نشریه محیط زیست طبیعی
سال هفتاد و ششم شماره 1 (بهار 1402)

Due to their special molecular structure, industrial effluents, such as effluents containing colored compounds, have one or more benzene rings with a resistant structure. This type of colored compounds is toxic and difficult to decompose. These effluents should be treated before being discharged into the environment, and thus treating the wastes containing dyes is one of the major environmental challenges and need to be conducted using an appropriate approach. In this study, an advanced oxidation method using a non-metallic carbon-nitride photocatalyst was used to remove the Reactive Blue21 dye. Carbon-nitride photocatalyst was prepared from urea-formaldehyde resin precursor with urea to a formaldehyde ratio of 1.25 The structure and properties of the photocatalyst produced were evaluated and confirmed using SEM, FT-IR, XRD and DRS analyses. The efficiency of the as-prepared photocatalyst was evaluated according to its capability for degradation of Reactive Blue21. Finally, to achieve maximum dye removal via the photocatalytic process, the effective parameters such as solution pH, the dose of the photocatalyst, and exposure time were optimized according to response surface methodology (RSM). The results showed that all three parameters are significantly effective in color removal. However, the effect of decreasing pH and color concentration was greater than increasing the amount of photocatalyst. Also, under optimal conditions, the percentage of paint removed was more than 99%. Based on the obtained results, the carbon nitride photocatalyst synthesized in this research can be used as an ideal cheap material to remove textile dyes from industrial wastewater.

Potentially toxic elements (PTEs) contain two classes of essential and non-essential elements that are significant in toxicological ecology. These elements have high stability and have the ability to cause toxicity in living organisms. Phytoremediation has been considered as one of the most appropriate and efficient methods to uptake these elements. The aim of this study was to investigate the ability of different forage species to absorb PTEs and to be aware of the compatibility and resistance of each to contamination, a comparison between species with different biological conditions. This study was performed in a greenhouse environment and Dactylis glomerata, Festuca ovina and Medicago sativa species were considered. To measure PTEs (lead and cadmium), dry ash extraction method was used. Also, to determine the phytoremediation potential of plant indices TF, BCF and BAC were used. To compare the data statistically, multivariate analysis of variance test in the form of general linear model was used and for multiple comparison of means, Duncan test was used. The results showed that D. glomerata with increasing concentrations of lead (200 to 800 mg/kg) and cadmium (50 to 200 mg/kg) increased their concentration in shoots and roots by about 84% and 86%, respectively in the shoot and root. The root uptake of M. sativa increased with increasing lead concentration, and as a result, M. sativa is an extractive plant for both cadmium and lead. In Festuca ovina species, with increasing lead concentration, the rate of uptake by roots and shoots was 70% and 58%, respectively, and for cadmium was 79% and 73%, respectively. In general, in the studied species, the efficiency of phytoremediation of lead was higher in the aerial parts to the root, but cadmium of the roots of D. glomerata and F. ovina, had more phytoremediation efficiency than the aerial parts.

Population growth with the growth of urban communities has been increased consumer demand and waste production. Waste collection and transportation, as the most expensive element in the waste management system, is so important that a slight change in the cost of management process will reduce the related costs in the waste management system. Among these, transfer stations, as facilities that reduce the costs of collection and transportation, are particular importance. The aim of this study is to select a suitable site for the construction of a waste transfer station and then prioritize suitable options in Karaj. The innovation of this research is in the number of criteria and sub-criteria used for locating and prioritizing options. After setting the major criteria and sub-criteria related to the location of the waste transfer station in this city, their maps were prepared. A total of 3 criteria and 14 sub-criteria were used in this study, then the prepared maps were standardized to a range of [0, 1] and the weight of each criterion and sub-criterion was determined using the pairwise comparison method. The weighted linear combination method was used to prepare the suitability map. The results showed that the major criteria for choosing the transfer station were the boundaries and distances, followed by the physical criteria of land and land use. Then 10 options were selected as the final option and 2 criteria of future development plans and land price were also added to the research and the options were prioritized using the TOPSIS method and the most suitable option with an area of more than 4 hectares was selected in 4 regions. The approach used in this research can be used in other cities.

