In this work, seafood wastewater was treated by using MBBR reactor over a novel carrier (PUF-PVA gel) derived from the combination of a porous (PUF) and hydrophilic surface (PVA gel). A freezing-thawing method was used for the preparation of the novel PUF-PVA gel which is reported for the first time. Experimental results indicated that PUF-PVA gel carrier which possesses an excellent textural structure (specific surface area of 3.4 m2/g, pore size in the range of 10 -40 μm and hydrophilic surface) accounts for faster water immersion and better microbial adhesion, resulting in the biofilm content attached at the start-up stage 2.4 times higher relative to conventional PUF carrier alone. The MBBR system can be operated stably at a hydraulic retention time (HRT) of 7 hours in which the organic loading rate ranged from 2.5 kg COD/m3.day to 5.1 kg COD/m3.day. When operated at the organic loading rate of 2.5 kg COD/m3.day, the maximum COD and the nitrogen removal efficiency of MBBR based on the PUF-PVA gel carrier were 92 ± 0.6% and 89 ± 3.4%, respectively, which is higher than that of the PUF carrier.

Aerodynamic drag reduction is required with new stringent constraints on pollutant emissions and fuel efficiency of ground vehicles. In this context, active flow control is a promising approach to achieve this target. This study focuses on applying different flow control strategies on the square-back Ahmed model to reduce aerodynamic drag. A steady blowing jet, a synthetic jet and an unsteady jet are located at the back edges of the model as flow control devices. A numerical study based on the 3D WMLES simulation was performed to evaluate the drag reduction capabilities of these devices at different operating conditions. The results showed that a maximum aerodynamic drag reduction of 26.51% was achieved when using a steady blowing jet, and 17.27% with an unsteady jet. In contrast, the effect of the synthetic jet on the aerodynamic drag of the model is solely at high control frequencies.