Assessment of the primary production statues of the international Gavkhooni Wetland, Iran

Wetlands are of the unique and productive ecosystems in the world. The present study was conducted to determine primary production statues of the international Gavkhooni Wetland, based on chlorophyll-a. Sampling was performed seasonally from March 2017 to February 2018. Four sampling stations were assigned based on latitude and longitude. Water salinity, temperature, pH, nitrate, phosphate, BOD5, TDS, EC, TSS and dissolved oxygen were determined in triplicate in each station. Trophy level was determined using index TSI. The results showed that there was no significant difference in mean chlorophyll-a content between the seasons. The highest and lowest chlorophyll-a contents were observed in spring and winter, respectively; and the significantly highest content was measured in the station A (Shakh Kenar). There was no significant difference in the water physicochemical parameters between the seasons (P>0.05). The mean water nitrate level of the sampling stations was 4.255 mg/l; the highest (5.07 mg/l) and lowest (3.35 mg/l) levels were recorded in the summer and autumn, respectively. The mean water phosphate level of the sampling stations was 1.082 mg/l; the highest (1.75 mg/l) and lowest (0.57 mg/l) levels were recorded to the winter and summer, respectively. The mean dissolved oxygen level during the study was 5.64 mg/l. According to the results, nitrate is the limiting factor for production in the Gavkhooni Wetland. Based on index TSI, the wetland is oligotrophic in the spring, autumn and winter, but mesotrophic in the summer

The trophic status of the Zayandeh River dam lake in the spring and summer, 2017

The Zayandeh River dam lake, supplies freshwater for municipal, agricultural and industrial activities of three central Iranian provinces. Monthly water sampling was conducted in the spring and summer 2017 at four stations in the lake to determine trophic state. Electro-conductivity, temperature, pH, turbidity, total suspended solids, total dissolved solids, nitrate, phosphate, dissolved oxygen, biological oxygen demand also chlorophyll-a levels were measured in the samples. The maximum value of Trophy State Index (TSI) was recorded in May and the minimum value in September. Based on TSI, the Lake was oligotrophic in the spring and summer. However, in the May, the lake was in mesotrophic state, probably due to floods, runoff and drainage of farmlands. Due to high temperatures and biological activity in the summer, nitrate and phosphate decomposition increased. On the other hand, agricultural activities decreased compared to the spring, resulted in decreases in the concentration of nutrients, especially nitrate. Therefore, the lake is in oligotrophic state from June to September

Determination of mancozeb toxicity and biochemical effects in common carp (Cyprinus carpio)

The aim of this study was to investigate mancozeb toxicity and its effects on physiological characteristics of common carp. Fish were reared for one week to acclimatize with the experimental conditions. For 96h-LC50 determination, the fish were stocked in 16 aquaria at the density of 10 fish per aquarium. The aquaria were exposed to 8 mancozeb concentrations (two aquaria per concentration) for 96 h (0, 0.94, 1.87, 3.75, 7.50, 15, 30 and 60 mg/L). 96h-LC50 was calculated based on the fish mortality, being 8.03 (4.95-13.2) mg/L. For sub-acute test, the fish were exposed to 0 (control), 1.6, 2.4 and 3.2 mg/L mancozeb (20, 30 and 40% of the 96h-LC50) for one week. Blood samples were taken from each treatment for determination of plasma glucose, total protein, albumin, globulin, calcium, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Mancozeb exposure led to increase in glucose and AST, and decrease in plasma proteins and ALT. In conclusion, mancozeb exposure causes stress response, health problem and tissue damage in common carp

The performance evaluation of TiO2 nanoparticles in the removal of chromium from aqueous solutions: adsorbent characteristics and isotherm study

