15.2 Photobiological Agents and Methods Used in PhotoBiological Reactors

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the oxygen absorption performance of microbubble generators was equated with

typical bubble generators. To assess each bubble generator, the liquid-phase volu-

metric oxygen transfer coefficient, gas hold-up, and power consumption per unit

liquid volume were restrained in a bubble column attached to each bubble genera-

tor. All the microbubble generators permitted the oxygen to dissolve faster than the

typical aerators. To improve an industrial wastewater treatment system, a novel aer-

ation system utilizing a spiral liquid flow-type microbubble generator was proposed,

which had a highest oxygen transfer coefficient flat at a low air flow rate, but it uses

high energy. Rewards such as compact size, portability, and fast oxygen dissolution

rate are helpful to confirm the performance for organic wastewater treatment.

Among all gas distributors, the microbubble generators exhibited better oxygen

absorption performance in contrast to the typical gas distributors. Specifically, the

spiral liquid flow-type microbubble generator had a much higher oxygen transfer

coefficient at a low superficial gas velocity. Although there is high power consump-

tion, the advantage of fast gas absorption is assessed. A novel wastewater treatment

system composed of a spiral liquid flow-type microbubble aerator, a draft tube, and

a filtration chamber displayed a much faster oxygen dissolution rate, and if it con-

sumes more energy than the typical ones, it is accessible either for oxygen supply into

an inactive region in an aerobic sludge tank or for use in a more compact tank [5].

15.2.1.4

Wastewater Produced from an Oilfield and Incessant Treatment

with an Oil-Degrading Bacterium

The species of Bacillus (M-12) decreased COD of the wastewater expressively, and

its competence is enhanced when a nitrogen source such as (NH4)2SO4 was added

into the wastewater. Oil-in-water emulsions can be treated; however, dissolved

hydrocarbons are highly toxic and hard to treat. Biological treatment is an actual

and economical way. Biodegradation of crude oil by the indigenous microorganisms

(bacteria, yeast, and fungi, that use crude oil as carbon source) is one of the main

mechanisms by which petroleum and other hydrocarbons are eradicated from

the wastewater. In contrast to pharmaceutical and food bio-transformations, they

can be effectively used in the degradation of toxic compounds during wastewater

treatment. Since the immobilized cells could be reused, it is cost-effective and has

great potential in oil wastewater treatment [6].

15.2.1.5

Pepper Mild Mottle Virus (a Plant Pathogen) as an Apt to Enteric Virus

The pepper mild mottle virus (PMMoV) can be used to assess microbial water

quality, and it acts as a useful indicator to assess wastewater treatment technologies

and to quantify viral removal in full-scale systems. The PMMoV often co-occurs

with pathogens of interest, and its natural high concentrations in wastewater were

vital for defining the degree and mechanisms of viral reduction during full-scale

treatment. Although PMMoV can be measured as an index virus for enteric viruses

in areas with untreated wastewater sources, it may not relate with infectious enteric

viruses in areas with better sanitation. The PMMoV detection and quantification

serve as an index for enteric viruses in environmental waters, which are exposed

to mixed-treated domestic wastewater. Before PMMoV is labeled as a universal