Impact of carrier media on oxygen transfer and wastewater hydrodynamics on a moving attached growth system

Abstract

This study investigated the impact of five different carrier media on oxygen transfer efficiency and flow mixing in a 2 m 3 moving attached growth system pilot-plant. The five media studied varied in shape (cylindrical and spherical), size, voidage and protected surface area (112-610 m 2 /m 3). In clean water tests, the media enhanced the overall oxygen transfer efficiency by 23-45% and hydraulic efficiency (HE) by 41-53%, compared with operation with no media. When using spherical media (Media 1, 2 and 3), the presence of biofilm increased the HE to 89, 93 and 100%, respectively. Conversely, Media 4 and 5 with biofilm contributed to a reduction in HE to 74 and 63%, respectively. The media protected surface area, the parameter traditionally selected to design biofilm processes, did not correlate with HE or with oxygen transfer efficiency in clean water tests. This study provides clear evidence that other media physical properties play a role in the mixing and oxygen transfer in moving attached growth systems. A correlation (R 2) of 0.89 and 0.90 was obtained between the media dimensionality times voidage (Di x Voi) and HE, with and without biofilm development, respectively. The combination of parameters (Di x Voi / HE) also correlated well with oxygen transfer efficiency in clean water (R 2 of 0.92 without biofilm and R 2 of 0.88 with biofilm). Dimensionality and voidage should be utilised to design and optimise media size and shape, to enhance mixing and oxygen transfer, ultimately contributing to energy savings and higher removal efficiencies.

Upgrading sequencing batch reactor using attached biofilm

“…than compensates for the higher oxygen demand. Dias et al, (2018) reported the presence of media and aeration had a positive impact on the reactor effective volume increasing hydraulic efficiency (HE) by 41-53%, compared with no media, and reducing the dead zones. The presence of media had improved aeration performance in comparison to results achieved without media.…”

Tailored Surface Porosity of Polyethylene-Based Co-continuous Structures for Moving Bed Biofilm Reactor Carriers

“…8 The shape of the PE carriers could be easily controlled by the designed mold to provide a protected specific surface area for microorganisms, which can effectively improve the loading biomass and the resistance to shearing-induced detachment. 6,20,21 In addition, a higher carrier biomass and better simultaneous nitrification and denitrification effect are obtained due to the more attaching sites for microorganisms provided by the enhanced surface roughness and increased specific surface area of the designed carrier. 8 Constructing a porous surface cannot only improve the surface roughness but also greatly increase the specific surface area in the bulk carrier, which provides a shelter surface for microorganisms and improves the shear resistance of the biofilm.…”

“…Electrostatic interactions between the cationic group on the carrier surface and negatively charged bacteria surface could improve the adhesion efficiency of microorganisms during the reversible initial adhesion stage and the shearing resistance of mature biofilms. ,, Physical modification of the PE carrier usually covers the shape design, increasing specific surface area and elevating surface roughness . The shape of the PE carriers could be easily controlled by the designed mold to provide a protected specific surface area for microorganisms, which can effectively improve the loading biomass and the resistance to shearing-induced detachment. ,, In addition, a higher carrier biomass and better simultaneous nitrification and denitrification effect are obtained due to the more attaching sites for microorganisms provided by the enhanced surface roughness and increased specific surface area of the designed carrier . Constructing a porous surface cannot only improve the surface roughness but also greatly increase the specific surface area in the bulk carrier, which provides a shelter surface for microorganisms and improves the shear resistance of the biofilm.…”

Combined UMBAF‐MBAF process treating detergent wastewater

“…To promote the performance of the BAFs, some studies have tried packing materials and improvement in configurations (Dias et al., ; Won, Jeon, Kwag, Kim, & Ra, ). In a BAFs system, different packing materials will affect the treatment efficiency of the biofilter (Han & Zhou, ).…”

“…In a BAFs system, different packing materials will affect the treatment efficiency of the biofilter (Han & Zhou, ). More importantly, optimizing the layered filling of different materials can improve the effect of mass transfer between wastewater and biofilm (Dias et al., ; Handayani, Paisal, Soepriyanto, & Chaerun, ). The most studied packing materials are ceramsite, zeolite, clay, and even waste plastic materials (Farabegoli, Chiavola, & Rolle, ).…”