Rainwater quality improvement using zeolite, activated carbon, limestone and preheated 400°C limestone

Resources of clean water have decreased significantly in recent years, one of the reasons is water pollution. Utilization of rainwater as clean water resource is among the best option, especially in big cities like Jakarta. Excessive rainwater during wet season can be saved and used as the source of clean water during dry seasons. However, rainwater contains some pollutants, thus suitable treatment method should be utilized to improve its quality as clean water for daily needs. This study compared the effectiveness of zeolite, limestone, activated carbon and preheated 400°C limestone as additive to improve the rainwater quality. Results show that both limestone and preheated 400°C limestone improve all the parameters observed, meanwhile both activated carbon and zeolite had shown to have detrimental effect on water conductivity

Impact of wastewater discharge on water quality of Karoon River in Iran

Preservation of the Karoon and Dez Rivers, the fresh water resource, is of high importance in Khuzestan province with its rapid growth of population and agricultural and industrial activities. In this paper the water quality and quality conditions of four study areas are mapped, agricultural, industrial and urban pollutant sources identified, and their impact on biological, physical and chemical water quality of Karoon River examined. Twenty five quality monitoring stations were established to determine the pollution load to the Karoon and Dez Rivers. The analysis shows that wastewater discharge has different impacts on chemical and biological water quality in the four study areas, in both the short and long term. © 2010 WIT Press

Wastewater project development of Tehran

Tehran, the capital city of Iran, has had many problems in the environmental field. Wastewater collection and treatment is one of most important of those. Tehran Sewerage Company has worked on the integrated wastewater management of Tehran by considering rapid population growth which results in increased water consumption and consequently more wastewater production. The wastewater project of Tehran began in 1959, but was stopped by the revolution in 1979. It was started again with financial support from the World Bank in 1990. This study conducted an environmental, social and financial assessment (short, medium and long term) of the Tehran Sewerage Project. Results showed that this project has moderate and temporary effects on environment and social communities. Furthermore, this paper proposes a management plan for mitigation measures (environmental monitoring and auditing). The combination of three solutions-governmental financial resources, public-private participation and the World Bank loan-as a function of three main factors-time, resources and quality-is discussed and investigated from an economic point of view. In this respect, supporting the private sector participation is considered as one of the critical factors for the success of the project. © 2010 WIT Press

River water quality assessment using environmentric techniques : case study of Jakara River Basin.

akara River Basin has been extensively studied to assess the overall water quality and to identify the major variables responsible for water quality variations in the basin. A total of 27 sampling points were selected in the riverine network of the Upper Jakara River Basin. Water samples were collected in triplicate and analyzed for physicochemical variables. Pearson product-moment correlation analysis was conducted to evaluate the relationship of water quality parameters and revealed a significant relationship between salinity, conductivity with dissolved solids (DS) and 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and nitrogen in form of ammonia (NH4). Partial correlation analysis (r p) results showed that there is a strong relationship between salinity and turbidity (r p = 0.930, p = 0.001) and BOD5 and COD (r p = 0.839, p = 0.001) controlling for the linear effects of conductivity and NH4, respectively. Principal component analysis and or factor analysis was used to investigate the origin of each water quality parameter in the Jakara Basin and identified three major factors explaining 68.11 % of the total variance in water quality. The major variations are related to anthropogenic activities (irrigation agricultural, construction activities, clearing of land, and domestic waste disposal) and natural processes (erosion of river bank and runoff). Discriminant analysis (DA) was applied on the dataset to maximize the similarities between group relative to within-group variance of the parameters. DA provided better results with great discriminatory ability using eight variables (DO, BOD5, COD, SS, NH4, conductivity, salinity, and DS) as the most statistically significantly responsible for surface water quality variation in the area. The present study, however, makes several noteworthy contributions to the existing knowledge on the spatial variations of surface water quality and is believed to serve as a baseline data for further studies. Future research should therefore concentrate on the investigation of temporal variations of water quality in the basin

Characterization and Antibiofouling Performance Investigation of Hydrophobic Silver Nanocomposite Membranes: A Comparative Study

Biofouling is one of the drawbacks restricting the industrial applications of membranes. In this study, different thicknesses of silver nanoparticles with proper adhesion were deposited on poly(vinylidenefluoride) (PVDF) and polyethersulfone (PES) surfaces by physical vapor deposition (PVD). The crystalline and structural properties of modified and pure membranes were investigated by carrying out X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Scanning electron microscope (SEM) and atomic force microscopy (AFM) analyses were employed to examine the surface morphology and the bacteria anti-adhesion property of the membranes. The morphology measurements confirmed that even though after silver grafting the surface became more hydrophobic, the homogeneity increased and the flux reduction decreased after coating. Moreover a comparison between PVDF and PES revealed that CFU (colony forming units) reduced 64.5% on PVDF surface and 31.1% on PES surface after modification. In conclusion, PVD improved the performance of the membrane antibiofouling, and it is more promising to be used for PVDF rather than PES

