جستجوی مقالات مرتبط با کلیدواژه « پساب » در نشریات گروه « کشاورزی »

Agricultural effluents contain nutrients such as phosphates, nitrates and ammonia, which cause surface and underground water pollution. By absorbing these nutrients, freshwater algae such as Spirulina can play an important role in reducing these types of pollutants. On the other hand, this type of wastewater, having nutrients, can be used as an alternative and cheap substrate for algae cultivation. Five concentrations of diluted sugarcane effluent (0, 25, 50, 75, and 100%) were prepared with Zarrouk’s medium and the growth rate, photosynthetic pigments, and the amount of some mineral substances, protein, and fat composition were evaluated. In high concentrations of wastewater (75 and 100% wastewater treatment), a very good growth of Spirulina was observed.The amount of chlorophyll a in the treatment of 100% of wastewater showed a significant increase compared to the control treatment (p < 0.05). The maximum amount of total carotenoids in the treatment of 50% of the Zarrouk’s medium was obtained at the rate of 1559 ± 226 mg/liter, which was more than 2 times the amount of total carotenoids in the control treatment. The maximum amount of total carotenoid in the treatment of 50% of Zarrouk’s medium was 1559 ± 226 mg/liter, which was more than 2 times the amount of total carotenoid in the control treatment.In addition, the produced algae can be used as livestock and aquatic food.

The attention to the control of aquatic ponds and the optimum use of water consumption can reduce pollution of the environment and maintenance ecological conditions of the region. This study investigated the effect of artificial wetlands on the reduction of ammonia and nitrate factors and also physical and chemical changes loading in wastewater to improve water efficiency in stellate sturgeon ponds over a ten-month growth period. To conduct this research, 5 ponds (4 m-2) and 5 cement canals were used. Three fiberglass ponds were used to culture of stellate sturgeon under the same conditions, two fiberglass ponds were used for culturing of Hediste diversicolor and Gammarus (Gammarus aequicauda) larvae, and cement channels were used to establish reed plants (Phragmites australis) in the treatments in the first to third rows, respectively. At this study was used 50% recyclution water and 50% freshwater. The ammonia and nitrate factors were measured in all ponds monthly. In the output of the reed plant, the highest percentage of ammonia (NH3-N) and nitrate (NO3-N) removal was related to the water that was passed through the gammarus ponds and stellate sturgeon, respectively. The results of percentage reduction of wastewater nutrients among the treatments showed that the highest ability to remove ammonia (15.6%), and nitrate (24%), was observed in the ponds of Phragmites australis and it also economically plays an important role due to the lack of food cost for feeding worms and Gamarus.

The utilization of non-conventional water sources, such as saline water, drainage, and sewage, has proven to be highly effective in managing droughts given the limitations of the country's water resources. The primary advantage of utilizing effluent from urban wastewater treatment plants is the stability of these sources, their accessibility, and their low cost for irrigating agricultural lands, which ultimately addresses the issue of water scarcity. In this study, the quality of Shiraz urban sewage treatment plant effluent was evaluated for agricultural purposes by calculating the National Sanitation Foundation of America water quality index (NSFWQI) and the Oregon water quality index (OWQI) using daily data from 2018 to 2019. Nine parameters were selected to calculate the NSFWQI index for the Shiraz treatment plant, including turbidity, temperature, phosphate, nitrate, coliform, biological oxygen demand (BOD), total dissolved solids (TDS), dissolved oxygen (DO), and pH. The OWQI quality index is similar to the NSFWQI index but includes eight parameters: temperature, dissolved oxygen, biological oxygen demand, pH, nitrogen, total phosphorus, total dissolved solids, and fecal coliform. The results showed that the average NSFWQI values varied between 28.73 and 31.54 in different months, indicating poor quality. The monthly OWQI values ranged from 4.38 to 7.95, indicating very poor quality. Therefore, given the low quality of the effluent, it is recommended for use only in irrigating non-productive plants, forest parks around Shiraz, and a limited part of urban green space.

