The aim of this study was to investigate the feasibility of the use of geotextile filters to decrease suspended materials of wastewater to use in trickle irrigation systems to perform the experiment, a metal box was designed and made. Experimental treatments included four wastewater heads which were continued until clogging occurred. Outflow index, wastewater heads between geotextile layers, influent and effluent TSS (Total Suspended Solids) from filtration system were measured at specific times. The results showed that clogging rate of geotextile filters depends on physical and biological parameters. Furthermore, these results indicate that flow rate variation and wastewater head loss were the same while passing the geotextile layers and was independent of the clogging factor. However, the clogging time was related to the parameters of the swage quality. The flow rate trend variation versus time was linear with dramatic change at the beginning of experiment. However, after a while, it became logarithmic and slow. The decrease in flow rate for the 70-cm height of wastewater head was 8.83 lit/s/m until 27 mintutes of the beginning of the experiment and 3.47 lit/s/m at 56 mintutes of the end of experiment, respectively. In this study, some equations were developed to model the flow rate and wastewater head loss (RMSE=9.6%, R2=0.86), clogging of the filtration system and wastewater head loss (R2=0.968 RMSE=0.773Lit/s/m). Our results confirmed the accuracy of the models.

Geotextiles are one of the most widely used synthetic materials in filtration and drainage applications. Since in real applications, geotextiles are subjected to various hydraulic gradients and confining stresses, hydraulic behavior of geotextiles under different circumstances is of great practical importance. In this study filtration and drainage properties of several nonwoven needle-punched geotextiles with different properties and unit mass per area of 200 g/m2, 400 g/m2, 500 g/m2 and 800 g/m2, under various confining stresses and hydraulic gradients, were studied using standard permittivity and transmissivity equipments. Prepared samples were subjected to hydraulic heads in the range of 10 cm to 60 cm and confining stresses up to 1000 kPa and their hydraulic behavior was investigated accordingly. In this study the flow regime through the geotextile fibers and also the anisotropic behavior of geotextile permeability were investigated. The results show that transmissivity will decrease exponentially with increasing the normal stress until a residual value is reached, and permittivity and transmissivity coefficients were seen to decrease with increasing the hydraulic gradient. The flow regime has found to be non-turbulent in all cases.The Geotextile hydraulic behavior is of great usage in the design of landfill covers, design of embankments and irrigation structures drainage systems, and in the design of protection systems in river engineering.

The filtration rate is one of the physiological indices in bivalves that indicates the degree of the effectiveness of the filtration function in exposure to contaminants. In this study, the changes in filtration rate of Dressina poly morpha were investigated after 7 and 14 days of exposure to silver nanoparticles. Bivalves were removed from the natural environment and transferred to the laboratory. The distribution of nanoparticles in water tanks was tested with the DLS device. Bivalves were exposed to concentrations of 0.25, 2.5 and 25 ppm of nanoparticles for 14 days. The results showed the highest filtration rate for the control group (96 ± 47.74 ml min-1 g-1DW). On day 7, the highest filtration rate was observed in the first treatment (88.58 ± 64.38 ml min-1 g-1DW) and the lowest filtration rate was observed in treatment 3 (47.67 ± 11.81) ml min-1 g-1DW), no significant difference was observed in the filtration rate betwen first treatment and control (P >0.05), but the filtration rate in the third treatment was significantly (P <0.05) lower than that of the other treatments and the control group. Moreover, the filtration rate on day 14 showed similar differences to day 7, but more significant. Therefore, it can be concluded that filtration rate changes are a good indicator for nanoparticles contamination.

The aim of the research is to determine the adequacy of dialysis in patients undergoing hemodialysis through the evaluation of serum Bun and Cr, before and after dialysis and investigate the biochemical effect of dialysis on kidney in Lar city.  This research was descriptive-analytical and cross-sectional on 135 patients undergoing dialysis. Data collection was done through the researcher's demographic questionnaire. Blood creatinine and urea levels were measured by Jaffe and enzymatic methods, respectively. Dialysis adequacy was calculated through KT/V and URR parameters. The data was analyzed using descriptive and inferential statistical tests in SPSS software and by Pair t-test. Most hemodialysis patients of these centers had KT/V less than 1.2. Also, 36.1% of the subjects had URR>65 and 47.5% had KT/V>1.2. A significant decrease in serum urea and creatinine after dialysis was observed. The comparison of the types of membranes in the amount of urea and creatinine clearance showed a difference between these membranes in correcting the amount of urea and creatinine, So, HD type was the most efficient and the R4 type was the least efficient. The S3 membrane has a higher filtration rate than others, which can be the reason for this difference. The average difference of alkaline phosphatase activity before and after dialysis with S3 membrane was more than other membranes, although this difference was not significant.  BUN and creatinine showed a significant decrease after hemodialysis compared to before hemodialysis. The result showed that 36.1% had adequate dialysis; But in others, do not have adequate dialysis efficiency.

