After drawing a linear map of the city, the spatial configuration parameters can be extracted for informal settlement. Copiapite and jarosite are located along the main stream in the middle part of the mine and the southern dump (Fig. 1A).
Survey of the magnetic field effect on arsenic removal from drinking water with and without iron filings
Investigation of the influence of a magnetic field on the removal of arsenic from drinking water with and without iron filings. The results showed that as the initial concentration of arsenic increased, the removal efficiency also increased. The results showed that as the initial arsenic concentration increases, the arsenic removal efficiency decreases.
By increasing the dosage of iron filings, the efficiency of arsenic removal also increased. 2007) showed that by increasing the dosage of iron filings, the removal efficiency of arsenite ions increases. The results showed that by increasing the contact time, desorption can occur at different times. The results showed that the magnetic field reduced the arsenic level in the samples without iron fillers, but increased the arsenic level in the samples with iron fillers.
Sodium arsenite (NaAsO2) reacts with iron hydroxide (Fe(OH)3) to form iron arsenite (Fe(AsO2)3) on the surface of the iron filings.
Effect of temperature on hydrothermal gasification of paper mill waste (Case study: The paper mill in North of Iran)
The amount of output gas is directly related to the temperature, and gas production increases as the temperature increases. This means that the amount of volume has increased by 66.9% at this temperature range and only under the influence of temperature changes. The amount of output of hydrogen gas is also higher than normal (dry) in thermal gasification method.
One of the reactions in hydrothermal gasification processes is the steam reforming reaction, in which a large amount of hydrogen is produced in a combination of water and methane. In summary, the changes in the amount of gas are as follows: the amount of CO2 and H2 increases, and the amount of CO and CH4 decreases altogether, illustrating a more optimized mode compared to the gasification mode without the presence of moisture. In general, we can conclude that the amount of gas generated increases with the increase in temperature in hydrothermal gasification and, conversely, its calorific value decreases while the carbon conversion rate increases.
The results of studying the waste characteristics before the hydrothermal gasification process and its output products show that the following changes occur: The amount of CO2.
Determination appropriate model for estimating soil water characteristic curve (Swcc) in various moisture conditions in the one compacted clay soil
PLLL
Determination of suitable model for estimation of soil water characteristic curve (Swcc) under different moisture conditions in the one compacted clay soil. For the standard compaction, the hammer was dropped on the soil in the mold 25 times on each of three soil layers (ASTM D1557). Then, soil samples were prepared by three compaction tests under three water content conditions including 2% dry of optimal, optimal and 2% wet of optimal water content.
In the witness sample, the SSR in models FX5 and VG is less than 10-3, while in modified compaction all models except Tani and Russo models in modified compaction, Expotential and FX5 models in standard compaction and also the VG model in standard compaction-dry, FX5 model with reduced compaction-dry and wet is less than 10-3. The default compaction optimum SSR in each model is not less than 10-3, which is within the range of the SSR values obtained by Leong and Rahardjo (1997) and Miller et al. All models have the best performance on clay soils, but the FX5 - and Tani models have the better and weakest performance respectively compared to the other methods.
Among the fitted models for Matlab experimental models, the FX5 and VG models presented the best performance compared to other models and the Thani model presented the weakest performance.
Comparison of linear and hybrid models in predicting the distribution of heavy metals using remote sensing and spatial analysis in East of Zanjan city
The obtained training and test error values of neural network-genetic algorithm hybrid model were less than corresponding values of multivariate stepwise linear regression. On the contrary, the values of coefficient of determination in of artificial neural network-genetic algorithm hybrid model were higher than corresponding values of multivariate stepwise linear regression. These results indicated that the prediction ability of heavy metals especially in high concentrations by artificial neural network-genetic algorithm hybrid model was higher than linear models.
This study defined the artificial neural network genetic algorithm and multivariate stepwise linear regression models to predict the distribution of heavy metals in different land uses from Landsat images. The root mean square errors of training data with artificial neural network genetic algorithm model for heavy metals studied were lower than the linear model. Models of the coefficient of determination of artificial neural network-genetic algorithm training and testing the hybrid model showed higher values than the linear model.
The results showed the success of the artificial neural network-genetic algorithm model in predicting the distribution of heavy metals using remote sensing.
The pollution effects of nitrate and phosphate on eutrophication status in Gomishan international wetland
Moreover, in these stations, in September compared to August, there was a positive correlation between the increase in the concentration of Chla and nitrates and the decrease of inorthophosphate. This issue pointed to the limitations of nitrogen resources, with the receipt of a small amount of phosphate resources, N/P decreased and the bloom level of cyanobacteria increased in September (Figs. 3 and 4 b). According to the results, coastal wetlands such as Gomishan where freshwater and sewage entered the inlets, the role of phosphorus was more effective than nitrate.
Shallow wetland depth also affected phosphate loading and caused eutrophication, especially in S3 and St4. The impact of the global warming process on the climatic conditions of the Caspian region, together with increasing human and agricultural activities in the Caspian Sea basin, was the cause of the shallowing. Gomishan Wetland in recent years. Although the wetland water originates mainly from the Caspian Sea, due to the shallow depth and dry and semi-arid condition of the Turkmen Sahra Plain, resulting in increased surface evaporation, saline geological formations (clay) and also urban drainage channels, the amount of dissolved substances observed in the wetlands was high in compared to the Caspian Sea, especially in summer. According to the measurements of Chl concentration between May and September (Table 1), the Gomishan wetland showed a eutrophic level.
