Jafari Hadi, Bagheri Rahim, Forghani Giti, Esmaeili Mahin
Faculty of Earth Sciences, University of Shahrood, Shahrood, Iran,
Environ Monit Assess. 2015 Jun;187(6):357. doi: 10.1007/s10661-015-4560-0. Epub 2015 May 16.
Wetlands are important ecosystems both at regional and global scales. They are home to a diverse group of flora and fauna, and provide water for drinking, irrigation, and recreational purposes. Miangaran endorheic wetland in SW Iran serves as the discharge point of the municipal wastewater of a nearby city; it receives agricultural return flows as well. To identify the consequences of the wastewater input, 29 water samples from the wetland's body and inlet streams were analyzed for physico-chemical parameters. The average EC of the wetland was 405 μS/cm; calcium, magnesium, and bicarbonate were the dominant ions. The average pH was high, about 8.6, due to carbonate dissolution in the drainage area which was exacerbated by photosynthesis process inside the wetland. The concentration of phosphate was over the eutrophication limit of 0.1 mg/L. Nitrate contents varied from 5.7 to 12.3 mg/L. Trophic state index based on total nitrogen was about 63, falling within the eutrophic group. Heavy metal concentrations were generally higher than WHO drinking limits. Highest values of EC, nutrients, and metals were observed in the south and northwest, clearly signifying the role of wastewater input as the main source of contamination, which has resulted in the eutrophication of the wetland.
湿地在区域和全球尺度上都是重要的生态系统。它们是多种动植物的家园，并为饮用、灌溉和娱乐提供水源。伊朗西南部的米亚格兰内流湿地是附近一座城市生活污水的排放点，同时也接纳农业回流。为了确定污水排放的影响，对湿地水体和入流溪流中的29个水样进行了理化参数分析。湿地的平均电导率为405μS/cm，钙、镁和碳酸氢根是主要离子。由于排水区域内碳酸盐溶解，且湿地内部的光合作用加剧了这种情况，平均pH值较高，约为8.6。磷酸盐浓度超过了0.1mg/L的富营养化限值。硝酸盐含量在5.7至12.3mg/L之间变化。基于总氮的营养状态指数约为63，属于富营养类别。重金属浓度普遍高于世界卫生组织的饮用水限值。在南部和西北部观察到电导率、营养物质和金属的最高值，这清楚地表明污水排放是主要污染源，导致了湿地的富营养化。
