Source identification and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments (Case study: Pars special economic energy zone)

Background and purpose: Polycyclic aromatic hydrocarbons (PAH) compounds are amongst the most hazardous environmental pollutants due to some features such as chemical stability, low degradation, bioaccumulation, and high toxicity for living organisms. Their resources are found in Persian Gulf beaches, so, this study aimed at investigating the concentration, source identification, and ecological risk of PAH compounds in coastal sediments in Pars Special Economic Energy Zone (PSEEZ), Iran. Materials and methods: In order to assess the concentration of PAHs, 16 stations along the coast were selected and in each station two samples were collected. After preparation and extraction of samples using Soxhlet, the concentrations of these compounds were determined by HPLC. The toxicity evaluation indicators and diagnostic ratios were used to assess the ecological risk and determining their origin. Results: Mean concentration of PAHs in sediment was 292.72±54.44 ng/g dry weight. The mean effects range-median quotient of the PAHs (M-ERM-Q, M-PEL-Q), toxic equivalence quotient (TEQ), and mutagenic equivalence quotient (MEQ) showed that current values were less than the permissible limit. Comparison of PAHs concentration with sediment quality standards (NOAA, SQGs, and EPA) showed that the values for all compounds were lower than the standard limits (PEC, TEC, PEL, TEL, ERM). However, among these compounds, the average concentration of Acl was higher than the ERL standard and the concentrations of Acl, Ace, and Phe were higher than the EPA toxicity threshold. Conclusion: In this study, moderate PHAs pollution was seen in the region. Both petrogenic and fuel sources were found to be involved in introduction of these compounds into coastal sediments depending on the location of the station and its sources of contamination. Also, in terms of ecological risk, these compounds have low risks for living organisms. © 2018, Mazandaran University of Medical Sciences. All rights reserved

Ocean Currents Modeling along the Iranian Coastline of the Oman Sea and the Northern Indian Ocean

The Makran Coast (Iranian Coastline of the Oman Sea on the Northern Indian Ocean) plays an important role in country’s future navigation and trade due to its accessibility. In 2014, the Iranian Makran coastline was selected by the PMO to be studied as the Phase 6 in the series of Monitoring and Modelling Studies of Iranian Coasts with all disciplines being in investigated including currents. All previously measured current data (in 2006, 2007 and 2008) along the Makran coastline showed an oscillating (reversing) alongshore currents with no detectable dominant frequency. The oscillation period of these currents varies approximately from 3 days to a week. The most significant objective of this study was to simulate the oscillating behaviour of the Makran coastal currents. In this regard, the global oceanic current pattern over the Northern Indian Ocean was simulated using a 3-dimensional non-structured model and comparisons with the data from several global resources have been made. The model was calibrated using the available vertical current profile data along the coastline

Determination and Ecological Risk Assessment of Heavy Metals (Cd, Pb, Cu, Zn) in Surface Sediments of Coastal Regions of Bushehr Province

Background: Persian Gulf is one of the most important ecosystems in the world that in recent decades has been exposed to various environmental pollutants such as heavy metals from human and natural activities. Therefore, the aim of this study investigates the concentration of heavy metals (cadmium, lead, copper and zinc) and ecological risk assessment of them in coastal sediments in of Bushehr province in Persian Gulf. Methods: In order to assess the concentration of metals, 54 stations along the coastal zones were selected and in each station three samples of sediment and plant were taken. After preparation and digestion of the samples, the concentrations of these metals were determined by using polarography. Results: The average of total concentration of detected metals Zn, Cu, Pb and Cd in sediment 52.40 ± 2. 62, 34.99±2.76, 11.53 ±2.01 and 2.41± 0.89 μg/g, respectively. Also, the results of comparison of heavy metals concentration in coastal areas in Bushehr Province (Jam, Deir, Bushehr, Dashti, Genaveh and Deilam) with ANOVA test showed there was a significant difference between the concentrations of sediments in different coastal areas. The results showed that the Pollution Load Index (PLI) and ecological risk represents less to moderately pollution in the region. Also, the environmental risk of metals in the region was evaluated as (Cd>Cu> Pb> Zn). Conclusion: According to the results, the pollution and ecological risk of metals in the region for Zn, Cu and Pb is low but for Cd is moderateevaluated