The groundwater level decline has caused an environmental issue in most of the Iranian aquifers. In this regard, aquifer storage and recovery (ASR) system can be used as a solution. On the other hand, the huge volume of treated wastewater in big cities can be used as a water source for aquifer storage purpose. In this study, the treated wastewater, soil and groundwater quality have been investigated through the unsaturated-saturated porous media. An experimental model, as L-shaped, has been designed using PVC pipe material with a diameter of 200 mm and a length of 15 m (2.5 m vertical and 12.5 m horizontal). The wastewater used in this research was obtained from the outlet of the sewage treatment plant in the south of Tehran. In order to avoid changes in the quality of wastewater during storage in the tank, it was tried to a regular change the treated wastewater in short intervals. After the initial investigations, a zone situated in center of in the Feshafuye plain, has been selected for treated wastewater injection. Then the required soil for laboratory setup has been collected for tis area. In this regard, firstly, the surface layer soil was removed, then the subsurface soil was transferred to the laboratory for the experimental setup. The required inflow water for this setup was taken from the aquifer of the same area and was changed regularly in order to establish the maximum real conditions. During this study, treated wastewater have been sampled and analyzed at 12 points along the flow path for 60 days. The results showed that the nitrate concentration decreased to less than 0.5 ppm after 7 m and microbial pollutants, total coliform and E. coli had been removed in a 100-cc sample after 6 m. In terms of salinity, the treated wastewater and soil quality have been improved from an EC of 4 to 3.3 dS/m. The BOD and COD have decreased by 81% and 87%, respectively. Due to improvement of treated wastewater quality through the unsaturated- saturated porous media, the ASR system can be implemented as a solution to prevent the groundwater level decline.

This research presents the application of phytoremediation to remove ammonia from effluent possessing high ammonium content and alkalinity in one of the most complex refineries in Iran. The objective of this research was to find new methods to protect and preserve water resources. At first, the algae distribution was investigated. After purifying the samples, Chlorella Vulgaris was selected as resistant algae in the areas that experienced ammonia shocks. A 10-liter container and an airlift photobioreactor with similar laboratory conditions were developed to control biomass production. Experiments were conducted over 20 days and maximum biomass production occurred in the first 16-17 days. Cell density was expressed as dry cell weight in ammonia concentration from 10 mg/L to 500 mg/L. It was also observed that when the Nitrogen content of the culture medium was less than 50 mg/L, ammonia was completely removed in both methods. At a concentration of 10 mg/L, total ammonia in both methods was removed in the first week. At 50 mg/L to 100 mg/L concentrations, about 94% of ammonia was removed in the glass container and about 95% in the bioreactor. In these concentrations, with high ammonia content, the final cell density, and absorption power were significantly low and this was evident at 500 mg/L. Prevention of water evaporation and biomass settling, better control of some vital parameters including pH, temperature, light, and energy intensity, effective mass and heat transfer, and carbon dioxide concentration led to better efficiency of the airlift photobioreactor. A noteworthy point in this result was the extraordinary performance of Chlorella Vulgaris in removing toxic pollutants such as ammonia and possibly using it in the biological systems of sanitary, refineries, and petrochemicals.

Nutrients in wastewater enrich the environment and cause environmental problems in aquatic environments. Conventional wastewater treatment systems are not capable of removing phosphorus effectively.  The  entry  of  phosphorus  into  water  resources  leads  to  the  formation  of  an Eutrophication  phenomenon. Micro-algae have been more effective among the various methods used for the removing of nutrients from wastewater. Wastewater biological-treatment using algae to eliminate nitrogen and phosphor and produce oxygen for aerobic bacteria is a new trend that has drawn a great deal of attention. Using sunlight, microalgae consume nutrients in wastewater and convert them into useful biomasses. Wastewater biological-treatment using microalgae was studied. Treatment efficiency of micro-algae depends on the species, algae mass concentration, aeration level, and the optimal time to maximize algae activity on wastewater.

