Iranian Journal of

Background and Objectives: Linear alkyl benzene sulfonates are widely used as surfactants in formulated detergent products. Because of their use in household and industrial detergents, LAS is discharged into wastewater collection systems and subsequently entered to wastewater treatment plants. Therefore, it is important to determine the concentration of LAS with accuracy. They are usually determined by standard method which is time-consuming,tedious and requires great quantities of chloroform. IN 2006 E.Jurado et al proposed a simplified method for measurement of LAS. In the present work the standard method and E.Jurado simplified method was compared economically.
Material and Methods: In this work NPV method was used for accounting the cost of initial investment, consumable material, non-consumable equipment and annual cost of staff and finally Net Present Value was calculated for them separately. The rate of interest was considered 15%.
Results: calculation showed initial investment, annual cost of staff and materials for standard method 13351981, 499968 and 1710981 RLS, respectively. And these costs for simplified method were 12048202, 83328 and 58202 RLS, respectively. Finally NPV for standard method and simplified method were equal to 30360709 and 14681848 RLS.
Conclusion: The method proposed by E.Jurdo et al is simple, time consuming and more economical than standard method .This technique can be suggested applying to the routine measurement of LAS in wastewater treatment plants.

Background and Objectives: Dust phenomenon has adverse effects on the health of the population.Due to the increasing concentration of Kermanshah dust phenomenon in recent years, The aim of this study was to measure the concentration of the sensitivity coefficients between dust phenomenon hospitalization and mortality rates for heart and respiratory.

Materials and Methods: This was a descriptive study in which we studied the sensitivity coefficient of hospitalization and mortality rates for heart disease and respiratory to changes of dust concentration.. The study duration was during March-September 2010 and 2011. We collected the dust phenomenon data from Kermanshah Province Environmental Protection Department. The admissions and mortality of the cardiovascular and respiratory sufferers was collected from the Imam Ali, Imam Reza, and Imam Khomeini governmental hosiptals in Kermanshah.

Results: 1% increase in air pollution caused by the dust phenomenon will result in increasing about 0.5 % of the respiratory patients, 1% cardiac patients, and about 0.3% of the heart disease mortality. The relationship between dust phenomenon and respiratory sufferers was statistically not significant.

Conclusions: We found that respiratory and cardiovascular hospital admission has a high sensitivity to dust phenomenon. This sensitivity has increased from 2010 to 2011. This sensitivity was greater for males than females. At least, during March-September 2010, for every 100% increase in the concentration of dust phenomenon, cardiovascular mortality increased by 29%.