Due to the increase in the risk of floods, especially in the cities, and the emergence of human, financial, and environmental risks due to its increase, the flood zoning areas are of great importance. Therefore, in this study, flood susceptible areas in Birjand plain were tried to be zoned with the help of effective criteria. In this regard, the data-driven methods of support vector machine (SVM) and random forest (RF) were used in combination with genetic algorithm to zoning flood susceptible areas. Therefore, in order to implement and validate the mentioned models, 42 flood prone locations in the study area were extracted. In addition, 19 hydrogeological, topographical, geological and environmental criteria affecting flood susceptibility in the study area were extracted to be used to predict flood susceptibility map. Area under the curve (AUC) and a variety of other statistical indicators including coefficient of determination (R2) and Root mean square error (RMSE) were used to evaluate the performances of the models. The values of R2, RMSE and AUC obtained from the SVM-GA method were 0.9032, 0.2751 and 0.931, respectively, and the RF-GA method were 0.9823, 0.2321 and 0.914, respectively, which indicate the compatibility and The RF model is more accurate than the SVM model. The results also showed that the susceptibility of flooding in the central areas of the study area, due to lower altitude and slope angle, is higher than other areas.

The increase in the urbanization rate along with land use changes has been resulted in the destruction of natural systems and the reduction of ecosystem services (ES). Identifying the stakeholders who are affected by ES or are influencing is a fundamental part of the integrating process of the ES concept in urban development plans. The prioritization of ES by stakeholders is one of the most important outcomes of stakeholders' participation due to the reduction of complexity, time and cost of their evaluation and management. This research was based on the mixed method (quantitative and qualitative) and in three steps. In the first step, key stakeholders (22 categories) were identified and classified using semi-structured interviews with experts (13 people) through the Interest-power matrix. In the second step, 34 interviewees were selected through snowball sampling from the 22 categories of key stakeholders identified in the previous step, and the important ecosystem services of Arak were identified using the focused focus group technique, then they determined most important effects of the city's comprehensive plan. In the third step, using the method of evaluating preferences in the form of a questionnaire by the interviewees, Arak ecosystem services were prioritized based on suitability for inclusion in the master plan. The results showed that from 22 stakeholder categories identified in Arak in four groups of government and organization, business, education and research, civil society, administration of roads and urban development and administration of environment of Markazi province have got the highest level of power and Interest to integrate ES in order to help for integrating ES into Arak urban plans. The results showed that services i.e., air quality (4.68), water supply (4.12) and climate regulation (4.03) are very important in Arak and according to the respondents, they have got more priority to be addressed in the master plan.

Air pollution is one of the consequences development, which increases with the increase in population and the expansion of urbanization, the development of transportation and the amount of fuel. Air pollution has become one of the serious dangers for many residents of big cities. The current research is theoretical-applied in terms of nature and descriptive-analytical in terms of study method. According to the subject under study and after extracting and collecting information and indicators using the library method and analyzing satellite images and examining the time series, the available information was obtained for the final analysis in such a way as to identify the ecological footprint of air pollution. As a result of mobile sources, four-stroke gasoline engines, motorcycles with two-stroke gasoline engines, and cars with four-stroke diesel engines were identified from the IPCC Inventory software. The results show that the changes and contribution of the pollutants obtained in the base year in the four studied sectors and especially in the CO2 sector during the study period have been accompanied by many changes, as well as the changes and transformations of the urban green space (vegetation). located in the study area has caused the instability of the environment in terms of air pollution in such a way that out of the total 49564092 m2 of land in the study area only 2153728 square meters were dedicated to vegetation the results of the carbon production process in this analysis The region showed that the carbon production trend increased from 43167344 kg in 2013 to 58925638 in 2017. In the automobile index, it has increased from 372189467 kg in 2013 to 497237450 kg in 2017.

Removals of petroleum contaminants from soil is an environmental necessity due to the negative impacts on human and other living organisms. In environmental and economic aspects, biodegradation is the best treating methods for in-situ removal of hydrocarbons from contaminated soil. In this method, application of indigenous microorganisms could minimize perturbation of the soil ecosystem, and thus the treated soil could maintain biological activities for agriculture prepuces after the treatment. In this study, the potential of removal of crude oil contamination from soil by biodegradation process was evaluated in mud pit zones in Naft Shahr resource. In order to evaluate biostimulation, two treatments were applied; plowing alone and plowing together with 0.1 kg/m2 of urea as a source of nitrogen. In order to evaluate bioagumentation, in addition to plowing and adding urea, a suspension of native microbial consortium (consisting of Bacillus thuringiensis, Arthrobacter citreus, and Candida catenulata (a biosurfactant producer yeast)) was added to the soil in an amount of 100 mL/m2. The results indicated that the total petroleum hydrocarbon (TPH) removal was increased from 10.73% to 53.83% after 120 days by the biostimulation treatment. Also, bioagumentation could remove up to 74% of TPH at the same conditions. In this study, removals of main heavy hydrocarbons (> C12) and higher biodegradation rate were the advantages of bioagumentation process by the microbial consortium.

