A bimetallic-catalyzed oxidative esterification reaction has been conducted between non-activated C(sp 3 )-H bonds of symmetric ethers and carboxylic acids with the presence of di-tert-butyl peroxide as the oxidant through a cross-dehydrogenative coupling (CDC) reaction. This approach allows the derivatives of cyclic ether substrates to interact with aromatic acids, giving excellent yields for the formation of a-acyloxy ethers. The bimetallic organic frameworks catalyst (Fe 2 Ni-BDC) that had been synthesized by solvothermal method was successfully utilized for the formation of a-acyloxy ethers based on the CDC reaction of carboxylic acid with diethylene oxide (approx. 84 % product yield). Besides, this material was also used as catalyst for research scope of benzoic acid containing various substituents.

Groundwater ammonia pollution is well investigated worldwide as well as in Viet Nam. The products of its conversion process, namely nitrite and nitrate, cause the toxicity of ammonia in water. In addition, the existence of ammonia in water causes the modification of water taste and smell, increases the risk of heterotrophic and contagious microorganism presence. Biofilm technique has been being applied to treat the ammonia in the groundwater recently. In this present study, fixed‐bed biofiltration technique was implemented to remove the ammonia at high concentration of 20‐50 mgN/L. The results indicated that the effluent reached the standard of domestic and drinking water quality (the ammonia concentration < 3 mgN/L) at all investigated ammonia concentrations. The specific nitrification rate of the microbial carrier used reached the maximum value of about 3.76 kgN.m‐3.day‐1 with the hydraulic retention time lower than 0.4 h and feed ammonia concentration of about 50 mgN/L. The biomass density in biofiltration column before experimental implementation was about 1000 mg/L.