Introduction: Water is the most common material in use so its quality plays an important role in the health of people. Water is contaminated easily and it may carry several contaminants and germs in it. It is necessary to make sure that drinking water is not contaminated (particularly with biological contaminants). Biological indices such as Coliform and the MPN test have been designed to assess the quality of water. In routine biological quality control procedures of water parasite rates, quality control has been neglected due to a need for complex devices that is required for water filtration in huge volumes (approximately 400 liters).  Materials and Methods: This was a Quasi-Experimental study to assess the efficacy of Vacuum pump less filters and membrane filters in removal of cysts, oocytes and parasites. Data was collected by observation and experimental tests. We designed a simple device for water filtration without a vacuum pump, and then we added a certain amount of giardia cysts (3 samples containing 3000000,30000 and 300 cysts in 50 liters of water) to a certain amount of water. The water was filtrated and the efficacy of the system was determined.  In the second stage, water sampling was performed by means of the designed device. We took 12 samples from the city water (7 samples from water sources and 5 samples from distribution networks) and 2 samples from 2 points in a refinery plant (entering raw water and refined outgoing water). a total of 400 liters of water was collected for testing. Results: This survey showed that the designed device was effective in removing giardia cysts up to 75%, 66% and 59% for 3000000, 30000 and 300 cysts respectively. According to the findings of this study all samples of water from different parts of city showed no parasictic contamination. only the entering raw water of the refinery plant contained a number of larvae, 4 giardia cysts and 2 Entamoeba coli cysts. Conclusion: The designed device showed to be effective in removing cysts and parasites from water, so it is suitable for use because it is a simple and cheap device. Water in the distribution network is relatively safe and it is much less likely for contaminated waters to enter the distribution system. Refinery plants' efficacy is high and all stages of decontamination are performed well. contamination of entering raw water by biological factors in the apper parts of the dam is due to agricultural and human sewage contamination.

Rainwater harvesting (RWH) systems represent a sustainable approach to managing freshwater resources, especially in regions with limited water supply. The effectiveness of these systems is critically influenced by policy, design, and climatic conditions. Policies and regulations are foundational to the reliability of RWH systems. They establish standards for system components, ensuring safety and preventing failures. Effective policies encourage RWH adoption by providing guidelines for design standards and incentives such as rebates. Regular maintenance and safety checks mandated by regulations contribute to system reliability, with policies also influencing the permissible uses of harvested rainwater, which can range from non-potable to potable applications. Several factors interplay to determine the reliability of RWH systems: Climatic Conditions: Rainfall frequency, intensity, and distribution are essential for water collection. Erratic rainfall makes systems less reliable. System Design: Properly designed systems tailored to local climatic patterns improve reliability. Key design elements include catchment area, storage capacity, and filtration mechanisms. Geographical Considerations: Variability in reliability across different settings necessitates context-specific designs to maximize effectiveness and cost-efficiency. Advancements in technology enhance RWH systems' reliability and efficiency. Innovations contribute to better integration into urban planning, addressing challenges posed by climate change and urbanization. As technology evolves, RWH systems are expected to become integral to sustainable urban design. Reliability analysis incorporates water balance simulations, statistical analysis, and modeling approaches, aiding in the design and evaluation of systems against climatic variability. This comprehensive approach ensures a consistent water supply, particularly in water-scarce regions. Studies indicate favorable benefit-cost ratios for RWH systems when appropriately designed. Cost-benefit analyses in various settings show that these systems can be economically viable and environmentally beneficial, supporting water conservation efforts. In conclusion, the integration of effective policies, innovative designs, and aquifer recharging projects, with reliability analysis methodologies, is crucial for the success of RWH systems. These systems play a significant role in sustainable water management, especially in the face of increasing water scarcity challenges.

 Increase in population and water demand is the reason why conventional rapid sand filters are not able to meet the water consumption demands.  Anthracite as a filter bed medium  (low density & large particles) is able to provide increased filtration rate. As anthracite is more expensive than sand, it is not possible to use it in many developing countries.  Two series of tests were conducted: 1- Anthracite characteristics determination: Determination of “carbon, ash, sulfur, moisture and volatile matter content, rate of solubility in acid and base, relative density, hardness and crushing rate during the backwash. 2- Pilot plant tests: Measurement of turbidity, residual chlorine, total organic carbon,  coliform content and surface over flow rate were preformed at the school of public health , Isfahan. For statistical analysis, the two statistical tests;T-test and co variance were used. The mean of “turbidities removal” in local and imported anthracite were 85.96 and 80.5 percent respectively (no significant value P>0.05) .The mean of “residual chlorine removal” in local and imported anthracite were 59.6 and 61/2percent respectively, (no significant value P>0.05). The mean of “total organic carbons removal” in local and imported anthracite were 47.2 and 63.4 percent respectively (significant value P<0.05). The mean time for receiving 1m height in filter pilot were 29min 30sec and 33min 42sec in the local and imported anthracite respectively (no significant value P>0.05).The local anthracite structural characteristics do not meet relevant standards, which is due to insufficient thermal processing.Reduction of residual chlorine and total organic carbon content in dual media filters is very complex and more studies are needed. “Surface over flow rate” results and also higher turbidity removal (5.5%) shows that imported anthracite has a more convenient grading than the local type. The study results show that local anthracite does not have a good grading for water treatment and needs revision on the grading.

Background and Objective: Raw water is one of the main sources of water supply in some communities. Filteration of surface water resources is a challenging point in the rainy seasons due to the highly turbidity. This study was done to evaluate the removal of turbidity in raw water using chitosan in electrocoagulation process using aluminum electrodes.Methods: In this the descriptive –analytical study, a Plexiglas electrocoagulation reactor in a lab scale to an approximate volume of 6 liter which was equipped with four aluminum electrodes having dimension of 200´20´2 mm was proposed. The effects of operating parameters including pH (5 to 9), applied voltage (10 to 30 V), the initial turbidity (100-600 NTU), initial chitosan concentration (0.5-2 mg/L) and contact time (5 to 30 min) were evaluated.Results: Turbidity removal efficiency was over 100% (pH=7, applied voltage=30 V and initial turbidity concentration of 100NTU) in the application of electrocoagulation with chitosan but in the application of electrocoagulation without chitosan removed 87% of turbidity in the same condition.Conclusion: Chitosan as coagulant aid in low amount can increase turbidity removal efficiency rather than application of electrocoagulation alone.