Also, for runoff control, it is essential to prevent the development of open drains which are seen in abundance around wetlands. Moreover, the interpretation of the observed chlA concentration is not limited to local-scale sediment inputs or composition, because climate change was also effective. .
Environmental assessment of urban water and wastewater systems from greenhouse gasses production point of view (Case study: City of Sari)
Environmental assessment of urban water and wastewater systems from the perspective of greenhouse gas production (Case study: The city of Sari). The total amount of the equivalent carbon dioxide produced in the drinking water life cycle in Sari city is shown in Figure 2. According to this figure, the total amount of the equivalent carbon dioxide produced in the drinking water cycle is 0.392 kg CO2/m3 water, where the phase of withdrawal water from its resources has the largest share (about 60% of the total equivalent carbon dioxide) in the production of the greenhouse gases.
Water distribution network, waste water treatment plant and waste water collection network have portions of approximately 20%, 12% and 8% respectively in the production of the greenhouse gases. In scenario 3 with hydroelectricity, 89% of greenhouse gases produced in the water extraction phase are reduced (Fig. 3). The equivalent carbon dioxide produced by various agents in introduced scenarios is shown in Figure 4.
It can be concluded that the operation of the Shahid Rajaee dam and Kiasar water treatment plant and the use of hydroelectricity will lead to a large reduction in electricity consumption and the production of greenhouse gases.
The amount of Cr+6 removal in different pH ranges between two adsorbents is shown in Figure 2a. According to a similar study, the adsorption of Cr+6 on COOH@NPG/Fe3O4 was significant under acidic conditions. The adsorption kinetic models of Cr+6 on adsorbent, together with their corresponding regression coefficients, are given in Table 3.
According to the regression coefficient (R2) in Table 3, the adsorption kinetic data were well fitted by the pseudo-second-order model. NPG/Fe3O4 was also functionalized with carboxyl (COOH@NPG/Fe3O4) for use as an adsorbent for the removal of Cr+6 from aqueous solution. The adsorption efficiency of Cr+6 was increased with decreasing solution pH and initial Cr+6 concentrations.
The Langmuir model showed that it is monolayer adsorption of Cr+6 on the surface of the adsorbent.
Investigation of heavy metals concentration in surface sediments of Choghakhor wetland
Various types of direct (geochemical) and indirect (statistical) methods are often used to calculate environmental pollution with heavy metals. Correlation and PCA analysis were used to determine the source of heavy metals in the sediment samples. Values of enrichment factor, geoaccumulation index and heavy metal pollution factor in Chogakhor wetland.
As previously mentioned, the concentrations of most heavy metals were lower than the background values. Therefore, it can be said that the distribution of heavy metals in sediment samples was mainly controlled by natural sources. In this study, we analyzed the spatial distribution of heavy metals in the entire area of the Chogakhor wetland.
The results showed that the mean concentrations of heavy metals were all lower than the background values.
Determination of the optimal water release of dam with considering quantitative and qualitative demands
Materials & Methods
- Environmental flow calculation
- Purposes
- Conflict resolution model
As already mentioned, one of the main purposes of this study is the provision of environmental flows. Therefore, one of the aspects to consider when determining the optimal release is the achievement of these purposes. The second objective should be defined as the reliability to determine the optimal discharge flows, taking into account the purposes of the impoundments.
Considering the purpose of reliability among the other purposes of the dam causes supply of water demand for all purposes (hydroelectric generation purposes, flood control, agricultural water management and creation of tourist attractions) in determining the optimal release. Given that the drinking water in the downstream regions, including Ahwaz city, is supplied from the Karun River and given the importance of providing high quality drinking water. Thus, in addition to the environmental flow, it is also necessary to consider a purpose to manage and control river pollution concentration.
If there is more than one interested party in the decision-making process, due to different goals and different priorities of the views of the interested parties, the decision-making process will not be done as there is a lack of agreement.
Case study
The Gotvand Dam was built to meet water needs for hydroelectric power generation, flood control, agricultural water management, and the creation of tourist attractions. Another important objective related to this issue is the supply of high quality water in the downstream regions. Therefore, another purpose, such as supplying downstream water needs, was to provide high-quality water for downstream regions.
Surface water pollution is an important phenomenon that threatens the health of people, animals and the environment. To calculate an average concentration greater than 1 ppm, the concentrations are averaged and the average value is taken as the BOD indicator concentration for the discharge flow. Concentrations of less than 1 mgr/l are not taken into account, because water in which concentrations of the BOD indicator are less than 1 mgr/l is considered clean.
In such matters, the decision is such that all views of all interested parties are taken into account and the rights of all interested parties are met.
Discussion of Results & Conclusions
- Environmental flow calculation
- Simulation BOD in the range of dam release
- Calculation of average concentrations and length polluted
- Determining the optimal release