Knowledge of habitat requirements of aquatic animals plays an important role in fisheries and protection programs of aquatic ecosystems. Hence, this study was conducted to investigate the suitability indices of habitat use and habitat suitability index (HSI) of Cyprinion macrostomum in its distribution range, Zab River. A number of environmental variables, including pH, temperature, EC, TDS, elevation, water depth, river width, river slope, velocity, substrate type, and the relative abundance of C. macrostomum at 6 stations and three replications from the downstream to upstream were examined during from the fall of 2021 to the summer of 2022. The results showed that habitat suitability of C. macrostomum is different during four seasons and this species prefers areas with pH in the range 9-10, high temperature, low altitude, low bed slope, medium velocity, and gravel and slate beds without vegetation, and these environmental factors expressed during the four seasons of the year are almost similar. But EC, TDS, river width and water depth factors are distinct in different seasons and it prefers different ranges of these factors during the seasons. In spring and summer preferred the lower width and depth of the river, and in winter and autumn seasons preferred the width greater and depth higher of the water.

Wetland resources are important environmental assets and their management and governance has become a big challenge for developing countries. In this regard, the current research was carried out with the aim of evaluating the state of good governance components in the Zarivar wetland ecosystem, Marivan County, to improve the knowledge of wetland governance, sustainability and preservation of its ecosystem services. This research is a descriptive-analytical type of study that was conducted by survey method. The required data has been collected using library studies and field method with questionnaire tool. The statistical population included 120 experts from institutions related to Zarivar wetland management and members of local environmental associations and organizations, who were selected by the full count method. The content validity of the questions of the research tool was confirmed by subject experts and its reliability was also confirmed by calculating Cronbach's alpha coefficient. In general, the good governance of the wetland was reported to be weak and inappropriate. The results of the t-test showed that there is a significant difference between the average of two groups of members of governmental and non-governmental institutions in relation to the components of transparency justice and fairness, inclusiveness, integrity, and accountability. Considering the average obtained and the reported significant level, the state of good governance of Zarivar wetland is in a good state in terms of inclusiveness and accountability indicators, but it is not in a favorable state in terms of transparency, capability and capacity, and integrity indicators. Good wetland governance is the successful implementation of all policy, legal and regulatory options that are necessary for the sustainability and development of its ecosystem services. Therefore, the plans, actions and future vision of the wetland should be targeted according to the indicators of good governance.

Inevitably, less than 0.1% of pesticides used for pest control reach their target pests and the rest enter the environment and pollute water resources causing adverse effects on fish. This study aimed to investigate the acute toxicity and histopathological damage of paraquat at different pH, hardness and temperatures on Gambusia holbrooki. Acute toxicity of paraquat was performed for 96 h and the physicochemical parameters were adjusted viz. pH  5, 7 and 10, hardness  0, 200 and 400 mg/L and temperature 18, 25 and 30 °C. Then, the histopathological effects of paraquat on gill tissue and intestine of Gambosia holbrooki were then evaluated after 21 days. Acute toxicity of Paraquat herbicide on Gambusia fish at pH = 5, 7 and 10, equal to 13.80, 17.78 and 15.48 mg/L, hardness= 0, 200 and 400 mg/L, equal to 7.94, 19.49 and 36.30 mg/L and temperatures= 18, 25 and 30°C were 64.56, 51.28 and 25.70 mg/L, respectively. Histopathological lesions of paraquat toxin in the gills of Gambusia holbrooki at pH=5 mg/L included hyperplasia, curvature, a fusion of lamellae and lamellar synechiae. Histopathological lesions of paraquat toxin in the intestine of Gambusia holbrooki demonstrated swelling and a higher number of goblet cells, necrosis and erosion. According to the present study results, it can be safely concluded that acute toxicity concentrations of paraquat herbicide can have adverse effects on gills and intestines of Gambusia holbrooki, the severity of which depends on the physicochemical properties of the aquatic environment.

