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This study examined the spatiotemporal climate variability over the Ceyhan River basin in Southern Anatolia, Türkiye using historical rainfall and temperature observations recorded at 15 meteorology stations. Various statistical and geostatistical techniques were employed to determine the significance of trends for each climatic variable in the whole basin and its three sub-regions (northern, central, and southern regions). The results revealed that the recent years in the basin were generally warmer compared with previous years, with a temperature increase of approximately 4 °C. The standardized temperature index analysis indicated a shift towards hotter periods after 2005, while the coldest periods were observed in the early 1990s. The spatial distribution of temperature showed non-uniform patterns throughout the basin. The first decade of the study period (1975–1984) was characterized by relatively cold temperatures, followed by a transition period from cold to hot between 1985 and 2004, and a hotter period in the last decade (2005–2014). The rainfall analysis indicated a decreasing trend in annual rainfall, particularly in the northern and central regions of the basin. However, the southern region showed an increasing trend in annual rainfall during the study period. The spatial distribution of rainfall exhibited considerable variability across the basin, with different regions experiencing distinct patterns. The standardized precipitation index analysis revealed the occurrence of multiple drought events throughout the study period. The most severe and prolonged droughts were observed in the years 1992–1996 and 2007–2010. These drought events had significant impacts on water availability and agricultural productivity in the basin.

Introduction Two complicated and difficult problems in the Islamic philosophy are knowledge and intellect. These were of great significance to philosophers from Plato and Aristotle to such Muslim philosophers as Avicenna, Fakhr al-Razi, Suhrawardi, and Nasir al-Din al-Tusi as well as to the Schools of Shiraz and Isfahan. Following them, Mulla Sadra raised the question of knowledge throughout his philosophical work. As the Sadrai thought is still dynamic and can be pursued, examined, critiqued or reconstructed, Muslim thinkers continue to publish their research in the form of books, dissertations, and articles on the issue of knowledge and the intellect. It goes without saying that in order to prevent doing what others already do or have already done the evolution of research on a problem needs to be brought to the researcher’s attention. Therefore, literature plays an important role in the research process, and the present article intends to assist researchers on Mulla Sadra with the literature review. It goes over scientific productions in the area of dissertations and articles from 2001 to 2020 on the subject of knowledge in Sadra’i philosophy. This includes 218 works, out of which 85 articles, 32 master’s degree dissertations and 9 PhD theses are written in the field of the intellect. Master’s degree dissertations and PhD theses on the subject of knowledge are 35 and 9 titles respectively, which does not show a marked difference to the field of the intellect. This is while the articles in the field of knowledge are 45 titles i.e. half as many as the articles written in the field of intellect. The research method As a systematic review, using the search engines and data bases such as Noormags, Comprehensive Portal of Human Sciences, Magiran, and the Treasure System (sāmāni-yi ganj) in the Iranian Research Institute for Information, Science and Technology (IranDoc), and Islamic World Science Citation Center (ISC), this article has searched titles of articles, dissertations, and PhD theses and conducted a statistical study of those Farsi titles written between 2001 and 2020 in Iran in the areas of knowledge and intellect in Mulla Sadra’s transcendent wisdom. A discussion of results More attention has been paid to the question of knowledge than that of the intellect. Within the subject of knowledge, discussions of divine knowledge are of the highest frequency, but less attention has been paid to the levels of the Creator’s knowledge and the status of the Creator’s knowledge in creation, or, to put it the other way, to the levels of knowledge in parallel to the levels of creation. When it comes to theology in the more specific sense, less attention has been paid to the knowledge-led Shia theology versus power-led Sunni theology, and the basics and results of such a discussion are not examined. Within the subject of intellect, discussions of the epistemology of the intellect are of the highest frequency, whereas less attention has been paid to various meanings and usages of the intellect in Islamic sciences including theosophy, philosophy, ethics, and to their distinction from the intellect in common parlance. Conclusion Among the conclusions is that there are methodological limitations: lack of attention to a needs assessment in the process of deciding research topics; lack of proper attention to other researchers’ findings (which leads up to many problems including repetitious work and lack of attention to certain topics, as witnessed by the results of the present study); lack of variety in the articles (for the most part, they are written for academic research journals, while a helpful research activity of high efficiency and influence relies on a whole variety of introductory studies, including reviews, which are visibly missing in the field of Islamic philosophy); and finally the lack of information about research activities in the field in the international arena and even Islamic countries.

Determining the spatio-temporal variations of precipitation patterns plays a key role in water resource management, control of natural hazards, and the design of infrastructures. In this study, the spatial and temporal alterations of daily precipitation concentration index (CI) in Iran territory for the period of 1987 to 2016 was determined, considering 80 metrological stations, Which are well distributed throughout the country. In addition, the trend of annual CI variations was examined using non-parametric Mann-Kendal test. The results indicated that CI varies between 0.57 and 0.71 in Iran, considering the last three decades. The highest CI values were obtained for the Caspian Sea and Persian Gulf coastlines, indicating the concentration of rainfall in limited days in these regions. Moreover, 64 out of 80 stations have experienced an increasing trend in CI values. According to spearman tests, the significant reverse correlation was revealed between CI value and elevation from sea level, and latitude.

The combination of oxidation and flocculation has been used to alleviate the membrane fouling in MBR systems. As common and cheap additives, NaOCl and FeCl3 were employed to prolong the operation life of the membranes. To achieve the highest performance in terms of the SMPs and COD removal, the optimum dosages of FeCl3 and NaOCl additives were first evaluated. To do so, using the jar test, optimum dosages of 2 mg/L and 2 mg/L were respectively determined for the FeCl3 and NaOCl, leading to the highest possible SMPs and turbidity removals of 20.1% and 91%. Using such optimal dosages, different scenarios were examined and the MBR experiments were then conducted in three stages designed to have no chemical addition (stage 1), FeCl3 (stage 2), and a combination of FeCl3 and NaOCl (stage 3) to assess the effect of the additives on membrane performance under continuous flow condition. The results revealed that, although at such dosages, the additives were not able to affect the nitrifying and heterotrophic bacteria, when simultaneously employed (stage 3), they were able to significantly lower the cake layer resistance and the operating time by 4.3 and 2.6 times when compared to the conventional MBR systems (stage 1) and the ones flocculated by FeCl3 (stage 2).

In this study, metal concentrations in the water column and surface sediment of the Sabalan Dam Reservoir (SDR) were determined. Moreover, heavy metal pollution index (HPI), contamination index (CI), heavy metal evaluation index (HEI), enrichment factor (EF), geo-accumulation index (Igeo), sediment quality guidelines (SQGs), consensus-based SQGs (C-BSQGs), and mean probable effect concentration quotients (mPECQs) were evaluated for water and sediments of SDR. It was observed that metal concentrations in river entry sediment were lower, but those in river entry water were higher than corresponding values in the vicinity of the dam structure. The HPI values of water samples taken from 10 m depth in the center of SDR exceeded the critical limit, due to high concentrations of arsenic. However, according to CI, the reservoir water was not contaminated. The HEI values indicated contamination of SDR water with metals at 10 m depth. A comparison of water quality indices revealed that HEI was the most reliable index in water quality assessment, while CI and HPI were not sufficiently accurate. For SQGs, As and Cu concentrations in sediments were high, but mPECQ, Igeo, and EF revealed some degree of sediment pollution in SDR. The calculated EF values suggested minor anthropogenic enrichment of sediment with Fe, Co, V, and Ni; moderate anthropogenic enrichment with As and Mn; and moderate to severe anthropogenic enrichment with Cu. A comparison of SQG values revealed that the threshold effect and probable effect levels were the most reliable metrics in the assessment of sediment toxicity. Statistical analysis indicated similarities between metal concentrations in the center of the reservoir and near to the dam structure, as a result of similar sediment deposition behavior at these points, while higher flow velocity at the river entry point limited deposition of fine particles and associated metals.

