ارزیابی حضور فلزات سنگین در نمک و آب دریاچه مهارلو در مقایسه با غلظت آنها در سنگ نمک معادن سیرجان، لار و فیروزآباد

نوع مقاله: مقاله پژوهشی

نویسندگان

1 کارشناس ارشد اداره استاندارد استان فارس، شیراز

2 دانشیار گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی شهرکرد

3 دانشجوی کارشناسی ارشد مهندسی منابع طبیعی، دانشگاه تربیت مدرس، تهران

4 کارشناس ارشد پژوهشکده میگوی کشور، تهران

چکیده

دریاچه مهارلو از مهم‌ترین اکوسیستم‌های آبی ایران است که در معرض خطرات ناشی از مدیریت آب، برداشت نمک و آلودگی‌های شدید، به‌ویژه فلزات سنگین قرار دارد. در این پژوهش غلظت کروم، مس، آرسنیک، کادمیم و سرب در نمک و آب مناطق شمالی و جنوبی دریاچه مهارلو ارزیابی شد. پس از هضم نمونه‌های برداشت شده از هر بخش، میزان فلزات سنگین توسط دستگاه جذب اتمی اندازه‌گیری شد. بر اساس میانگین مقادیر اندازه‌گیری شده، ترتیب فلزات در نمونه‌های نمک در شمال و جنوب دریاچه مشابه و به‌صورت  Cr> Cu> As> Cd> Pb بود. در نمونه‌های آب، ترتیب مقادیر فلزات در هر دو بخش یکسان (Cr > Cu > As > Pb > Cd) بود. نتایج نشان داد غلظت فلزات موجود در نمک و آب، به‌جز فلز سرب، در بخش شمالی دریاچه نسبت به بخش جنوبی آن بیشتر است. همچنین مقایسه میانگین غلظت فلزات مورد بررسی در نمک دریاچه با سنگ نمک معادن سیرجان، لار و فیروزآباد نشان داد که بیشترین غلظت فلزات مس، کادمیم و سرب در نمک دریاچه و برای آرسنیک و کروم به‌ترتیب در سنگ نمک لار و فیروزآباد وجود دارد. به‌طور خلاصه می‌توان نتیجه گرفت که تغییرات غلظت فلزات در دو بخش شمالی و جنوبی دریاچه ناشی از ورود فاضلاب‌ها و پساب‌های مختلف شهری، صنعتی و بیمارستانی شهر شیراز و سایر فعالیت‌های انسانی به‌ویژه فعالیت‌های کشاورزی در حوزه‌های منتهی به بخش شمالی دریاچه است و اقداماتی برای پیشگیری در منطقه، بیش از پیش لازم است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Heavy Metals in Salt and Water Samples from Maharloo Lake and their Comparison with Metal Concentrations in Samples from Sirjan, Lar, and Firoozabad Salt Mines

نویسندگان [English]

  • Farahnaz Sabet 1
  • Mojtaba Bandegani 1
  • Mehraban Sadeghi 2
  • Masoud Hatami Manesh 3
  • Mohsen Mirzaei 3
  • Arash Haghshenas 4
1 MSc, Standard Bureau, Fars Province, Shiraz
2 Assoc. Prof. of Environmental Engineering, Faculty of Public Health, Shahrekord University of medical sciences, Shahrekord
3 MSc Student of Natural Resources Engineering, Tarbiat Modarres University, Tehran
4 MSc, Institute of Shrimp, Tehran, Iran
چکیده [English]

Maharloo Lake is one of the most important water ecosystems in Iran, which is nowadays exposed to multiple risks and threats due to poor water management, salt extraction, and heavy metal pollution. In this study, the concentrations of such heavy metals as chromium, copper, zinc, arsenic, cadmium, and lead in both water and salt samples collected from areas in the north and south of the lake were determined by atomic absorption (AA-670G) after the samples had been digested. Results showed that metal concentrations in the salt samples taken from both the northern and southern areas had identical mean values in the order of Cr> Cu> As> Cd> Pb. An almost similar pattern was detected in metal concentrations in water samples taken from the same areas but with a slight difference in the way they were ordered (Cr> Cu> As> Pb> Cd). It was found that both water and salt samples collected from the northern areas had higher metal concentrations, except for that of Pb which was slightly lower. Comparison of the mean values of metal concentrations in the Salt Lake and those of Sirjan, Lar, and Firoozabad salt mines revealed that copper, cadmium, and lead had their highest concentrations in the Salt Lake while arsenic and chromium recorded their highest values in samples taken from Lar and Firoozabad salt mines, respectively. Based on these findings, it may be concluded that the increased metal concentrations observed in samples from both northern and southern areas of the lake are due to the sewage and effluents from urban, industrial, and hospital sources in Shiraz disposed into the lake as well as such other human activities as farming in the areas around the lake, especially in the northern stretches. These observations call for preventive measures to avoid further water quality degradation in the area.

کلیدواژه‌ها [English]

  • heavy metals
  • Maharloo Lake
  • Table Salt
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