In this study, the effect of the effluent from rainbow trout ponds was investigated on the yield, concentration and uptake of nitrogen, phosphorus and micronutrients on the silage corn in the Golpayegan research station for Husbandry and Agriculture in Isfahan. 45000 fish with an average weight of 10 ± 2 g were uniformly divided in 9 ponds (20 × 2.2 × 1.3 m) for six months. The research was conducted in a complete randomized block design with five treatments in triplicate. The treatments were included 1) irrigation with well water without any fertilizer as the control, 2) irrigation with well water and use of urea, triple superphosphate and potassium sulfate as the fertilizers, 3) irrigation with fish ponds effluents without any fertilizer, 4) irrigation with fish ponds effluents and use of the fertilizer, and 5) irrigation with fish ponds effluents with 50 percent of the fertilizer. Results showed that the use of fish ponds effluents significantly caused increasing in corn yield and concentration of zinc, cupper, nitrogen, phosphorus, manganese and iron (p<0.05). In addition, using fish ponds effluents with the 50% of chemical fertilizer led to increase corn yield by 44 percent compared to the control group (p<0.05). Moreover, the uptake of iron, zinc, copper and manganese by corn were increased significantly compared to the control group through use of fish ponds effluents water with fertilizer (p<0.05). The highest and lowest yield of corn was obtained in the irrigation with the effluent of fish ponds effluents coupled with chemical fertilizers and the control group, equal to 73.7 and 44.4 tons per hectare, respectively, which had significant difference with each other (p<0.05). Therefore, the use of fish farm effluents for production of corn not only increased the yield but also dramatically enhanced fertilizer utilization.

Due to the lack of rainfall and the negative balance of groundwater aquifers in recent years, the use of unconventional water sources such as effluents and sewage for artificial feeding is one of the important methods to deal with decline in groundwater aquifers. In the Borujen-Faradonbeh plain, in order to reduce the effects of drought on groundwater resources, the aquifer of this plain has been artificially fed using the effluent of the Borujen treatment plant. The aim of this study was to investigate the effects of the effluent of Borujen water treatment plant on the quality of groundwater resources in this plain.

To investigate the quality of effluent and its effect on the downstream water of the treatment plant, water wells downstream and upstream were sampled. The samples were immediately transferred to the laboratory and analyzes including the concentrations of Mg, Ca, K Li, Na, S, St, Si, Sc, V, Ba, Cr and V were performed on the samples.

The results showed that except for calcium, potassium and chromium elements which were not statistically significant differences between the water samples taken from the upstream and downstream of the treatment plant (sig> 0.05) but the number of other elements differed between the upstream and downstream wells of the treatment plant. Were significant (sig <0.05). But the same amount is within the set standards. Also, IDW maps related to these elements showed that the northern and northwestern parts of the plain (downstream of the Borujen city treatment plant) have areas with high concentrations of these elements.

The aim of this study was investigating the antimicrobial activity of microalgae Sandosmus and Spirulina cultivated in the BG-11 culture medium and the effluent of the desalination facility of Bandar Turkmen unit, Golestan province, in inhibiting the growth of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Algae were extracted by water-alcohol method in proportion (500cc of alcohol and 50cc of distilled water) and determination of minimum inhibitory concentration (MIC) was checked by broth micro dilution method (96 house plates), and were compared to their usual environment with the amount of antibacterial activity grown in water. The results of two mentioned bacteria in the presence of different concentrations of aqueous-ethanolic extract within 24 hours showed that in the extract of the genus Sandosmus and Spirulina grown in BG-11 culture medium and 50 and 100% effluent dilutions, there was no antibacterial effect against Escherichia coli and Staphylococcus aureus bacteria during (24 hours). Sandosmus extract grown in BG-11 with 25 and 50 concentrations had higher E. coli bacteria volume than spirulina in the early hours. As the concentration increases, the volume of bacteria decreases in the early hours. Spirulina extract grown in BG-11 showed high resistance to Staphylococcus bacteria in the early hours compared to Sendesmus. Sendesmus extract grown in 50% wastewater compared to Spirulina had the highest amount of E. coli bacteria in the final hours, so it showed a high resistance to E. coli compared to spirulina. Also, in the extract of Sandosmus grown in 50% wastewater at concentrations of 25, 100 and 200 mg/ml in the final hours, the volume of Staphylococcus bacteria was higher than the concentration of 50 mg/ml, and in spirulina there was a constant trend in the final hours. In both extracts grown in 100% wastewater against E. coli bacteria in all concentrations within 4 hours, they showed the highest amount of bacteria. Therefore, in all concentrations of both extracts, they showed an increase in the volume of Staphylococcus bacteria over time (2-4 hours). Therefore, spirulina grown in 100% wastewater had a stable trend in the last hours compared to Sandosmus and showed more resistance to staphylococcus.

