Based on the health risk assessment model of water quality recommended by United States Environmental Protection Agency (USEPA), the health risk of five centralized drinking water sources in small towns of Beibei Dist...Based on the health risk assessment model of water quality recommended by United States Environmental Protection Agency (USEPA), the health risk of five centralized drinking water sources in small towns of Beibei District, Chongqing City was evaluated. The results showed that the risk of health hazard of chemical carcinogen arsenic did not exceed the acceptable level recommended by the International Commission on Radiological Protection (ICRP)(5.0×10 -5 a -1 ), but was still at the same order of magnitude as the recommended value of ICRP. The risk of the highest health hazard was 127 times higher than the maximum acceptable level recommended by Sweden EPA and Holland EPA (1.0×10 -6 a -1 ). The health risk of As in genetic toxic substances at monitoring points A, B, and C accounted for 99.99% of the total risk, showing that As was the main pollutant that posed the health risk, so priority should be given to the prevention and control of As pollution in the centralized drinking water sources in Chongqing towns.展开更多
以江苏盱眙凹凸棒原土为原料,采用静水沉降-离心分离法对其提纯,探索提纯土中降低铁含量、提供最大硅源的改性方式,采用碱溶-水热晶化工艺,调整n(Na2O)∶n(SiO2)∶n(Al2O3)∶n(H2O)的配比、晶化温度、晶化时间的因素参数,以X-ra...以江苏盱眙凹凸棒原土为原料,采用静水沉降-离心分离法对其提纯,探索提纯土中降低铁含量、提供最大硅源的改性方式,采用碱溶-水热晶化工艺,调整n(Na2O)∶n(SiO2)∶n(Al2O3)∶n(H2O)的配比、晶化温度、晶化时间的因素参数,以X-ray diffraction(XRD)表征、结晶度、产出率与NH4^+离子交换容量为指标分析4A分子筛的制备条件;考察其吸附NH4^+性能.结果表明,PA基于3mol/L HCl酸浸除铁-800℃煅烧活化-5mol/L Na OH碱溶处理,滤液添加铝源后水热晶化可合成高结晶度-产出率的4A分子筛ACAPA-4AMS,当n(Na2O)∶n(SiO2)=2.1,n(H2O)∶n(Na2O)=60,n(SiO2)∶n(Al2O3)=1.5,在90℃晶化8h时,NH4^+交换容量最高,为159mmol/100g,符合工业标准.5℃ACAPA-4AMS饱和吸附量68.04mg/g,吸附符合Freundlich方程且为吸热过程,但温度对低浓度(5mg/L)NH4^+-N的去除率影响不大.该研究为凹凸棒土在严寒村镇高氨氮水源水的应用提供理论基础.展开更多
基金Supported by Scientific Research Planning Project of Beibei District,Chongqing City(2017-18)
文摘Based on the health risk assessment model of water quality recommended by United States Environmental Protection Agency (USEPA), the health risk of five centralized drinking water sources in small towns of Beibei District, Chongqing City was evaluated. The results showed that the risk of health hazard of chemical carcinogen arsenic did not exceed the acceptable level recommended by the International Commission on Radiological Protection (ICRP)(5.0×10 -5 a -1 ), but was still at the same order of magnitude as the recommended value of ICRP. The risk of the highest health hazard was 127 times higher than the maximum acceptable level recommended by Sweden EPA and Holland EPA (1.0×10 -6 a -1 ). The health risk of As in genetic toxic substances at monitoring points A, B, and C accounted for 99.99% of the total risk, showing that As was the main pollutant that posed the health risk, so priority should be given to the prevention and control of As pollution in the centralized drinking water sources in Chongqing towns.
文摘以江苏盱眙凹凸棒原土为原料,采用静水沉降-离心分离法对其提纯,探索提纯土中降低铁含量、提供最大硅源的改性方式,采用碱溶-水热晶化工艺,调整n(Na2O)∶n(SiO2)∶n(Al2O3)∶n(H2O)的配比、晶化温度、晶化时间的因素参数,以X-ray diffraction(XRD)表征、结晶度、产出率与NH4^+离子交换容量为指标分析4A分子筛的制备条件;考察其吸附NH4^+性能.结果表明,PA基于3mol/L HCl酸浸除铁-800℃煅烧活化-5mol/L Na OH碱溶处理,滤液添加铝源后水热晶化可合成高结晶度-产出率的4A分子筛ACAPA-4AMS,当n(Na2O)∶n(SiO2)=2.1,n(H2O)∶n(Na2O)=60,n(SiO2)∶n(Al2O3)=1.5,在90℃晶化8h时,NH4^+交换容量最高,为159mmol/100g,符合工业标准.5℃ACAPA-4AMS饱和吸附量68.04mg/g,吸附符合Freundlich方程且为吸热过程,但温度对低浓度(5mg/L)NH4^+-N的去除率影响不大.该研究为凹凸棒土在严寒村镇高氨氮水源水的应用提供理论基础.