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Showing 8 results for Pollution


Volume 1, Issue 1 (7-2003)
Abstract

Core samples from the sediments of the Dee Estuary were collect-ed from the chosen sites to study the distribution of pesticides in the sediments. The organic compounds were extracted by a microwave sample preparation system from 56 sediment samples and gas chromatography. Mass spectrometry (GC-MS) was employed for the organic compound analysis. Distribution of n-alkanes in the analysed sediments and calculation of their carbon preference index indicate a continental source for the organic compounds in all samples. Different search strategies were applied to find pesticides in the sediments. Maneb was the only pesticide found in the samples. The distribution of Maneb showed a zigzag pattern with depth in all the four studied areas in the Dee estuary, corresponding to the pattern of distribution of total organics. The highest concentration level of Maneb was 16.33 ng/g of sediment at a depth of 14 cm. The distribution of Maneb with depth is attributed to the seasonal application and release to the environment
T Nasrabadi,
Volume 9, Issue 2 (9-2015)
Abstract

In contrast with Mobility Factor (MF) and Risk Assessment Code (RAC) indices, IR attributes a risk share to metal species bound to reducible and oxidizable phases which are totally neglected in both of the two above-mentioned indices. In other words, besides the absolutely mobile fractions, the potentially mobile ones are also regarded in risk evaluation process elaborated by IR. The different structure of the newly-developed index may prevent risk level underestimation especially in case where a remarkable percent of bulk concentration is accumulated within reducible and oxidizable phases. The independency of the index value to the bulk concentration makes it possible to discuss the potential risk in different levels of bulk concentration. Furthermore, the index capability in indication of risky pollution, regardless of the pollution source type, may prevent the probable misleading caused by distinct separation of bulk concentration into geopogenic and anthropogenic portion
Mehdi Zare, Ali Moradzadeh, Abolghasem Kamkar-Rouhani, Faramarz Doulati-Ardejani,
Volume 14, Issue 3 (11-2020)
Abstract

Introduction
"Sulfide-carbonate" deposit is a term, which comprises a series of sulfide minerals such as Zn-Pb ore minerals, mainly considered as related to weathering of Zn-Pb sulfide concentrations and influence in sedimentary hosts (carbonate). There are more than 350 Zn-Pb deposits located in Iran, including world-class deposits such as Angouran, Mehdiabad and Irankouh. Due to the mining activity of these deposits, it creates a significant amount of mine waste that releases of these wastes in the environment causing severe problems. One of the main problems is the formation of Acid Mine Drainage (AMD). AMD is produced by oxidation of sulphide minerals, particularly pyrite (FeS2) in waste dump. Due to low pH and the ability to dissolve metals and other compounds, it can host a number of environmental problems. A phenomenon known as natural or alkaline mine drainage (NAMD) occurs at high pH values ​​when the neutralizing minerals are significantly present in the mine waste or when the oxidation of the sulfide minerals is poor. However, the metals and cationic species, such as Cu, Pb and Cd, are more soluble at low pH. In contrast, elements that form anionic species, such as Se, Cr, V, and Mo, tend to be more soluble at high pH and Ni, Zn, Co, As, and Sb, are soluble at near-neutral pH, and can potentially contaminate mine effluents, even without acidic conditions. Therefore Acid or Neutralization potential (AP&NP) of waste dump is significantly affects on the composition, transfers and fates of contaminations transmitted from waste dump. The aim of this study was to monitoring heavy metals concentrations and assessments of pollution potential of waste dumps in Anguran mine by static method and has been compared by mineralogical approach.
Material and methods
The Angouran Zn-Pb deposit is located in the 135 kilometers southwest part of Zanjan Province, NW Iran. This area belongs to the northwestern part of the Sanandaj-Sirjan Zone, a metamorphic belt related to the Zagros orogeny. Angouran mine is one of the most important carbonate hosted Zn-Pb deposits in Iran that mining activity has been created a significant amount of waste dump in around pit. To achieve the goals, the 47 samples taken from different surficial parts of the waste dump were analyzed by using the ICP-MS method to determine the concentration of elements and heavy metals. These elements and metals includes: Ca, Mg, S and As, Cd, Cr, Cu, Ni, Pb, Zn. The pollution index (PI) were modeled for heavy metal contamination risk zoning then modified Acid Base Accounting (ABA) static method was used to evaluate of acid and neutralization potential (AP&NP) of the waste dump samples and the results were modeled by Kriging method. At the end, mineralogical approach (Mg + Ca concentration) was used to determine the source of neutralization and to better interpret the static results.
Results and discussion
The results of contamination index showed that zinc, arsenic and cadmium had the highest average contamination index (18.89, 12.13 and 5.8, respectively) and the trend of total metal changes in the region as Zn> As> Cd> Pb > Ni> Cr> Cu was rated.
Datas measured in modified ABA method were modeled in 2D maps using the Kiriging method. Due to the low total sulfur content (less than 1%), all of the samples were Net Neutralization Potential (NNP) with a range of 49- 990 kg calcium carbonate per ton, and the study area was classified into three neutralization potential (NP), High (NP) and Very High (NP) levels. The mineralogical approach (Mg + Ca concentration) was used as a useful tool for better interpretation of modified ABA results and determines the neutralizing source. Mineralogical approach results indicate that calcite species are the main source of neutralization and have high correlation coefficient (R = 0.99) with the modified ABA method. In order to validate the results, the presence of mineral calcite was confirmed by XRD analysis on 4 samples.
Assessment of AP and NP of sulfide – carbonate waste dump in this research can be used as a basis model for other similar mines to control environmental problems and to identify the behavior and to transfer heavy metals in mine drainage in the future. Mineralogical approach results show that neutralizing potential and neutralizing source can be obtained without using expensive mineralogy analyses in this type of carbonate-sulfide deposit



