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With the increase in the production of plastics and their destructive effects on water quality, soil and the health of living organisms, It is necessary to know these materials and their production sources. Meanwhile, wastewater treatment plants are one of the main sources of discharge of microplastics into the environment. In the present study, the frequency of microplastics in wastewater and sediments of Kerman were evaluated. For this purpose, 36 samples of wastewater and sediments are taken simultaneously per month that in each sample, about 30 liters of wastewater was collected from the exhausting of initial deposition in 2021–2022. The percentage of organic materials in these samples was measured by using the hydrogen peroxide digestion method and the amount of microplastics was extracted and analyzed by a density-based separation method with sodium iodide salt. Investigation of microplastic contamination in wastewater sediments was done by the Van Veen Grab method. Separation of samples was performed by using hydrogen peroxide and the number of separated samples were determined by the amount of particles per 100 gram of dry sediment. Then the microplastics were examined in terms of color, shape and size. The results demonstrate that in samples of Kerman wastewater, 3576 microplastics were found, which about 98% were fiber types and about 2% were particle type, the dimensions of most of these particles were between 37–300 µm. In addition, 90% of microplastics found in wastewater were blue. There were about 4864 microplastics in all sediment samples. Of these, about 98% were related to fibers, 18% particles and 0.001% membranous particles. Sediment grading also demonstrate that the particle size of 100–250 µm had the highest frequency with 39%. In this investigation, the frequency of separated microplastics in red, black and blue were 30%, 26% and 22%, respectively. Based on the results of the analysis of the questionnaires, it was concluded that it’s not much needed to study microplastics and their sources of production and dissemination. The present study can provide useful information to get more acquainted with the types of microplastics sources and their classification, to control and monitor these pollutants in municipal wastewater.

بر خلاف شاخص های فاکتور جابه جایی MF و کد ارزیابی ریسک RAC که آن ها نیز نقش پیوندهای فلزی را در تفسیر آلودگی لحاظ می کنند، در شاخص جدید مستقیما سهمی از مخاطره به فازهای احیا شونده و اکسید شونده داده شده است که این مسئله در هیچ یک از دو شاخص مذکور دیده نشده است. به بیان دیگر در شاخص جدید پیوندهای فلزی که به شکل بالقوه قابلیت رهاسازی فلز در محیط را دارند نیز با تخصیص وزن های جداگانه در تفسیر مخاطره آلودگی موجود دخالت دارند. این مشخصه شاخص جدید امکان تفسیر واقعی آلودگی موجود فلزی به ویژه هنگامی که بخش چشم گیری از غلظت همۀ فلز در فازهای احیا شونده و اکسیدشونده جمع شده است را ممکن می سازد. وابستگی نبودن سطح مخاطره به غلظت کل در شاخص جدید سبب می شود تفسیری از مخاطره در سطوح مختلف غلظت کل ارائه شود. علاوه بر این توانایی شاخص در تفسیر مخاطره آلودگی فلزی فارغ از منبع تولید اعم از انسان ساخت و طبیعی نداشتن قطعیت های ناشی از تفکیک این دو نوع آلودگی را نیز کاهش می دهد.

Suspended particles in rivers can act as carriers of potentially bioavailable metal species and are thus an emerging area of interest in river system monitoring. The delineation of bulk metals concentrations in river water into dissolved and particulate components is also important for risk assessment. Linear relationships between bulk metal concentrations in water (CW,tot) and total suspended solids (TSS) in water can be used to easily evaluate dissolved (CW, intercept) and particle-bound metal fluxes (CSUS, slope) in streams (CW,tot = CW + CSUS TSS). In this study, we apply this principle to catchments in Iran (Haraz) and Germany (Ammer, Goldersbach, and Steinlach) that show differences in geology, geochemistry, land use and hydrological characteristics. For each catchment, particle-bound and dissolved concentrations for a suite of metals in water were calculated based on linear regressions of total suspended solids and total metal concentrations. Results were replicable across sampling campaigns in different years and seasons (between 2013 and 2016) and could be reproduced in a laboratory sedimentation experiment. CSUS values generally showed little variability in different catchments and agree well with soil background values for some metals (e.g. lead and nickel) while other metals (e.g. copper) indicate anthropogenic influences. CW was elevated in the Haraz (Iran) catchment, indicating higher bioavailability and potential human and ecological health concerns (where higher values of CSUS/CW are considered as a risk indicator).