As a new product, nanoabsorbents play an important role in controlling and removing environmental pollution. Fe3O4 nanoparticles, due to their high absorption level, have a great ability to increase the efficiency of zeolite adsorbents in removing pollutants. Naeej et al. (2013) explained Zeolite modified with zero iron nanoparticles, due to having many absorption sites as a reducing agent, can have a great ability to remove nitrate from drinking water. Yaghmaian et al. (2015) investigated the removal of nitrate from aqueous solutions with zero-valent iron nanoparticles and stated that at a pH of 5.8 and a contact time of 55 minutes, more than 80% absorption is obtained. Qarlaqi et al. (2015) investigated the efficiency of iron oxide nanoparticles for urban sewage treatment. They stated that at pH equal to 3 and contact time of 15 minutes, the maximum amount of absorption is obtained. Therefore, in this study, clinoptilolite zeolite adsorbent and nano composite prepared from A Zeolite Fe3O4 nanoparticles were prepared in order to remove nitrate ions from real wastewater in industrial system. Also, zeolite treatment and zeolite- clay treatment were tested for comparison.

In this research, Fe3O4 nanoparticles were used to increase the efficiency of zeolite in removing nitrate from aqueous solutions and real wastewater. Laboratory columns made of PVC material with a height of one meter and a 100 mm diameter were used. The investigated columns were filled up to a height of 60 cm with the investigated materials and 20 cm of wastewater was continuously placed on the columns. The investigated treatments include three adsorbent materials: a) six kilograms of zeolite (clinoptilolite), b) three kilograms of zeolite and three kilograms of clay, and c) six kilograms of nanocomposite prepared from zeolite and nanomagnetic with an optimal ratio (Ratio of Zeolite: 0.5 Fe3O4) was laboratory. Synthetic wastewater with a concentration of 40 ppm was prepared and used. The temperature of the wastewater used was 20 degrees Celsius and the pH of the treated wastewater was measured as 7.2. The experiment was carried out factorially and in the form of a completely random basic design in three replications.

The results showed that the nano composite based on zeolite and Fe3O4 can absorb 70% of nitrate in a small laboratory scale and non-continuous flow. In continuous flow and on a large-scale laboratory that has industrial application, the absorption rate of nanocomposite will reach 27% after 8 hours of continuous flow. This absorption rate is 17% for zeolite-clay and 13.4% for zeolite. Decreasing the contact time and increasing the amount of wastewater in continuous flow will reduce the effect of absorbents. The results of the average comparison of the nitrate concentration in the wastewater from the columns with different absorbers show that the difference between the nitrate concentration in all measurement times between the nanocomposite absorber and the other two absorbers is statistically significant at the 1% level. Also, the results of one-way analysis of variance to compare the effect of wastewater removal on an industrial scale between the adsorbents used showed that the nanocomposite adsorbent used has more efficiency than zeolite and zeolite-clay adsorbents. Due to the fact that the composition of nanocomposite (zeolite modified with nano Fe3O4) has more surface area than zeolite and clay adsorbent due to having nano compounds, so the reactivity of this adsorbent is increased and nitrate absorption in this adsorbent is more than other adsorbents. In general, the results of this research show that the nanocomposite used in this study has a relative ability to remove nitrate from the water environment, and if the contact time is increased, it can be used on an industrial scale with a suitable absorption percentage. The current research was done with continuous flow and short contact time. This is despite the fact that in most of the investigated studies, the contact time was more than 50 minutes. Therefore, the amount of absorption is less than the laboratory scale and non-continuous flow. To solve this problem, the continuous flow system should be designed in such a way that the contact time reaches at least more than 50 minutes. In addition, with proper design, passing through the filter can be done in two stages so that maximum absorption takes place.

Tetraselmis tetrathele is a species of saltwater that is widely used in industry and aquaculture due to its high nutritional value, bioactive compounds, and ease of cultivation. In this study, mass cultivation of this species was evaluated using effluent from dairy and yeast factories to evaluate growth, viability, and biochemical compounds (protein, fat, carbohydrate). The experiment was performed in a completely randomized design with six treatments; Conway, raw milk and yeast effluents as culture media, each in two modes, diluted (5 ml per liter of culture medium) and concentrated (10 ml per liter of culture medium) for 11 days. The results showed that this species was able to grow on dairy and yeast wastewaters, but the highest cell density in diluted Conway (9.12 × 106 cells per ml and 0.87 per day) and the highest specific growth rate in diluted yeast (6.68 × 106 cells per ml and 2.84 per day) were measured. However, the diluted raw dairy treatment had more survival than other treatments. The highest amount of protein and fat was obtained in the concentrated dairy treatment (44.6% and 9.71% of dry weight, respectively) and the highest amount of carbohydrates was obtained in the concentrated yeast treatment (31.49% of dry weight). Based on the specific growth rate, viability, and biochemical compositions it can be concluded that dairy and yeast wastewaters can be used as a suitable semi-industrial culture medium for mass cultivation of this species and it is recommended for the production of bioactive compounds and biofuels from the obtained biomass.

