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D002122:Calcium Chloride; D002254:Carbonates; D003300:Copper; D007220:Industrial Waste; D007501:Iron; D009570:Nitriles; D009573:Nitrites; D011108:Polymers; D013451:Sulfonic Acids; D062065:Wastewater; D014874:Water Pollutants, Chemical; C005741:sulfamic acid
keywords: Biodegradability; Fe/Cu/air process; Phthalonitrile resin; Reduction of nitrite nitrogen; Ultra-high concentration hazardous wastewater