تعیین غلظت و میزان آلودگی فلزات سنگین در گرد و غبارهای بخشی از استان بوشهر

نوع مقاله : مقاله کامل علمی پژوهشی

نویسندگان

دانشگاه صنعتی اصفهان

چکیده

سابقه و هدف: افزایش صنعتی‌شدن و فعالیت‌های انسانی، انتشار آلودگی‌های مختلف در محیط را تشدید می‌کند. آلودگی هوا به علت اثر روی اکوسیستم و سلامت انسان یکی از مهم‌ترین چالش‌های زیست‌محیطی است. فلزات سنگین که از منابع مختلف مانند فعالیت-های صنعتی و کشاورزی وارد محیط می‌شوند خطرات زیست‌محیطی جدی ایجاد مینمایند. برای کاهش تأثیر این فلزات، شناسایی مناطق آلوده حیاتی است. هدف این مطالعه بررسی برخی ویژگی‌های شیمیایی و غلظت عناصر سنگین آهن، روی، سرب، مس، و نیکل در ریزگرد شهرهای بوشهر و عسلویه به‌عنوان مناطق شهری و صنعتی و همچنین ترانسکت (به طول 300 کیلومتر) بین این دو شهر به‌عنوان مناطق غیر‌شهری است.
مواد و روش‌ها: تعداد 50 نمونه ریزگرد به ‌صورت خشک از روی برگ‌های درختان نخل جمع‌آوری شد. نمونه‌برداری در شهریور ماه 1391 در 50 نقطه شامل 15 نمونه از منطقه شهری (شهر بوشهر)، 12 نمونه از منطقه صنعتی (شهر عسلویه) و 23 نمونه از ترانسکت بین دو شهر انجام شد. همچنین 50 نمونه خاک سطحی (عمق 10-0 سانتی‌متر) از مجاور همان درختان گرفته شد. سپس غلظت کل آهن، روی، سرب، مس و نیکل نمونه‌های ریزگرد و خاک بعد از هضم به‌وسیله اسید نیتریک شش نرمال (11، 24، 27) توسط دستگاه جذب اتمی تعیین شد. ارتباط بین فلزات سنگین در ریزگرد و منشأ آن‌ها با استفاده از ضرایب همبستگی، روش تجزیه مؤلفه اصلی و تجزیه خوشه‌ای تعیین شد.
یافته‌ها: در هر سه منطقه مطالعاتی، میانگین غلظت تمام فلزات سنگین ریزگرد به جز سرب در بوشهر، نسبت به خاک بیشتر بود. غلظت عناصر روی، سرب و مس در مناطق شهری (بوشهر) و صنعتی (عسلویه) نسبت به منطقه غیرشهری (ترانسکت) افزایش معنی‌دار آماری نشان داد. بیشترین غلظت عناصر سنگین مس و سرب در ریزگرد در شهر بوشهر مشاهده شد، اما غلظت عنصر روی در ریزگرد عسلویه ببیشتر از مناطق دیگر بود. براساس تجزیه مؤلفه اصلی، تجزیه خوشه‌ای و ضرایب همبستگی، دو منبع مهم برای غلظت فلزات سنگین در ریزگرد فرونشسته روی برگ‌های نخل تشخیص داده شد. به‌نظر می‌رسد روی، مس و سرب منشأ انسانی دارند، در حالی‌که احتمالاً آهن و نیکل از منابع غیرانسانی ناشی می‌شوند. مقدار فاکتور آلودگی نشان می‌دهد که ریزگرد منطقه صنعتی عسلویه و شهر بوشهر از لحاظ عناصر روی و مس در کلاس آلودگی قابل‌توجه قرار دارند.
نتیجه‌گیری: رشد فرآیند صنعتی‌شدن و فعالیت‌های انسانی ورود عناصر سنگین را به اتمسفر استان بوشهر افزایش داده است. بنابراین، رعایت استانداردهای زیست‌محیطی در منطقه ویژه پارس جنوبی و گسترش حمل‌و‌نقل عمومی در شهر بوشهر جهت کاهش ورود آلاینده‌ها به اتمسفر ضروری است.

کلیدواژه‌ها


عنوان مقاله [English]

Determining the concentration and contamination level of heavy metals in dust from selected areas of Bushehr Province

نویسندگان [English]

  • Hossein Khademi
  • Zeinab Naderizadeh
  • Shamsollah Ayoubi
چکیده [English]