With the reduction of natural sources of fresh water, the activity of desalination factories is increasing. The effluent of these factories is returned to the sea environment. The effluent contains a lot of chemicals and salt, which in case of improper discharge will disturb the balance of the sea environment. Using numerical models to check different discharge methods is one of the cheapest methods. In this research, the results of CORJET, VISJET and RNG (k-ε) models are validated for the discharge of concentrated wastewater. For this purpose, the simulation results of these models in static and dynamic environments are compared with the results of various laboratory studies. According to the results, the RNG model estimates the axial velocity of the jet well and with a small error compared to the integral and laboratory models. All three models estimate most of the parameters related to the discharge of concentrated wastewater in comparison with the laboratory studies. CORJET and VISJET models estimate the amount of effluent dilution with a high error, but the RNG model estimates the amount of effluent dilution with an acceptable error due to the consideration of flow turbulence. The most important advantage of CORJET and VISJET integral models is easy modeling and very low calculation time compared to RNG turbulence model. According to the presented results, it can be concluded that the RNG model is suitable for carrying out studies related to the discharge of concentrated wastewater from desalination plants due to considering the flow turbulence and providing accurate results.

In order to investigate the effect of using treated wastewater in agriculture on the chemical quality of groundwater at the northern region of Isfahan, an area of 6000 hectares was studied during the years 2018 and 2019 by sampling 46 wells. The location of the studied wells was in two areas under long-term irrigation with effluent for at least 10 years and the control area. Chemical parameters of the samples such as electrical conductivity (EC), chemical reaction (pH), anions including bicarbonate, sulfate, chloride, nitrate and cations including calcium, magnesium and sodium were measured. The results showed that the effect of using treated wastewater on groundwater quality of the region, in shallow and deep wells has a different behavior. Due to the long-term use of treated wastewater for irrigation of agricultural lands, none of the chemical parameters of the deep wells were significant in compared to the control area. But, in area with shallow groundwater, the chemical parameters of EC, bicarbonate (HCO3) and chlorine (Cl) were significant at 5% level as compared to the control. Most of the wells in this area are deep and only 8% of the wells are shallow. Therefore, according to the results, the use of treated wastewater for agriculture in this region has a negligible effect on the chemical quality of deep groundwater and therefore is recommended for use in agriculture.

Water pollution is a major global problem that affects plants and living organisms. Factors affecting water pollution include industrial, agricultural, and human pollutants. Qarasu river is very important in terms of pollution due to the use of river water in the agriculture and aquaculture sectors. In this research, the effect of intensive fish farms and the riverbed material was investigated on the abundance of macrobenthic communities. For this purpose, four stations 1) the station upstream and before the fish farms (as control station), 2) the station between the fish farms, 3) the last station of the farms, and 4) the downstream station at a distance of 4 km from the last farm were selected. A sampling of the macrobenthos and riverbeds was done in two seasons, winter and spring, and their frequency was calculated in the sampling stations and months. The highest abundance was related to the family’s Chironomidae (1456 numbers per m2) and Simolidae (2737 numbers per m2) from the Diptera order, which were observed in the effluent of station 2 and station 4 in the winter season, respectively. In addition, the type of the river bed was determined to find the correlation with macrobenthic species. The identified macrobenthos was classified into trophic groups and the relationship with the type of substrate was determined using the Pearson correlation. The correlation of different macrobenthic species with sampling stations and months was found using Canoco software and CCA statistical analysis. The present study showed that the effluent from intensive fish farms had an effect on the abundance of macrobenthos in the Qarasu River, which could be due to the increase in nutrients in the river water from the release of the effluent, and decrease in temperature and decrease in the decomposition of nutrients in the winter season. Therefore, based on the findings, the presence of different functional macrobenthic groups is affected by the type of riverbed and different seasons of the year.