Abstract Floods in urban environments often result in loss of life and destruction of property, with many negative socio-economic effects. However, the application of most flood prediction models still remains challenging due to data scarcity. This creates a need to develop novel hybridized models based on historical urban flood events, using, e.g., metaheuristic optimization algorithms and wavelet analysis. The hybridized models examined in this study (Wavelet-SVR-Bat and Wavelet-SVR-GWO), designed as intelligent systems, consist of a support vector regression (SVR), integrated with a combination of wavelet transform and metaheuristic optimization algorithms, including the grey wolf optimizer (GWO), and the bat optimizer (Bat). The efficiency of the novel hybridized and standalone SVR models for spatial modeling of urban flood inundation was evaluated using different cutoff-dependent and cutoff-independent evaluation criteria, including area under the receiver operating characteristic curve (AUC), Accuracy (A), Matthews Correlation Coefficient (MCC), Misclassification Rate (MR), and F-score. The results demonstrated that both hybridized models had very high performance (Wavelet-SVR-GWO: AUC = 0.981, A = 0.92, MCC = 0.86, MR = 0.07; Wavelet-SVR-Bat: AUC = 0.972, A = 0.88, MCC = 0.76, MR = 0.11) compared with the standalone SVR (AUC = 0.917, A = 0.85, MCC = 0.7, MR = 0.15). Therefore, these hybridized models are a promising, cost-effective method for spatial modeling of urban flood susceptibility and for providing in-depth insights to guide flood preparedness and emergency response services.

Increasing water flowing into the Arctic Ocean affects oceanic freshwater balance, which may lead to the thermohaline circulation collapse and unpredictable climatic conditions if freshwater inputs continue to increase. Despite the crucial role of ocean inflow in the climate system, less is known about its predictability, variability, and connectivity to cryospheric and climatic patterns on different time scales. In this study, multi-scale variation modes were decomposed from observed daily and monthly snowcover and river flows to improve the predictability of Arctic Ocean inflows from the Mackenzie River Basin in Canada. Two multi-linear regression and Bayesian neural network models were used with different combinations of remotely sensed snowcover, in-situ inflow observations, and climatic teleconnection patterns as predictors. The results showed that daily and monthly ocean inflows are associated positively with decadal snowcover fluctuations and negatively with interannual snowcover fluctuations. Interannual snowcover and antecedent flow oscillations have a more important role in describing the variability of ocean inflows than seasonal snowmelt and large-scale climatic teleconnection. Both models forecasted inflows seven months in advance with a Nash–Sutcliffe efficiency score of ≈0.8. The proposed methodology can be used to assess the variability of the freshwater input to northern oceans, affecting thermohaline and atmospheric circulations.

The field of neurotechnology has a bright future ahead of it due to its direct impact on human health and the various technological applications. Consequently, this field is of great importance to many developed countries. As far as we know, since most of the neurotechnologies are emerging technologies, there is no proper strategic analysis for this field in the country. The purpose of this study is to determine the technology readiness level (TRL) for the branches of neurotechnology and identify and prioritize the appropriate strategies by evaluating the current state of the country in the neurotechnology field. To achieve this goal, questionnaires are distributed among 40 experts in neuroscience and neural technologies. In the strategy prioritization and data analysis step, the SWOT matrix-based method is used; then, the weights of internal and external factors are determined. After performing a pairwise comparison for selecting the top 5 strategies, a quantitative strategic planning matrix (QSPM) is used in order to rank the selected ones. The results indicate that Iran has the highest technology readiness level (level 6) in the brain-to-computer interfaces and the lowest technology readiness level (level 1) belongs to brain-to-brain interfaces. Finally, 5 top strategies which are weakness- opportunity (WO) strategies are determined.

In an effort to improve tools for effective flood risk assessment, we applied machine learning algorithms to predict flood-prone areas in Amol city (Iran), a site with recent floods (2017–2018). An ensemble approach was then implemented to predict hazard probabilities using the best machine learning algorithms (boosted regression tree, multivariate adaptive regression spline, generalized linear model, and generalized additive model) based on a receiver operator characteristic-area under the curve (ROC-AUC) assessment. The algorithms were all trained and tested on 92 randomly selected points, information from a flood inundation survey, and geospatial predictor variables (precipitation, land use, elevation, slope percent, curve number, distance to river, distance to channel, and depth to groundwater). The ensemble model had 0.925 and 0.892 accuracy for training and testing data, respectively. We then created a vulnerability map from data on building density, building age, population density, and socio-economic conditions and assessed risk as a product of hazard and vulnerability. The results indicated that distance to channel, land use, and runoff generation were the most important factors associated with flood hazard, while population density and building density were the most important factors determining vulnerability. Areas of highest and lowest flood risks were identified, leading to recommendations on where to implement flood risk reduction measures to guide flood governance in Amol city.

Abstract High‐latitude lakes are warming faster than the global average with deep implications for life on Earth. Using an approximately six‐decade long in situ data set, we explored the changes in lake surface‐water temperature (LST), lake deep‐water temperature (LDT), lake depth‐weighted mean water temperature (LDMT), and ice‐free days in Lake Kallavesi, a boreal lake in central Finland, when the lake was stratified (June–August). Our results suggest that the LST is warming faster than the local air temperature (AT). As for the LST, fast warming was also observed in the LDT and LDMT, but at rates slower than those in the LST. The number of ice‐free days also shows an upward trend, with a rate of about 7 days per decade during the study period. The corresponding local AT is the main driver of the LST, followed by the ice‐free days and annual mean AT. Air temperature and ice‐free days also mainly contribute to the changes in the LDMT. The LDT is affected more by the North Atlantic Oscillation signals in this freshwater lake. The AT in the prior months does not affect the LDT in Lake Kallavesi although the AT during the prior season, that is, spring, is the main driver of summer LDT. This highlights the local AT impact on the LDT at time scales longer than a month. The warming rates in the lake water are at a minimum in June because the lake is not yet strongly stratified in this month when compared to July and August. These findings improve our knowledge of long‐term changes in the lake water temperature in a high‐latitude lake, a region with severe environmental consequences due to fast changes in the AT and lake ice phenology.

Energy harnessing from renewable energy sources has become more flexible with power electronic technologies. Recent advancements in power electronic technologies achieve converter efficiency higher than 98%. Today, reliable power electronic devices are needed to design a PV-based energy converter (inverter) to reduce the risk of failure and maintenance costs during operation. Wide-bandgap SiC devices are becoming more common in power electronic converters. These devices are designed to reduce switching loss and improve the efficiency of the system. Nevertheless, the cost of SiC devices is a major concern. Hence, to improve the reliability of the PV inverter while considering the economic aspects, this paper develops a highly reliable PV inverter with a hybrid Si/SiC power module that consists of a Si-IGBT with a SiC anti-parallel diode. A test case of a 3 kW PV inverter is considered for reliability analysis. The loading of the PV inverter is done under uncertain environmental conditions by considering the yearly Mission Profile (MP) data related to Ambient Temperature (AT) and Solar Irradiance (SI) at the India and Denmark locations. The effectiveness of the proposed hybrid Si/SiC power module is tested by comparing it with a conventional IGBT power module. The results showcase the marked improvement in PV inverter reliability with the proposed hybrid power module.

