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Abstract:The photostability of poly(vinyl chloride), PVC, containing various Schiff base metal complexes (0.5% by weight) was investigated. Various indices corresponding to a number of functional groups were monitored with irradiation of polymeric films to determine their photostabilization activities. The quantum yield of the chain scission (Φcs) of modified polymeric films was found to be (1.15-4.65)ˆ10 6 . The surface morphology of a PVC sample was investigated by the use of atomic force microscope (AFM). The photostability of PVC films in the presence of Schiff base additives was found to follow the following order: PVC < PVC + CuL 2 < PVC + CdL 2 < PVC + ZnL 2 < PVC + SnL 2 < PVC + NiL 2 . Various mechanisms for PVC films photostability containing the Schiff base additives have been suggested.

A variety of multidimensional anthropogenic activities, especially of industrial level, are contaminating our aquatic and terrestrial environments with a variety of metallic and non-metallic pollutants. The metallic and non-metallic pollutants addressed specifically in this review are heavy metals and various compound forms of sulfates, respectively. Direct and indirect deleterious effects of the both types of pollutants to all forms of life are well-known. The treatment of such pollutants is therefore much necessary before their final discharge into the environment. This review summarizes the productive utility of sulfate-reducing bacteria (SRB) for economical and concomitant treatment of the above mentioned wastes. Utilization of agro-industrial wastes and some environmental contaminants including hydrocarbons, as economical growth substrates for SRB, is also suggested and proved efficient in this review. Mechanistically, SRB will utilize sulfates as their terminal electron acceptors during respiration while utilizing agro-industrial and/or hydrocarbon wastes as electron donors/carbon sources and generate H2S. The biogenic H2S will then react vigorously with dissolved metals present in the wastewaters thus forming metal sulfide. The metal sulfide being water insoluble and heavier than water will settle down in the water as precipitates. In this way, three types of pollutants i.e., metals, sulfates and agro-industrial and/or hydrocarbon wastes will be treated simultaneously.

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The most common effluent created by the oil industry is oily wastewater. This produced water (PW) corrodes the steel piles in the infrastructure of bridges, which shortens their service life. It is important to remove organic content in PW to prevent this outcome. Samples from the Ahdab oil field were used in this study. Two catalysts were selected: zinc oxide (ZnO) and titanium dioxide (TiO2) with photo presence as an energy source. The results were organic elimination of 96.4% and 93.4% using ZnO and TiO2, respectively. The experimental conditions were pH = 3 and an irradiation time of 120 min. Due to the ability of ZnO to adsorb high amounts of organic content from PW, there was an increased elimination of organic content. Hence, the maintenance of steel piles durability is a good alternative to approach the goals of this study. The results of the study demonstrated that the organic adsorption on a catalyst agent reinforced in nonappearance of radiation photo is insignificant.

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