In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton a...In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.展开更多
This research aimed to evaluate the alga Scenedesmus obliquus toxicity induced by textiledyeing effluents(TDE).The toxicity indicator of TDE in alga at the physiological(algal growyth),biochemical(chlorophyll-a(Chl-a)...This research aimed to evaluate the alga Scenedesmus obliquus toxicity induced by textiledyeing effluents(TDE).The toxicity indicator of TDE in alga at the physiological(algal growyth),biochemical(chlorophyll-a(Chl-a)synthesis and superoxide dismutase(SOD)activity)and structural(cell membrane integrity)level were investigated.Then we further study the relationship among toxicity indicators at physiological and biochemical level,and supplemented by research on algal biomacromolecules.According to the analysis of various endpoints of the alga,the general sensitivity sequence of toxicity endpoints of Scenedesmus obliquus was:SOD activity>Chl-a synthesis>algal growth.The stimulation rate of SOD activity increased from day 3(57.25%~83.02%)to day 6(57.25%~103.81%),and then decreased on day 15(-4.23%^-32.96%),which indicated that the antioxidant balance system of the algal cells was destroyed.The rate of Chl-a synthesis inhibition increased gradually,reaching19.70%~79.39%on day 15,while the rate of growth inhibition increased from day 3(-12.90%~10.16%)to day 15(-21.27%~72.46%).Moreover,the algal growth inhibition rate was positively correlated with the inhibition rate of SOD activity or Chl-a synthesis,with the correlation coefficients were 0.6713 and 0.5217,respectively.Algal cells would be stimulating to produce excessive reactive oxygen species,which would cause peroxidation in the cells,thereby destroying chloroplasts,inhibiting chlorophyll synthesis and reducing photosynthesis.With increasing exposure time,irreversible damage to algae can lead to death.This study is expected to enhance our understanding of the ecological risks through algal tests caused by TDE.展开更多
Nitrogenization is an effective method for improving the capacitive deionization(CDI)performance of porous carbon materials.In particular,polymer organic frameworks with heteroatom doping,containing an ordered pore st...Nitrogenization is an effective method for improving the capacitive deionization(CDI)performance of porous carbon materials.In particular,polymer organic frameworks with heteroatom doping,containing an ordered pore structure and excellent electrochemical stability,are ideal precursors for carbon materials for high-performance CDI.In this study,a nitrogen-enriched micro-mesoporous carbon(NMC)electrode was fabricated by carbonizing a Schiff base network-1 at 500,600,and 700℃.Scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,N_(2) adsorption-desorption,the contact angle of water,cyclic voltammetry,and electrochemical impedance spectroscopy were used to characterize the morphological structure,wettability,Brunauer–Emmett–Teller surface areas,and electrochemical performance of the NMCs.The results showed that the NMC carbonized at 600℃ achieved the best specific capacitance(152.33 F/g),as well as a high electrosorption capacity(25.53 mg/g)because of its chemical composition(15.57%N)and surface area(312 m^(2)/g).These findings prove that NMC is viable as an electrode material for desalination by high-performance CDI applications.展开更多
Ion-exchange polymer and modified carbonization bacterial cellulose(CBC)electrodes were fabricated using varying amounts of cation-exchange polymers(glutaric acid(GA)and sulfosuccinic acid(SSA))and assembled within an...Ion-exchange polymer and modified carbonization bacterial cellulose(CBC)electrodes were fabricated using varying amounts of cation-exchange polymers(glutaric acid(GA)and sulfosuccinic acid(SSA))and assembled within an asymmetric capacitive deionization unit(p-CDI).The performance of selective NO2-electro-adsorption was studied.The AC/CBCSSA group showed a better salt adsorption capacity(14.56 mg/g)and nitrite removal efficiency(71.01%)than the AC/CBC-GA(10.72 mg/g,47.83%)and AC/AC(4.81 mg/g,12.74%)groups.It was confirmed that the CBC-SSA/GA electrodes enhanced nitrite selectivity and increased the adsorption capacity,and the total amounts of adsorbed anions increased when the applied voltage was increased from 0.8 to 1.2 V,while the molar fraction of nitrate decreased.The competitive and preferential adsorption of anions was further investigated using different binary solutions of anions and occurred in the following sequence:NO2->SO42->NO3->F-≈Cl-.Furthermore,the p-CDI units were applied to remove nitrite in real wastewater samples,and the results showed that they had excellent reusability and application for use in dyeing wastewater treatment.展开更多
基金supported by the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (No.2017BT01Z032)the National Natural Science Foundation of China (No.21577027)。
文摘In the oxidation treatment of textile dyeing sludge,the quantitative and transformation laws of organic chlorine are not clear enough.Thus,this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl^(-),the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon,and the removal and formation mechanism of organic chlorine.The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine,and the content of adsorbable organic chlorine (AOCl) was 0.30 mg/g (dry sludge).In the Fenton system with pH=3,500 mg/L Cl-,30 mmol/L Fe^(2+)and 30 mmol/L H_(2)O_(2),the removal of phenanthrene was promoted by chlorine radicals (·Cl),and the AOCl in sludge solid phase increased to 0.55 mg/g (dry sludge) at 30 min.According to spectral analysis,it was found that ·Cl could chlorinate aromatic and aliphatic compounds (excluding PAHs) in solid phase at the same time,and eventually led to the accumulation of aromatic chlorides in solid phase.Strengthening the oxidation ability of Fenton system increased the formation of organic chlorines in liquid and solid phases.In weak acidity,the oxidation and desorption of superoxide anion promoted the removal and migration of PAHs and organic carbon in solid phase,and reduced the formation of total organic chlorine.The Fenton-like system dominated by nonhydroxyl radical could realize the mineralization of PAHs,organic carbon and organic chlorines instead of migration.This paper builds a basis for the selection of sludge conditioning methods.