Impact assessment of master plan of "attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products" on Bushehr city environment: A case study, Shoghab research station

This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess the environmental effects of Specific Pathogen Free shrimp production complex on surrounded region in Persian Gulf (Shoghab) research station in Bushehr city. The environmental impacts were assessed in Bandragah research station in Bushehr city by usage of comprehensive method for impacts prediction, and Pastakia Matrix for assessment during Feb 2012 till Sep 2014. Results showed 8 negative and 3 positive environmental factors that affect by operating phase including 48% very slightly negative and 44.5% slightly positive and 7.5% very slightly positive effects. Although there is no significant different between negative and positive effects but based on national strategy on getting the technology doing such a projects is highly recommended. By the usage of technical methods in effluents treatment control and reduction of bad impacts is achievable

Impact assessment of master plan of "attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products" on Bushehr city environment: A case study, Shoghab research station

This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess the environmental effects of Specific Pathogen Free shrimp production complex on surrounded region in Persian Gulf (Shoghab) research station in Bushehr city. The environmental impacts were assessed in Persian Gulf (Shoghab) research station in Bushehr city by usage of simple checklist for impacts prediction, and scaling check list for assessment during Feb 2012 till Sep 2014. Flushing the effluents to the sea is the biggest concern of this project that can resulted in health impacts on aquatic and human communities that can be avoided by treatment. Low diversity in activities beside lack of environmental sensitive elements in the region leads us to use of scaling check list for impact assessment. Environmental grade of each activity can be achieved by stratification of them according to their intensity, significance and scale. We reached +320 and -198 for positive and negative points respectively that sounds a clear yes for execution choice

A Robust Four-Fluid Transient Flow Simulator as an Analysis and Decision Making Tool for Dynamic Kill Operation

The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster, outcomes of blowouts are unknown and should be studied before starting an operation. Plans should be available to prevent blowouts or provide safe and secure ways of controlling the well before the drilling operation starts. The plan should include procedures in case of any blowout incident as a proactive measure. A few commercial softwares are available in the industry for dynamic kill and transient modeling. All models are proprietary and very complex which reduces the flexibility of the program for specific cases. The purpose of this study is to develop a pseudo transient hydraulic simulator for dynamic kill operations. The idea and concept is to consider the flow of each phase as a single phase flow. The summation of hydrostatic and frictional pressure of each phase determines the bottomhole pressure during the dynamic kill operation. The simulator should be versatile and capable of handling special cases that may encounter during blowouts. Some of the main features of the proposed dynamic kill simulator include; quick and robust simulation, fluid properties are corrected for pressure and temperature, sensitivity analysis can be performed through slide bars, and capable of handling variety of wellbore trajectories. The results from the proposed simulator were compared to the result of commercial software, OLGA ABC. The results were in agreement with each other. It is recommended to apply the simulator for operations with required kill fluid volumes of one to two wellbore volumes

Temporal ans spatial distribution of Polychatees in Iranian waters of the Persian Gulf and Oman Sea

The study aimed to assess temporal and spatial variations in the population of polychaetes, a significant invertebrate group in deep-sea ecosystems, across the northern waters of the Persian Gulf and the Oman Sea. Sampling occurred from fall 2018 to winter 2020, covering regions in Hormozgan, Bushehr, Sistan and Baluchestan, and Khuzestan. A total of 115 stations were surveyed, utilizing 0.1 square meters and a 500 μm sieve (repeated thrice) to collect bed sediments within the depth range of 12 to 90 meters. Within this study, 35 species/genus of polychaetes were identified in the waters of the Persian Gulf and the Oman Sea. Notably, Flabelligra sp., Manayunkia aestuarina, and Glycinde sp. exhibited the highest abundance, with Flabelligra sp. and M. aestuarina serving as indicator species in both regions. The provinces of Sistan and Baluchestan and Bushehr displayed the highest Shannon diversity and species richness, recording 3.592 and 6.998, respectively. Comparing these findings with prior reports revealed a reduction in the diversity of identified polychaete species in the Persian Gulf. This decline could stem from various factors such as habitat damage due to fishing equipment, and the incidence of contaminants. Continual research and database establishment for time series analysis could significantly aid researchers, authorities, and environmental advocates in comprehending the health status of the Persian Gulf and the Oman Sea. Such efforts would facilitate environmental monitoring and pollution prevention measures, contributing to the preservation of these ecosystem