Lack of water resources in Mazandaran province and the volume of effluent produced in different sectors, ‎has caused that in order to reduce the withdrawal of surface and groundwater resources in the province, the ‎use and management of unconventional water resources, much attention is paid. The purpose of the present ‎study is to evaluate the application of unconventional water use scenarios on the amount of runoff and ‎sediment in six stations (including Kordakhil, Garmroud, Varand, Vastan, Parvijabad and Aliabad stations) in ‎the Tejn watershed during the years 2000 to 2017 using the SWAT model. Recalibration and validation of the ‎model using data from 2003 to 2012 and 2013 to 2017 and then to evaluate the scenarios of allocating 30% of ‎the available wastewater for agriculture (scenario one), allocating 30% of unconventional water to feed ‎aquifers in the conditions of applying scenario one (scenario two) and a 20% reduction in the extraction of ‎underground water sources for irrigation and the use of unconventional water sources as alternative sources ‎to meet environmental needs (scenario three).‎‏ ‏Evaluating the efficiency of the model using R2 and NSE ‎coefficients shows the proper performance of the model in simulating these two parameters. The results ‎indicate that the application of scenario one did not affect the amount of runoff and sediment in the basin, but ‎with the application of scenario two, the amount of runoff and sediment decreased by 13.4% and 9.1%, ‎respectively. Applying Scenario three should be 10 to 20% of the annual discharge for the second six months ‎and 30 to 40% of the average annual discharge for the first six months of the year in order to meet the ‎environmental needs. The results obtained from the present research show that the use of non-conventional ‎water, in addition to solving the water shortage, also reduces the problems caused by the flow of runoff and ‎the settling of sediments.‎

The metropolis of Tehran has seven drinking water treatment plants, which according to the water needs, ‎more than one billion cubic meters of water treated by the treatment plants are provided to the customers ‎annually. Five percent of the volume of water entering the treatment plants is converted into wastewater, ‎which is estimated at 50 million cubic meters per year. If managed in the recycling process, it will play an ‎important role in balancing water resources and preventing water loss. Therefore, this study seeks to evaluate ‎the recycling process of water treatment in the field of drinking water supply in Tehran to increase the ‎stability of water supply and demand cycle. For this purpose, in order to effectively regenerate this cycle, it ‎was evaluated in the treatment plant No. seven in Tehran with an incoming water volume of 155 million cubic ‎meters per year. In this regard, the results of evaluation of the recycling process change in the treatment plant ‎showed that by changing the wastewater treatment process and the use of polyelectrolyte, the amount of ‎effluent decreased by 95%. The results showed that the volume of effluent decreased from 7.7 million cubic ‎meters per year to 310,000 cubic meters per year, which in fact, Five percent efficiency of effluent production ‎to three tenthe of percent of effluent production in this process change. This change in the effluent system ‎produced in the drinking water treatment plant can greatly contribute to the sustainability of water resources, ‎especially groundwater, given the volume of water resources required by Tehran.‎

The expansion of industries in the world, the limitation of resources and the increasing consumption of water have led researchers to pay more attention to wastewater treatment than in the past. Wastewater treatment is done in order to stabilize the produced organic matter, reuse water and solid materials resulting from wastewater treatment, and also to be able to discharge the waste water into the environment and protect the environment.

This research has been investigated with the method of biological treatment information modeling using fuzzy logic. One of the cost-effective methods for purifying the sanitary wastewater of the refinery is modeling using the fuzzy logic method. Fuzzy inference systems are a popular computing framework based on the concept of fuzzy sets, if-then rules, and fuzzy reasoning. This category of systems has a successful application in the fields of automatic control, data classification, decision analysis, expert systems, time series prediction, robotics and pattern recognition. In this research, MATLAB R2012 software has been used for fuzzy logic modeling by Mamdani method. Information obtained from the tables in the article "H.A. Hegazi. 2013".

