Sorption by biodegradable polyesters of several aromatic chemicals as model compounds for hydrophobic organic contaminants (HOCs) was studied. The biodegradable polyesters used were poly(butylene succinate), poly(3-hy...Sorption by biodegradable polyesters of several aromatic chemicals as model compounds for hydrophobic organic contaminants (HOCs) was studied. The biodegradable polyesters used were poly(butylene succinate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(ε-caprolactone), poly(butylene succinate/ terephthalate), and poly(L-lactic acid). Petrochemical plastics, low-density polyethylene and polyethylene terephtalate, were used for comparison. The target HOCs were biphenyl, bisphenol-A, dibenzofuran, diethylstilbestrol, nonyl-phenol, and chlorophenols. The treatment of the HOC solutions with each of the biodegradable polyesters resulted in the nearly complete removal of the chemicals by sorption from the aqueous phase, except for the case of poly(L-lactic acid). Low-density polyethylene adsorbed biphenyl and dibenzofuran selectively, and polyethylene terephtalate did not adsorb any of the HOCs. The adsorptive interaction between the plastics and the HOCs might be related to both the glass transition temperature of the former and the nature of the latter as defined by the Fujita's inorganicity/organicity ratio. The toxic effect of 3,5-dichlorophenol on bacte-rial growth in liquid culture was removed by the addition of a biodegradable polyester. These results provide a basis for the applicability of the biodegradable plastics as the adsorbents for the removal of HOCs from aquatic environments.展开更多
Environmental fate and ecological impacts of fipronil and its transformation products(FIPs)in aquatic environment have caused worldwide attention,however,the influence of dissolved organic carbon(DOC)on multimedia dis...Environmental fate and ecological impacts of fipronil and its transformation products(FIPs)in aquatic environment have caused worldwide attention,however,the influence of dissolved organic carbon(DOC)on multimedia distribution,bioavailability,and toxicity of FIPs in field waterways was largely unknown.Here,we collected 11 companion water and sediment samples along a lotic stream in Guangzhou,South China.FIPs were ubiquitous with total water concentrations ranging from 1.22 to 43.2 ng/L(14.8±12.9 ng/L)and fipronil sulfone was predominant in both water and sediment.More than 70%of FIPs in aqueous phase were bound to DOC and the KDOC values of FIPs were approximately 1–2 orders of magnitude higher than K_(d-s)/K_(OC),emphasizing the significance of DOC in phase partitioning and transport of FIPs in aquatic environment.Water and sediment samples were more toxic to Chironomus dilutus than Hyallela azteca,and FIPs(especially fipronil sulfone)pronouncedly contributed toxicity to C.dilutus.Toxic units(TU)based on freely dissolved concentrations in water determined by solid phase microextraction significantly improved toxicity estimation of FIPs to the invertebrates compared to TUs based on aqueous concentrations.The present study highlights the significance of DOC association on fate and ecological risk of hydrophobic insecticides in lotic ecosystem.展开更多
Sorption by soil organic matter(SOM)is considered the most important process affecting the bioavailability of hydrophobic organic chemicals(HOCs)in soil.The sorption capacity of SOM for HOCs is affected by many enviro...Sorption by soil organic matter(SOM)is considered the most important process affecting the bioavailability of hydrophobic organic chemicals(HOCs)in soil.The sorption capacity of SOM for HOCs is affected by many environmental factors.In this study,we investigated the effects of soil pH and water saturation level on HOC sorption capacity of SOM using batch sorption experiments.Values of soil organic carbon-water partition coefficient(K_(OC))of six selected polycyclic aromatic hydrocarbons(PAHs)were measured in an artificial soil under various soil pH and water saturation conditions.Passive sampling was used to measure K_(OC)with polydimethylsiloxane as the sampling material.Regardless of soil pH,K_(OC)increased with increasing soil water saturation level for lower-molecular-weight PAHs.In contrast,K_(OC)decreased with increasing soil water saturation level for higher-molecular-weight PAHs.Despite some fluctuations,K_(OC)tended to decrease with increasing soil pH at all water saturation levels.This indicates that earlier studies on the effects of soil pH on K_(OC)under saturated conditions could be extended to unsaturated soils.These K_(OC)tendencies were reproduced in three different natural soils,suggesting that the effects of soil water saturation level and pH might be generalized,at least for PAHs.The PAH sorption capacity of SOM was found to be resilient under dynamic soil pH conditions,which can be used to adjust the effects of soil pH.展开更多
提出了一种新型的基于半透膜被动采样技术的微萃取方法(semi-permeable membrane based micro-extraction,SPM-ME),并以菲为模型污染物,测试了SPM-ME用于测定土壤间隙水中自由溶解态憎水性有机污染物的可行性。结果表明,菲在该SPE-ME装...提出了一种新型的基于半透膜被动采样技术的微萃取方法(semi-permeable membrane based micro-extraction,SPM-ME),并以菲为模型污染物,测试了SPM-ME用于测定土壤间隙水中自由溶解态憎水性有机污染物的可行性。结果表明,菲在该SPE-ME装置与水相间的平衡可在6h内达到,并且随着装置中三油酸甘油酯含量的增加,单元SPE-ME对于菲的富集系数也相应增加。该装置对土壤间隙水中菲的富集在10d内能达到平衡,整个过程主要受菲从土壤向间隙水的传质控制。该装置测得间隙水中菲的浓度与实际测得间隙水浓度十分吻合,而由传统的相平衡分配法计算所得间隙水浓度则高出实测值4～5倍。同时,该装置对体系中污染物的耗竭小于体系中污染物总量的1%。因此,SPE-ME是一种准确、有效、非耗竭式的微萃取技术。展开更多
基金the National Natural Science Foundation of China (No.20507009)the Program for New Century Excellent Talents in University (NCET) of the Ministry of Education of China,the Natural Science Foundation of Jiangsu Province for Outstanding Young Scientist (No.BK2006518)and the International Foundation for Science (No.C/3958-1).
