Background: Heavy metals pollution is a serious threat to environment and human health. Therefore, it is vital to find an effective method to remove heavy metals from natural resources.

Background: Lead is a toxic metal with a poor electrical conductivity. This metal can be hazardous and poisonous even in low concentrations. Objectives: The objective of this study is the evaluation of Prosopis Mimosaceae sawdust as a low-cost adsorbent for removal of the lead from effluents. Materials and Methods: The experiment was conducted in a batch system and the effect of pH, the amount of adsorbent, contact time, and the initial concentration of lead were examined. The most common isotherms and kinetics of adsorption were applied to analyze lead adsorption and the reaction rate, also the morphological characteristics of Prosopis Mimosaceae sawdust were determined before and after the separation process by using scanning electron microscope (SEM). Results: According to the results, the maximum efficiency of lead adsorption was 96.12%, which was obtained in pH of 7, contact time of 30 minutes, and 10 g/L of adsorbent. With the increase of the initial concentration of lead, the adsorbed metal at first increased, but later the removal percentage decreased. The data from this study indicated a good correspondence with both isotherms of Longmire and Freundlich. The kinetic analysis indicated that lead adsorption is consistent with the second-degree kinetic adsorption model (R 2 = 1). Conclusions: According to the high efficiency of lead removal by the sawdust of Prosopis Mimosaceae, this method can be applied as an efficient and low-cost method for the removal of lead.

A waste stabilization pond (WSP) is a hole in which household wastewater and other types of sewage are stored for long periods so that organic materials existing in them are deposited, decomposed and stabilized through exposure to light, heat, growth of algae and microorganisms. In this study, wastewater samples collected and treated by the treatment plant of a slaughterhouse in Ahvaz region of Iran and compared the relevant measured parameters with the standards, which set by the Environmental Protection Organization of Iran in order to determine the efficiency of WSPs in treating wastewater and making them usable for irrigation purposes. The results indicate that Turbidity, BOD5, PH, COD, TDS, and TSS values for the treated wastewater stood at >1000 NTU, 912 mg/l, 8.78, 1520 mg/l, 1052 mg/l, and 2180 mg/l respectively. A comparison of these values with the standard values set by the Environmental Protection Organization of Iran revealed a significant difference. This finding shows that the wastewater treatment plant under study had a poor productivity and performance. The wastewater treated by that facility should not be used for irrigation or discharge into surface water. Key Words: Environmental standards, Wastewater reuse, Waste stabilization pondİran'ın Ahvaz Bölgesinde Mezbahane Stabilizasyon Havuzu Arıtma Veriminin Araştırılması ÖZ: Atık stabilizasyon havuzu (ASH), evsel atık su ve diğer kanalizasyon türlerinin uzun süre bekletildiği, içinde bulunan organik materyallerin ışığa, ısınmaya, alg ve mikroorganizmaların büyümesine ortam hazırlayarak çökelmesine, parçalanmasına ve stabilize edilmesini sağlayan bir kuyudur. Bu çalışmada; İran'ın Ahvaz bölgesinde bulunan bir mezbahane toplanan ve arıtma tesisinde arıtılmış atık sulardan numune alınarak ASH ile atık suyun arıtımındaki verimin saptanması ve sulama amaçlı kullanılabilmesi için İran Çevre Koruma Örgütü tarafından belirlenen standartlarla ilgili ölçülen parametrelerin karşılaştırılması yapılmıştır. Çalışma sonucunda, arıtılmış atık suyun Türbiditesi, BOİ5, pH, KOİ, TÇKM ve TAKM değerleri sırasıyla > 1000 NTU, 912 mg/L, 8.78, 1520 mg/L, 1052 mg/L ve 2180 mg/L olarak elde edilmiştir. Bu değerlerin İran Çevre Koruma Örgütü tarafından belirlenen standart değerlerle karşılaştırılması sonucunda anlamlı bir farklılık gözlemlenmektedir. Bulgular sonucunda çalışmakta olan atık su arıtma tesisinin verimlilik ve performans açısından zayıf olduğu görülmektedir. Tesis tarafından arıtılan atık su, sulama için kullanılmamalı ve yüzeysel suya deşarj edilmemelidir.