Abstract Iran's groundwater hydrochemistry has not been well understood. In this study, Iran's groundwater hydrochemistry is evaluated using a rich, ground‐trusted data sampled from 9,468 wells distributed across the country in 2011. Twelve groundwater quality parameters were analyzed in each sample, resulting in 113,616 parameters over the study period. Examination of anions‐cations shows that concentrations of sodium, calcium, chloride, and sulphate are higher than the acceptable threshold for drinking‐use suggested by the World Health Organization in about 40%, 21%, 25%, and 20% of the samples, respectively. The results of the water quality index reveal that most of the groundwater resources in the central, southern and eastern regions of Iran, which supply the majority of the domestic water for populated cities, do not meet the requirements for drinking‐use. Although the groundwater in northern parts fulfills the requirements for irrigation‐use, it is only suitable for irrigation of salinity‐friendly crops in central, eastern and southern regions. Ionic types and hydrochemistry facies indicate the dominance of mix water type in 13 out of 30 of Iran's sub‐basins, followed by sodium‐chloride water type in nine sub‐basins. Local geology and lithology are mainly attributed to the distribution of groundwater facies in Iran. In general, our findings reveal a distinctive relationship between Iran's geological‐geomorphological features and hydrochemical facies/groundwater quality. The findings can be used in the formulation of new strategies and policies for Iran's groundwater quality management in the future.

Flooding is a natural disaster that causes considerable damage to different sectors and severely affects economic and social activities. The city of Saqqez in Iran is susceptible to flooding due to its specific environmental characteristics. Therefore, susceptibility and vulnerability mapping are essential for comprehensive management to reduce the harmful effects of flooding. The primary purpose of this study is to combine the Analytic Network Process (ANP) decision-making method and the statistical models of Frequency Ratio (FR), Evidential Belief Function (EBF), and Ordered Weight Average (OWA) for flood susceptibility mapping in Saqqez City in Kurdistan Province, Iran. The frequency ratio method was used instead of expert opinions to weight the criteria in the ANP. The ten factors influencing flood susceptibility in the study area are slope, rainfall, slope length, topographic wetness index, slope aspect, altitude, curvature, distance from river, geology, and land use/land cover. We identified 42 flood points in the area, 70% of which was used for modelling, and the remaining 30% was used to validate the models. The Receiver Operating Characteristic (ROC) curve was used to evaluate the results. The area under the curve obtained from the ROC curve indicates a superior performance of the ANP and EBF hybrid model (ANP-EBF) with 95.1% efficiency compared to the combination of ANP and FR (ANP-FR) with 91% and ANP and OWA (ANP-OWA) with 89.6% efficiency.

In the drastic period of climate change the con- tinuous data monitoring of snow characteristic is required.The immensely impact of snow on hydro production, water resource management and its inhabitants, drive to the need for the importance of snow information such as its extent, dynamics and water it holds at global and local scale. At present, there are various approaches such as traditional ground-based approach, optical satellite imaging and the radio, which are available for snow monitoring at global scale. However, the use of these approaches incurs from large labor and high monitoring cost. Since, the advance in sensor technologies and Internet of Things (Iot), provides an appealing possibility to develop a framework for monitoring snow parameters at enormously low cost. In this study. we implemented two machine learning classifiers model based on the input acquired from the low-cost wearable sensor platform. The results of Random forest classifier showed the accuracy of 88.8%, indicate a promising alternative in snow depth measurements with in-situ validation, when data or wireless sensor network are not available or affordable.

Vegetation height plays a crucial role in various ecological and environmental applications, such as biodiversity assessment and monitoring, landscape characterization, conser- vation planning and disaster management. Its estimation is traditionally based on in situ measurements or airborne Light Detection and Ranging sensors. However, such methods are often proven insufficient in covering large area landscapes due to high demands in cost, labor and time. Since, the emergence of wearable technology, ubiquitous sensors and Internet of Things offers an appealing framework for monitoring environmental parameters at extremely low cost, which, in turn, contributes to the development of affordable real-time vegetation monitoring system. This is especially relevant to rural environments and underdeveloped countries. We proposed a methodology for data acquisition from a ubiquitous sensor wearable platform and developed a machine-learning model to learn vegetation height on the basis attribute associated with pressure sensor. The proposed methods are proven particularly effective in a region where the land has forestry structure. The results of linear regression model (r2 = 0.81 and RSME = 16.73 cm) and multi-regression model (r2= 0.83 and RSME = 15.73 cm), indicate a promising alternative in vegetation height estimation when in situ or Light Detection and Ranging data or wireless sensor network are not available or affordable, thus facilitating and reducing the cost of ecological monitoring and environmental sustainability planning tasks.

Iranian peasants and farmers have long sought to devise and use appropriate methods to provide water for their cultivation by limiting water resources for agriculture. Studying the different traditional methods of water extraction in the central plateau of Iran, which faced with more serious limitations, can help to identify their indigenous knowledge in this regard. The prominence of the emergence of the knowledge of Iranian peasants worldwide indicates the maturity of Iranian civilization in this geography. Although, in some parts of Iran, with a little more detailed exploration and examination, clear examples of this kindcan be observed. Therefore, this study attempts to investigate and introduce one of the manifestations of indigenous knowledge of villagers of central plateau of Iran in water extraction for agriculture. The concept of cow-wells especially reasons, necessities and especially the characteristics of the knowledge contained therein can be a reflection of Iranian culture, civilization and knowledge in this arid region. The cow-wells of Haj Ibrahim in Varzaneh district in Isfahan township due to being in the driest part of the Iran and the constant exposure to drought on the one hand reflects the genius of Iranians in the past and also on the other hand, its revived by a farmer (Haj Ibrahim) indicated of adaptation of innovation for Iranian farmers' to takes advantage of its traditional cultural and economic and social benefits for achieve the sustainable development in this region. The use of entrepreneurial approaches, especially the creation of sustainable jobs in the field of tourism development for themselves and others can be one of the positive aspects of using such an approach in difficult conditions and water shortages in the region. Continuing to pay attention to traditional cultural heritage, and especially to the underlying knowledge base, along with the need to support not only the material but the spiritual revival of these traditions, may be the result and suggestion of the present study.

Abstract Background Fibroblast growth factors (FGFs) are growth factors that have diverse biological activities including broad mitogenic and cell survival activities. They function through the activation of a specific tyrosine kinase receptor that transduces the signal by activating several intracellular signaling pathways. Objective To identify the different signaling pathways involved in the mechanism of action of FGF8 and FGF18 on ovine granulosa cells using mass spectrometry. Materials and Methods Ovine ovarian granulosa cells were harvested from adult sheep independently at the stage of the estrous cycle and were cultured at a density of 500,000 viable cells in 1 ml DMEM/F12 medium for five days. The cells were then treated on day 5 of culture with 10 ng/mL FGF8 and FGF18 for 30 minutes, and total cell protein was collected for mass spectrometry. Results Mass spectrometry showed that both FGF8 and FGF18 significantly induce simultaneous upregulation of several proteins, including ATF1, STAT3, MAPK1, MAPK3, MAPK14, PLCG1, PLCG2, PKCA, PIK3CA, RAF1, GAB1, and BAG2 ( > 1.5-fold; p < 0.01). Conclusion ATF1 and STAT3 are important transcription factors involved in cell growth, proliferation and survival, and consequently can hamper or rescue the normal ovine reproductive system function.

