Climate and Ecosystem of Arid and Semi-arid Regions

Climate and Ecosystem of Arid and Semi-arid Regions

Effect of Planting Cupressus sempervirens in the Natural Broadleaf Forests on the Physical and Chemical Properties of the Soil (Case Study: Pilambra Forest of Paresar, Gilan)

Document Type : Original Article

Author
Associate Professor, Department of Forestry in Arid Region, Faculty of Desert Studies, Semnan University, Semnan, Iran
Abstract
Background and Objectives: Landfill centers, as places for accumulation of various wastes, can become sources of soil and groundwater pollution. Waste leachate generated from municipal landfills constitutes a highly toxic and hazardous form of wastewater, recognized as a potential source of environmental contamination. Heavy metals are among the most important pollutants present in these centers, which, due to their high toxicity and long persistence in the environment, pose a serious threat to human health and the ecosystem. Currently, over 90% of waste generated in Mazandaran Province is managed through traditional disposal methods, which include either burial or surface piling at waste disposal centres. Accumulation of waste in the forest ecosystems leads to elevated concentrations of heavy metals, including lead, cadmium, selenium, zinc, and arsenic. Additionally, various pollutants infiltrate the soil and compromise the natural moisture regulation mechanisms, resulting in toxicity. Certain tree species exhibit high sensitivity to sewage leachate and may exhibit rapid desiccation. The present study aims to investigate the concentration of such heavy metals as chromium, lead, nickel, and zinc in landfill leachate located in the Semskandeh Sari landfill center.
Materials and Methods: The Semeskandeh habitat is situated along the southern edge of the historic Sari-Neka road within the Mazandaran Province, encompassing an area of over 1041 hectares. Predominantly, this region is characterized by diverse forest ecosystems. The area supports a range of tree and shrub species, including oak, Azad (almond), Angelica, maple, alder, larch, milkweed, hornbeam, black and white ash, oleander, wild plum. For this purpose, 6 sampling stations were considered along a waterway that extends from the landfill center into the forest. At each station, three sampling points were considered. The first sampling point was soil sampling at a depth of 10 cm from the bottom of the water channel where the leachate flows, the second point was less than 10 meters from the channel, and the third point was more than 10 meters from the center of the channel, and a sample was taken from a depth of 10 cm. To investigate the trend of changes in leachate composition, soil sampling was carried out to examine the concentration of 4 heavy elements (lead, nickel, zinc, chromium).
Results: Results of the investigations showed that the highest concentration of all 4 studied elements, except for zinc, was obtained at station number 2, with chromium at 55.14 ppm, lead at 51.33 ppm, nickel at 32.55 ppm, and zinc at 12.82 ppm. Gradually, the concentrations decreased with distance from the landfill center. Also, the highest concentration at the three sampling points was obtained at the bottom of the channel, with chromium at 57.59 ppm, lead at 28.93 ppm, nickel at 49.67 ppm, and zinc at 99.08 ppm. Also, the area located within 10 meters from the canal exhibited the highest concentrations of pollutants in the second place, while samples from areas beyond 10 meters showed significantly lower levels. The highest concentrations of elements were recorded in the canal bottom samples, with a gradual decline in element concentrations observed as the distance from the channel increased.

Conclusion: The findings of this study demonstrate elevated concentrations of all analysed elements at various distances from the landfill site. Given that forest lands in this city have been utilized for landfilling, this practice poses significant harmful effects. These effects encompass environmental pollution from various hazardous substances detrimental to the health of all living organisms, air quality degradation, and particularly groundwater contamination. The latter is especially concerning as it serves as the primary water supply for residential areas surrounding these forests.
Subjects