Water Quality Evaluation of the Intertidal Zone of Pars Special Economic Energy Zone in Differ-ent Seasons by Measuring the Concentration of Heavy Metals and Using WQI and TRIX

Background: Pars Special Economic Energy Zone (PSEEZ) in Bushehr province, Iran is a coastal ecosystem that is severely influenced by industrial and municipal activities. The present study was therefore conducted to monitor the health status of the intertidal zone of this ecosystem in different seasons using the Water Quality Index (WQI), Trophic Index (TRIX) and the concentration of heavy metals, including lead, copper, zinc and iron. Materials and Methods: To assess the desired indicators, 16 stations were selected along the region’s coast, and three samples were taken from each station. The required parameters of each index were then measured using standard methods. Results: Investigating the variations in WQI in different seasons found WQI to be the lowest (WQI=27.89) in winter, suggesting a bad status, followed respectively by summer (WQI=30.63), autumn (WQI=31.42) and spring (WQI=31.77), suggesting a relatively bad situation. The values of TRIX showed that the overall water quality of the intertidal zone is classified as oligotrophic. Moreover, the highest TRIX was associated with winter (TRIX=3.53) and the lowest with autumn (TRIX=1.93). The sequence of the overall mean concentrations of heavy metals in the water samples was also measured as Zn> Fe> Cu> Pb. Conclusion: The obtained findings attribute the high concentration of heavy metals and the low water quality of the coasts in winter to leaching contaminants from industrial, municipal and agricultural activities and the transmission of pollutants by surface currents to the coast of the region

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

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

Measurement and Evaluation of Ecological Risk of Heavy Metals in Surface Sediments of Pars Special Economic Energy Zone

Background: Today, heavy metals pollution in aquatic ecosystems is one of the most important global environmental problems. Because this metals have characteristics such as chemical stability, low degradability and bioaccumulation ability at different levels of the food chain cause the abundant ecological risks for organisms. Therefore, this study investigates the concentration of heavy metals (mercury, cadmium, lead, chromium, copper, nickel, zinc and iron) and ecological risk assessment of them in coastal sediments in the Special Economic Energy Zone - South Pars. Materials and Methods: In order to assess the concentration of metals, 16 stations along the coast was selected and three samples were taken at each station. After preparation and digestion of the samples, the concentrations of these metals were determined by using Polarography. Results: The results showed that the average total concentration of metals in sediment were (Fe > Zn> Cu > Ni> Cr > Pb > Cd > Hg), to amount (56.065 ± 2.04 > 45.91±12.035 > 28.58±1.77 > 18.96 ± 0.84 > 8.59±0.47 > 0.447 ± 0.07 > 0.03 ± 0.016 mg/kg) respectively. In addition, evaluation indicators of the environment such as; Geo accumulation index (Igeo), Contamination factor (CF), Pollution Load Index (PLI) represents less pollution and partly average in the region. Also the investigation ecological risk and environmental risk of heavy metals showed the risk was alike with (Cd >Cu> Pb> Ni> Zn> Cr> Hg) respectively. Conclusion: According to the results, it can be concluded that pollution in the region for Hg, Zn, Cr, Pb and Ni were low and moderate for Cd and Cu. High concentrations of cadmium in comparison with the corresponding amount in the crust of the Earth, along with high levels of pollution factor, pollution modified for Cd, Cu implies the effects of human activities on pollution and accumulation of these heavy metals in sediments. Based on the calculation of the ecological risk index of metals we can expressed that among the measured elements, sediments in terms of Cadmium are in moderate ecological risk. &nbsp