To reduce the problem of sedimentation in open channels, calculating flow velocity is critical. Undesirable operating costs arise due to sedimentation problems. To overcome these problems, the development of machine learning based models may provide reliable results. Recently, numerous studies have been conducted to model sediment transport in non-deposition condition however, the main deficiency of the existing studies is utilization of a limited range of data in model development. To tackle this drawback, six data sets with wide ranges of pipe size, volumetric sediment concentration, channel bed slope, sediment size and flow depth are used for the model development in this study. Moreover, two tree-based algorithms, namely M5 rule tree (M5RT) and M5 regression tree (M5RGT) are implemented, and results are compared to the traditional regression equations available in the literature. The results show that machine learning approaches outperform traditional regression models. The tree-based algorithms, M5RT and M5RGT, provided satisfactory results in contrast to their regression-based alternatives with RMSE = 1.184 and RMSE = 1.071, respectively. In order to recommend a practical solution, the tree structure algorithms are supplied to compute sediment transport in an open channel flow.

Abstract The anthropogenic impacts of development and frequent droughts have limited Iran's water availability. This has major implications for Iran's agricultural sector which is responsible for about 90% of water consumption at the national scale. This study investigates if declining water availability impacted agriculture in Iran. Using the Mann‐Kendall and Sen's slope estimator methods, we explored the changes in Iran's agricultural production and area during the 1981–2013 period. Despite decreasing water availability during this period, irrigated agricultural production and area continuously increased. This unsustainable agricultural development, which would have been impossible without the overabstraction of surface and ground water resources, has major long‐term water, food, environmental, and human security implications for Iran.

Herein, how robotic and autonomous systems and smart wearables complement and support healthcare delivery and the healthcare staff during the COVID‐19 pandemic are presented. For instance, robotic and telerobotic systems significantly reduce the risk of infectious disease transmission to frontline healthcare workers by making it possible to triage, evaluate, monitor, and treat patients from a safe distance. Various examples of where the medical, engineering, and science communities come together to aid the healthcare system, healthcare workers, and society during the current crisis are presented. The goal is to encourage an interdisciplinary dialog so that ethical, practical, and beneficial technological solutions are found to effectively tackle this and similar crises.

The study shows that the current network of hydrometeorological observation in the permafrost zone of Russia is insufficient to provide data for the statistical approaches adopted at the state level for engineering surveys and calculations. The alternative to the financially costly and practically impossible expansion of the monitoring network is the development of hydrological research stations and the implementation of new methods for calculating streamflow characteristics based on mathematical modeling. The data of the Kolyma Water-Balance Station, the first research basin in the world in a permafrost environment (1948–1997), and the process-based hydrological model Hydrograph are applied to simulate streamflow hydrographs in remote mountainous permafrost basins. The satisfactory results confirm that mathematical modeling may substitute or replace statistical approaches in the conditions of extreme data insufficiency. The improvement of the models in a changing climate requires the renewal of historical observations at currently abandoned research stations in Russian permafrost regions. The study is important for forming the state policy in climate change adaptation and mitigation measures.

Contrary to conventional fossil fuel-based electricity generation technologies, renewable energy centered technologies, specifically small hydropower, release a lesser amount of anthropogenic greenhouse gases but are normally more expensive. A major segment of the capital investment in the current small hydropower scenario accounts for equipment and construction process costs. The construction and cost administration process are generally limited to analysis of the capital cost of civil constructions, electro-mechanical equipment works, neglecting the costs related to operating and maintaining the plant, replacement or refurbishment, certified emission reductions, among others. Contemporary studies indicate that these costs form a substantial fraction of the total capital investment. Consequently, for cost management and investment decision making, small hydropower plant developers are drawing increased attention in recent years towards conducting life cycle costing studies that take into account the ignored costs. In addition, small hydropower plants in developing nations can become more competitive by trading the emission reductions achieved under the provision of the Clean Development Mechanism, an outcome of the Kyoto Protocol proposed at the United Nations Framework Convention on Climate Change. In this paper, a modest attempt has been made to determine the Levelized cost of electricity generation using life cycle costing methodology, which accounts for all the costs over operating lifetime on a range of small hydropower plants and the results are analyzed.

Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results indicated that compared to microbubble aeration, nanobubble aeration increased the concentration of dissolved oxygen in the mixed liqueur of the reactor (from 2 to 4.5 mg/l), while reducing the production of excess sludge from 100 to 40 ml/g (SRT: 15-40 d). With the same SRT duration, these values were within the range of 160-70 ml/g using fine-bubble aeration. According to the results, nanobubble aeration could increase the efficiency of aeration, thereby increasing the capacity of the treatment plant and reducing the costs of biological wastewater treatment.

Abstract Background Recently, it has been indicated that free nitrous acid (FNA) and Fenton pre-treatment of waste activated sludge can enhance methane production in anaerobic digestion of waste activated sludge. In addition, it has been revealed that the substances used in these pre-treatments are both eco-friendly and economically attractive because not only are they produced in anaerobic digestion, but they are also low priced. Since primary sludge and waste activated sludge are mixed prior to anaerobic digestion in the majority of wastewater treatment plants, this study aims to assess the influence of combined FNA and Fenton on the anaerobic digestion of mixed sludge. Results According to this study’s results, methane generation from anaerobic digestion of mixed sludge was enhanced when using FNA and Fenton pre-treatment, affirming the effectiveness of the individual and combined pre-treatments in anaerobic digestion of mixed sludge. The enhanced methane production was significant in combined pre-treatments (up to 72%), compared with FNA and Fenton pre-treatment alone (25% and 27%, respectively). This corroborates the positive synergistic effect of the combined pre-treatments on methane production. The enhanced methane can be attributed to augmented soluble fractions of organic matter in addition to increased readily biodegradable organic matter, caused by the pre-treatments. Additionally, the amount of chemical oxygen demand (COD) was assessed during anaerobic digestion, and it was revealed that COD decreased considerably when the pre-treatment strategies were combined. Conclusions This study reveals that the pre-treatments are potentially applicable to full-scale wastewater treatment plants because a mixture of primary sludge and waste activated sludge was used for the pre-treatments. Additionally, combined FNA and Fenton pre-treatments prove more effective in enhancing methane production and organic removal than these pre-treatments alone. The enhanced methane production is important for two reasons: a higher amount of renewable energy could be generated from the enhanced methane production and the COD of digested sludge reduces in such a way that facilitates application of the sludge to agricultural lands and reduces sludge transport costs.

Background: Background: Increasing nitrate concentrations in groundwater resources is considered a common environmental and public health problem worldwide. In this research, an autotrophic up-flow bioreactor with pumice as media was used to study the effects of the sulfur-to-nitrogen (S/N) ratio and empty bed contact time (EBCT) on nitrate removal efficiency and byproducts. Methods: Experiments were carried out in a 3.47 L up-flow, fixed-bed reactor with 3 sampling ports. To evaluate the overall impact of S/N ratio and EBCT on the performance of the bioreactor, several phases with different S/N ratios and EBCTs were applied. Results: At a constant S/N ratio of 3.85 g/g, as EBCT decreased from 24 hours to 2 hours, the nitrate removal efficiency decreased from 98% to 64%. On the other hand, at the desired EBCT of 4 hr, as S/N ratio decreased from 3.85 to 1.51 g/g, nitrate removal efficiency was reduced from 85% to 32%. Changing the EBCT and S/N ratio also affected the effluent nitrite and sulfate concentrations as byproducts. At the S/N ratio of 3.85 g/g and EBCT of 24 hours, effluent nitrite and sulfate concentrations were 0.1 mg NO2--N/L and 463 mg SO4 2-/L, respectively. Decreasing the S/N ratio to 1.51 g/g and the EBCT to 4 hours caused drastic changes in effluent nitrite and sulfate concentrations. Conclusion: The results indicated that the autotrophic denitrification with thiosulfate as electron donor and pumice as media was feasible and applicable for nitrate contaminated groundwater.

