1887

Abstract

A significant global environmental opportunity of today is finding beneficial reuse for industrial and domestic wastewater through appropriate treatment, redistribution and application. Although industrial wastewater may present various challenges in terms of exotic or hard to treat constituents, finding effective and efficient treatment options and subsequent reuse opportunities will be beneficial for many facets of the environment, especially in regions of the world where water scarcity is an issue. Numerous remediation methods have been developed to purify wastewater. Most of these are physiochemical in nature, which are often not effective to implement on a large scale and can be expensive. This research explores an environmentally natural approach using biological processes (microbial activity) to achieve the degradation of petroleum hydrocarbons. The objective of this study was to study microbes native to Qatar, in particular those found within microbial mats that are found in various areas around the country. The steps taken were to first estimate the area of microbial mats using GIS, identify the microbial species within these regionally specific mats, isolate and culture cyanobacteria from these mats and explore the applicability of using these organisms for treatment of industrial wastewater.

Microbial mat samples were collected from three geographical areas around Qatar, namely Ras Abrouq, Al Zubara and Khor Al Adaid. The collected microbial mats were firstly enriched in cultured medium. Different strains of cyanobacteria were isolated from these enriched mats and were cultured using solid media ASN-III and MN. Single strains of cyanobacteria were then sub cultured in BG-II liquid medium and were used to test the biodegradability of a test set of hydrocarbons (benzene, toluene and hexadecane). The optical densities of the cyanobacteria were measured using a spectrophotometer and the rate of biodegradation of the hydrocarbons were found using a Gas Chromatography Mass Spectrophotometer (GCMS).

Results show that most of the microbial mats identified in Qatar are found on the Dukhan coastline area. Another important area of mats is found at Khor Al Adaid (Inland Sea) located in the southeastern portion of the state. Different species of cyanobacteria were identified from these mats. The most common species identified from mats at Al Zubara were Oscillatoria, Phormidium, Microcolous, Lyngbya, and Spirulina. Those from Khor Al Adaid were Plectonema, Synechococcus, Phormeduim, Lyugbya, Oscillatoria, and Trichodesmium. Those from Ras Abrouq consisted mostly of Microcolous, Lyngbya, Pseudanabena, Oscillatoria, Phormidium, Spirulina, Gloeocapsa, and Aphanothecechroococcus.

Two species of the cyanobacteria, Oscillatoria and unicellular Cyanococcus, were successfully cultured and sub cultured in BG-II medium and used for biodegradation studies with hydrocarbons. Initial results suggest these species are capable of degrading hydrocarbons, but further studies are required to determine to what extent.

For future research, the duration of incubation of microbes with the chemicals of interest for degradation could be increased to help confirm capability. Furthermore, mixtures of different species of cyanobacteria could be used to understand if populations play a role in achieving effective biodegradation of hydrocarbons. This work is also being expanded to explore other microbes found around Qatar and testing their applicability to be effective “biodegraders”. All this research may be beneficial with our larger goal of finding more effective, efficient and environmentally natural approaches to treating industrial wastewater.

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/content/papers/10.5339/qfarc.2018.EEPD725
2018-03-12
2020-08-09
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http://instance.metastore.ingenta.com/content/papers/10.5339/qfarc.2018.EEPD725
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