MIXED CULTURE BIOLOGICAL ACTIVITY IN
WATER CONTAINING VARIABLE LOW CONCENTRATIONS OF
CYANIDE, PHENOL, AND BOD
Abulbasher M. Shabalam, Associate Professor
Civil Engineering Department
Yarmouk University
Irbid, Jordan
INTRODUCTION
During recent years, the potential effects of industrial pollution on water quality have become
increasingly apparent. Specifically, the effluent discharges from coal, petroleum, and steel industries
containing chemicals such as oil, grease, cyanide, ammonia, phenol, and heavy materials raised controversy over the development and imposition of pollution control regulations. Main reasons of controversies are due to the facts that the conventional pollution parameters, such as Biochemical Oxygen
Demand (BOD) and Dissolved Oxygen (DO), do not adequately represent the pollution levels created
by the industrial discharges. Moreover, the knowledge of the transport and degradation mechanisms
and interrelationships of these chemicals during the process of the degradation is very limited.
Every polluted water body to some extent possesses the property of self-purification through the
processes of sustaining biological activity, hydrolysis, volatilization, chemical reactions, and absorption and adsorption into the suspended and bottom solids. The biological conversion of unsafe chemicals into gas or safer chemicals is one of the most important natural phenomena contributing to the
process of natural water purification.
It has long been known that a biological population degrading a chemical compound does not
depend only on the concentration of its main food chemicals but also on its environmental conditions.
The environmental conditions include temperature, pH, and presence of other chemicals in the water.
It is also known that the types of predominantly active biological population in waters vary depending
upon the available food chemicals. Within the context of this knowledge, it is apparent that to evaluate the bioactivity in a stream receiving industrial wastes, one should carefully study the total environment resulting from the discharges of different chemical wastes discharged simultaneously in the same
water body. Hence a laboratory scale study was performed with the following purposes: (1) to determine the biodegradation rates of phenol, cyanide, and total organic carbon (TOC) utilizing mixed culture microorganisms within a solution containing low concentrations of these chemicals as normally
observed in an industrially polluted stream; and (2) to investigate the effects of phenol and cyanide on
the bioactivity related to the parameter of BOD.
Cyanide in open water body disappears mainly by three mechanisms; namely, the biodegradation,
volatilization, and hydrolysis. One of the ionic hydrolysis product of cyanide is ammonia. Thus,
ammonia concentration is affected by the disappearance of cyanide by hydrolysis. To determine the
biodegradation of cyanide, an account of the cyanide losses due to volatilization and hydrolysis is
essential. In this study, the effects of volatilization and hydrolysis were accounted for by utilizing
information reported elsewhere [1].
LITERATURE REVIEW
The capability of microbes to degrade phenol was established by several investigators [2,3]. Pitter
[4] determined the biological degradation rates of several phenolic substances. McKinney et al [5]
investigated the biodegradability of several industrially important phenolic compounds by utilizing
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