The Effect Of Electromagnetic Field On Hard Water Treatment And Scale Formation Using Variable Flow Rate

Scale deposition in water pipe due to hard water circulation often leads to various technical and economical problems. The conventional chemical treatment methods use hazardous chemical which affects human health as well as water chemistry. This study shows the effect of physical water treatment methods like pulsating electromagnetic field on water characteristics and scale reduction under different turbulent flow conditions and pipe materials. The scale removal rate was analyzed by the formation of aragonite crystal in water pipes in place of calcite crystals after electromagnetic treatment. The morphology of aragonite and calcite crystals was analyzed by field emission scanning electron microscope on different pipe materials. The water flow rate was maintained at 3, 5, and 7 L/min. After electromagnetic treatment, the result shows that the scale removal rate increases from pipe wall and reduces the total dissolved solids, electrical conductivity, hardness, and alkalinity of water. These water characteristics are further decreasing on increasing the flow rate from 3 to 7 L/min. The reduction rate of these water characteristics was higher for the first 15 h of circulation time than the remaining 15 h. On investigating the effect of electromagnetic treatment on pipe material, it was obtained that the polyvinyl chloride pipe is much effective than the galvanized iron and copper pipes.KeywordsElectromagnetic water treatmentPulsating magnetic fieldScalingHard waterPipe materialFlow rate

Due to hard water circulation, the scale is formed on pipe walls which are difficult to remove. The conventional methods which are used for scale removal used hazardous chemicals which affects human as well as water chemistry. This study shows that the use of physical water treatment method like magnetic treatment is safe and effective method for scale removal as well as water treatment. Static magnetic field of 3800 Gauss was applied in the experimental setup on different pipe materials. The scale removal rate was analyzed based on the formation of aragonite crystals in water pipes, after water passing through the magnetic field. The crystal’s morphology was measured by field emission scanning electron microscope on the different materials of pipe. The water flow was maintained at 3, 5, and 7 L/min. After magnetic treatment, the result shows that the scale removal increases from pipe walls and reduced the total dissolved solids (TDS), electrical conductivity (EC), hardness, and alkalinity of water. These water characteristics are further decreased as on raising the flow rate from 3 to 7 L/min. The TDS, EC, hardness, and alkalinity reduction rate were higher for the first 15 h of circulation than remaining time. On investigating the effect of magnetic treatment on the pipe material, it was obtained that the polyvinyl chloride (PVC) pipe is much efficient than galvanized iron (GI) and copper pipes.KeywordsMagnetic water treatmentPermanent magnetsScaling

In the East Nile Delta Region, Egypt, water scarcity is a major concern, as the shallow Quaternary aquifer has been observed to experience a persistent decline in groundwater levels alongside a deterioration in groundwater quality. The present study was carried out to identify the processes that control water quality mainly in relation to salinity sources and the suitability for drinking and irrigation purposes in the study area. To achieve this aim, 19 surface water and 110 groundwater samples were analyzed for physical parameters (TDS, pH, temperature, and EC), major ions (Na, Ca, K, Mg, Cl, SO4, and HCO3) along with spatial and multivariate statistical analysis. The geospatial distribution of the total dissolved solids (TDS) and majority of the major chemical ions show an evident increase toward the north and northeast parts of the study area. Graphical methods using Gibbs plot and Piper diagram showed that water chemistry was mainly affected by weathering and water rock interaction while the geochemical evolution results revealed the dissolution and precipitation of carbonates and silicates, ion exchange processes, dissolved evaporite minerals, and anthropogenic activities. Still, the geochemical processes of surface water and groundwater were different. Additionally, the chemical data were analyzed using factor analysis to identify the most important factors influencing the variation in water quality. In the present study, three main factors explaining 92.47 and 80.95% of the total variance were identified as responsible for the surface water and groundwater chemistry variations from which the first factor (53.79% and 54.08% for surface water and groundwater, respectively), represented a natural weathering and salt accumulations, the second factor (28.60 and 13.52% for both waters) constituted agricultural activities, and the third factor (10.9 and 13.89% for the two types of water) is a contribution from dissolution processes. The results also indicated that 66.3% of the samples fell into the excellent category, 16.4% were considered good, 11.8% were doubtful, and 5.5% were unsuitable. In terms of surface water, 89.5% were classified as excellent, with 10.5% rated as good for irrigation, because of their high sodium levels and salinity. The study results provide a basis for the sustainable utilization of regional water resources.

Although red water is a primary focus for consumer complaints about water quality, none of the models currently available adequately address iron release in drinking water distribution systems. This lack is understandable, given the complex nature of iron sources, iron release mechanisms, often‐conflicting influences of various physicochemical and biological factors, pipe material and age, and the cocktails of corrosion products released. This work describes a mathematical and pilot‐scale empirical development of a zero‐order flux model. Iron concentration was found to depend on surface‐release flux (Km), pipe material, pipe geometry, and hydraulic retention time. Flux is a function of pipe material, water chemistry, and Reynolds number (Re). For the specific water quality used in this study, the galvanized‐iron Km(mg Fe/m2/d) values were 1.99 and 0.0045/(Re −2,000) + 1.99 under laminar and turbulent flow conditions, respectively. Similarly, Km was found to be 4.16 and 0.009/(Re −2,000) + 4.16 for unlined cast‐iron pipe under laminar and turbulent flow conditions, respectively.

