Catalytic etherification is a new and developing method for the upgradation of pyrolysis bio-oil into high performance bio-based long-chain ethers. In this work, the application of bio-based long-chain ether oxygenated additives in diesel engines have been checked by focusing on their regulated emissions and PAH emissions. Four bio-based long-chain ethers with similar structures, including: Polyoxymethylene dimethyl ether , diglyme , dipropylene glycol dimethyl ether and tripropylene glycol methyl ether have been blended with diesel fuel and tested in a small-duty diesel engine. The results showed that long-chain ethers were beneficial to the reduction of regulated emissions by comparing to pure diesel. Polyoxymethylene dimethyl ether and tripropylene glycol methyl ether showed best performance among the four tested ethers. Polyoxymethylene dimethyl ether could reduce 56% CO, 23% NO and 93% soot emissions, while Tripropylene glycol methyl ether could reduce 52% CO, 28% NO and 88% soot emissions. Besides, the particle sizes of soot particles from the blended fuels were also reduced. What's more, the addition of bio-based long-chain ethers could reduce particulate PAHs emissions by 39% ~ 67% and reduce gaseous PAHs emissions by 25% ~ 44%, and the PAHs toxicity was also reduced by 32% ~ 55%. This work proved that the structure of oxygen atoms evenly distributed in the chain could efficiently suppress the production of soot precursors and eventually reduce the soot emission
Rapid and highly effective enrichment of nuclides containing liquid effluent is crucial for online monitoring of radioactive trace elements from nuclear power plants (NPPs). In this study, auxiliary electrodialysis (AED) was proposed for high enrichment of trace ions in the liquid effluents of NPPs. The effects of the auxiliary ion type and concentration and the operating voltage on the AED concentration performance were investigated. When the volume ratio of the solution was 140: 1 with 0.03 mol/L HNO 3 as the auxiliary electrolyte, most of the nuclide ions were concentrated more than 50 times after the two-stage electrodialysis experiment. In the first-stage electrodialysis, the concentration of most ions, with the exception of the higher valence ions (Ru 3+ and Zr 4+ ), tends to increase with increasing operating voltage. The diluate stream volume could be minimized to 98.8% with a total energy consumption of 9.5 kWh/m 3 . By considering the impact of boron in the liquid effluents, more than 52 times concentrations could still be achieved by extending the running time of the first-stage ED (increasing the ion removal rate). The transmembrane fluxes of various cations decreased in the order of Cs + > Sr 2+ > Zn 2+ > Co 2+ ≈ Ni 2+ ≈ Mn 2+ > Fe 3+ > Cr 3+ > Ru 3+ > Zr 4+ , which is attributed to the experimental operating parameters and ionic properties. This research provided a viable technique for rapid and highly effective enrichment of nuclides containing liquid effluents for both radioactive element monitoring and wastewater volume reduction.
Li Jianan,Cheng Weixiao,Xu Like,Jiao Yanan,Baig Shams Ali,Chen Hong
In this study, the occurrence of 8 antibiotics [3 tetracyclines (TCs), 4 sulfonamides, and 1 trimethoprim (TMP)], 12 antibiotic resistance genes (ARGs) (10 tet , 2 sul ), 4 types of bacteria [no antibiotics, anti-TC, anti-sulfamethoxazole (SMX), and anti-double], and intI 1 in two wastewater treatment plants (WWTPs) were assessed and their influences in downstream lake were investigated. Both WWTPs’ effluent demonstrated some similarities, but the abundance and removal rate varied significantly. Results revealed that biological treatment mainly removed antibiotics and ARGs, whereas physical techniques were found to eliminate antibiotic resistance bacteria (ARBs) abundance (about 1 log for each one). UV disinfection did not significantly enhance the removal efficiency, and the release of the abundantly available target contaminants from the excess sludge may pose threats to human and the environment. Different antibiotics showed diverse influences on the downstream lake, and the concentrations of sulfamethazine (SM2) and SMX were observed to increase enormously. The total ARG abundance ascended about 0.1 log and some ARGs (e.g., tet C, intI 1, tet A) increased due to the high input of the effluent. In addition, the abundance of ARB variation in the lake also changed, but the abundance of four types of bacteria remained stable in the downstream sampling sites.
危险品化学品经营许可证（带存储）