Zhiguo Chen,Wenqing Cao,Yan Li,Jingpeng Song,Yiyun Liu,Juncheng Liu,Rong Zhang,Rongxin Su,He Bai
The remediation of the chlorinated organic compounds via zero-valent iron (ZVI) and microorganisms coupling method in the groundwater has received increasing attention and research. However, the addition of external microorganisms has poor adaptability in complex environmental applications, and ZVI is easily inactivated and has weak long-term degradation performance in the environment. The existing modification preparation of ZVI modified materials seem relatively lacking economical and environmentally friendly methods. This study obtained a new type of highly efficient degradation bacterium BL5, and introduced an economical and simple method for preparing the functional CS@ZVI biological stimulation materials. The performances of CS@ZVI-BL5 systems for the removal of TCE, chloroform , 1,2-dichloroethane, and chlorobenzene were all reached 100 % after 12 days, which was significantly improved the degradation efficiency by the CS@ZVI or BL5 (95.65 %, 93.64 %, 90.54 %, 88.85 %) alone. This is the first method that extracted and screened an autochthonous high-efficiency degrading bacterium from contaminated sites, and developed a biological stimulation material to improve the remediation. Here we demonstrate that the modified CS@ZVI with BL5 microorganisms synergistically enhanced the degradation performance.
Li Jingkun,Li Huijuan,Zhao Yanfang,Wang Shanshan,Chen Xiangfeng,Zhao Ru-Song
A solid-phase microextraction (SPME) fiber coated with a hollow microporous organic network (H-MON) was fabricated for the analysis of short-chain chlorinated paraffins (SCCPs). The sorbent was prepared by reacting tetra(4-ethynylphenyl)methane and 1,4-diiodobenzene using bis-(triphenylphosphine) palladium(II) as the catalyst in the presence of silica sphere templates, which then were removed by hydrofluoric acid. The SCCPs were quantified by GC-MS working in the negative chemical ionization mode. The H-MON has a high specific surface (701 m 2 ·g −1 ) and microporosity (pore size <2 nm). Extraction temperature, extraction time, and ionic strength of the sample solutions were optimized by using the Box-Behnken design. The head-space SPME exhibits better extraction performance than the direct immersion mode. Under optimal working conditions, the detection limit (3 times of the standard deviation) is 0.03 ng·mL −1 in the water samples. Response is linear in the 0.05–10 ng·mL −1 concentration range. Repeatability and reproducibility, expressed as the relative standard deviations, ranged from 4.6 to 11.0%. The method was successfully applied in the analysis of SCCPs in water, sediments, organisms, and atmospheric particulate matter samples.
Schematic of the fabrication of a hollow microporous organic network (H-MON) on stainless steel fibers for use in SPME. The method was applied to the determination of short-chain chlorinated paraffins in biological, environmental water and atmospheric particulate matter (PM2.5) samples.