Background and objectives: Increasing industrialization and human activities intensify the emission of various pollutants into the environment. Air pollution has been considered one of the most important environmental challenges because of its effect on ecosystems and human health. Heavy metals which enter the environment from many different sources such as industrial and agricultural activities cause serious environmental risks, To reduce the negative impact of heavy metals, it is necessary to identify contaminated areas. The aim of this study was to examine selected chemical properties and concentrations of heavy metals such as iron (Fe), zinc (Zn), lead (Pb), copper (Cu), and nickel (Ni) in dust from Bushehr and Assaluyeh cities as urban and industrial areas, respectively, and also from the transect ( about 300 km) between the two cities as a non-urban area.
Materials and methods: Fifty dust samples (dry deposition) were taken from the leaves of the date palm trees at. The sampling was carried out in September 2012 at 50 sites including 15 samples from the urban area (Bushehr city), 12 from the industrial area (Assaluyeh city), and 23 from the non-urban area along the transect between the two cities. Also, fifty surface soil samples (0-10 cm) were taken from the sites adjacent to the same trees from which dust samples were collected. Then, the total concentrations of Fe, Zn, Pb, Cu, and Ni of dust and soil samples were measured by an atomic absorption spectrometer after digestion with 6N nitric acid (11, 24, 27). The relationships between heavy metals in the dust samples and their origins were determined using correlation coefficients, PCA and CA.
Results:The mean concentrations of the heavy metals in the dust from the three areas were found to be higher than those of the nearby soils except for Pb in Bushehr. A significant increase in dust Zn, Cu, and Pb concentrations was found in industrial and urban areas (Bushehr and Assaluyeh) as compared to the non-urban transect. The highest dust Cu and Pb concentrations were observed in Bushehr, but dust Zn concentration of Assaluyeh was higher than those in other areas. The two main sources of different heavy metals in atmospheric dust deposited on date palm leaves were identified based on the principal component analysis, cluster analysis and correlation coefficients. Zn, Cu, and Pb seem to have anthropogenic sources, whereas Fe and Ni in the atmospheric dust presumably derive from non-anthropogenic sources. Values of contamination factor indicate that dust in Bushehr and also in industrial area of Assaluyeh falls in considerably contaminated level in terms of Zn and Cu.
Conclusion: Increasing industrialization and human activities intensified the entering of heavy metals into Bushehr Province atmospheric. In general, implementation of environmental standards in Assaluyeh industrial zone and improvement of public transportation in Bushehr city are necessary to reduce the level of pollutants entering the atmosphere.

کلیدواژه‌ها [English]