Groundwater quality of Tehran city is considered in this study. Nine sampling stations were selected, and composite sampling campaign was performed in summer 2012. Groundwater sampled from northern stations appeared to have acceptable characteristics for agricultural and drinking uses. The southern station samples did not meet the required guidelines. Concentration of SO4 2−, Na+ and Cl− obey a sharp ascending trend southwards. Accordingly, the electrical conductivity of the last station at the very southern areas is more than fifteen times greater than that of the first northern station. Tehran city is located in a semi-arid climate and experiences long hot summers. High rates of evapo-transpiration within urban green spaces and agricultural lands facilitate the salinization phenomenon in root zones. As a result, excess irrigation water eases the consequent percolation into aquifers. Furthermore, saline water intrusion from salt marshes located down south of the city is an expected consequence of wells overpumping. Such case is especially remarkable in hot seasons when an increased urban water demand is observed. Remarkable sulfate concentrations in saline water are mainly justified by percolation of sulfate containing fertilizers which are broadly used by local farmers in an uncontrolled manner. Surface run-offs and municipal wastewater leakage may also trigger the salinization process.

The purpose of this research is to simulate the impact of climate changes on the need for energy consumption in household cooling and heating systems using degree-day index. To this end, general circulation model has been applied to identify future climate changes and simulate degree-day values. The research findings show an increase of energy consumption for cooling in households in 2075. Also, with warm seasons prolonging and cold seasons shrinking in a year, the need for the continuous supply of energy consumption for air cooling and ventilation increases.

In order to evaluate the feasibility of implementation of horizontal-flow roughing filtration for drinking water treatment a pilot was designed and run at the bank of Zayandehroud river near the village of Chamkhalifeh. Pilot running was performed in summer 2003 (July, August and September), when the quality of river water was in relatively worst condition. The filter is comprised from three different parts which are separated with perforated baffles. Each compartment is filled with some local sand and gravel considering a special decreasing size regime. The overall function of the filter in removing turbidity and total suspended solids is acceptable. Additionally, iron, manganese and color and coliform removal are also been covered to some extent. Achieved results in this study shows that horizontal-flow roughing filtration may be considered as a packed, low-cost and efficient pretreatment process incase surface water is used as water supply for treatment. Furthermore, when small scale societies are considered and when no major pollutants exist in the water supply as the case in this study_ this system may be posed as a total treatment system, in which treated water exited from the filter may be sent to distribution network after a simple post chlorination.

Aras water basin is located in northwest of Iran. Sungun mine which is the largest open-cast copper mine of Iran is located in this region and is in the primary stages of extraction. The influence of mining activity on the quality of regional surface water has been taken in to consideration in this study. Accordingly, sampling was done from 5 local streams in the study area. In order to consider the effect of flow quantity on the amount of different parameters, sampling was done in July and November 2005 when the local streams had the minimum and maximum flow rate respectively. The concentrations of major anions and cations as well as As, Mo, Al, Cu, Cd, Cr, Fe, Mn and Zn were determined. The results showed that the concentrations of metallic ions like aluminum, chromium, copper, manganese, molybdenum and iron in samples collected in July are above USEPA (Environmental Protection Agency) limits; however, mentioned concentrations are lessened remarkably in the samples collected in November. This fact is justified considering dilution of ions concentration via more amount of water in November. The chemical characteristics of water compositions on the basis of major ion concentrations were evaluated on a Schoeller and Piper diagram. Accordingly, the dominant type of water in July and November is considered to be Ca-HCO3 (calcium-bicarbonate type). Regarding Schoeller diagram, despite relatively high concentration of calcium, the current status of local surface water is acceptable for drinking purposes. By commencing mining excavation with designed capacity in near future, the minerals will come in to contact with air and water resulting in dissolution, especially in ponds, which, in turn, increases the concentration of heavy metals in surface water. Considering consequent uses of this water including drinking, irrigation, industrial, etc. precautions must be taken in to consideration.