The effluent from copper industries is important in terms of production volume, environmental pollution and cost of treatment and disposal. In addition to its economic reasons, the effluent recovery also reduces the pollutant load. Such cases therefore prove the necessity of investigating different methods for reducing water consumption and effluent generation. This study investigated the minimization of water consumption and effluent production in Khatoon Abad copper refinery plant. For this purpose, the conventional method of reducing water consumption and a new technology called water pinch were explained. The water pinch technology was examined for three pollutant indices (TSS, TDS and turbidity) in three high consumption units of Khatoon Abad copper refinery plant. For TSS, TDS and turbidity as pollutant indices, total 614, 525 and 451 cubic meters of raw water consumption per day equivalent to 40.96, 35 and 30 percent could be saved, respectively. According to the results, the pinch technology could help researchers to make decisions for reducing water consumption and according to the observations, suspended solids are regarded as the basis for reducing water consumption. Minimization of water consumption, Water pinch, Mass transfer networks, Water reuse, Total suspended solids, Turbidity.

River flow in cold climates is known to be one of the hydrological systems most affected by climate change, playing a central role in the sustainability of downstream socio-ecological systems. Numerous studies on the temporal and spatial variations of streamflow characteristics have been done, and a comprehensive study on the variation of hydrologic extremes is becoming increasingly important. This study evaluated the long-running changes in the magnitude, time, and inter-annual variability of hydrologic extremes, including high and low flow in 16 major Finnish rivers. We applied four new hydrologic extreme indices for summer–winter low flow ratio, spring-absolute high flow ratio, time-to-peak index, and increasing rate index during the snowmelt period to analyze the spatiotemporal variations of extreme streamflow from 1911 to 2020. The most detected trends in flow regimes have started in the last six decades and become more severe from 1991 to 2020, which is likely to be dominated by anthropogenic global warming. The results also indicated that alteration of low pulses in most rivers was associated with an increase (decrease) in winter (summer) flows, suggesting the annual minimum flow in summer frequently contradicts natural hydrologic regimes in Arctic rivers. Southern Finland has experienced higher variations in extreme hydrology over the last century. A new low flow regime was detected for southern rivers, characterized by frequent annual minimum flow in summer instead of winter. Moreover, the annual maximum flow before/after spring dictated a new high-flow regime characterized by frequent double peak flows in this region.

Objective: Influenza A virus infections are still a major health problem and the choices available for the control and treatment of the disease are limited. This research evaluated in vitro and in vivo antiviral effects of Peganum harmala L. seeds (PHS) extract against influenza A virus. Materials and Methods: In this research, in vitro anti-influenza A virus activity of the extract was assessed in Madin-Darby canine kidney (MDCK) cells. In order to evaluate anti-influenza activity of PHS extract in vivo, BALB/c mice were infected with 5LD50 of mouse-adapted influenza virus (H1N1; PR8) and received 200 mg/kg/day of PHS extract or 20 mg/kg/day oseltamivir. Lungs of seven mice per group were removed on day 3 post-infection and lung virus titers were determined by qRT-PCR. Mice survival, body weights and general conditions were observed for up to 14 days post-infection. Results: The results demonstrated that, the ethanolic extract of PHS possesses high activity against influenza virus with IC50 value of 15.7 (CI95%:11.7-21) μg/ml in MDCK cells. Our results also showed that, oral administration of PHS extract (200 mg/kg/day) or oseltamivir (20 mg/kg/day) to infected mice, increased the survival rate, reduced body weight loss, and decreased lung virus titer. Conclusion: Based on our findings, P. harmala seeds extract can inhibit influenza A virus replication in vitro and in vivo. Therefore, isolation and characterization of the plant’s active compounds and investigation of the underlying mechanisms of its antiviral action are highly suggested.

Referring the World health Organization definition, a safe drinking water should not threat the consumer health over the lifetime of consumption. The objective of the present study is to investigate the present guidelines in order to improve the Iran drinking water guidelines. To obtain this, the present drinking water guidelines in Iran (named 1053 and 1011 standards) and some well-known guideline (WHO,US EPA and the European Communities) were studied. The Iran guidelines were compared to the other ones and the different points and values were presented as Tables. It was understood that the present drinking water guidelines of Iran do not cover areas such as the water quality indicators based on their resources and lack some suggestions about in-network monitoring plans. It is recommended that Iran guidelines should be revised in two categories: 1. The primary standard including the pollutants threatening the consumers health and the Secondary standards which should be prepared by the local water authorities. Keywords: Drinking water, drinking water standards, water quality indicators, World Health Organization, Iran drinking water standards

Background: Car wash wastewater contains several contaminants such as organic matter, oil, grease, detergents and phosphates, all of which are harmful for the environment. In this study, the application of electrocoagulation (EC) to treat car wash wastewater has been studied, and the operating parameters optimized. The electro-Fenton (EF) for further contaminant removal was also investigated. Methods: In EC process, the effect of pH, current density, and the reaction time of the removal efficiency of chemical oxygen demand (COD), phosphate, and turbidity were investigated using the response surface methodology (RSM). The electrochemical cell consisted of four iron electrodes that were connected to a power supply using a monopolar arrangement. In the EF process, the effect of pH, reaction time, and hydrogen peroxide concentration on COD removal efficiency were probed. Results: The optimum pH, current density, and the reaction time for the EC process were 7.3, 4.2 mA cm-2 and 20.3 minutes, respectively. Under these conditions, the COD, phosphate, and turbidity removal percentages were 80.8%, 94.9% and 85.5%, respectively, and the specific energy consumption was 1.5 kWh m-3. For the EF process, the optimum pH, reaction time, current and hydrogen peroxide dosage were 3, 10 minutes, 2 A and 500 mg L-1, respectively. The EF showed higher COD removal efficiency (85.6%) with a lower specific energy consumption (0.5 kWh m-3) and reaction time compared to the EC. Conclusion: This study shows that both EC and EF can effectively treat car wash wastewater with high removal efficiency within a short reaction time.

In terms of fuel resource, hydropower possesses a prominent advantage over any other large power plants which burn fossil fuels to generate electricity. Moreover, due to the abundance in resource availability (as a domestic source in small streams and rivers), small hydropower (SHP) plants are showing prominence all over the world. SHP plants have led to improved access to electricity usage in under-developed and developing nations, thereby contributing to sustainable development goals and social empowerment. SHP, as a technology, is regarded as the largest density renewable resource with high adaptability, and low investment costs. The primary objective of the paper is to study and analyze recent developments in SHP technologies with reporting statistical figures in terms of installed capacity and MW potential in several parts of the world. Methodologies adopted by researchers to conduct techno-economic analysis of SHP projects are reviewed. Various costs involved in conducting pre-feasibility studies—such as constructing, maintaining, and sustainably operating SHP projects—are studied. The results of the study indicate cost and regulatory issues are the major factors affecting the growth of the small hydropower sector in many nations. Major impediments to construction, development and deployment of SHP projects, mutually existing among the nations worldwide, are also reported. Technical hindrances include non-availability of the grid and very limited accessibility to SHP sites, emissions due to storage of water, disruptive technologies with limited manpower and non-technical hindrances include discouragement from local bodies and groups, lack of suitable and precise pathways to accomplish SHP goals of a nation, lack of incentives for encouraging private players to invest in SHP projects, complex approval processes, and many more.