By examining all the diagrams and models, we found that the modeling done is reliable and can be used to obtain the results of other experiments without conducting experiments. Also, the best operating conditions can be called rice husk adsorbent concentrations of 50, 60, 60, 60, 60, for the removal of Fe, Pb, Cd, Cu and Ni metals. For the ash absorbent, the absorbent concentrations of 60, 60, 60, 50, and 60, respectively, were called optimal absorbent concentrations for metals. Also, among the two absorbents, rice husk is a better absorbent. The accuracy of the model was reached around 95% and proved the reliability of the model. It can also be concluded that ash and rice husk worked very well as natural absorbents and the removal efficiency was up to 90%.

Iris species are known to be a rich source of isoflavonoids. Iris germanica L. is one of the most important species of bearded irises which is known as Irsa in traditional medicine. In this study, the amount of phenolic compounds and antioxidant activity of the waste obtained during the essential oil extraction process of 34 samples of German iris rhizomes (6 parent samples, 27 hybrid samples and 1 commercial sample) were evaluated. Iris samples were collected from the Ornamental Plants Research Center (OPRC) in Mahallat city and commercial sample were purchased from the market. After extracting the EO, samplings were carried out using the extract in balloon. The phenol content was measured by Folin-Ciocalteu method, flavonoid by Aluminum-chloride method and antioxidant activity with DPPH and FRAP assay. The results of variance analysis showed that all measured factors were affected by the type of hybrid, which was significant in all factors (P<0.01). The results of mean comparison showed that samples with purple and violet flower colors had the highest amount of phenol and flavonoid, followed by the highest level of antioxidant activity. In other words, the highest amount of flavonoid (113.22 mg QUE/g DW plant) and antioxidant activity (DPPH) (817.73 mg TBHQ/gDW plant) was observed in sample P6 (purple parent) and the highest amount of phenol content (261.31 mg GAE/g DW plant) was observed in sample P3 (violet parent). In general, the water residues from the Iris EO extraction can be used as a suitable and cheap source for obtaining natural antioxidants.

Destruction of aquatic ecosystems, reduction of urban water quality and shortage of water caused countries to use unconventional water sources. Currently, the water resources of populated cities like Tehran are under severe pressure. In this research, the Elahieh canal in Tehran 3rd district was selected as a case study. The purpose of this study is to reuse canal water as an important method of sustainable management of water resources. The present research has investigated the supplying, purification and reuse of urban canal water with the aim of irrigating a part of the green areas in the 3rd district of Tehran. The data that is used in this research was collected by field observation method and the analyzes were done in the accredited laboratory. Some of the most important water quality results are as follows: the average amount of coliform bacteria was 1100 MPN/100cc, this value indicates microbial contamination. The presence of sodium reduces the permeability of water in the soil and inhibits the growth of plants. The amount of sodium in the water of this channel is 34 mg/lit, which has exceeded the threshold. The amount of BOD5 and COD was 38 and 72 mg/lit, respectively. Also, the heavy metal test results showed that boron exceeded the threshold with an average of 52 ppb. Finally, the testing of the samples showed that this water will be prepared for reuse by performing various stages of physical and advanced purification and also disinfection. Also, the results showed that using the Elahieh canal water for irrigation, reduces the pressure on the underground water table. Currently, 560 cubic meters per day are being pumped from the Fakhar well, if recycled water is used instead of Fakhar well, 560 cubic meters per day will be saved.

