Textile wastewater is a combination of various chemicals and different types of dyes and has a salty nature. In this study, an SBR (sequencing batch reactor) was used to treat synthetic and real textile wastewaters in a 24 h cycle time. Remazol Brilliant Blue R, a reactive dye, was used as the model dye. Dye concentrations ranged from 125 mg/L to 500 mg/L, and TDS (total dissolved solids) concentrations ranged from 1000 mg/L to 10,000 mg/L in synthetic wastewaters. For the highest dye concentration (500 mg/L) with low TDS, an 80.71% COD removal efficiency was obtained; at a TDS concentration of 5000 mg/L, a 59.44% COD removal efficiency was obtained. When the TDS concentration of wastewater was raised to 10,000 mg/L, COD removal decreased to 14.92% and reductions in MLSS (mixed liquor suspended solids) and MLVSS (mixed liquor volatile suspended solids) concentrations were observed. According to the results, increasing the TDS concentration of wastewater up to 5000 mg/L did not affect COD removal efficiency of the activated sludge microorganisms in the treatment system.

In the present investigation down core variations of heavy metals such as; Zn, Ni, Co, Mn, Fe and Al in a sediment core from Bay of Gorgan adjacent to the Caspian Sea was studied. Inter-relationship amongst various parameters was brought out through correlation coefficients and cluster analysis. The results of present study reveals that Zn, Ni, Co and Mn possess both lithogenous and non-lithogenous sources. The increasing trend of Al towards top of sediment core is indicative higher erosion in the recent years. Interestingly, concentration of all studied metals increases toward core top (except for Fe) that might be indicative of influence of man's activities residing in catchment area of Gorgan Bay and also oil exploration in the Caspian Sea.

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In special petroleum areas where the petrochemical, petroleum and gas industries are located, ambient emissions are the first and most environmental pollutants that are undetectable. The present study aims to assess the environmental pollutants resulting from leaks and fixed resources of Olefin unit in the Arya Sasol Petrochemical Complex located in Asaluyeh, south of Iran. In this study, the LIAM method (LDAR, IR Camera, Analyzing & Modeling) was for sampling process during four seasons from 2016 to 2017. Leak points of the unit were detected by IR Camera and LDAR program. AERMODE software was also used to model the dispersion of SO 2 , NO X , CO 2 and particulate matters released from the fixed resources. In the next, IDW method in ArcGIS 10.2 was conducted to interpolate the environmental pollutants. The interpolation of the annual average of pollutants showed that the concentration of benzene, butadiene, ethylbenzene, heptane and SO 2 in some sections is higher than the environmental standards. The results of AERMODE modeling showed that the maximum 24-h concentration and annual average of SO 2 only in autumn have exceeded the clean air standard. The combination of proposed methods in this study can be used as a smart way to evaluate the industrial pollutants.