جستجوی مقالات مرتبط با کلیدواژه « تصفیه خانه آب » در نشریات گروه « محیط زیست »

Purified water is one of the most important elements in the health of human societies, so trying to purify water through water treatment plants is justifiable even with high costs. Surface waters often have a greater variety of pollutants than underground waters, and for this reason, treatment processes may be more complicated for such waters. In water treatment plants, the purification process starts through the inlet pipe to the treatment plant and enters the urban water stream by passing through garbage collection structures, aeration, microstrainer, rapid mixing, superpulsator, sand filter and tank. Like the concentrator, the recycling tank and the contaminated mechanical dewatering are divided into two parts that can be treated and cannot be treated, and the non-degradable solids are directed out of the tank.

This article has investigated the construction method and performance of different parts of water treatment plants in an executive and scientific way by reviewing reliable scientific databases and the experiences of the authors.

The performance of different parts of the treatment plant and their construction methods have been analyzed and the importance and position of each part has been discussed.

The process of water purification from the time of entering the water treatment plant to the time of its exit was investigated in detail, including the construction method, which provides useful information for planners, designers and activists in this field

The effluent from the backwashing of the filters used in water treatment can be considered as one of the potential functions for reuse for various applications, provided that it has the required quality. The purpose of this study was to determine the quality of effluent from backwashing of rapid sand filters in Sanandaj water treatment plant for reuse. For this purpose, in two high and low water seasons, the effluent of phases 1 and 2 of the water treatment plant was sampled and the physical, chemical and microbial properties of the samples were studied using standard methods for drinking water, agriculture and green space uses. The data were analyzed using SPSS software and one-sample t-test and independent t-test. The results showed that the mean value of all the studied parameters in the effluent from the backwashing of the filters of the phases No. 1 and 2 of the treatment plant was less than the standard of agricultural and green space use. Compared with the drinking water standard, only the mean values of turbidity (48 NTU in phase 1 and 45 NTU in phase 2), total coliform (4 MPN for phase 1 and 6 MPN for phase 2) and fecal coliforms (1 MPN for both phases) parameters in the effluent were significantly higher than the standard (p <0.05). The results also showed that there was no significant difference between the mean of the studied parameters in the treatment plant effluent in the two phases and the autumn and winter seasons (p <0.05). Finally, it was found that it is possible to use the effluent for agricultural and green space use, but it could be reused for drinking purpose only after treatment.

Routine biological quality check and water safety plan at small treatment plants should be considered as a part of the control requirements due to the health deprivation and the possibility of further contamination. Zangalanlou Water Treatment Plant is often contaminated due to flood. After examining the damage, improvement was performed to remove and prevent the introduction of contamination and the system's efficiency was controlled considering some parameters. This cross-sectional study was carried out on a real scale in Zangalanlou Treatment Plant in 2017. Improvement performance and comparison of the efficiency of the treatment processes (grit removal chamber, slow sand filter and equalization pond) was statistically analyzed and calculated through measurement of turbidity, heterotrophic bacteria count (HPC), total coliform (TC), fecal coliform (FC) before and after the improvement. Cryptosperidium, Giardia and total organic carbon (TOC) were also examined after improvement. Then, the measured physicochemical parameters of water resource were analyzed for 14 years. The turbidity and HPC in the distribution network and Filter, and HPC in the equalization pond were significantly reduced compared with before improvement. FC, TC and TOC were within the standard limits and the two parasites were not observed but the presence of Blastocystis was confirmed in both raw water and filter inlet, but absent in the output. The physicochemical analysis indicated an increase in total hardness, electrical conductivity, calcium, sulfate and magnesium. Generally, improvements had a significant effect in the removal of contamination at the outlet of the treatment plant, filter and equalization pond, and the physicochemical parameters pridected the water salinity in future.

Drinking water supply with proper quality is one of the main goals of water treatment plants. Filtration is a process which has the largest share of quality making in water treatment plants and about 20% of the cost is allocated to this process. The main indicator used for filters efficiency is water turbidity at outlet.
In this research, the effect of various heights (20-50-70-90 cm), effective sizes (0.75-1) and uniform coefficients (1-1.5) sand filter’s packing on turbidity removal and coliforms has been studied for four months from May 2010. Sampling was performed according to standard procedures and the samples were analyzed immediately in Tehran Islamic Azad University of Science Research laboratories and water treatment plant laboratory.
Finding: Results of coarse packing filter show the maximum efficiency of turbidity reduction was 83.58% for turbidity of 5 NTU and packing height of 90cm. The minimum turbidity reduction was 29.25% for turbidity of 10 NTU and packing height of 20cm. The maximum coliform reduction was about 87.92% for turbidity of 2 NTU and packing height of 90cm and the minimum coliform reduction was about 38% for turbidity of 10 NTU and packing height of 20cm. The effective height which causes maximum turbidity and coliform reduction is 90cm. The longest operation time in the context of a coarse bed was 35 hours in turbidity of 2 NTU and the shortest operation time in the context of a coarse strainer was 23 hours in turbidity of 10 NTU.
Results of fine packing filter show the maximumefficiency of turbidity reduction which was 93% for turbidity of 2 NTU and packing height of 90cm. The minimum turbidity reduction was 54.9% for turbidity of 7 NTU and packing height of 50cm. The maximum coliform reduction was about 91.92% for turbidity of 2 NTU and packing height of 90cm and the minimum coliform reduction was about 45% for turbidity of 10 NTU and packing height of 20cm. The effective height which causes maximum turbidity and coliform reduction is 90cm. According to the results, efficiency of the fine bed and coarse bed filter directly depends on outlet turbidity and operation of previous unit (sedimentation). The maximum and minimum operation times in fine bed were about 28 hours (NTU=2) and 14 hours (NTU=10) respectively.

Increase in population and development of various industrial and agricultural activities, makes supply of enough water with appropriate quality an ever increasing difficult task. On the basis of various researches different types of hazardous and perhaps dangerous chemical substances have been observed in the water supply reservoirs of large cities. A large proportion of these chemical substances contain organic material. Drinking water of Tehran city is mainly from free surface sources which are treated in ordinary plants where no units are considered for removal of organic pollutants. Therefore, knowledge of the organic materials is necessary. In the present research, the inflow of the organic material to the treatment plant emphasizing on TOC and also percentage of its removal were measured separately from April to October. Considering the average concentration of the organic material on the plant outflow, changes are necessary in conventional water treatment plants. In majority of the treatment plants including present case, disinfection byproduct is carried out before pre-chlorination. Therefore production of side materials from primary disinfection is not impossible and solutions are suggested accordingly. Finally, the TOC in sewerage resulted by wash out of the filters and raw water are compared.