زمینه و اهداف: کروم از طریق آب آشامیدنی وارد بدن می­شود وحذف آن، امری ضروری است. در این پژوهش، از نانو ذره دی‌اکسیدتیتانیوم به­ عنوان جاذب استفاده شد. مواد و روش­ها: در ابتدا خصوصیات نانوذرات دی­اکسید تیتانیوم با استفاده از آنالیز­­های XRD و FTIR تعیین شد. آزمایشات جذب به صورت ناپیوسته با استفاده از محلول­های آزمایشگاهی حاوی کروم انجام گرفت و فاکتورهای مختلف pH، غلظت اولیه یون­ فلزی، زمان تماس و مقدار جاذب بر میزان جذب در سطوح مختلف بررسی شد. همچنین در کلیه مراحل پژوهش موازین اخلاقی رعایت شد و هیچگونه دخل و تصرفی از جانب محقق در مراحل انجام پژوهش صورت نگرفت. یافته ­ها: درصد جذب در pH برابر ۳ با اختلاف معنی­داری بیشتر از دیگر pH­ها بود(88/50%) و کمترین درصد آن با اختلاف معنی­داری در pH برابر ۳ بود(38/03%). درصد جذب در غلظت 0/5 گرم در لیتر با اختلاف معنی­داری بیشتر از سایر غلظت‌ها بود(61/52%) و کمترین درصد جذب با اختلاف معنی­داری در غلظت 5 گرم در لیتر بود(6/57%). کارایی جذب در زمان­های مختلف اختلاف معنی­داری با یکدیگر نداشتند و میزان جذب بعد از زمان 30 دقیقه به ­صورت ثابت درآمد. تاثیر مقدار جاذب دی‌اکسیدتیتانیوم در 4 گرم در لیتر با اختلاف معنی­داری بیشتر از دیگر مقدار جاذب بود(68/31%) و کمترین درصد جذب جاذب­ با اختلافی معنی­دار در 1 گرم در لیتر مشاهده شد(18/54%). برازش ایزوترم­های جذب نشان داد که جذب با مدل فروندلیچ مطابقت داشت(0/75=R2). نتیجه‌گیری: جاذب دی‌اکسیدتیتانیوم، کارایی بالایی در جذب فلز کروم از فاضلاب دارد و می­تواند برای پالایش فاضلاب­های صنعتی مورد استفاده قرار گیرد.Background and Aims: Chromium (Cr), as a metallic pollutant, enters to the body through drinking water. Due to the toxic and dangerous characteristic of hexavalent chromium, its removal is necessary. In this research, titanium dioxide nanoparticles were used as an adsorbents to remove Cr from water. Materials and Methods:  The characteristic of TiO2 nanoparticles were determined using XRD and FTIR analyses. Batch adsorption experiments were performed using synthetic aqueous solutions containing chromium. The optimal conditions of adsorption were investigated at various pHs, initial concentration of metal ion, contact time and the adsorbent dosage on Cr adsorption capacity. Also, the study was carried out ethically and there was no bias and confinement on the part of the researcher during the research process. Results: The results showed that the removal percentage at pH=3 (88.50%) was significantly more than the other studied pHs. The lowest removal percentage was observed at pH = 9 (38.03%). at the highest Cr adsorption was noticed in concentration of 0.5 g/L (61.52%), which was statistically significant as compared to other concentrations Accordingly, the lowest adsorption was observed at 5 g / L concentration (6.75%). Adsorption performance was not significantly different at different times, and the amount of adsorption was almost constant after 30 minutes. Cr adsorption by TiO2 nanoparticles increased with increase in adsorbent dose and the maximum amount of adsorption occurred at 4 g/L (68.31%) which again was significantly higher than other studied dosages. The lowest removal percentage was observed at 1 g/L (18.57%). The sorption isotherm studies showed that adsorption of chromium by titanium dioxide was fitted well to Freundlich isotherm model (R2 = 0.78). Conclusion: Titanium dioxide demonstrate high efficiency in adsorbing chromium from wastewater and thus can be a promising sorbent for the treatment of industrial wastewaters

Efficacy of fish oil- and linseed oil-enriched Artemia nauplii on growth performance and stress resistance of tiger barb larvae (Puntius tetrazona)

Fish oil is the important fat source in fish nutrition. High demand for fish oil and low global supply arise a need of alternative oils in fish culture. Plant oils are a good candidate in this case. The aim of the present study was to compare the efficacy of fish oil and linseed oil on growth and stress resistance of tiger barb (Puntius tetrazona) larvae. Artemia nauplii were enriched by 2.5, 5 and 7.5 of each oil. The enriched nauplii were offered to larvae for 14 d. thereafter, fish were fed non-enriched nauplii for another 14 d. At the end of the trial, larvae were subjected to osmotic stress and their survival was recorded. There was no significant difference in final weight, SGR and weight gain among the treatments at day 14. However, oil type and oil levels significantly affected these parameters after 28 d. Fish of 2.5-LO and 5-FO groups showed the best and worst performance, respectively. There was no significant difference in survival rate among the treatments, after 14 and 28 d; however, oil type significantly affected survival of the larvae after osmotic stress. Survival of larvae fed on linseed oil-enriched nauplii was significantly higher than that of those fed on fish oil-enriched nauplii. Linseed oil showed significantly better results in growth performance and stress resistance compared to fish oil. It is concluded that linseed oil is more suitable than fish oil for Artemia enrichment to feed tiger barb larvae. The potential reasons for the better performance of larvae fed on linseed oil-enriched Artemia were discussed

