جستجوی مقالات مرتبط با کلیدواژه "turbidity" در نشریات گروه "آب و خاک"

The increase in the human population and the growth in water consumption on one hand, and the rise in sewage production on the other hand, have led to the expansion of environmental pollution threats. The objectives of the present study include launching a pilot project for the localization of knowledge in the design of artificial wetlands in accordance with the quantitative and qualitative conditions of domestic sewage in Iran (specifically, the dormitory of the University of Agricultural Sciences and Natural Resources in Sari) and investigating the possibility of replacing wetland systems with conventional domestic sewage treatment systems in the country.

This study was conducted at the University of Agricultural Sciences and Natural Resources in Sari, involving the construction of six artificial wetlands, each with a length of 3 meters, width of 2 meters, and a height of 1.5 meters, using reinforced concrete. One of the ponds was excluded from the system due to leakage. Inside the ponds, artificial filters at different depths (1 meter: d1 and 1 meter and 30 centimeters: d2) and plant filters (Phragmites australis: p1 and Arundo donax: p2) were filled and planted. D10 and the coefficient of unifo rmity (CU) of the substrate materials were obtained as 2 millimeters and 3.625, respectively, from the grain size analysis. The hydraulic conductivity and porosity of the substrate were 2.523 cm/s and 39.2%, respectively. The specific surface area (SSA) of the substrate materials was calculated as 1.336 m²/kg (2245 m²/m³ of substrate materials). The effluent from the septic tank of the dormitory's baffled septic tank was injected onto the beds after a settling and dilution stage using a pump. In the initial loading, the beds were submerged below the surface, and a three-day retention time was allowed for the first sampling. Quality parameters of the wastewater, including biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), fecal coliform (FC), and total coliform (TC), were monitored to assess the performance of the treatment system.

Although the injected wastewater was diluted up to 25%, a significant removal efficiency of 51 to 55, 41 to 79, 74 to 89, 70 to 95.3, and 78 to 95 percent was achieved for BOD, COD, TSS, FC, and TC, respectively, in different treatments. Among the treatments, the weakest performance was associated with treatment P1D2, while the best purification performance was observed in treatment P2D1. This indicates the dominance of the physical characteristics of the systems at the beginning of the startup period on the purification performance. However, the initial performance of the treatment system was very promising and the removal of some parameters such as TSS and FC was at the average level of a full-fledged wetland treatment system.

This wastewater treatment technology is recommended for all managers and experts in the country's wastewater industry, especially in rural areas with inexpensive land and a population of fewer than 5000 people. These conditions encompass all towns, universities, military barracks, and military facilities as well.

Wastewater treatment of steel industries as one of the most important and water-consuming industries is of high important, especially in terms of wastewater reuse. One of the most important and newest methods for industrial wastewater treatment is the coagulation and flocculation method, in which the efficiency of the process can be greatly improved by controlling various factors such as temperature, pH, retention time and coagulation concentration. In this study, the efficiency of polyaluminum chloride in removing the turbidity of simulated hot-rolled effluent of a steel plant was evaluated in the presence of independent variables of pH, stirring time, temperature, oil concentration and suspended solids. The experiments were performed by Design expert 8 software. To do so, the central composite design method was applied as the most common type of design in the response procedure method. The results showed that increasing the polyaluminum chloride coagulant to about 5 mg / l increases the turbidity removal efficiency, thus reducing the turbidity to less than NTU 20, which is a standard for water turbidity used in the rolling process. Increasing the temperature from 27 to 55 degrees has slightly enhanced the turbidity removal efficiency. According to the test design results, the best turbidity removal efficiency from the studied effluent (51 to 62%) was achieved at polyaluminum chloride of 1 mg / l, the amount of suspended solids of 1500 mg / l and the stirring time of 30 seconds. In this case, the range of turbidity removal efficiency was. The results showed that pH, temperature and oil content had the lowest effectiveness. Overall, the results of the present study indicate that the optimal addition of polyaluminum chloride to the effluent improves the effluent turbidity removal.