During the recent decades, the increasing trends in nitrate ion concentration in ground water sources have meant more research to find effective procedures for the prevention of even more water contamination by nitrogen sources. In this study a pilot was designed to examine the application of biological method for eliminating nitrate from the water of well No.903 of Mehrabad Airport, Tehran, Iran. Design, installation and running processes were done from April to November 2003. A fixed biological bed containing five-centimeter trunk pipes 16 mm in diameter were installed in the reactor and the system was operated with upflow current. Instead of Methanol, Acetic acid was used as the carbon source because of its easier acceptance by the public, lower price and availability as well as easier storage. The pilot was run in different hydraulic retention times from 48 h up to one hour. Considering economical, operational and maintenance factors, retention time of 2 h was determined to be optimum, in which 77% nitrate removal was achieved. Considering a ratio of 2 for COD/N, inlet COD of about 140 mg/L and the optimum retention time, COD removal of about 80% is also accomplished in this process. The amount of nitrite concentration, pH values, COD and turbidity is also evaluated versus different hydraulic retention times.

Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of Iran’s Kurdistan province is considered. To investigate the potential risk and hazard level regarding arsenic-contaminated drinking water and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of Qorveh County were considered for evaluation of arsenic concentration in water. Sampling campaign was performed in August 2010 and arsenic concentration was measured via the Silver Diethyldithiocarbamate method. The highest and lowest arsenic concentration are reported in Guilaklu and Qezeljakand villages with 420 and 67 μg/L, respectively. None of thirteen water samples met the maximum contaminant level issued by USEPA and Institute of Standards and Industrial Research of Iran (10 ppb). The highest arsenic concentration and consequently risk and hazard levels belong to villages situated alongside the eastern frontiers of the county. Existence of volcanic activities within the upper Miocene and Pleistocene in this part of the study area may be addressed as the main geopogenic source of arsenic pollution. Quantitative risk values are varying from 1.49E-03 in Qezeljakand to 8.92E-03 in Guilaklu and may be interpreted as very high when compared by similar studies in Iran. Regarding non-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic daily intakes are greater than arsenic reference dose. Such drinking water source has the potential to impose adverse carcinogenic and non-carcinogenic effects on villagers. Accordingly, an urgent decision must be made to substitute the current drinking water source with a safer one.

The Haraz River is one of the most significant rivers in the southern Caspian Sea basin. Towards the estuary, the river receives discharges of industrial, agricultural, and urban wastes. In the present investigation, bulk concentrations of Cu, Zn, As, Cd, Pb, Fe, Ni, Cr, Co, and Sr in Haraz River (Iran) bed sediments were measured from several sample locations. In addition, association of studied metals with various sedimentary phases was assessed to determine the proportions of metals in different forms. The intensity of sediment contamination was evaluated using an enrichment factor (EF), geo-accumulation index (Igeo), and a newly developed pollution index (Ipoll). Both EF and Igeo formulae compare present concentrations of metals to their background levels in crust and shale, respectively. In a specific area with its own geological background like Haraz River water basin where naturally high concentrations of metals may be found, such a comparison may lead to biased conclusions regarding levels of anthropogenic contamination. Accordingly, chemical partitioning results are substituted for the mean crust and shale levels in the new index (Ipoll). The Pearson correlation coefficient between the anthropogenic portion of metallic pollution in Haraz river-bed sediments with Ipoll showed much more value in comparison with those of geochemical accumulation index and enrichment factor. The order of metals introduced by anthropogenic activities are as follows: Sr > Pb > Co > Cd > Zn > Cu > Ni > As > Cr > Fe. The results showed relatively higher concentrations of Cd, As, Sr, and Pb in comparison with those of shale. However, based on the chemical partitioning of metals, it is found that Sr, Pb, Co, and Cd are the most mobile metals. In spite of the high As concentrations in sediments, it is not likely that this element is a major hazard for the aquatic environment since it is found mainly in the residual fraction. Also, Fe, Cr, and Ni are present in the greatest percentages in the residual fraction, which implies that these metals are strongly linked to the sediments.