Physical Water Treatment for Fouling Prevention in Heat Exchangers

Effects of water chemistry, temperature, pipe material, and hydraulic conditions on total chlorine dissipation were investigated using laboratory‐ and pilot‐scale experiments. Chlorine demand in the bulk phase depends on water chemistry, and the bulk‐phase dissipation constant (kb) generally increased with increasing dissolved organic carbon. A 10°C rise in temperature resulted in a threefold increase in kb. Pipe material significantly influenced total chlorine dissipation rates in the following order: galvanized iron > unlined cast iron > polyvinyl chloride (PVC) > lined cast iron. Total chlorine consumption predominantly occurred at the wall surface in small‐diameter unlined cast‐iron and galvanized‐iron pipes and predominantly in the bulk phase for lined cast‐iron and PVC pipes. The mass transfer coefficient (kf) and the overall dissipation constant (K) increased with increasing Reynolds numbers. The wall constant (kw) is an intrinsic pipe property and is therefore a true constant; an increase in kw with increasing Reynolds number was observed. However, this may be attributed to dynamic changes in particulate surface area associated with release of corrosion products from the pipe surface.

Physical, chemical and isotopic characteristics of groundwater and surface water in the Lake Chilwa Basin, Malawi

The Indian state of Odisha has a number of thermal springs. These thermal springs are located at eight places (Attri, Tarabalo, Deulajhari, Magarmuhan, Bankhol, Badaberena, Taptapani and Boden) and belong to Mahanadi Geothermal Province, which is an Archean/Pre-Cambrian Geothermal Province. The thermal water discharging from these springs shows moderately acidic to moderately alkaline character (pH: 5.05–8.93) and the temperature ranges from 28 (Boden) to 58 °C (Tarabalo). Total dissolved solids (TDS) also shows a wide variation between 16.9 (Bankhol) and 595 mg/L (Deulajhari). A wide variation in the chemical characteristics of the thermal waters has been observed as they are located in different geological settings. Based on water chemistry, all the thermal springs can broadly be grouped into three water types: Na–Cl, Ca–HCO3 and Na–HCO3. The thermal spring water from Attri, Tarabalo and Deulajhari belongs to Na–Cl water type which is due to the circulation through granitic rocks. Higher concentrations of Cl and F in these thermal waters further suggest limited mixing and longer residence time as compared to the other areas where Ca–HCO3 and Na–HCO3 water types were found. Anion variation diagram clearly indicates that the thermal waters from Attri, Tarabalo and Deulajhari are fast ascending and fall in the mature water field; thus, their chemical signatures can be used to determine the reservoir temperature. However, in other areas, water chemistry is shaped by near-surface groundwater mixing processes and thus the chemical geothermometers may not be applicable to determine the reservoir temperature. No appreciable temporal variations have been observed in the water chemistry of the thermal waters.

The chemical characteristics of Ordovician formation water and its relationship with hydrocarbons in the Halahatang depression (Tabei Uplift, Tarim Basin, NW China) were analyzed on the basis of the detailed formation water test data. The formation water in the Halahatang depression can be characterized as CaCl2 type with high total dissolved solids (TDS) generally. The TDS concentration has a weak negative relationship with the depth, and is above 200 g/L in the North Region (north of the pinch-out line), then gradually decreases to the south, but is still greater than 50 g/L. The ion-proportionality coefficients of formation water, including the sodium-chlorine coefficient, desulfurization coefficient and metamorphic coefficient, reflect that the present strata are well sealed and had once experienced strong water-rock interactions. Furthermore, the source and evolution of the formation water presents a closed relationship with the hydrocarbon accumulation. The meteoric source of the formation water indicates the denuding by the Ordovician formation and the damage from the previous oil and gas reservoirs. The reservoir quality was also improved due to the strong karstification during the denudation, which was beneficial for hydrocarbon accumulation. The distribution of the TDS concentration is controlled by the caprock (Sangtamu Formation) and the high salinity fluids from overlying strata and adjacent regions. A geological model was established, the high salinity fluids penetrated the Ordovician strata resulting in the TDS increases in the northern part. Whereas, the South Region (south of the pinch-out line) was less affected due to the shielding layer of the O3s. The favorable preservation conditions reflected by the high TDS and ion-proportionality coefficients correspond to the stable subsidence of strata since the Triassic era, the oil and gas reservoirs formed in the Himalayan can be preserved.

