Petroleum residues in the waters of the Shatt al-Arab River and the northwest region of the Arabian Gulf

During April 1980, water samples were collected from 12 sites in the Shatt al-Arab River and its estuary in the northwest region of the Arabian Gulf. The samples were extracted and the concentration of petroleum hydrocarbons were determined spectrofluorometrically, in order to provide information on the background values of oil generally present in these waters. Total hydrocarbon concentrations of these samples ranged from 2.7 to 86.7 μgL^?1 expressed in terms of Kuwait crude oil equivalents. The highest concentrations were found at sites in the Shatt al-Arab River that are near port areas.     

Residues of organochlorine pesticides in environmental samples from the Shatt al-Arab River, Iraq

Application of high resolution gas chromatography has confirmed relatively low residue levels of sumDDT, endrin and dieldrin in the Shatt al-Arab River. Thus, average concentration of these compounds in the edible portion of the cyprinid (Barbus xanthopetrus) were 21, 4 and 2 microg kg(-1) wet weight respectively. Mean values of sumDDT, endrin and dieldrin in surface sediments were 5, 40 and 20 microg kg(-1) dry weight respectively. Shrimps sampled from the Shatt al-Arab River were found to contain residues of o, p'-DDD only (average concentration was 2 microg kg(-1) wet weight). However, comparison of these samples with those from an area affected directly by a point source of organochlorine pesticides has shown that the cyprinid of the same age group contained significantly higher residue levels (average concentrations of sumDDT, endrin and dieldrin were 166, 20 and 7 microg kg(-1) wet weight respectively). Thus, it may be concluded that there was no direct input of organochlorine pesticides to the Shatt al-Arab River, and transportation via the natural processes, such as drainage, appeared to be the sole source. Based upon the observation that the original compound (p,p'-DDT) has not been detected in this river, it has also been concluded that there was no recent contribution of DDT here. Relatively higher residue levels of sumDDT, endrin and dieldrin were encountered in the muscles of the Indian shad captured from the Shatt al-Arab River (average concentrations were 163, 80 and 28 microg kg(-1) wet weight respectively). However, these elevated values were attributed to this fish being migratory and it being exposed to these pesticides elsewhere.     

Harvesting of microalgae biomass from the phycoremediation process of greywater

The wide application of microalgae in the field of wastewater treatment and bioenergy source has improved research studies in the past years. Microalgae represent a good source of biomass and bio-products which are used in different medical and industrial activities, among them the production of high-valued products and biofuels. The present review focused on greywater treatment through the application of phycoremediation technique with microalgae and presented recent advances in technologies used for harvesting the microalgae biomass. The advantages and disadvantages of each method are discussed. The microbiological aspects of production, harvesting and utilization of microalgae biomass are viewed.