Water pollution due to industrial wastes

Water pollution due to industrial wastes

Many of aromatic toxic compounds of petroleum oil and crude petroleum affect on the various species of aquatic life in several ways.Mainly, when the petroleum is spilled on the surface of any aquatic form that blocks the Oxygen and carbon dioxide exchange and equilibrium in that aqua-medium.It brings the ultimate result of harmful PH value due to low concentration of Oxygen and higher concentration of carbon dioxide gases and some other biologically required gaseous substances.

The petroleum constituents of primary interest to human health have been the aromatic hydrocarbons (i.e., benzene, ethylbenzene, toluene, and xylenes), poly nuclear aromatic hydrocarbons (PAHs), gasoline additives (e.g., MTBE, TBA), and combustion emissions from fuels (e.g., carbon monoxide, benzene, acetaldehyde, formaldehyde, diesel particulates). The aromatic hydrocarbons are identified as chemicals of interest for health risk assessments at most petroleum-contaminated sites  and for sites affected by petroleum solvent.  Benzene is the only aromatic hydrocarbon classified by the U.S. Environmental Protection Agency and other health and environmental agencies as a “known human carcinogen,” and therefore, is the primary focus of many petroleum hydrocarbon risk assessments.

The potential exposure to benzene at a petroleum-contaminated site depends on the concentrations of benzene in the soil, water, and air, and the frequency and duration of expected human contact with the contaminated media. Benzene and the other aromatic hydrocarbons are taken up through the skin, lung, and digestive system, so all three routes of exposure (dermal uptake, inhalation, and incidental ingestion) need to be considered in assessing health risks.

Assessing the health risks associated with the use of petroleum solvents requires additional consideration beyond those of a site risk assessment. Benzene is not added to petroleum solvents but was historically found in solvents, at relatively low levels, occurring as a contaminant in the distillate fraction that composes the majority of the solvent. Little is known about the benzene concentrations in many of these solvents, except that levels were less than 0.1 weight percent (1000 ppm by weight), which is the OSHA reporting limit for material safety data sheets (MSDSs). 

Hydrocarbons,pharmaceutical substances, poly aromatic hydrocarbons,radio-active substances,heavy metals are the most significant and prominent bio-system pollutants which shows possible major threats to aquatic and terrestrial  eco systems as well as their life.Normally some rare species of microbes can secrete enzymes that is able to decompose above toxic substances in to non toxic natural substances and they shows the ability of rapid multiplication in cell division of asexual reproduction.Such a bio remediation process provides the best non toxic natural substances for environmental stability in neutralization and the elimination of bio-hazardous substances.

                                                               biomediators-bacteria


Usually organic compounds of pollutants are degraded by aerobic micro organisms such as Pseudomonas while anaerobic micro organisms degrade the particular hydrocarbons  and halogenated compounds and mineralize the recalcitrant organic substances. bio mediators such as Alcanivorax borkumenesis cleans the spilled oil puddles by eagerly consuming the petroleum of affected sites.Above kind of hydrocarbonoclastic bacteria are introduced in both of ways of in situ or ex situ contexts.

Any way, this is done by introduction of special group of naturally occurring bacterial species or introduction of genetically modified microbes.The latter kind of microbes fasten the process of decomposition of oil spills and heavy metals

Biologically modified microbes are able to fasten the decomposition rate of pollutants in to natural substances but  they also make the kind of suppression of growth for many of naturally occurring species in such eco systems.These genetically modified species have a risk of modification in to different available food sources for their survival after the end of spilled oil substances.This is a possible risk of bio meditation process of environmental cleaning.

(S.M Anuradha Senarathna----BSc(Hon's)PG Dip in socio---youths for good politics,sera idea blogspot.com