Background: The influenza virus is one of the most important factors for higher morbidity and mortality in the world. Recently, researchers have been focused on influenza conserved antigenic proteins such as hemagglutinin stalk domain (HA2) for vaccine production and serological studies. The HA2 plays a major role in the fusion of the virus with host cells membrane. The immunity system enables to produce antibody against HA2. The aim of this study is polyclonal antibody production against influenza HA2. Methods: This study was done in the Influenza Research Lab, Pasteur Institute of Iran, Tehran for one year from September 2013 to October 2014. In the present study, recombinant HA2 protein was produced in prokaryotic system and purified using Nickel affinity chromatography. The purified HA2 was mixed with Freund’s adjuvant (complete and incomplete) and injected into two New Zealand white rabbits by intramuscularly and subcutaneously routes. Immunization was continued for several months with two weeks interval. Before each immunization, blood was drawn by venous puncture from the rabbit ear. Function of rabbit's sera was evaluated using radial immunodiffusion (RID) in both forms, Single RID (SRID) and Double RID (DRID). Finally, antiserum activity against HA2 was evaluated using western blotting as serological assay. Results: Sedimentary line and zone was observed in RID assays (SRID and DRID) represent interaction between HA2 protein and anti- HA2 antibody. As well as, western blotting results was positive for HA2 protein. Therefore, these results showed that polyclonal antibody produced against HA2 protein can identify HA2 protein antigenic sites. Conclusion: These findings show that humoral immune responses have properly been stimulated in rabbits and these antibodies can identify HA2 protein and may be suitable for other serological methods.

The aim of this study was to investigate the application of micro-filtration and ultra-filtration membrane systems in order to improve the physical and microbial quality and the reuse of backwash water from the sand filter units in water treatment plants. The backwash water from filters makes up for 3 to 5 percent of the total water treated, which is disposed in most WTPs. However, the treatment and reuse of the backwash water is more admissible from technical and economic viewpoints, especially in view of the present water scarcity. For the purposes of this study, use was made of membrane modules of micro- and ultra-filters on a pilot scale. The micro-filter employed consisted of a polypropylene membrane module with a porosity of 1 micron in size and a fiberglass module with a porosity of 5 microns. The ultra-filter was made of PVC hollow fiber with a molecular weight of 100,000 Dalton. In order to feed the two pilots, backwash water from a sand filter was collected from one of the WTPs in Tehran. After samples were taken from the backwash water, the physical and microbial removal efficiency was periodically evaluated based on the standard method and the micro-filtration, ultra-filtration, and combined MF/UF processes were compared with respect to their performance. The results indicate that the combined MF/UF process is able to decrease turbidity, MPN, COD, TSS, and Fe with efficiency values of 99.9, 100, 61.5, 99.9 and 98.8 percent, respectively. Overall, the findings confirmed the technical capabilities of this method for the recovery and reuse of the effluent produced in the backwashing mechanism of sand filters in WTPs.

During the past three decades, sea water level (SWL) in the Caspian Sea has declined by about 2 m and sea area has decreased by about 15 000 km ^2 . This has affected coastal communities, the environment and economically important gulfs of the sea (e.g. Dead Kultuk). To assess the effects of coastline change and evaluate zones vulnerable to desiccation, we simulated SWL using total inflow from feeder rivers and precipitation and evaporation over the sea. We determined potential vulnerable areas of the sea over the past 80 years by comparing the minimum and maximum annual water body maps (for 1977 and 1995). We then determined the linear regression between SWL rise and covered potential vulnerable area (CVA), using annual Normalised Difference Water Index (NDWI) maps and SWL data from 1977 to 2018. Combining SWL-CVA regression and SWL simulation model enabled us to determine desiccated areas in different regions of the Caspian Sea due to changes in precipitation, evaporation and total inflow. The results showed that 25 000 km ^2 of the sea is potentially vulnerable to SWL fluctuations in terms of desiccation, with 70% of this vulnerable area located in Kazakhstan. Potential vulnerable area per kilometre coastline was found to be 6 km ^2 in Kazakhstan, 4 km ^2 in Russia and whole of Caspian Sea, 1.5 km ^2 in Iran, 1 km ^2 in Azerbaijan and 0.5 km ^2 in Turkmenistan. The results also indicated that SWL in the Caspian Sea is sensitive to evaporation and that e.g. a 37.5 mm decrease in mean annual net precipitation would lead to a 1875 km ^2 decrease in the sea area, while a 1 km ^3 decrease in mean annual inflow would lead to a 1400 km ^2 decrease in the sea area. Thus the developed framework enabled the spatial consequences of changes in water balance parameters on sea area to be quantified. It can be used to assess future changes in SWL and sea area due to anthropogenic activities and climate change.

مقدمه: ویروس‌های آنفلوانزا عامل عمده‌ی بیماری و مرگ و میر ناشی از بیماری‌های تنفسی در جهان به شمار می‌روند و واکسیناسیون، بهترین راه پیشگیری می‌باشد. به علت تغییرات آنتی ژنیك ویروس آنفلوانزا، بازآرایی هر ساله‌ی واكسن اجتناب ناپذیر است. یکی از روش‌های مقابله با این مشكل، طراحی واکسن با استفاده از آنتی ژن‌های حفاظت شده‌ی ویروس آنفلوانزا است. پروتئین 2M که در پوشش ویروس، كانال یونی را تشكیل می‌دهد و با تغییرات pH باعث ورود ویروس و ایجاد عفونت در سلول‌های میزبان می‌شود، در بین همه‌ی ویروس‌های آنفلوانزای A حفاظت شده است و هدف مناسبی برای تولید واكسن با ایمنی وسیع‌الطیف می‌باشد. در این مطالعه، به منظور تولید یك واكسن كارآمد، بخشی از ژن 70HSP (70Heat shock proteins) لیشمانیا ماژور به ژن 2M ویروس آنفولانزای 1N1H/A متصل شد و پروتئین نوترکیب كایمر در سیستم پروکاریوتی بیان گردید. روش‌ها: برای ساخت سازه‌ی بیانی، ابتدا ژن كد كننده‌ی HSP در پلاسمید a28pET در بین محل اثر آنزیم‌های BamHI و HindIII جای‌سازی گردید. سپس ژن 2M به روش PCR (Polymerase chain reaction) و با استفاده از پرایمرهای اختصاصی، تکثیر یافت و در محل اثر سایت آنزیمی BamHI در وکتور خطی و دفسفریله شده‌ی a28pET و در بالادست ژن 70HSP کلون گردید. پس از تعیین ترادف و تأیید صحت كلونینگ، بیان پروتئین نوتركیب در سلول‌های 21BL مورد بررسی قرار گرفت. یافته‌ها: نتایج کلنی PCR و هضم آنزیمی، صحت سازه‌های نوترکیب را تأیید کردند. نتایج تعیین توالی نشان داد كه ژن 2Mدر وكتور a28pET و در بالادست ژن 70HSP به طور صحیح و در قاب خواندنی دنباله‌ی هیستیدینی كلون شده است. تولید پروتئین‌های نوتركیب به روش وسترن بلات (Western blot) تأیید گردید. نتیجه‌گیری: پروتئین‌های شوک حرارتی توانایی تحریک و ایجاد هر دو نوع ایمنی ذاتی و اکتسابی را دارند و اتصال آن به آنتی ژن هدف باعث افزایش پاسخ‌های ایمنی می‌شود. پروتئین كایمر تهیه شده در این مطالعه، پس از تخلیص می‌تواند به عنوان یك كاندیدای واكسن زیر واحدی مناسب برای پیشگیری از عفونت آنفلوانزا در نظر گرفته شود. برای بررسی اثرات ادجوانتی 70HSP لیشمانیا ماژور بر روی پروتئین 2M، ارزیابی ایمونوژنیسیتی آن در مدل‌های حیوانی در مطالعات آتی انجام خواهد شد.

