224

15 Photobiological Reactors for the Degradation of Harmful Compounds in Wastewaters

treatment could also be pragmatic as initial step to ease the anaerobic digestion of

the waste material [3].

The OMWs are called as alpechin, and they are antimicrobial and phytotoxic

because of their high organic content, mainly simple phenolic compounds. More-

over, number of compounds found in alpechin is inhibitory for microorganisms.

Antimicrobial activity of alpechin can be used in many feasible applications. More

appropriately tetracycline could be among alpechin components. The polyphenols

from alpechin are virtuous antifungal compounds and regulate a number of fruit

and vegetable diseases. Oligomers from alpechin can serve as biological response

modifiers, and inquiries on polysaccharides obtained by alpechin biotransforma-

tion would be exciting to initiate. The organic acids should also be deliberated as

biological response modifiers, and enzyme inhibitory assays are treasured as airing

tools for the discovery of the bioactive actions of alpechin extracted compounds.

All these activities can be harnessed from OMWs by filtering wastewater by using

acid-producing filamentous fungus, A. niger NB2 and its actions are enhanced by

soluble phosphate.

15.2.1.2

Isolation of Alkane-Degrading Bacteria from Petroleum Tank

Wastewater

Petroleum hydrocarbons are the major environmental pollutants, and oil spills

pose an excessive threat to terrestrial and marine ecosystems, and they had become

main environmental challenges. When sampling was done in the petroleum

reservoir, alkane-degrading bacteria were secluded with hexadecane as sole source

of carbon and energy. The isolated strains were recognized by amplifying 16S rDNA

and sequencing and specific primers were used for the identification of alkane

hydroxylase gene. The strains that contain alkane hydroxylase gene and vital for

biodegradation are Rhodococcus jostii, Stenotrophomonas maltophilia, Achromobac-

ter piechaudii, Tsukamurella tyrosinosolvens, Pseudomonas fluorescens, Rhodococcus

erythropolis, Pseudomonas aeruginosa. This study infers that there is a high diversity

of degradative bacteria secluded from petroleum reservoir wastewater.

Growth Rate and Hexadecane Elimination by Bacterial Strains All bacterial strains were

grown in hexadecane (1%) for one week with shaking (160 rpm) and hexadecane

biodegradation was analyzed by gas chromatography with flame ionization detector

(GC–FID). The strains, A. piechaudii O1 and R. erythropolis G2 have shown high

percentage of hexadecane biodegradation (93% and 84% respectively) and growth

rate. Conversely, P. aeruginosa strain B showed the lowest percentage of hexadecane

exclusion (38%) and low growth rate among other isolated strains [4].

15.2.1.3

Development of Microbubble Aerator for Wastewater Treatment

by Means of Aerobic Activated Sludge

The aerobic biochemical reactor is the most significant component in large-scale

wastewater treatment plants where the oxygen supply to the microorganisms

determines the overall wastewater treatment rate. Various types of microbubble

distributors have been established to augment the oxygen dissolution in water, and