Background: The phosphorous as one of the agricultural, industrial, and urban pollutants has an important role in the eutrophication phenomenon of the surface waters. Objectives: In this research, the effect of three species of aquatic plants, including Salicornia (Persica), Typha, and Juncus, were investigated and compared with the potential of phosphate uptake. Methods: After preparing the condition and cultivation of plants, they were irrigated by synthetic wastewaters with various phosphate concentrations (7, 18, and 28 mg. L-1) for 28 days. In this test, the adsorbed phosphate was calculated based on mg. g-1 of the plant dry tissues weight using two methods: mass balance and wet digestion methods. Results: The results showed that increase in the pollutants concentration and passing time had a significant effect on the accumulative increase in phosphate uptake in all three plants at 5% level. Thus, the maximum adsorption capacity was obtained on the 28th day in high concentration of pollutant which was measured for Salicornia, Juncus, and Typha as 9.68, 6.37, and 7.68 mg. g-1 of plant dry tissues weight, respectively. Also based on the reported regression coefficients values and the obtained equations, it can be concluded that the variable 'time' was more effective than the 'concentration' variable in terms of adsorbed phosphate by the studied plants. The results of the measurement of phosphate uptake in the terrestrial and aerial parts showed that the maximum uptake was measured as 6.35 and 10.33 mg. g-1 of terrestrial and aerial parts dry weight in Salicornia plant, respectively. Moreover, the results showed that the translocation factor in Salicornia, Juncus, and Typha plants were 1.54, 1.12, and 1.46, respectively, as Salicoenia was maximum and Juncus was minimum. Conclusions: Finally, according to the obtained results from research, all three plants can be known as the hyper-accumulate plants, and they can be used for phytoremediation of phosphate from the agricultural soils according to the high capacity of these plants and prevent these pollutants from entering to the surface waters.

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ABSTRACT:The main objective in designing an embankment dam is to achieve a structure that keeps water and in addition prevents seepage in downstream that has piping and rupture. Therefore, the present study examined the effect of height on upstream and downstream slope stability of heterogeneous embankment dams with the same characteristics but with different heights at the end of construction and Steady-State Seepage and Rapid Drawdown. To investigate the effects of height, two dams with a height of 62 meters and 133 meters and 6 meters crest width were modeled in Geostudio software. The embankment dam is composed of 14 different areas with different characteristics. To analyze the dam stability, SLOP/W and to model the movement of water in dam due to presence of water behind the dam in a Rapid Drawdown and Steady -State, seepage SEEP/W in Geostudio was used. Finally, the obtained safety factors in two dams with different height are compared with each other and the obtained safety factor was compared with USBR safety factor. This research showed that the safety factor is safer for 62 meters dam. The safety factor in shorter dam is safer than long dam. Key Words: Embankment dam, Height, Geostudio, Slope/w, Stability analysis, Hetorojen Embankment Barajların Statik Stabilisezi Üzerinde Yüksekliğin EtkisiÖZ: Bir dolgu baraj tasarımında temel amaç suyu tutan bir yapı elde etmektir ve buna ek olarak b oru ve yırtılması olduğu mansabında sızıntı önler. Bu nedenle, bu çalışmada inşaat ve-Kararlı Hal Sızma ve hızlı Drawdown sonunda aynı özelliklere sahip heterojen dolgu barajların memba ve mansap şev stabilitesi üzerine ancak farklı yükseklikleri ile yüksekliğinin etkisi incelenmiştir. yüksekliği etkilerini araştırmak amacıyla, 62 metre ve 133 metre 6 metre kret genişliği yüksekliğinde iki baraj Geostudio yazılımında modellenmiştir. su bendi, farklı özelliklere sahip 14 farklı alanlardan oluşmaktadır. Yansımalar SLOP/W , baraj kararlılığını analiz etmek ve nedeniyle hızlı Drawdown ve Sabit -Devlet baraj arkasında suyun varlığına baraj su hareketini model, Geostudio içinde sızıntı SEEP / W kullanıldı. Son olarak, farklı yüksekliğe sahip iki baraj elde edilen güvenlik faktörleri birbirleriyle karşılaştırılmış ve elde edilen güvenlik faktörü USBR emniyet faktörü ile karşılaştırıldı. Bu araştırma emniyet faktörü 62 metre baraj için daha güvenli olduğunu göstermiştir. kısa baraj emniyet faktörü uzun baraj daha güvenlidir.

Background: Different factors affect walking biomechanics disturb the postural control. Genu valgus is one of the most important lower limb malalignments that affects the postural control and disrupts the posture. The purpose of the present study was to investigate the acute effect of knee brace on the electromyography activity of lower limb muscles in individuals with genu valgus during walking. Methods: In this semi-experimental and a laboratory typ study,. 24 boys with genu valgum (20-30 years old) volunteered to participate in the study. The electrical activity of the selected muscles was recorded by an electromyography system during walking with and without knee brace. Paired t-test was used for statistical analysis at a significance level of 0.05. Results: There was a significant increase in electrical activity of the semitendinosus muscle during walking with knee brace compared to walking without it (p = 0.037, d = 0.89). The electrical activity of other lower limb muscles did not show any significant differences during acute use of knee brace (P >0.05). Conclusion: The semitendinosus muscle in individuals with genu valgus is weak. Therefore, significant increase in the electrical activity of the semitendinosus muscle during wearing of knee brace means delaying the fatigue and indicating improvement in the muscular function.