Study of Andimeshk's drinking water resources in Iran

This study was conducted to evaluate the application of different indices for the quality evaluation of eight groundwater resources of Andimeshk city on three months. Six corrosion indices of Langelier saturation index, Ryznar (saturation) index, calcium carbonate precipitation potential, Puckorius scaling index, Aggressiveness index and Larson-Skold corrosive index, were determined. Most of these resources had a high amounts of sulfate and affected the Laurence corrosion index, however were not exceeded the WHO standards. In the view of Larson-Skold corrosive index these water resources are corrosive for water facilities affected by chloride and sulphate, such as mild steel facilities. This index caused different results among other indices. From other indices, Ryznar (saturation) index and Puckorius scaling index indices showed different results among other indices and while other indices defined some resources as a non-corrosive, Ryznar (saturation) index and Puckorius scaling index predicted as a corrosive. In just one of the water resources, all the six indices had same results (moderately corrosive). Application of one index may not be able to predict water corrosivity, some factors such as water quality and water installation material should be regarded too. Some of those resources had high amounts of nitrate and phosphate which were contaminated by agricultural and domestic wastewaters

Homology for one-dimensional solenoids

Smale spaces are a particular class of hyperbolic topological dynamical systems, defined by David Ruelle. The definition was introduced to give an axiomatic description of the dynamical properties of Smale's Axiom A systems when restricted to a basic set. They include Anosov diffeomeorphisms, shifts of finite type and various solenoids constructed by R. F. Williams. The second author constructed a homology theory for Smale spaces which is based on (and extends) Krieger's dimension group invariant for shifts of finite type. In this paper, we compute this homology for the one-dimensional generalized solenoids of R. F. Williams

Earthquake damage detection in Tehran’s water distribution system

Iran is located in the one of world's large seismicity zones called ALPA (AlpHimalaya) and the mega city Tehran has is in a particularly dangerous situation. In a destructive earthquake, considerable damage occurs in buried structures such as the urban water supply system. In this study, the following objects are investigated: review of the damage analysis and seismic design of the water networks, review of the seismic information for water distribution systems, earthquake damage detection in water distribution systems, using an artificial neural network (ANN) and a general back error propagating perception to detect pipelines damaged due to earthquakes. The failure points are obtained by using the amount of water discharged from the tanks. The states probable failures have to be computed, the mathematical model for different states of pipe failure by which the damaged pipes could be detected through a back analysis. Since there are various types of failure, therefore, the ANN has been applied. Through a parametric study, different geometry, shape diameters and pressure of the water network are surveyed and the best network architecture for each case is obtained. The peak responses and phase delays are assumed to be network outputs. The network is trained in a supervised manner. The study shows the efficiency and capability of the ANN for modelling the observed nonlinear behaviour

Application of modified qualitative index for surveillance of water-filtration process in turbidity removal by different media

Several media have been used in treatment plants, however, their efficiency for turbidity removal, which is determined by qualitative indices, has been considered. Current qualitative indices such as turbidity and escaping particle number could not completely measure the efficiency of the filtration system; therefore defining new qualitative indices is essential. In this study, the efficiency of two different dual media filters in turbidity removal was compared in different operating condition using qualitative indices. The pilot consisted of a filter column (1-m depth) in which the filter-1 was consisted of a layer of anthracite (450-mm depth) and a layer of silica sand (350-mm depth); and filter-2 had the same media characteristics except for the first layer that was light expanded clay aggregates (LECA). Turbidities of 10, 20, and 30 NTU, coagulant concentrations of 4, 8, and 12 ppm and filtration rates of 10, 15, and 20 m/h were considered as variables. Results showed that the media of filter-2 is a suitable substitute for the media of filter-1 (P value < 0.05). Turbidity removal efficiencies in different condition were 79.97 ± 1.79 to 91.37 ± 1.23% for the filter-2 and 75.12 ± 2.75 to 86.82 ± 1.3% for the filter-1. The LECA layer efficiency in turbidity removal was independent of filtration rates and due to its low head loss; LECA can be used as a proper medium. Results also showed that the particle index was a suitable index as a substitute for turbidity and escaping particle number as indices