基金supported by the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the Natural Science Foundation of China(No.21577027)+1 种基金the 2017 Central Special Fund for SoilPreliminary Study on Harmless Treatment and Comprehensive Utilization of Tailings in Dabao Mountain(No.18HK0108)
文摘This research aimed to evaluate the alga Scenedesmus obliquus toxicity induced by textiledyeing effluents(TDE).The toxicity indicator of TDE in alga at the physiological(algal growyth),biochemical(chlorophyll-a(Chl-a)synthesis and superoxide dismutase(SOD)activity)and structural(cell membrane integrity)level were investigated.Then we further study the relationship among toxicity indicators at physiological and biochemical level,and supplemented by research on algal biomacromolecules.According to the analysis of various endpoints of the alga,the general sensitivity sequence of toxicity endpoints of Scenedesmus obliquus was:SOD activity>Chl-a synthesis>algal growth.The stimulation rate of SOD activity increased from day 3(57.25%~83.02%)to day 6(57.25%~103.81%),and then decreased on day 15(-4.23%^-32.96%),which indicated that the antioxidant balance system of the algal cells was destroyed.The rate of Chl-a synthesis inhibition increased gradually,reaching19.70%~79.39%on day 15,while the rate of growth inhibition increased from day 3(-12.90%~10.16%)to day 15(-21.27%~72.46%).Moreover,the algal growth inhibition rate was positively correlated with the inhibition rate of SOD activity or Chl-a synthesis,with the correlation coefficients were 0.6713 and 0.5217,respectively.Algal cells would be stimulating to produce excessive reactive oxygen species,which would cause peroxidation in the cells,thereby destroying chloroplasts,inhibiting chlorophyll synthesis and reducing photosynthesis.With increasing exposure time,irreversible damage to algae can lead to death.This study is expected to enhance our understanding of the ecological risks through algal tests caused by TDE.
基金supported by the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the National Natural Science Foundation of China(No.21577027)the 2017 Central Special Fund for Soil,Preliminary Study on Harmless Treatment and Comprehensive Utilization of Tailings in Dabao Mountain(No.18HK0108)。
文摘Nitrogenization is an effective method for improving the capacitive deionization(CDI)performance of porous carbon materials.In particular,polymer organic frameworks with heteroatom doping,containing an ordered pore structure and excellent electrochemical stability,are ideal precursors for carbon materials for high-performance CDI.In this study,a nitrogen-enriched micro-mesoporous carbon(NMC)electrode was fabricated by carbonizing a Schiff base network-1 at 500,600,and 700℃.Scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,N_(2) adsorption-desorption,the contact angle of water,cyclic voltammetry,and electrochemical impedance spectroscopy were used to characterize the morphological structure,wettability,Brunauer–Emmett–Teller surface areas,and electrochemical performance of the NMCs.The results showed that the NMC carbonized at 600℃ achieved the best specific capacitance(152.33 F/g),as well as a high electrosorption capacity(25.53 mg/g)because of its chemical composition(15.57%N)and surface area(312 m^(2)/g).These findings prove that NMC is viable as an electrode material for desalination by high-performance CDI applications.
基金supported by the Special Applied Technology Research and Development of Guangdong Province(major project)(No.2015B020235013)the National Natural Science Foundation of China(No.21577027)the 2017 Central Special Fund for Soil,Preliminary Study on HarmlessTreatment and Comprehensive Utilization of Tailings in Dabao Mountain(No.18HK0108)
文摘Ion-exchange polymer and modified carbonization bacterial cellulose(CBC)electrodes were fabricated using varying amounts of cation-exchange polymers(glutaric acid(GA)and sulfosuccinic acid(SSA))and assembled within an asymmetric capacitive deionization unit(p-CDI).The performance of selective NO2-electro-adsorption was studied.The AC/CBCSSA group showed a better salt adsorption capacity(14.56 mg/g)and nitrite removal efficiency(71.01%)than the AC/CBC-GA(10.72 mg/g,47.83%)and AC/AC(4.81 mg/g,12.74%)groups.It was confirmed that the CBC-SSA/GA electrodes enhanced nitrite selectivity and increased the adsorption capacity,and the total amounts of adsorbed anions increased when the applied voltage was increased from 0.8 to 1.2 V,while the molar fraction of nitrate decreased.The competitive and preferential adsorption of anions was further investigated using different binary solutions of anions and occurred in the following sequence:NO2->SO42->NO3->F-≈Cl-.Furthermore,the p-CDI units were applied to remove nitrite in real wastewater samples,and the results showed that they had excellent reusability and application for use in dyeing wastewater treatment.