Recently, increasing attention has been paid to the environmental impact of solid waste in Iran. Consequently, solid waste management has become a remarkably important issue. Solid waste comprises a wide range of materials and comes from a variety of sources. Having a population of about 10 million (about 1/7 of Iran's total population), Tehran is among the most populated capitals in the world. With 22 different districts, this city generates approximately 7,000 metric tons of municipal waste per day that culminates in a total of 2.5 million tons annually. If no reduction strategy on the waste stream is implemented, this huge amount of waste will be buried in Kahrizak (the exclusive landfill site of Tehran). Land and underground water resource degradation in the vicinity of the landfill site-as well as disease outbreaks in the area surrounding the site may be considered alarming warnings for further catastrophic consequences of uncontrolled waste dumping. In this study, the composition of Tehran's solid wastes is analyzed. In order to physically analyze waste generated, waste sampling was carried out by trained workers of the Tehran organization of waste recycling and compost in 2004 for 10 successive days in the middle of each of four seasons. As a result of the study, some practical recommendations are made to reduce the waste stream load directed toward the land. Furthermore, this study evaluated people's concern about the fate of the waste they generate. According to the data collected in a survey, citizens' participation is not remarkably high, but even the modest cooperation recorded may cause a great benefit if extrapolated to the whole city. By virtue of sharp decreases in the cost of total waste collection and transport, as well as the benefits of land and underground water resource preservation, separation of wastes at their source by individual households makes economic sense.

Iran is one of 27 countries that are likely to face increasing water shortage crises between now and 2025 unless action is taken to reduce currently high-per-capita urban water consumption. Accordingly, consumption control in the mega-city of Tehran will be an invaluable achievement. A study of Tehran water consumers has determined that household consumers are responsible for 70 percent of the total consumption. Keeping that figure in mind, the authors set out to assess rates of consumption by water fixtures, with an emphasis on household users, and to examine the effects of installing subcounters and reducers. They selected an apartment complex in which it was possible to install water subcounters for each unit. The first step was to evaluate resident attitudes. Block 3, which had 10 units, was selected to cooperate with the project. The second step was to install counters for all 10 units to determine consumption by different fixtures. (The counters were installed in kitchens, in bathrooms, on toilets, on washing machines, and on flash tanks). In the next step, data entry forms for fixture consumption were completed for a period of 10 days. Then single-handle faucets and reducers were installed, and the outcomes were logged for a period of 10 days. Counter readings were performed by the volunteer residents or by educated personnel every 24 hours, and the total volume of inside consumption was compared with the consumption registered by a base counter placed outside each unit. In the course of the project, the consumption per capita was calculated every 24 hours to yield a real and unbiased model that is applicable to city of Tehran. The results showed a total reduction in water consumption of about 20 percent. Thus, with suitable planning and application of cultural and technical methods, it is possible to optimize consumption in Tehran in the near future.

The Caspian region (including the Golestan, Mazandaran, and Guilan provinces of Iran) occupies 58,678 square kilometers (22,651 square miles) and has a population of 6,270,192, according to the census of 1996. This part of Iran is attractive to tourists because of its proximity to the Caspian Sea. In addition, the region boasts invaluable forests and grasslands, and is the exclusive producer in the country of key agricultural crops like rice and tea. The lack of systematic solid waste management has put this region on the edge of irreparable environmental damage. The large number and dispersion of open-dumping landfills, as well as the faded role of functional elements like waste minimization and processing, have sped up the environmental deterioration. This article evaluates the current status of solid waste management in the Caspian region and suggests practical alternatives. As a result of a field and desk study, the authors offer some instructions for separation of putrescibles, paper and cardboard, plastics, and so forth. Finally, after considering all aspects of the environmental impact assessments for different alternatives, the authors recommend the construction of two compost-producing facilities in Golestan province with a combined capacity of 500 metric tons per day and a total cost of $60,000, and four incineration sites in southern and southwestern parts of the region (Mazandaran and Guilan provinces) with a total capacity of 2,000 metric tons per day and total cost of $75 million.