Investigating the Use of Straw in Removing Oil Pollution from Water

Organic hydrocarbons as a result of carcinogenesis and mutation caused many concerns. In this research, straw and chalk absorber was used as an organic adsorbent to remove oil pollution from wastewater. The adsorption experiments were performed discontinuously using oil-containing laboratory solutions. Optimum adsorption conditions were obtained by changing the factors affecting adsorption including pH, initial concentration of contaminant, contact time and adsorbent amount on adsorption at different levels, the oil absorption was determined by weighting method. Ultimately, the use of adsorbent for laboratory wastewater was studied. The highest absorbent efficiency at the time of equilibrium was observed for absorbing oil in 15 minutes a bout 28.85% absorbance, which did not have a significant difference with other contact times, which could be due to low contact time and the lowest value was observed with a significant difference of 3 minutes about 17.82% absorption, with the absorption rate being most significant in relation to the time of low, due to increased absorption time Increases. The highest rate of straw absorption was observed in pH = 7, which did not have a significant difference with other pH about36.95% absorption and the lowest percentage of adsorption was observed at pH = 9, which had no significant difference with other  pHs (19.09% absorption; P <0.05). The effect of straw absorbent values in 2 g/L was significantly higher than other amount of adsorbents about 61.05% absorption and the lowest percentage of adsorption was significantly different from other values in 0.25 and 0.5 grams per liter about 25.92%. Therefore, it can be concluded that the straw absorbent, in the form of adding more contact time, has a high efficiency in absorbing oil from wastewater and can be used in the treatment of industrial wastewater

Evaluation of Landfill Gas Generation for Exploitation Energy (Case Study: Landfill No. 2 of Shahinshahr)

Background and objective: The paper aims to estimate the environmental gases of Landfill No. 2 in Shahin Shahr (total landfill gas, methane gas and carbon dioxide gas), comparison of gas emissions over a period of 30 years, and the availability of landfill for energy extraction. Methods: The field of research is Landfill No. 2 at Shahin Shahr Recycling Plant (Isfahan) located in Ja&rsquo;farabad Mountains, whose capacity was completed in 1391 and landfill gas assessment was carried out. The total amount of produced gases, methane and carbon dioxide has been calculated using the first-order degradation model over a period of 30 years. Results: The amount of these gases in Landfill has been calculated from 1394 to 1424.The results show that the amount of landfill gases has declined over time. The most amounts of methane and carbon dioxide production is about 1050000 and 287000 kilograms in 1394 and the least amount of methane and carbon dioxide production is estimated about 174 and 476 thousand kilograms, respectively, in 1424. The total volume of gases produced in this landfill has been estimated to be about 15 million cubic meters in 30 years, of which 27 percent are methane and 73 percent are carbon dioxide. The amount of methane and carbon dioxide gas is estimated to be about 15 million and 42 million kilograms in 30 years, respectively. Conclusion: Generally, landfill gases have declined over time. It is recommended to use energy recovery technologies for controlling greenhouse gas emissions and generation of required energy for the ShahinShahr recycling plant in order to use this volume of gas. &nbsp

Study on the efficacy of mineral wool wastes in adsorption of waterborne oil contamination (Kerosene)

Background and aim: water oil contamination has occurred in Iran since the previous century and environmental oil accumulation threatens the country water resources’ health. There are several methods to remove oil and its derivatives contamination. In the present study, mineral wool waste was used as low price adsorbent for wastewater oil contamination (kerosene) removal. Materials and methods: first, XRF and XRD analyses were used to determine chemical composition. Then, adsorption tests were conducted discontinuously using laboratory solutions containing oil to determine optimum adsorption conditions by adjustment of effective factors such as pH, initial concentration, exposure time and adsorbent concentration. Thereafter, application of adsorbent for laboratory wastewater was studied. Results: after 15 min exposure, the adsorbent (mineral wool wastes) efficacy was significantly higher than the other times (76.01 % adsorption;

Efficacy of fish oil- and linseed oil-enriched Artemia nauplii on growth performance and stress resistance of tiger barb larvae (Puntius tetrazona)

Fish oil is the important fat source in fish nutrition. High demand for fish oil and low global supply arise a need of alternative oils in fish culture. Plant oils are a good candidate in this case. The aim of the present study was to compare the efficacy of fish oil and linseed oil on growth and stress resistance of tiger barb (Puntius tetrazona) larvae. Artemia nauplii were enriched by 2.5, 5 and 7.5 of each oil. The enriched nauplii were offered to larvae for 14 d. thereafter, fish were fed non-enriched nauplii for another 14 d. At the end of the trial, larvae were subjected to osmotic stress and their survival was recorded. There was no significant difference in final weight, SGR and weight gain among the treatments at day 14. However, oil type and oil levels significantly affected these parameters after 28 d. Fish of 2.5-LO and 5-FO groups showed the best and worst performance, respectively. There was no significant difference in survival rate among the treatments, after 14 and 28 d; however, oil type significantly affected survival of the larvae after osmotic stress. Survival of larvae fed on linseed oil-enriched nauplii was significantly higher than that of those fed on fish oil-enriched nauplii. Linseed oil showed significantly better results in growth performance and stress resistance compared to fish oil. It is concluded that linseed oil is more suitable than fish oil for Artemia enrichment to feed tiger barb larvae. The potential reasons for the better performance of larvae fed on linseed oil-enriched Artemia were discussed