CHEMOSPHERE
·
2019
·
IF 5.108
Chao Song,Hua-Yu Liu,Shuang Guo,Shu-Guang Wang
As the most typical geological environment, limestone landforms are widespreading in the world and affect the waters that flow around them, which may also change the fate of organic contaminants in these waters. In this study, aquatic environment surrounding limestone was simulated with calcium carbonate , and the photolysis of tetracycline was evaluated under UV irradiation (30 μW/cm 2 ). More tetracycline (up to 98%) was removed in 4 h in the presence of calcium carbonate while only 50% of tetracycline was eliminated in control experiment. The removal of tetracycline was greatly enhanced due to the major roles of alkaline pH and minor roles of Ca 2+ and HCO 3 − /CO 3 2− . In alkaline pH, tetracycline existed as TCs − with higher electronic density in the ring structures, which was more easily attacked by OH. Besides, it could also change the bond orbital energy to facilitate tetracycline absorbing more photon. Moreover, alkaline pH was beneficial to generate more OH and thus promote the indirect photolysis. In addition, alkaline pH also changed the degradation path of tetracycline and rapidly convert tetracycline to the byproducts with m/z 457 via hydroxylation and hydrogen abstraction. This work provides not only better understanding about the fate of tetracycline in aquatic environments but also new insights into the treatment of antibiotic-contaminated water.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Zhendong Liu,Longguan Zhu,Bingjian Zhang
The surface weathering of open-air limestone caused by long-term acid-rain erosion and thermal stress is an urgent issue to solve. In this study, seven concentrations of diammonium phosphate and aluminum chloride hexahydrate (fixed molar ratio of 1000:1) were used to generate aluminum phosphate protective materials in situ with high lattice matching with calcite for surface consolidation. The compatibility test, mechanical property evaluation, and protective mechanism of the material were elucidated by color change, porosity, permeability, surface hardness, infinite compressive strength, Fourier-transform infrared spectroscopy, and scanning electron microscopy–energy-dispersive X-ray spectroscopy. It was found that aluminum phosphate had good aesthetic compatibility and water–vapor exchange balance with the matrix and surrounding environment. Meanwhile, the surface coating grown by crystal accumulation could play a role in filling pores and agglomerated particles, thereby improving the hardness (83.5 HD), infinite compressive strength (4.05 MPa), and acid-rain erosion resistance of the limestone weathering layer. Aluminum phosphate can play a vital role in the treatment and prevention of limestone surface-weathering diseases and has high research value and broad application prospects.
研究领域:
材料科学
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文物保护
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 11
·11170-11178
·
IF 2.914
Sun Kaixuan,Sun Yuanyuan,Gao Bin,Xu Hongxia,Wu Jichun
Retention and transport of sulfonamides (SAs) in subsurface can strongly affect groundwater quality. In this work, a range of laboratory batch sorption and column transport experiments were conducted to determine the effect of cation type in mixed Ca-Na systems on the retention and transport of two typical SAs, sulfadimethoxine (SDM) and sulfacetamide (SCA), in saturated limestone porous media. Column experimental data showed divalent cation Ca 2+ played a more important role than monovalent cation Na + in decreasing the transport of only SDM in co-cation systems in the saturated limestone media. Further, in the single-cation (i.e., including either Ca 2+ or Na + ) system, increasing ionic strength (IS) of either NaCl or CaCl 2 had little effect on SCA transport; however, increasing of IS of CaCl 2 promoted the retention of SDM in the saturated limestone porous media. This is mainly due to the cation bridging effect of Ca 2+ on SDM and limestone. Overall, SDM showed much higher retention in the limestone columns than SCA, which can be attributed to the two SAs’ different physicochemical properties. Moreover, limestone showed stronger ability to retain the two SAs than quartz sand. Findings in this study suggest that cation type and the concentration of certain electrolyte (e.g., CaCl 2 ) as well as medium type play an important role in controlling the environmental fate and transport of antibiotics.
研究领域:
环境科学
·
水文学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HYDROLOGY
·
2021
·
IF 5.722
Peiyao Dong,Wenhui Qiu,Xin He,Yong Zhang,Chunmiao Zheng
Sulfonamide antibiotics (SAs) are commonly used antibiotic classes in livestock worldwide. SAs are discharged to the environment and then may accumulate in rivers and aquifers, thereby diminishing water quality and the overall health of the ecosystem. While the occurrence and distribution of SAs in water environments have been the subject of numerous investigations, the fate and transport of SAs in aquifers have been less understood. In the present work, four of the most used SAs, including sulfadiazine (SDZ), sulfathiazole (STZ), sulfamethazine (SM2), and sulfamethoxazole (SMX), were selected for laboratory experiments and modeling analysis. The experiments were conducted in saturated columns filled with two common porous media, quartz sands and limestone grains. Results showed that the SAs had mobility changing on the order (from high to low) of SMX > SM2 > SDZ > STZ in the column, with SMX being the least absorbed SA by quartz sand or limestone grains. Moreover, calcium ions inhibited the transport of SAs more strongly than that of sodium ions, while the inhibitory effect was slightly enhanced with an increasing Na + concentration from 0 to 10 mM. In contrast, the presence of humic acid facilitated the transport of SAs. Although the four SAs have similar molecular structures, their adsorption and transport characteristics were shown to be quite different. The dynamics of the adsorption and transport of SAs in groundwater can be effectively described by a two-site adsorption model coupled with advection and dispersion. This study sheds new light on the transport of SAs, contributing to a better understanding of how to control the presence and migration of antibiotics as new emerging contaminants in groundwater.
研究领域:
环境科学
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水文地质学
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水质
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污染物传输
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产品关联
DOI
高影响因子
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