The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose...The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation–reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S（nitrate/sulfide）ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.展开更多
Lanthanide complex-based luminescent probes/chemosensors have shown great utilities in various biological and environmental assays with time-resolved detection mode to eliminate background noises.In this work,by conju...Lanthanide complex-based luminescent probes/chemosensors have shown great utilities in various biological and environmental assays with time-resolved detection mode to eliminate background noises.In this work,by conjugating di（2-picolyl）amine（DPA）with a tetradentateβ-diketone 1,2-bis[4＇-（1＂,1＂,1＂,2＂,2＂-pentafluoro-3＂,5＂-pentanedion-5＂-yl）benzyl]-4-chlorosulfo-benzene（BPPBCB）,a novel dual-functional ligand that can coordinate to Eu^（3＋）for responding to Cu^（2＋）and S^2 ions in aqueous media,DPA-BPPBCB,has been designed and synthesized.Theβ-diketone moiety of DPA-BPPBCB can form a strongly luminescent complex with Eu^（3＋）.Upon reaction with Cu^（2＋）,accompanied by the formation of heterobimetallic complex Cu^（2＋）-DPA-BPPBCB-Eu^（3＋）,the Eu^（3＋）luminescence was quenched.While in the presence of S^2,owing to the high affinity of S^2 to Cu^（2＋）,stable CuS was formed,which resulted in the release of Cu^（2＋）from Cu^（2＋）-DPA-BPPBCB-Eu^（3＋）,to restore the luminescence of the Eu^（3＋）complex.This unique＂on-off-on＂luminescence response of the Eu3＋complex enabled Cu^（2＋）and S^2 ions in aqueous media to be detected with time-resolved luminescence detection mode.展开更多
基金supported by the National Natural Science Foundation of China (No. 50908131)the Major Science and Technology Program for Water Pollution Control and Treatment of China (No. 2011ZX07301-002)Tsinghua University Initiative Scientific Research Program (No.20121087922)
文摘The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation–reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S（nitrate/sulfide）ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.
基金Financial support from the National Natural Science Foundati of China(No.21477011)
文摘Lanthanide complex-based luminescent probes/chemosensors have shown great utilities in various biological and environmental assays with time-resolved detection mode to eliminate background noises.In this work,by conjugating di（2-picolyl）amine（DPA）with a tetradentateβ-diketone 1,2-bis[4＇-（1＂,1＂,1＂,2＂,2＂-pentafluoro-3＂,5＂-pentanedion-5＂-yl）benzyl]-4-chlorosulfo-benzene（BPPBCB）,a novel dual-functional ligand that can coordinate to Eu^（3＋）for responding to Cu^（2＋）and S^2 ions in aqueous media,DPA-BPPBCB,has been designed and synthesized.Theβ-diketone moiety of DPA-BPPBCB can form a strongly luminescent complex with Eu^（3＋）.Upon reaction with Cu^（2＋）,accompanied by the formation of heterobimetallic complex Cu^（2＋）-DPA-BPPBCB-Eu^（3＋）,the Eu^（3＋）luminescence was quenched.While in the presence of S^2,owing to the high affinity of S^2 to Cu^（2＋）,stable CuS was formed,which resulted in the release of Cu^（2＋）from Cu^（2＋）-DPA-BPPBCB-Eu^（3＋）,to restore the luminescence of the Eu^（3＋）complex.This unique＂on-off-on＂luminescence response of the Eu3＋complex enabled Cu^（2＋）and S^2 ions in aqueous media to be detected with time-resolved luminescence detection mode.