 
Ms Najmeh Mohammadi, Dr. Giti Forghani Tehrani, Dr. Afshin Qishlaqi,
Volume 16, Issue 4 (12-2022)
Abstract



Acid mine drainage (AMD) as the most important environmental issue in mining sites is considered a significant source of environmental pollution.  AMD is typically produced by the oxidation of sulphide minerals, especially pyrite. The present study aims to investigate the acid production potential of the wastes of Mehmandoost coal washing plant located in NE Damghan. For this purpose, mineralogical, geochemical, and statistic tests were carried out on 7 representative coal washing waste samples. The obtained results show that although coal washing wastes are not enriched in Cu and Mn, they are moderately enriched in Ni and Co, significantly enriched in Cr, Sb and Zn, strongly enriched in Cd and As, and extremely enriched in Pb and Mo. The main mineral phases presented in the studied samples include quartz, muscovite, clinochlore, kaolinite, illite, montmorillonite, calcite and pyrite. In most of the studied samples, the pH and electrical conductivity (EC) of the saturated paste is <3 and > 2000 μm/cm, respectively. Moreover, in most samples the Net Neutralization Potential (NNP) is < -20. Also, in most of the samples, the Net Acid Production Potential (NAPP) is positive and the Neutralization Potential ratio (NPR) is < 3. The pH of Net Acid Formation (NAG pH) of these samples is < 4.5 and the ratio of Acid Neutralization Capacity to Maximum Acid Potential Acidity (ANC/MPA) is < 1. According to the results of static tests, there is a possibility of production of acidic drainage by the studied samples, therefore, taking suitable management measures to control acid production in the area is of crucial importance.


 


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Volume 17, Issue 1 (3-2023)
Abstract

Waste management is a cornerstone of societal needs. The volume and composition of waste dictate the available disposal options, with landfill being a primary method. The selection of landfill sites is critically dependent on site characteristics and requires thorough and ongoing evaluation, particularly in the areas of water and soil contamination. This study started with geoelectrical and geochemical investigations in the vicinity of the landfill in the city of Damavand. It included 24 geoelectric soundings using the Schlumberger array, organized into 4 profiles covering three intervals. In parallel, three water samples, five soil samples and one leachate sample from two intervals were collected for laboratory analysis. Analyses revealed soil contamination at the waste accumulation site to a depth of two meters with a southerly extent. In particular, a cementitious layer prevents leachate from penetrating deeper into the soil. This, together with a very deep groundwater table, ensures that groundwater contamination is currently and in the foreseeable future prevented. Additional factors such as the depth of the groundwater table, the thickness of the unsaturated zone, the short life of the landfill, reduced rainfall and increased evaporation limit the volume of leachate. The pH of the leachate tends to be alkaline during dry periods and acidic during wet periods. Currently, parameters such as EC, TDS and various ionic and metallic concentrations remain within acceptable limits, ensuring minimal environmental impact.