Heavy metals are one of the most important causes of environmental pollution in the world due to the industrialization of societies. Wastewater production is one of the problems of waste accumulation in waste collection sites. Urban wastewater contains almost all known chemical elements and persistent pollutants in the environment such as heavy metals that are not biodegradable. Due to the ability of heavy metals to accumulate and cause toxicity in living organisms, this type of pollution is considered a serious and fundamental problem. Some heavy metals such as lead, cobalt and cadmium can be distinguished from other pollutants, because not only are they not biodegradable, but they can accumulate in the structure of living organisms and cause various diseases, even in high concentrations. be very low The use of plants as an effective and cost-effective technology to remove metal pollutants from contaminated soils and waters has been recommended as a new environmentally friendly method instead of other costly measures. The purpose of this research was to investigate the absorption of some heavy metals in urban wastewater by vetiver and canna plants and its effect on some physiological and anatomical characteristics, as well as to evaluate the resistance of vetiver and oleander plants against heavy metals in urban wastewater. For this purpose, an experiment was conducted in the form of a randomized complete design with three replications using vetiver and canna plants. The plants at the same size and the same weight including vetiver plant and the rhizomes of canna plants were obtained from their cultivation places in Guilan province and placed in the pots at the end of the winter season that is, in the month of March, containing 10 kg of sifted soil. The control pots were irrigated with 500 ml of urban water and the treated pots with 500 ml of urban wastewater twice a week, and this process of watering the control pots and the treatment continued for 6 months. In addition, 3 pots containing 10 kg of sifted soil without plants were also irrigated with urban wastewater during 6 months, like the treated samples. After 6 months, the amount of heavy metals in different organs of vetiver and canna plants was evaluated and the anatomical structure of the roots of vetiver and canna plants treated with urban wastewater was compared to the control plants. Also, the amount of lipid peroxidation of the cell membrane, the amount of proline and soluble sugars in the leaves of the plants treated with urban wastewater were measured in comparison with the control plants. The results of investigating the effect of 6 months of irrigation with urban wastewater and urban water on the amount of zinc metal accumulation in the roots, stems and leaves of vetiver and canna plants showed that the amount of zinc was more than the standard level (200 mg/kg). The transfer factor (TF) for zinc element (Zn) was calculated as 0.72, which indicated the accumulation of zinc element in vetiver roots under treatment. Despite the high absorption of about 150 mg/kg zinc by treated plants, a significant amount of zinc element was observed in the final soil, which indicated the high contamination of urban wastewater with zinc element. The bioaccumulation of zinc element in the present research was 2.45 and this shows that vetiver plant is a good plant accumulator for zinc element in the root. In addition, the highest concentration of zinc element was found in the root of canna plant. The results of investigating the effect of 6 months of irrigation with urban wastewater and city water on the amount of chromium metal accumulation in the roots, stems and leaves of vetiver and canna plants showed that the bioaccumulation rate of chromium in the treated canna plant was 4.43 and can indicate this the issue is that canna is a good absorber for chromium. The transfer factor (TF), which is the ratio of chromium metal concentration in the dry weight of shoot to root, was 1.64 for canna plant. This amount shows that the transfer of chromium to the aerial organs happened more, although the chromium element was also significantly accumulated in the roots. The results of investigating the effect of 6 months of irrigation with urban wastewater on the root anatomy of canna and vetiver plants showed that the diameter of the root and the diameter of the central cylinder in the treated plants were reduced compared to the control plants, as well as the number of vascular vessels in the treated plants compared to the control. Heavy metals have different effects on the anatomy of plant roots, and the absorption and accumulation of metals in high concentrations has led to structural changes in the roots of various plants.According to the investigation, the stress of cadmium and copper caused a decrease in the thickness of the mentioned parenchyma. According to the acidification of the soil after six months of irrigation with urban wastewater and the standard limit set for zinc metal, it was observed that zinc metal in the pure soil (soil without plants that was irrigated with urban wastewater with each irrigation period) was higher than the standard level. The effect of 6 months of irrigation with urban wastewater on the amount of malondialdehyde, proline and soluble sugar in leaves of vetiver and canna showed that the plants that were treated with urban wastewater had higher levels of malondialdehyde in their leaves than the control plants, so that high concentrations of zinc and cadmium led to an increase in lipid peroxidation in treated plants. Based on the results of this research, 6 months of watering vetiver plant with urban wastewater containing heavy elements of zinc and chromium, a high accumulation of zinc was observed in vetiver plant, which shows that vetiver plant is a good absorber for zinc. In the canna plants treated with urban wastewater contaminated with heavy elements of zinc and chromium, high accumulation of zinc was also observed in the canna plants, which shows that the canna plant is also a good absorber for zinc, but since the large amount of these elements for these plants are stress-producing, the evidence of physiological and anatomical stress was observed in the treated plants. The highest level of urban wastewater pollution used in this research was attributed to the zinc element, and according to the bioaccumulation factor and the results of this research, canna and the vetiver plants are good absorbers for zinc and chromium elements. In such a way that both elements zinc and chromium were mostly accumulated in the roots of canna, but the investigation of the transfer factor showed that zinc and chromium elements were more transferred to the aerial parts of the canna plant and so the canna plant has the ability to absorb these two metals through plant extraction, and the vetiver plant, which did not show significant transfer in the aerial parts of the plant, showed the ability to absorb these two metals through plant stabilization. Therefore, it is recommended to plant the studied plants in soil polluted by urban water to refine the soil.