Existence of antibiotic in wastewater causes wastewater treatment more difficult. The amount of antibiotic consumption, especially Cephalexin, is considerable so that it concentration in pharmaceutical wastewater is usually high. This study attempts to determine the efficiency removal of Cephalexin by iron nanoparticles from synthetic wastewater. Moreover, the effect of operating parameters such as initial concentrations of Cephalexin, pH, amount of iron nanoparticles and detention time on removal efficiency are investigated and the optimum operating range for each of these operating variables is experimentally determined. The preparation of iron nanoparticles were carried out daily. Samples were prepared with different concentration from a stock solution with 100 mg/L Cephalexin concentration. Cephalexin concentration in each experiment was determined by HPLC method. The results showed that the removal efficiency of Cephalexin in the optimal condition (initial Cephalexin concentration, of 100ppm; detention time, of 10min; iron nanoparticles amount, of 0.8gr; pH, of 5) about 52%.

Background: Considering the toxic effects of heavy metals and microbial pathogens in industrial wastewaters, it is necessary to treat metal and microbial contaminated wastewater prior to disposal in the environment. The purpose of this study is to assess the removal of heavy metals pollution and microbial contamination from a mixture of municipal and industrial wastewater using membrane bioreactor. Methods: A pilot study with a continuous stream was conducted using a 32-L-activated sludge with a flat sheet membrane. Actual wastewater from industrial wastewater treatment plant was used in this study. Membrane bioreactor was operated with a constant flow rate of 4 L/hr and chemical oxygen demand, suspended solids concentration, six heavy metals concentration, and total coliform amounts were recorded during the operation. Results: High COD, suspended solids, heavy metals, and microbial contamination removal was measured during the experiment. The average removal percentages obtained by the MBR system were 81% for Al, 53% for Fe, 94% for Pb, 91% for Cu, 59% for Ni, and 49% for Cr which indicated the presence of Cu, Ni, and Cr in both soluble and particle forms in mixed liquor while Al, Fe, and Pb were mainly in particulate form. Also, coliforms in the majority of the samples were

Arsenic which is present in the underground and surface water is one of the most toxic elements threating human health and animals. Arsenic has been removed in different type of ways. In this study Arsenic removal from drinking water and its decreasing rates were investigated by NZVI (nanoparticle zerovalent iron) to standard limit (I.e. 0.01 mg/lit) . The tests were conducted on reactor containing 100 ml water containing 1mg/L. Arsenic by virtue of Batch method. The mixture was executed in mixing was done an Oultrasnic device in order to have better mixture and complete distribution of nanoparticles in water. Then the arsenic was removed from the water by VATMAN paper of 0.45 Hm. The remained arsenic in the water was measured by ICP device. In this article the influence of the parameters including mixture time , PH ,NZVI and arcenic doses were examined . Having perfomed many tests the results showed that 1 mg arsenic can be removed 100 percent by 0.05 g NZVI in 8 min. It is possible to remove by 98 percent arsenic in 5-10 PH range. Iron nanopaticle way is an effective and rapid way to remove arsenic from water and various conditions have not considerable effect on it.

In this study, the performance of an anaerobic baffled reactor (ABR Pilot 100 l and six compartments) for sulfate removal from the wastewater from Amirkabir Industrial Estate was investigated. The reactor was started with a hydraulic retention time (HRT) of 25 h at 35°C to be gradually reduced to 3.33 h. The best reactor performance was observed at a HRT of 4 h and a sulfate loading rate of 3.318 Kg SO4/m3.d at which the sulfate removal efficiency was 89.15%. In this condition, the highest sulfate removal was observed in the first compartment (69.08%) which had the lowest pH as acidogenesis and acetogenesis had taken place in earlier compartments. This result demonstrated that the sulfidogenesis occurred in the acidogenic phase. Maximum sulfate removal (66.11%) was obtained when temperature was reduced to 20°C (HRT of 4 h). Under the same conditions, the fourth compartment which had lowest pH level exhibited maximum sulfate removal percent (28.98%). This indicates that decreasing temperature leads to the acidogenic phase to shift toward the following reactor compartments. Also, these findings are a further indication of the ability of the acidogenic phase for sulfate removal.

Most organic compounds are resistant to conven­tional chemical and biological treatments. For this reason, other methods are being studied as alter­natives to the biological and classical physico-chemical pro­cesses. In this study, advanced photochemical oxidation (APO) processes (UV, UV/H2O2, UV/H2O2/Fe(II), andUV/H2O2/Fe(III)) were investigated in lab-scale experiments for the degradation of phenol in an aqueous solution. A medium-pressure 300 watt (UV-C) mercury ultraviolet lamp was used as the radiation source and H2O2 30% as the oxidant. Phenol (initial concentration= 0.5 mmol/L) was selected as the model due to its high use and application. Some important parameters such as pH, H2O2 input concentration, iron catalyst concentration, the type of iron salt, and duration of UV radiation were studied based on the standard methods. The results showed that the Photo-Fenton process was the most effective treatment under acidic conditions producing a higher rate of phenol degradation over a very short radiation time. The process accelerated the oxidation rate by 4-5 times the rate of the UV/H2O2 process. The optimum conditions were obtained at a pH value of 3, with a molar ratio of 11.61 for H2O2/Phenol and molar ratios of 0.083 and 0.067for Iron/H2O2 in the UV/H2O2/Fe (II) and the UV/H2O2/Fe (III) systems, respectively.

The excessive biological sludge production is one of the disadvantages of aerobic process such as SBR. So the problem of excess sludge production along with its treatment , and disposal in aerobic processes in municipal and industrial waste water can be seen in many parts of the world even in our country . to solve the problem of excess sludge production , reducing in by oxidizing some of the sludge by Ozone is a suitable idea , thus reducing the biomass coefficient as well as the sewage sludge disposal. In this study, Two SBR reactors with of 20 liter being controlled by on-line system are used. After providing the steady state in the reactors, along the 8 month research sampling and testing parameters such as COD, MLSS, MLVSS, DO, SOUR, SVI, residual ozone and Yield coefficient were done. The results showed that during the solid retention time of 10 days the kinetic coefficient of Y and Kd was 0.58 (mg Biomass / mg COD) and 0.058 (1/day) respectively. At the next stage of research, different concentrations of ozone in one liter of the returned sludge to reactor were used to reduced the excess biological sludge production. The results showed that the 20 mg ozone per gram of MLSS in one liter of the returned sludge to reactor is able to reduce Yield coefficient from 0.58 to 0. 28 (mg Biomass/mg COD),In other words, the biological excess sludge by 52 % .but the soluble COD increased slightly in the effluent and the removal percentage decreased from 92 in blank reactor to 64 in test reactor. While the amount of SVI and SOUR in this consumed ozone concentration reduced 9 mgO2/h.gVSS and 20 ml/g respectively. No sludge was seen in the 25 mg ozone concentration per gram of MLSS in one liter of the returned sludge to reactor.