文摘Sorption by biodegradable polyesters of several aromatic chemicals as model compounds for hydrophobic organic contaminants (HOCs) was studied. The biodegradable polyesters used were poly(butylene succinate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(ε-caprolactone), poly(butylene succinate/ terephthalate), and poly(L-lactic acid). Petrochemical plastics, low-density polyethylene and polyethylene terephtalate, were used for comparison. The target HOCs were biphenyl, bisphenol-A, dibenzofuran, diethylstilbestrol, nonyl-phenol, and chlorophenols. The treatment of the HOC solutions with each of the biodegradable polyesters resulted in the nearly complete removal of the chemicals by sorption from the aqueous phase, except for the case of poly(L-lactic acid). Low-density polyethylene adsorbed biphenyl and dibenzofuran selectively, and polyethylene terephtalate did not adsorb any of the HOCs. The adsorptive interaction between the plastics and the HOCs might be related to both the glass transition temperature of the former and the nature of the latter as defined by the Fujita's inorganicity/organicity ratio. The toxic effect of 3,5-dichlorophenol on bacte-rial growth in liquid culture was removed by the addition of a biodegradable polyester. These results provide a basis for the applicability of the biodegradable plastics as the adsorbents for the removal of HOCs from aquatic environments.
基金supported by the National Natural Science Foundation of China(Nos.U1901220,41977343 and 42007365)Guangzhou Municipal Science and Technology Bureau(No.202103000046)Innovative Research Team of Department of Education of Guangdong Province(No.2020KCXTD005).
文摘Environmental fate and ecological impacts of fipronil and its transformation products(FIPs)in aquatic environment have caused worldwide attention,however,the influence of dissolved organic carbon(DOC)on multimedia distribution,bioavailability,and toxicity of FIPs in field waterways was largely unknown.Here,we collected 11 companion water and sediment samples along a lotic stream in Guangzhou,South China.FIPs were ubiquitous with total water concentrations ranging from 1.22 to 43.2 ng/L(14.8±12.9 ng/L)and fipronil sulfone was predominant in both water and sediment.More than 70%of FIPs in aqueous phase were bound to DOC and the KDOC values of FIPs were approximately 1–2 orders of magnitude higher than K_(d-s)/K_(OC),emphasizing the significance of DOC in phase partitioning and transport of FIPs in aquatic environment.Water and sediment samples were more toxic to Chironomus dilutus than Hyallela azteca,and FIPs(especially fipronil sulfone)pronouncedly contributed toxicity to C.dilutus.Toxic units(TU)based on freely dissolved concentrations in water determined by solid phase microextraction significantly improved toxicity estimation of FIPs to the invertebrates compared to TUs based on aqueous concentrations.The present study highlights the significance of DOC association on fate and ecological risk of hydrophobic insecticides in lotic ecosystem.
基金supported by the Subsurface Environment Management Projects funded by the Korea Environmental Industry and Technology Institute,Korea(No.2020002440005)。
文摘Sorption by soil organic matter(SOM)is considered the most important process affecting the bioavailability of hydrophobic organic chemicals(HOCs)in soil.The sorption capacity of SOM for HOCs is affected by many environmental factors.In this study,we investigated the effects of soil pH and water saturation level on HOC sorption capacity of SOM using batch sorption experiments.Values of soil organic carbon-water partition coefficient(K_(OC))of six selected polycyclic aromatic hydrocarbons(PAHs)were measured in an artificial soil under various soil pH and water saturation conditions.Passive sampling was used to measure K_(OC)with polydimethylsiloxane as the sampling material.Regardless of soil pH,K_(OC)increased with increasing soil water saturation level for lower-molecular-weight PAHs.In contrast,K_(OC)decreased with increasing soil water saturation level for higher-molecular-weight PAHs.Despite some fluctuations,K_(OC)tended to decrease with increasing soil pH at all water saturation levels.This indicates that earlier studies on the effects of soil pH on K_(OC)under saturated conditions could be extended to unsaturated soils.These K_(OC)tendencies were reproduced in three different natural soils,suggesting that the effects of soil water saturation level and pH might be generalized,at least for PAHs.The PAH sorption capacity of SOM was found to be resilient under dynamic soil pH conditions,which can be used to adjust the effects of soil pH.
文摘提出了一种新型的基于半透膜被动采样技术的微萃取方法(semi-permeable membrane based micro-extraction,SPM-ME),并以菲为模型污染物,测试了SPM-ME用于测定土壤间隙水中自由溶解态憎水性有机污染物的可行性。结果表明,菲在该SPE-ME装置与水相间的平衡可在6h内达到,并且随着装置中三油酸甘油酯含量的增加,单元SPE-ME对于菲的富集系数也相应增加。该装置对土壤间隙水中菲的富集在10d内能达到平衡,整个过程主要受菲从土壤向间隙水的传质控制。该装置测得间隙水中菲的浓度与实际测得间隙水浓度十分吻合,而由传统的相平衡分配法计算所得间隙水浓度则高出实测值4～5倍。同时,该装置对体系中污染物的耗竭小于体系中污染物总量的1%。因此,SPE-ME是一种准确、有效、非耗竭式的微萃取技术。