The most important natural and anthropogenic factors affecting stream water and groundwater chemistry in the Carpathians were identified mainly on the basis of hydrochemical case studies from numerous small headwater Carpathian catchments. The most important natural factor determining water chemistry in the Carpathians is geology. In areas formed of poorly soluble granite and gneiss rocks (crystalline portion of the Tatra Mountains), the total dissolved solids (TDS) and concentration of main cations and anions are many times lower than that in areas formed of highly soluble carbonate rocks (sedimentary portion of the Tatra Mountains, Pieniny Mountains) and also clastic rocks forming so-called Carpathian flysch (Beskidy Mountains, Carpathian Foothills). Stream water and spring water chemistry in the Carpathians change primarily due to hydrologic factors—changes in discharge. As discharge increases, TDS declines and the concentrations of most main ions also decline, while the concentration of K+, NO3−, and PO43− increases. Elevation and geographic location of springs and streams in given climate zone and vegetation zone are additional natural factors affecting water chemistry, and this is particularly true of SO42− and Cl− concentration as well as pH. Anthropogenic factors affecting water chemistry in the Carpathians include acid rain, deforestation, agriculture, and tourist-generated wastewater. The effects of acid rain are felt in the form of low concentrations of main cations in stream and spring water in the western part of the Carpathians. This region was affected by very high acidic sulfur and nitrogen deposition in the second half of the twentieth century. Deforestation in the Carpathians impacts mainly spruce monocultures declining due to acid rain, strong winds, and bark beetle infestation, and is the main cause of increasing NO3− concentrations in stream water and spring water. Agricultural land use does not threaten stream water and groundwater due to low usage of mineral fertilizer. Threats that do exist are associated with unregulated releases of wastewater in rural areas. Wastewater generated by tourists is a major threat to stream water quality in areas with a high environmental value that are highly popular with tourists. Tourist lodges release wastewater into Carpathian streams leading to excess nitrogen and phosphorus concentration in stream water.

Geochemistry of formation waters and crude oils in the Shulu Sag, Bohai Bay Basin, NE-China, to assess quality and accumulation of hydrocarbons

<p><strong>Introduction</strong></p> <p>The presence of biofilms in drinking water distribution systems (DWDS) leads to a number of issues, i.e. secondary (biological) drinking water contamination, pipe damage and increased flow resistance. Among other operational factors, the selection of pipe material plays an important role in biofilm development. Up to now, the studies that have investigated this correlation provide contradictory results in terms of which material might be the most advantageous in the DWDS biofilm control strategy. Hence, to understand the influence of pipe material on biofilm formation, we focused on developing a standardized methodology that allows a multi-stage assessment of biofilm development on real pipe materials.</p> <p><strong>Results</strong></p> <p>Development of the methodology consisted of three steps: 1) material coupon sterilization, 2) biofilm cultivation and 3) biofilm analysis, using  transparent polyvinyl chloride (PVC) as a study material. For the coupon sterilization, methods utilizing immersion in different disinfectant solutions with and without pre-cleaning by rubbing the coupons in a surfactant solution. The results showed that mechanical cleaning before washing  is crucial and without it, reproducible sterilization was difficult to achieve. Biofilm formation on the PVC coupons was performed in a 6-well plate assay (24, 48 and 72 h; under agitation) using DWDS biofilm strains (<em>Sphingomonas spp</em>. and <em>Pseudomonas extremorientalis</em>) and <em>Pseudomonas aeruginosa</em> as a positive control. Bacterial fitness and ability to secrete EPS and form biofilms on the PVC surfaces were tested by monitoring optical density (OD600 nm), chemical oxygen demand (COD) and protein concentration. The formed biofilm and the morphology of attached bacteria were visualized using crystal violet staining (that allow qualitative (bright field microscopy) and quantitative (OD at 570 nm) evaluation), by scanning electron microscopy (SEM) and DNA staining (4′,6-diamidino-2-phenylindole; DAPI) with fluorescence microscopy. Combination of those techniques gave a complete overview of patterns involved in biofilm development by selected drinking water bacterial strains in presence of a PVC surface. The developed methodology was also applied  for the analysis of bacterial growth on real-grade pipe materials, such as PVC and polyethylene (PE), to understand their role in biofilm formation.</p> <p><strong>Conclusions</strong></p> <p>Implementation of various analytical and microscopic techniques is important in understanding mechanisms behind biofilm development in DWDS and the influence of pipe material in the process. The proposed approach allows the observation of biofilm formation in time, but also of the typical bacterial morphology of attached cells. In this study it was shown that to obtain reproducible results, it is crucial to select an appropriate sterilization technique and the influence of mechanical cleaning cannot be ignored in preparation of polymeric surfaces.</p>

Thermo-mechanical characterization of banana particulate reinforced PVC composite as piping material

Effects of advanced treatments using granular activated carbon adsorption with ozonation and ultrafiltration on chlorine decay

Advanced self-healing coatings based on ZnO, TiO2, and ZnO-TiO2/polyvinyl chloride nanocomposite systems for corrosion protection of carbon steel in acidic solutions containing chloride