The lack of water for humans and the environment is one of the serious problems of today's world. Drinking water in Sari city and its dependent villages are provided with groundwater. The poor quality of the outlet water after the pressurized sand filters in the Moallemkola water treatment plant led to investigate the effective factors on the efficiency of the above filters. The pressurized sand filters substrate was composed of three types of silica granulation. This research investigated the physical and chemical parameters of pressurized sand filters by choosing the type of granulation and the use of a single layer and double layer in the pressurized sand filters bed (silica, silica-anthracite, and leca-anthracite), as well as changing their surface load in seven steps. Samples were taken in all steps and from five points in the water treatment plant (inlet water, after aeration, at the beginning of the filter operation, at the end of filter function and after chlorination). The results showed that the best option is the simultaneous use of silica and anthracite in the filter bed, employing 1.5 times of surface load in the water treatment plant, along with the use of aeration and sedimentation units. The removal efficiency of turbidity, TDS, TSS, calcium, magnesium and iron parameters was obtained 85.41, 23.54, 56.94, 21.08, 32.28 and 89.47%, respectively. Therefore, the use of double layer of silica and anthracite will increase the quality of water, and it is recommended for areas with high turbidity.

Due to lack of water resources and per capita consumption in Iran, conservation of water resources is one of the most important and basic priorities. Drinking water in Sari city and its dependent villages are provided with groundwater resource. The poor quality of the outlet water especially the high amount of iron after the pressurized sand filters in the refinery of Moallemkola led to investigate the effective factors on the efficiency of the above filters. The purpose of this study is to investigate groundwater resource by changing the bed and surface load of pressurized sand filters to improve the removal of physical and chemical parameters of the water refinery.

In this research investigated the physical and chemical parameters of pressurized sand filters with the change in filter granulation using a pressurized sand filter model and using different substrates (silica, silica-anthracite and leca-anthracite). Samples were taken after treatment at three points in the refinery (at the beginning of the filter operation, at the end of the filter operation and after chlorination) after 4 months. The measured parameters included determination of suspended solids, turbidity, total soluble solids, hardness, calcium, magnesium and iron. The experiments were carried out in factorial and completely randomized design with three replications. Statistical analysis of data was done using SAS software and comparison of means was done by Duncan method at 5 percent probability level.

The results showed that the effect of substrates materials on TSS, Tu, TDS, Ca and Fe parameters was significant at 1% probability level. The effect of sampling point on all parameters was significant different at 1% probability level. The silica-anthracite bed had the greatest effect on the reduction of all parameters, especially the reduction of turbidity and iron content. So that the reduction of turbidity and iron content in the silica-anthracite bed was close to 70% relative to the silica bed. The leca-anthracite bed was better than the silica substrate. The best reduction in chemical parameters of water was related to silica-anthracite in pressurized sand filters with a surface load of 54 cubic meters per hour. The interaction effect of different materials inside the filter and sampling point was also significant at 1% probability level on TSS, TDS and Fe parameters. The results of the comparison of the average of the physical and chemical parameters of the water studied at different points of sampling showed that the output water at the end of the disinfection had the lowest values relative to the water outflow from the filter at the beginning of the operation and the outlet water from the filter at the end of the operation.

The option of using silica-anthracite in pressurized sand filters in addition to improving the water quality, will reduce the cost of operating (maintenance and repair) of the filters.

One of the influential processes on Total Suspended Solids (TSS) and Turbidity (TUR) removal can behorizontal roughing filter (HRF). Lack of water resources has addressed using of treated wastewater as one of the approaches to solve the problem. Therefore, low cost and natural methods are considered to improve polluted water quality. In this paper, HRF performance was evaluated in pilot scale with four compartments of difference size of sand and also in three filtration rates of 0.5, 1 and 1.5 meter per hour. The performance of constructed HRF was monitored throughout the pilot operation period under the effect of effluent from a wastewater treatment plant which contains TSS and TUR exceeding the Iranian Environment Protection Organization limits(even for agricultural use which its permissive standard is more than the allowable one for discharging surface water). Comparing the three filtration rates indicated that maximum efficiency, which is equal to 72 percent, has occurred in 0.5 meter per hour. Analyzing of samples in the rate of 0.5 meter per hour showed that as filter operation time (T) increases, at first, TSS and TUR removal rise to 72 and 54 percent until the third month of T and then falls to 39 and 33.5 percent to the end of T, respectively. It was demonstrated that the four compartments HRF, in comparison with three compartments in previous studies improve system efficiency. Moreover, according to Iranian Environment Protection Organization standards, outlet TSS from the HRF with four compartments (40 mg/L) was within the allowable limits to discharge surface water and suitable for use in agriculture and irrigation.