Dr Seyed Yahya Mirzaee, Phd Student Zahra Chaghazardi, Dr Manouchehr Chitsazan, Dr Farshad Alijani,
Volume 17, Issue 1 (3-2023)
Abstract

The Evan plain is located in the Khuzestan province in the southwest of Andimshek city. Groundwater is one of the available water resources for irrigation, drinking, and industry in this region. Due to the importance of examining the ground water quality of the Evan plain, hydrochemical parameters and nitrate pollution have been evaluated. Nitrate is one of the most widespread pollutants of ground water in the world. However, few studies have been conducted on this pollutant in the Evan plain. Therefore, to assess the quality of ground water in this area with emphasis on nitrate pollution, sampling was carried out in September of the water year (1400-1401) from 22 wells in this plain. During the sampling, field parameters (temperature, pH, EC), concentrations of major elements (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO32-, CO32-), and nitrate were measured. The results of the factor analysis demonstrated three influencing factors, namely EC, Na+, K+, Mg2+, Ca2+, Cl-, SO42-  (as the first factor), pH and Hco32- (as the second factor), and NO3- (as the third factor), with a total of 89.72% having the most changes in the Evan plain aquifer. The dominant water type in the Evan plain is sulfate-calcite. Hierarchical clustering analysis shows the three clusters for the regionalization of nitrate data. In general, the changes in nitrate ion concentration in the groundwater of the Evan plain are affected by the size of the soil particles, the depth of the groundwater, and the utilization of chemical fertilizers in the area.
 

Majid Dashti Barmaki, Zahra Yazdani Barmaki, Massoud Morsali,
Volume 17, Issue 4 (12-2023)
Abstract

In order to design and optimize the quality monitoring network in areas with several sub-basins, it is necessary to know the criteria that affect them, so that in each sub-basin the presence or absence of a monitoring station and the required parameters can be determined. In this respect, the use of the surface water pollution index, namely WRASTIC, can be effective. The WRASTIC model is a practical and advanced method for assessing the risk and potential of pollution in sub-basins. Due to its role in the drinking water supply of the city of Bandar Abbas, monitoring the quality of the Shamil-Takht study area is very beneficial. Therefore, to assess the risk of pollution in this plain, the basin was divided into 16 sub-basins using Global Mapper software. The WRASTIC index was presented as different layers of information, and its value was calculated for each sub-basin by rating by expert judgement method, weighting by hierarchical analysis method, and merging layers using weighted overlap. The results showed that three sub-basins have high risk and three sub-basins have low risk. Then, according to the condition of the streams in each sub-basin, the pollution index and its importance, the number of quality monitoring stations and the necessary parameters in this area were determined. Accordingly, five stations were added to the existing ten hydrometric stations at different locations. In the final 15 stations, the measurement of general parameters and major ions was included in the proposed agenda. The measurement of parameters such as phosphate/phosphorus and nitrate/nitrite was also included in six sub-basins, and heavy metals in three sub-basins.

Prof. Hamid Reza Nassery, Eng. Maryam Arab, Dr. Zahra Kayhomayoon,
Volume 18, Issue 2 (9-2024)
Abstract

The study of the aquifer hydrogeochemical processes and the detailed investigation of the groundwater pollutants in order to control the pollution and prevent its environmental consequences are of special importance. The aim of this research is to investigate the effect of the Siahroud River on lead and nitrate contamination of groundwater in Qaimshahr-Joibar plain. For this purpose, two surface water samples were collected from Siahroud River, before and after Qaimshahr city, and 13 groundwater samples were collected from 13 wells, located in the bed of Siahroud river, in three periods during 2019-2020. The of nitrate, lead and dissolved oxygen concentrations of the samples were measured in the laboratory of Mazandaran Regional Water Company. The assessment of the pollution of water resources in the area shows that the discharge of urban, rural and industrial sewage and agricultural drains into the Siahroud River has caused an increase in the concentration of nitrate and lead ions in the groundwater. The Siahroud River has had an impact on groundwater pollution in the Qaimshahr plain in the upstream and some middle parts of the range due to the direction of groundwater flow and the exchange that exists between the river and the aquifer, as well as the direct discharge of pollutant sources to surface water.


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