Assessing water quality is an important step toward the optimal and appropriate use of drinking water resources. Therefore, the necessity of studying water quality characteristics in water resource management programs has been highly considered. Ambiguity and lack of inherent certainty governing water resources in the evaluation of goals, criteria, and decision-making units, as inconsistency and carelessness in the opinions and judgments of decision-makers have led to the tendency towards theories of fuzzy sets and, as a result, fuzzy logic as an efficient and useful tool for planning and making decisions. In the present underground water quality water was first classified by international standard methods (definitive evaluation method) for drinking purposes. Then classification was modeled and compared using Mamdani fuzzy inference. For this purpose, the four-year average of quality parameters of underground water sources related to 33 sources including 10 well rings, 22 spring mouths, and an aqueduct in operation in Sardasht Cityre used as inputs in two cases. In the deterministic evaluation method (Schoeller diagram), the characteristics and the water quality determination diagram were determined. In the four-year average fuzzy inference model, eight water quality parameters were classified into three groups, in the first group the parameters of Na+, Ca+2, and Mg+2, in the second group the parameters of HCO3-, SO4-2, and Cl- were placed in the third group of two TH and TDS parameters. After determining each group with two input parameters, each input parameter was considered including three membership functions, so that the rules considered for it were estimated as nine (3x3). The results based on the deterministic method showed that all the studied samples were in the good to acceptable group. But Mamdani's fuzzy findings showed that two samples with a confidence level of 50% were in the acceptable category and other samples with a confidence level of 83-87% were placed in the desirable category for drinking.

During photosynthesis, plants secrete atmospheric mineral carbon into their biomass, which is eventually stored in the soil through plant debris. It was used and finally the organic carbon balance was calculated. The area has three land uses, including agriculture (wheat, canola, beans and alfalfa), pasture and palm grove. From each land use, 5 plant samples in quadrats with dimensions of 1m ×1m were taken. Samples were milled and the percentage of carbon in the total plant biomass and each part of the plants (stem, leaf, and root) was calculated. The amount of gases emitted from the soil surface was also measured by a closed chamber. The results showed that the percentage of carbon in the total plant biomass of the studied land uses is significant at 99% confidence level, so that the average percentage of carbon in rapeseed, wheat and beans is the highest and in rangeland and palm crops is the lowest. Also, the percentage of carbon in different parts of plants (stem, leaf, and root) in each cultivation was performed according to a factorial experiment based on a completely randomized block design with 2 replications in SAS software. The results showed that the highest percentage of carbon was present in the stems, roots and leaves of the plants of each use, and the organic carbon balance was the highest in the agricultural use and the lowest in the pasture land use.

The purpose of this research is to analyze the managerial narratives of managers and officials of the natural resources and environment in relation to the issue of forest fire, in order to identify the management views governing the process of fire management in the country's forests. In this regard, using the qualitative content analysis method, after collecting the published narratives, their classification has been done in the form of sub-themes, main themes and dimensions. Content analysis has been done on 30 news interviews or news-analytical reports published in national newspapers. Based to the results, in the dimension of perception of fire, two main themes are operational description and management description, in the dimension of causes and development of fire, there are six main themes of social challenge, security challenge, support challenge, climatic challenge, topographical challenge and management challenge, in the dimension of actions management for fire control, three main themes of equipment practices, administrative and organizational practices and educational practices  and finally, the requirements needed for fire control, six themes of judicial requirement, financial requirement, equipment requirement, executive management requirement, trans-departmental management requirement and the requirement of participatory management was separated. A total of 91 sub-themes in the form of 17 main themes and 4 dimensions have been extracted from managers' narratives. The analysis of the themes showed that from the point of view of the managers, the fire in the forest is a managerial-operational event that can be prevented and controlled if it occurs by applying management measures and requirements. Therefore, the view of managers on the issue of fire is placed in the framework of managerialism approach. An approach that itself is the basis for the more complicated exposure the fire issue in the country's forests. Ignoring the need to rebuild and revive the fire-damaged areas is one of the key issues that have been severely neglected in the managers' management statements. Managers need a broader view of all the various fields of the incident, fire control and finally the restoration of the damaged areas, so that they are able to make optimal use of the management capacities in the forest fire management process.