Kurdistan Province, with an area of 28,203 square kilometers, is located in a mountainous area in the western part of Iran. From 1967 to 1997, the urban population in the major eight cities of the Kurdistan Province-namely, Baneh, Bijar, Divan Darreh, Saghez, Sanandaj, Ghorveh, Kamyaran, and Marivan-increased from 102,250 to 705,715. The proportion of the population residing in urban areas increased 90 percent during this period. In most of the cities, solid waste handling remains primitive, and well-organized procedures for it have not been established. Traditional methods of disposal, with marginal inclusion of modern conveniences, appear to be the common practice. In general, the shortcomings of the prevailing practices can be summarized as follows: The municipal solid waste management systems (MSWMSs) in this province include unsegregated collection and open dumping of municipal solid wastes. Separation of municipal solid waste in this province is in the hands of scavengers. The MSWMSs in this province lack essential infrastructure. Thus, design and implementation of modern MSWMSs in this province are essential. Principal criteria for and methods of implementing these systems are as follows: (1) rationally evaluating all functional elements so that they operate in a steady-state or equilibrium manner; (2) creating all support elements for the MSWMS in each city; (3) introducing gradual privatization of MSWMS activities; (4) creating guidelines, regulations, and instructions for all elements of MSWMSs; and (5) giving priorities to source separation and recycling programs. This paper reviews the present status of MSWMSs in eight major cities of Kurdistan Province and outlines the principle guidelines and alternatives for MSWMSs.

The foremost role of a building is to assure the comfort of its occupants. The thermal comfort of a building depends on the outdoor climate and requires a demand in energy for heating and cooling. In this paper, demand of energy (heating/cooling) in the buildings is discussed in Douala, Cameroon. Daily data of the last 40 years coming from five weather stations of Cameroon have been studied. Some forecasts have been carried out with 14 GCM models, associated to three future climate scenarios B1, A2, and A1B. However, only INCM3 of General Circulation Model (GCM) and A2 scenario was used. Energy demand in buildings is valued by HDD (heating degree day) and CDD (cooling degree day) indices. Obtained results show that the temperature evolves more quickly in dry season than in rainy season in Douala. Climate rise indicates an increasing demand of energy in the buildings for cooling. Global Douala heating shows a definite effect on outdoor comfort. From 2045 to 2075, the demand of energy for cooling will be superior to 50%. The total demand in energy for heating in the buildings is estimated to be 67.882 kcal from 1970 to 2000 and will be around 67.774 kcal from 2013 to 2043.

Sludge, which is produced as a by-product of all treatment processes, has considerable potential as a fertilizer and soil conditioner. Many authorities now discharge the sludge after treatment directly to agricultural land in liquid form, while some others dewater and dry it first. In either case, with proper marketing, it is generally possible for an authority to earn revenue by this means, although it is rare for the income to cover all the cost involved. In some industrial sludge the total solid concentration may range between 2000-100000 ppm and it is reported that more than 6000 waste water treatment plants use the conventional sludge drying sand bed. An experimental investigation was carried out to assess the efficacy of solar energy for drying of sludge from pharmaceutical industrial waste over a sand bed covered with glass as compared to the conventional sludge drying over a sand bed as well as to reduce environmental pollution The two drying beds are constructed in 12 cm thick brick wall with cement mortar and has an effective area of 0.5 m (2). On the 0.4 m thick layer of gravel and send the sludge layer from pharmaceutical industry was deposited. The Solar Sludge Drying Sand Bed (SSDSB) reduced drying time by about 25-35% as compared to the Conventional Sludge Drying Sand Bend (CSDSB). The rate of evaporation from the sludge surface and hence the drying was a function of solar radiation. The condensed evaporated water was qualitatively analyzed for probable reuse.