Wenbo Chai

Graphite/isobutylene-isoprene rubber highly porous cryogels as new sorbents for oil spills and organic liquids.

The preparation, by a freeze-thaw method, of new graphite/isobutylene-isoprene rubber (IIR) sorbents for oil and organic liquid is described. Graphite was expected to improve the adsorption properties. The cryogels were prepared by solution crosslinking IIR rubber in the presence of graphite in benzene at various temperatures, using sulfur monochloride as the crosslinker, and characterized by SEM and contact angle measurements. The dried cryogels, with interconnected macropores were sponge-like soft materials, with excellent buoyancy and hydrophobicity. They also showed excellent sorption characteristics, with the best sample exhibiting maximum sorption capacities of 17.8 g g(-1) for crude oil, 21.6 g g(-1) for diesel oil, and 23.4 g g(-1) for lubricating oil, respectively. The samples also showed excellent sorption capability for organic liquids, absorbing up to around twenty times their own mass. After rapid and effective desorption, taking just 3-5 h, the cryogels were recovered. They could also be reused more than 30 times by simply centrifuging to remove the sorbed liquid. These characteristics mean that the cryogels prepared in this study are promising materials for removal of large-scale oil or toxic organic spills.

Pomelo peel modified with acetic anhydride and styrene as new sorbents for removal of oil pollution.

Pomelo peel (PP), as one of the well-known agricultural wastes, is cost-effective and environmentally friendly. Based on PP, two new kinds of oil sorbents were prepared by using acetic anhydride and styrene. The structures of raw pomelo peel (RP), acetic anhydride-treated pomelo peel (AP) and styrene-treated pomelo peel (SP) were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), contact-angle (CA) measurements. The optimum reaction conditions for preparation of AP and SP were also investigated. The resulting products exhibited better oil sorption capacity than that of RP for diesel and lubricating oil, also SP had better oil sorption capacity than AP, while the oil sorption capacities of SP for diesel and lubricating oil reached 18.91 and 26.36 g/g, respectively. Adsorption kinetics was well described by the pseudo-second-order model. The results indicated that AP and SP, especially SP could be used as the substitute for non-biodegradable oil sorption materials.

The use of proteomic analysis for exploring the phytoremediation mechanism of Scirpus triqueter to pyrene.

Scirpus triqueter has been reported to be an effective phytoremediation plant for pyrene dissipation. The study of S. triqueter in response to pyrene is crucial to understand the mechanism of phytoremediation. To gain a certain extent understanding of S. triqueter in response to pyrene, S. triqueter seedlings were exposed to 50 mg kg(-1) pyrene and a comparative proteomic analysis of total proteins was performed. 37 and 55 proteins were significantly differentially expressed in the shoot and root of S. triqueter upon exposure, respectively. 24 proteins (17 proteins in shoot and 7 proteins in root) were identified on the basis of the homology of their peptide profiles with existing protein sequences using mass spectrometry analysis. Analysis of protein expression patterns revealed that proteins in shoot associated with photosynthesis, defense, energy and matter metabolism, coenzyme metabolism and protein metabolism. Moreover, the proteins related photosynthesis accounted for more than 70% of the identified proteins. The proteins in root associated with stress, defense, energy metabolism, protein modification and carbohydrate metabolism. Pyrene appears to have an important deleterious effect on primary carbon metabolism, the synthesis of proteins and signal transduction. The present study demonstrates the use of proteomic approach to help us understand the phytoremediation mechanism of S. triqueter.

Sorption of oil from simulated seawater by fatty acid-modified pomelo peel

AbstractA new, low-cost and locally available sorbent, pomelo peel (PP), was tested for its ability to remove spilled oil from simulated seawater. The experiments were conducted to evaluate the oil sorption capacities of PP modified by fatty acids (oleic acid and stearic acid). The effects of temperature, salinity, and oscillation frequency on the oil sorption capacity of the PP were studied in simulated seawater. It was found that the oil sorption capacity of the PP was greatly enhanced by the surface modification. The results showed that the PP modified by oleic acid had better oil sorption capacity than that treated with stearic acid. The sorption kinetics of unmodified and modified PP were well described by the pseudo-second-order kinetic model. The results indicated that PP was an attractive candidate for removing oily pollutants from seawater.

Preparation and characterization of polypropylene fiber-grafted polybutylmethacrylate as oil sorbent

AbstractPolypropylene fiber-grafted polybutylmethacrylate (PP-g-PBMA), a new oil absorbent, was prepared by suspension polymerization using butyl methacrylate as monomer, benzoyl peroxide (BPO) as initiator, and N,N′-methylenebisacrylamide as cross-linker. The effects of monomer concentration, initiator concentration, and cross-linker dosage on the oil absorbency were studied. The results revealed that the pseudo-second-order kinetics model fitted well with the experimental results. The sorption isotherms studies indicated that the equilibrium process was well described by the Freundlich isotherm model. The structures of polypropylene fiber (PP) and PP-g-PBMA were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 adsorption–desorption, contact-angle (CA) measurements, and differential thermogravimetric analysis. The results of FTIR and SEM show that PBMA was successfully grafted onto PP fiber substrate. The maximum oil sorption capacity of PP-g-PBMA fo...