  • "Urban and industrial areas"
  • "Multivariate analysis"
  • "Anthropogenic sources"
  • "Contamination class"
1.Ahmed, F., and Ishiga, H. 2006. Trace metal concentrations in street dusts of Dhaka city, Bangladesh. Atmos. Environ. 40: 3835-3844.
2.Al-Khashman, O.A. 2004. Heavy metal distribution in dust, street dust and soils from the work place in Karak Industrial Estate, Jordan. Atmos. Environ. 38: 6803-6812.
3.Al-Khashman, O.A. 2007. Determination of metal accumulation in deposited street dusts in Amman Jordan. Environ. Geochem. Health. 29: 1-10.
4.Al-Khashman, O.A., Al-Muhtaseb, A.H., and Ibrahim, K.A. 2011. Date palm
(Phoenix dactylifera L.) leaves as biomonitors of atmospheric metal pollution in arid and semi-arid environments. Environ. Pollut. 159: 1635-1640.
5.Al-Khlaifata, A.L., and Al-Khashman, O.A. 2007. Atmospheric heavy metal pollution in Aqaba city, Jordan, using Phoenix dactylifera L. leaves. Atmos. Environ. 41: 8891-8897.
6.Birmili, W., Allen, A., Bary, F., and Harrison, R. 2006. Trace metal concentrations and water solubility in size-fractionated atmospheric particles and influence of road traffic. Environ. Sci. Tech. 14: 1144-1153.
7.Bushehr Meteorological Organization. 2012. Climatic data for Bushehr Province. Retrieved from http://www.bushehrmet.ir. (In Persian)
8.Catinon, M., Ayrault, S., Clocchiatti, R., Boudouma, O., Asta, J., Tissut, M., and Ravanel, P. 2009. The anthropogenic atmospheric elements fraction: A new interpretation of elemental deposits on tree barks. Atmos. Environ. 43: 1124-1130.
9.Chen, X., Lu, X., and Yang, G. 2012. Sources identification of heavy metals in urban topsoil from inside the Xi'an Second Ringroad, NW China using multivariate statistical methods. Catena. 98: 73-78.
10.Duong, T.T.T., and Lee, B.K. 2011. Determining contamination level of heavy metals in road dust from busy traffic areas with different characteristics. J. Environ. Manag. 92: 554-562.
11.Facchinelli, A., Sacchi, E., and Mallen, L. 2001. Multivariate statistical and GIS-based approach to identify heavy metal sources in soils. Environ. Pollut. 114: 313-324.
12.Fattahi, A., and Ghannad, H. 2010. Analysis of synoptic patterns of dust storms in the southwest of Iran. J. Geograph. 4: 49-62. (In Persian) 
13.Fayadh, J.M., and Al-Showiman, S.S. 1990. Chemical composition of date palm
(Phoenix dactylifera L.). J. Chem. Soc. Pak. 12: 84-103.
14.Hojati, S., Khademi, H., Faz Cano, A., and Landi, A. 2012. Characteristics of dust deposited along a transect between central Iran and the Zagros Mountains. Catena. 88: 27-36.
15.Lu, X., Wang, L., Li, L.Y., Lei, K., Huang, L., and Kang, D. 2010. Multivariate statistical analysis of heavy metals in street dust of Baoji, NW China. J. Hazard. Mater. 173: 744-749.
16.Mahmoudi, Z. 2011. Geochemical and mineralogical properties of atmospheric dust in IsfahanCity. M.Sc. Thesis, College of Agriculture, IsfahanUniversity of Technology.
(In Persian) 
17.Maisto, G., Alfani, A., Baldantoni, D., De Marco, A., and De Santo, A.V. 2004. Trace metals in the soil and in Quercus ilex L. leaves at anthropic and remote sites of the Campania Region of Italy. Geoderma. 122: 269-279.
18.Modaihsh, A.S. 1997. Characteristics and composition of the falling dust sediments on Riyadh city, Saudi Arabia. J. Arid Environ. 36: 2. 211-223.
19.Nan, Z., Zhao, C., Jijun, L., Chen, F., and Sun, W. 2002. Relations between soil properties and selected heavy metal concentration in spring wheat (Triticum aestivum L.) grown in contaminated soil. Water Air Soil Poll. 133: 205-213.
20.Norouzi. S., and Khademi, H. 2014. Spatial and temporal distribution and pollution monitoring of heavy metals in atmospheric dust of Isfahan city. National Conference on Environment & Green Industry, IsfahanUniversity. (In Persian) 
21.Onder, S., and Dursun, S. 2006. Air borne heavy metal pollution of Cedrus libani (A. Rich.) in the city centre of Konya (Turkey). Atmos. Environ. 40: 1122-1133. 
22.Preciado, H.F., and Li, L.Y. 2006. Evaluation of metal loadings and bioavailability in air, water and soil along two highways of British Columbia, Canada. Water Air Soil Pollut.
172: 81-108.
23.Prospero, J.M., Ginoux, P., Torres, O., Nicholson, S.E., and Gill, T.E. 2002. Environmental characterization of global sources of atmospheric soil dust identified with the Nimbus 7 total ozone mapping spectrometer absorbing aerosol product. Rev. Geophys. 40: 2-31.
24.Rodrıguez Martın, J.A., Lopez Arias, M., and GrauCorbı, J.M. 2006. Heavy metals contents in agricultural topsoils in the Ebro basin (Spain). Application of the multivariate geoestatistical methods to study spatial variations. Environ. Pollut. 144: 101-1012.
25.Salt, D.E., Prince, R.C., Pickering, I.J., and Raskin, I. 1995. Mechanisms of cadmium mobility and accumulation in Indian mustard. Plant Physiol. 109: 1427-1433.
26.Shrestha, S., and Kazama, F. 2007. Assessment of surface water quality using multivariate statistical techniques: A case study of the Fuji river basin, Japan. Environ. Modell. Softw. 22: 464-475.
27.Taghipour, M., Ayoubi, S., and Khademi, H. 2011. Contribution of lithologic and anthropogenic factors to surface soil heavy metals in western Iran using multivariate geostatistical analyses. Soil Sediment. Contam. 20: 921-937.
28.Viard, B., Pihan, F., Promeyrat, S., and Pihan, J.C. 2004. Integrated assessment of heavy metal (Pb, Zn, Cd) highway pollution: bioaccumulation in soil, Graminaceae and land snails. Chemosphere. 55: 1349-1359. 
29.Walkley, A., and Black, I.A. 1934. An examination of the Degetiareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Sci. 37: 29-38.
30.Wedyan, M.A., Altaif, K.I., and Aladaileh, S. 2009. Heavy metals in wet deposition of south of Jordan. Europ. J. Sci. Res. 36: 554-560.
31.Wong, C.S.C., Li, X.D., and Zhang, G. 2003. Atmospheric deposition of heavy metals in the Pearl River Delta, China. Atmos. Environ. 37: 767-776.
32.Yao, Q., Wang, X., Jian, H., Chen, H., and Yu, Z. 2015. Characterization of the Particle Size Fraction associated with Heavy Metals in Suspended Sediments of the Yellow River. Int. J. Environ. Res. Public Health. 12: 6. 6725-6744.
33.Zhang, X.Y., Cao, J.J., Li, L.M., Arimoto, R., Cheng, Y., Huebert, B., and Wang, D. 2002. Characterization of atmospheric aerosol over Xi'an in the south margin of the Loess Plateau, China. Atmos. Environ. 36: 4189-4199. 
34.Zhao, N., Lu, X., Chao, S., and Xu, X. 2015. Multivariate statistical analysis of heavy
metals in less than 100 μm particles of street dust from Xining, China. Environ. Earth Sci. 73: 2319-2327.