A combination of ozonation and an aerobic biological process such as the activated sludge has been recently developed as an alternative solution for sludge reduction with the objective of minimizing the excess biological sludge production. In this study, two SBR reactors each with a capacity of 20 liters and controlled by an on-line system are used. Once the steady state conditions were set in the reactors, sampling and testing of such parameters as COD, MLSS, MLVSS, DO, SOUR, SVI, residual ozone, and Y coefficient were performed over the 8 months of research. Results showed that during the solid retention time of 10 days, the kinetic coefficients of Y and Kd were 0.58 mg biomass/mg COD and 0.058 1/day, respectively. In the next stage of the study, different concentrations of ozone in the reactor were intermittently used to reduce the excess biological sludge production. The results showed that 22 mg of ozone per 1 gram of MLSS in the reactor was able to reduce the yield coefficient Y from 0.58 to 0.23 mg Biomass/mg COD. In other words, the excess biological sludge reduced by 60% but the soluble COD increased slightly in the effluent and the removal percentage decreased from 92 in the blank reactor to 76 in the test reactor. While the amount of SVI and SOUR for this level of ozone concentration reached 6 mgO2/h.gVSS and 27 ml/g, respectively. No excess sludge was observed in the reactor for an ozone concentration of 27 mg per 1 gram of MLSS.

Coagulation and flocculation are the principal units in water treatment processes. In this study, the Jar test was used to investigate the effects of the pH and TOC on FeCl3 and PACl coagulants for further removal of turbidity, organic matter, aluminum, total organic carbon (TOC), dissolved organic carbon (DOC), organic Aadsorption at a wavelength of 254 nm (UV254 nm ), alkalinity, residual aluminum and ferric, total trihalomethans (TTHMs) in the Karaj River in the year 2007- 2008. These experiments were conducted through a bench scale study using conventional coagulation in the influent to Tehran Water Treatment Plant No. 2 (TWTP2).With normal pH levels, PACl demonstrated more efficiency than FeCl3 in removing turbidity, TOC, UV254 nm, and TTHMs. The lower coagulant consumption, high floc size, lower floc detention time, lower sludge production, lack of the need for pH adjustment in turbidity of 25 NTU and the lower alum consumption were the advantages of PACl application instead of FeCl3 as a coagulant. Also, PACl application was efficient at low turbidity (2 NTU), average turbidity (6 NTU), and high turbidity (100 NTU) in TOC, turbidity, UV254 nm , and DOC removal. Thus, PACl is an economical alternative as a coagulant in TWTP2.

Subsurface flow wetlands are one of the natural treatment methods used for municipal and industrial wastewater treatment that are economical in terms of energy consumption and cost-effectiveness. Much research has been conducted on wetland operation with continuous flow but not enough information is available on batch flow. This study investigates wetland efficiency in batch flow. For the purposes of this research, two pretreatment units of the anaerobic pond type with digestion pits and two subsurface flow wetlands with a 2-day detention time were built on the pilot scale. The cells were charged with sand of 5 mm effective size, uniformity coefficient of 1.5, and a porosity of 35%. One wetland cell and one pretreatment unit were used as control. The municipal wastewater selected to be monitored for the one-year study period had a flow rate of 26 m3/day and average BOD5 of 250mg/l, TSS of 320mg/l, TKN of 35mg/l, TP of 12mg/l and TC of 2×108 MPN/100ml from Sabzevar Wastewater Treatment Plant. The average removal efficiencies of BOD5,TSS,TKN,TP, and TC in the continuous flow for the combined control pretreatment and wetland cell were 77.2%, 92%, 91%, 89%, 96.5% while the same values for the batch flow for the combined experimental pretreatment and wetland cell were 92%, 97%, 97.5%, 97%, and 99.75%, respectively. The removal efficiency in the subsurface flow wetlands in the batch flow was higher than that of the continuous flow. Thus, for wastewaters with a high pollution level, the batch flow can be used in cell operation in cases where there is not enough land for spreading the wetland cell.

Natural organic matter (NOM) forms the group of principal precursors to organic disinfection by-products (DBPS), which have been recognized to be human carcinogens. In fact, a high TOC concentration, used as an indicator of NOM, indicates a high potential for DBP formation. The aim of the present work was to investigate the effects of nanofiltration with and without preozonation on TOC removal. Nanofiltration alone at operating pressures of 4 and 8 bars could reduce TOC levels to slightly less than 2 mgL-1, which recorded a profile of success for all the experiments. This is while preozonation at a concentration of 2 mgL-1 recorded an effluent TOC level of 3.3 mgL-1, which is not an acceptable record. Preozonation at a concentration of 4 mgL-1 increased effluent TOC to 4.2 mgL-1, which indicates that preozonation could convert NOM from higher- to lower-MW fractions, thus increasing effluent TOC. It was also shown that preozonation-nanofiltration increased effluent TOC, as compared to nanofiltration alone.

Numerous advantages have been reported on PAC (poly aluminum chloride) used as a coagulant over other coagulants such as alum and ferric chloride used in conventional water treatment process with medium and high turbidity levels. These include lower amounts of PACL required specially in removing turbidity, larger floc grain formation, reduced floc sedimentation time, lower sludge production, and relaxation of the need for pH adjustment by lime, among others. The present study aims to evaluate the effects of different coagulants such as ferric chloride and PACL on direct filtration and to identify the most effective material based on both turbidity and particle removal efficiencies. A perfectly experimental pilot system, including raw water preparation, coagulation, flocculation, distribution measurement, and filtration units, was designed and used. Raw water turbidity level in the experimental pilot was below 10 NTU. The effects of various parameters such as coagulant type, filtration rate, and coagulant dosage on the performance of the filter were investigated. The results obtained from several filtration cycles under different conditions indicated that average effluent turbidity level, effluent particle numbers, effluent turbidity variation graph, and effluent particle graph were lower throughout the filtration cycle when PACL was used compared to when ferric chloride was used as the coagulant. Increasing filtration rate led to increased turbidity and particle number. Addition of 2 mg/l of PACL (poor coagulation and flocculation scenario) was compared with addition of 5 mg/l of ferric chloride (strong coagulation and flocculation scenario). The results indicated that higher average values of turbidity removal but lower turbidity and particle removal efficiencies obtained in the case of the poor coagulation and flocculation scenario.

The aim of present work was to investigate effects of the water pressure and ion compound present in water to be treated on nitrate removal efficiency of a nanofiltration membrane. Experiments were performed using sodium salts (NaNO3, Na2SO4, NaF), KNO3, Ca(NO3)2, and Mg(NO3)2 added to tap water. The effects of operating pressures were investigated for a pressure range of 4-10 bars for a nitrate concentration of 150 mg.L-1(NO3-). The effects of concentration levels were studied for the levels 50, 100, 150, 200, 250 and 300 mg.L-1(NO3-). Finally,the effects of anions were investigated for concentration levels of 50, 100, 150, 200 and 250 mg.L-1 of F- and SO42-. The results showed that nitrate removal increased with increasing pressure by up to 8 bars beyond which removal goes steady. Increased nitrate salt concentrations in monovalent salts led to reduced nitrate removal but in divalent salts led to increased nitrate removal. The effect of associated cation on nitrate removal was observed to be higher in the case of NaNO3 compared to KNO3. It was further observed that increasing sulfate ion concentrations reduced nitrate removal while increasing fluoride levels increased nitrate removal.