1. Abu-Daabes, M., Abu Qdais, H., & Alsyouri, H., 2013. Assessment of heavy metals and organics in municipal solid waste leachates from landfills with different ages in Jordan. Journal of Environmental Protection, 4, 344-352.
2. Al Yaqout, A. F., & Hamoda, M. F. 2003. Evaluation of landfill leachate in arid climate- A case study. Environment International, 29(5), 593-600.
3. Behbahaninia, A., Mirbagheri, S. A., & Nouri, J. 2010. Effects of sludge from wastewater treatment plants on heavy metals transport to soils and groundwater. Iranian Journal of Environmental Health Scieence and Engineering, 7(5), 401-406. [In Persian]
4. Culbard, E. B., Thornton, I, Watt, J., Moorcroft S., & Brooks, K. 1983. Sources and distribution of lead and cadmium in United Kingdom dusts and soils. In: Proceedings of the 4th International Conference on Heavy Metals in the Environment, CEP, Edinburgh, pp. 426-429.
5. Gharib, Z., 2014. Heavy elements in soils and wastewater influence. Journal of Scientific Research and Development, 1(1), 38-44.
6. Gibson, M. J., & Farmer, J. G. 1983. A survey of trace metal contamination in Glasgow urban soils. In: Proceedings of the 4th International Conference on Heavy Metals in the Environment, CEP, Edinburgh, 1144 p.
7. Gotvajn, Z., Tisler T., & Zagorc-Koncan, J. 2009. Comparison of different treatment strategies for industrial landfill leachate. Journal of Hazardous Materials, 162(2-3), 1446-1456.
8. Haines, R. C., & Pocock, R. L. 1980. Heavy metal land contamination: Background levels and site case histories in the London Borough of Greenwich. Research notes 16 Birmingham, Joint Unit for Research on the Urban Environment, University of Aston, Birmingham.
9. Javan, S., Didehvar, M., Raiesi, R., Abbasian, M., Ahmadi, S., & Nouri, R. 2016. Investigation of the mobility and risk assessment of heavy metals, cadmium, chromium, and lead in Zahedan vermicompost. Journal of Environmental Health Engineering, 3(2), 81-91. [In Persian]
10. Lema, J. M., Mendez, R., & Blazquesz, R. 1998. Characteristics of landfill leachate and alternatives for their treatment: A review. Water Air Soil Pollution, 40, 223-250.
11. Olajire, A. A., & Ayodele, E. T. 1998. Heavy metal analysis of solid municipal wastes in the western part of Nigeria. Water Air Soil Pollution, 103, 219-228.
12. Parry, G. D. R., Johnson, M. S., & Bell, R. M. 1981. Trace metal surveys of soil as a component of strategic and local planning policy development. Environmental Pollution, Series B, 2, 97-107.
13. Sabbagh, M., Mollashahi, M., & Moshki, A. 2017. Investigating the effects of landfills on soil in forest ecosystems (Semeskandeh forest wildlife refuge study). Faculty of Desert Studies, Semnan University, 95 p. [In Persian]
14. Sartaj, M., Sadouq, M. B., & Jalalvandi, H. 2007. Application of geographic information systems (GIS) in locating special waste disposal sites. Third National Conference on Waste Management, pp. 271-281. [In Persian]
15. Shokoh, A., Safari, A., & Hashemi, S. H. 2014. Investigating the quality of leachate from a municipal landfill and compost plant (Case study: Mashhad city). Environmental Science and Technology, 11(4), 97-105. [In Persian]
16. Tedder, R. B. 1992. Memorandum-landfill liner cost benefit analysis. Florida Department of Environmental Regulation, September 8.
17. Yousefi Kebria, D., Darvishi, G., Taghizadeh Khalili, M., & Shoosh Pasha, A. 2011. The effect of leachate infiltration on landfill soils. Fifth Specialized Conference on Environmental Engineering, University of Tehran, Faculty of Environment, Tehran.
Volume 2, Issue 1 - Serial Number 2
September 2025
Pages 138-148

  • Receive Date 14 April 2024
  • Revise Date 29 July 2024
  • Accept Date 21 September 2024