Thallium contamination in water can cause great danger to the environment.In this study,we synthesized manganese oxide-coated sand(MOCS)and investigated the transport and retention behaviors of Tl(I)in MOCS under diff...Thallium contamination in water can cause great danger to the environment.In this study,we synthesized manganese oxide-coated sand(MOCS)and investigated the transport and retention behaviors of Tl(I)in MOCS under different conditions.Characterization methods combined with a two-site nonequilibrium transport model were applied to explore the retentionmechanisms.The results showed that Tl(I)mobility was strongly inhibited in MOCS media,and the retention capacity calculated from the fitted model was 510.41 mg/g under neutral conditions.The retention process included adsorption and oxidative precipitation by the manganese oxides coated on the sand surface.Cotransport with the same concentration of Mn(II)led to halving Tl(I)retention due to competition for reactive sites.Enhanced Tl(I)retention was observed under alkaline conditions,as increasing pH promoted electronegativity on the media surface.Moreover,the competitive cation Ca^(2+)significantly weakened Tl(I)retention by occupying adsorption sites.These findings provide new insights into understanding Tl(I)transport behavior in water-saturated porous media and suggest that manganese oxide-coated sand can be a cost-effective filter media for treating Tl-contaminated water.展开更多
通过运用锰砂、黄铁矿及PHBV等功能性填料,构建以特定方式分层填充的生物滤柱(BF-MP)和对照组滤柱(BF-MN、BF-PP、BF-CK),为实现硝化-反硝化处理微污染水提供新方式。探究不同条件下氮转化效果,分析不同形态的氮及磷沿程变化,探索氮磷...通过运用锰砂、黄铁矿及PHBV等功能性填料,构建以特定方式分层填充的生物滤柱(BF-MP)和对照组滤柱(BF-MN、BF-PP、BF-CK),为实现硝化-反硝化处理微污染水提供新方式。探究不同条件下氮转化效果,分析不同形态的氮及磷沿程变化,探索氮磷去除途径。结果表明,脱氮效果受水力停留时间(HRT)、温度(T)影响,延长HRT或提高温度出水总氮降低,BF-MP硝氮去除率可达100%。沿程变化表明,NO_(3)^(-)-N主要在黄铁矿和PHBV混合填充区通过反硝化过程去除。BF-MP在HRT=12 h T=20~25℃时,脱氮除磷性能均较好,总氮去除率达到79.87%,磷酸根去除率达到75.19%,且长期运行出水稳定,具有良好的应用前景,为生物滤池及人工湿地的设计运行提供新思路。展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.51878092 and 52070029)。
文摘Thallium contamination in water can cause great danger to the environment.In this study,we synthesized manganese oxide-coated sand(MOCS)and investigated the transport and retention behaviors of Tl(I)in MOCS under different conditions.Characterization methods combined with a two-site nonequilibrium transport model were applied to explore the retentionmechanisms.The results showed that Tl(I)mobility was strongly inhibited in MOCS media,and the retention capacity calculated from the fitted model was 510.41 mg/g under neutral conditions.The retention process included adsorption and oxidative precipitation by the manganese oxides coated on the sand surface.Cotransport with the same concentration of Mn(II)led to halving Tl(I)retention due to competition for reactive sites.Enhanced Tl(I)retention was observed under alkaline conditions,as increasing pH promoted electronegativity on the media surface.Moreover,the competitive cation Ca^(2+)significantly weakened Tl(I)retention by occupying adsorption sites.These findings provide new insights into understanding Tl(I)transport behavior in water-saturated porous media and suggest that manganese oxide-coated sand can be a cost-effective filter media for treating Tl-contaminated water.
文摘通过运用锰砂、黄铁矿及PHBV等功能性填料,构建以特定方式分层填充的生物滤柱(BF-MP)和对照组滤柱(BF-MN、BF-PP、BF-CK),为实现硝化-反硝化处理微污染水提供新方式。探究不同条件下氮转化效果,分析不同形态的氮及磷沿程变化,探索氮磷去除途径。结果表明,脱氮效果受水力停留时间(HRT)、温度(T)影响,延长HRT或提高温度出水总氮降低,BF-MP硝氮去除率可达100%。沿程变化表明,NO_(3)^(-)-N主要在黄铁矿和PHBV混合填充区通过反硝化过程去除。BF-MP在HRT=12 h T=20~25℃时,脱氮除磷性能均较好,总氮去除率达到79.87%,磷酸根去除率达到75.19%,且长期运行出水稳定,具有良好的应用前景,为生物滤池及人工湿地的设计运行提供新思路。