The present study was conduct in order to surveying the efficiency of Chitosan in performance improvement of coagulant of poly aluminum chloride in removing the turbidity, Al, and organic materials including TOC and UV254(Absorption of the organic materials by ultraviolet at 254 nm) at the slow mixing phase from drinking water. This study conducted in the labscale using jar test device in water treatment plant of Ahvaz. Optimal dosage of poly aluminum chloride together with chitosan was obtained 5 mg/L and 0.02 mg/L respectively. The efficiency of removing the turbidity, TOC, Al and UV254 in the optimal conditions of Chitosan performance were obtained for 96.59, 46.15, 80.49, and 67.86% respectively. The dominant mechanism for instable making colloidal particles and removing the natural organic materials by bridging between the particles-polymers, neutralizing the colloidal NOM charge, and common deposition mechanism by surface absorption are justified. In addition, floces formed by chitosan were coarser due to the high molecular weight and needed to the less time in order to being deposited.

Many of irrigated agriculture problems are resulting from chemical and physical composition of irrigation water. The irrigation water quality is effective on soil moisture characteristic curve by effect on soil structure, pore size distribution and continuity of them. The aim of this study was to evaluate the effect of different water salinity in the presence of constant turbidity on the soil moisture curve. The salinity treatments at five levels (1, 2, 4, 6 and 8 dS/m) with constant turbidity (200 NTU) were applied. These treatments were investigated at three depths of soil (0 to 15, 15 to 30 and 30 to 45 cm) with a silt-loam texture with three replications in a randomized complete block design. Soil water retention curve was determined by using pressure plate method. The results were statistically analyzed with MSTATC software. The results showed that the water percent of the soil of S2, S3, S4, S5 treatments of irrigation water quality increased to values 13.65, 20.20, 23 and 30 percent compared to S1 treatment. Comparison of water percent of soil at various depths showed that the depth of the second and third compared to the first decreased to 1.40 and 2 percent.

Shahrekord aquifer is the primary resource of water for various uses across Shahrekord plain. The main objectives of this study were to investigate the fluctuations in spatial variability and zonal mapping of conductance (EC), total dissolved solids (TDS), total suspended solids (TSS) and turbidity of Shahrekord groundwater during a year. Ninety-seven wells were sampled during four occasions (June, July, September, and November) in 2010. The mean of EC (both approximately 530 µS/cm) in June and July reduced to 370 µS/cm (P<0.05). The mean of TDS in June (400 mg/L) was higher (P<0.05) than the means in other samplings (300 mg/l). TSS decreased along with approaching the fall (P<0.05). A Gaussian variogram model described the spatial variations of EC and TDS in all sampling times while for TSS a spherical and sometimes an exponential model suited the best. According to the maps, TDS and TSS are highest in the southern half of the aquifer in all sampling occasions. On average, TDS is always suitable for drip irrigation while TSS indicates a moderate dripper clogging in most cases.

surface run off from different levels of a land carry many types of impurities and so it should be purified before any consumption. To separate these materials three processes can be used: sedimentation, filtration and flotation. The objective of this study is comparing the flotation and conventional systems in removed turbidity. This is an experimental - intervention in a pilot scale study that compare the turbidity, alkalinity, temperature, pH and TSS in conventional sedimentation system with those of dissolved air flotation. Method in this study, poly aluminum chloride used as a coagulants and kaolin was used to produce turbidity. The results showed that was turbidity removal efficiency of dissolved air flotation system in turbidities NTU20, NTU50-30 and NTU110-90,were respectively 14.7, 11.1 and 10.9 percent higher than those of the conventional deposition system, determined of the level of (p<0.01). According to these results to remove turbidity by dissolved air flotation system then is more effectively to common sedimentation. System Using this system for turbidity removal in a water treatment plant with a relative turbidity from stormy areas that often receives turbid water, is recommended.