Journal of Applied Research in Water and Wastewater
Volume:3 Issue: 1, Winter and Spring 2016

One of the most important problems in rivers restoration and management is the problem of fine sediment deposition in the bottom of gravel beds. In fact, such phenomena can affect fauna and flora in various area. In Present study, a series of video camera measurements in an open channel with gravel bed was carried out in order to investigate the process of fine particles entry in the matrix of a gravel bed. Specifically, the present study focuses on a spatial pattern of fine sediment deposition and entrapment. The results show that deposition and entrapment of fine particles caused by the intrusion of large gravel particles and thus fine sediment deposition pattern are mostly in agreement with bed topography. Indeed, fine particles generally deposited on the downstream side of the gravel particles, while they rarely settled down in the upstream side of the gravel particles. Moreover, the results highlighted the formation of quite long longitudinal sand bars which are repeated in whole cross-section. These observations are in agreement with near bed common flow characteristics such as sweep and ejection events and strong secondary currents formation. The combined effects of sand ribbons and bed topography lead to the complex spatial pattern of deposition which questions the applicability of common transport thresholds which were developed based on the bulk properties of the flow like shear velocity.

In meandering rivers, the flow behavior is very complex due to topography and flow depth changes. In general, effective forces on bend flow pattern include centrifugal force due to non-uniformity of the vertical velocity profile and radius pressure gradient induced by the lateral slope of water surface. In this paper, the 60° bend flow pattern is simulated by developing FLUENT computational software based on finite volume method (FVM), numerically. The k-ε (RNG) turbulence model and volume of fluid (VOF) method are used for turbulence and flow depth modeling. The FVM numerical results are verified by existing experimental data in velocity and flow depth. The results illustrate that the FVM model has high accuracy in prediction flow variables in the bend. As the average value of root mean square error (RMSE) and mean absolute percentage error (MAPE) values between the observational and numerical results for depth-averaged velocity (DAV) in the different transverse profile are 4.5 and 9%, respectively, which is an acceptable error percentage. The advanced software can well simulate the both major and minor secondary current cells with opposite rotation direction in the vicinity of channel bed and vicinity the water level in the outer wall, respectively. By the development of the major and minor secondary currents in sections located 40 (cm) after the bend, longitudinal velocity shift, and the high-velocity zone moves further to the outer wall (and the channel bed) in depth. Therefore, it can be said the developing FLUENT software can be utilized in practical cases in design and execution of curved channel.

Aquifers are underground porous domains containing groundwater. Confined aquifers are surrounded by the impermeable layers. They are saturated by pressurized water and are suitable for energy storage purposes. They have low thermal conductivity and large storage volume. In design of aquifer thermal energy storage (ATES) an applicable model is necessary to predict the aquifer behavior. In this research, by developing a three dimensional finite volume model via FLUENT software, the effects of operative parameters on pressure distribution are investigated. In the ATES, heat transfer is performed by both convection and conduction phenomena. The convective heat transfer in the ATES is occurred because of pressure gradient and hence, recognition of effects of operative parameters on pressure distribution is essential. These effective parameters are some geological parameters such as groundwater natural flow, porosity and permeability, injection and withdrawal rates from wells, number and arrangement (being linear, triangular or rectangular) of wells.

Phenol- formaldehyde resin (PFR) is used bad-tempered protecting agent in blending of different percentage by weight of Sulphonated Abutilon indicum, Linn.carbon (SAIC). we provide a synopsis of current developments in the use of ion exchange techniques in wastewater treatment. The prepared materials (PFR, composites, and SAIC) were characterized by FT-IR spectra, SEM and thermal (TGA) studies. The low cost ion exchangers (IERs) are used for the removal of some selective metal ions such as Na+, K+, Ca2+, Cu2+, Mg2+, Zn2+ and Pb2+. Thermodynamic equilibrium constants (ln Kc) are calculated for Zn2+- H+ ion exchanges using the composite resins and also the thermodynamic parameters such as Ho, Go&So are evaluated from Van’t Hoff plot. The cation exchange capacity (CEC) of the composites were found to decreased with the increasing the percentage of SAIC in PFR matrix. It was observed that the composites up to 20 % (w/w) blending of SAIC2 retain all the properties of original PFR. Hence, the blended composites could be used as low cost ion exchangers when SAIC partially replaces the original PFR up to 20 % (w/w) SAIC2 blending without affecting the physico-chemical, thermal, spectral properties and CEC values of PFR.

Water is essential part of life and quality of ground water control the adjudged that water is suitable for human consumption. The quality of ground water is mainly lower, virtue of reaction between alkaline elements with natural resources. Fluoride is one of the major alkaline elements that to lowered the water quality. So defluoridation of drinking water is the only possible option to overcome the problem of excessive fluoride in drinking water. Therefore, in this paper, we focused on synthesize a low cost eco- friendly technique for removal of fluoride in the ground water. The present study describes the synthesis of calcium and phosphate based material for removal of fluoride from groundwater. Characterization of the synthesize material performs with ICP (OES), XRD, FTIR shows that crystalline material of Hydroxyapetite. Kinetics study of fluoride removal from drinking water analysis is performed through jar test apparatus as a function of coagulant dose, pH of the solution, contact time, initial fluoride concentration and temperature. The highest percentage of removal of fluoride was 96 % observed when at initial dosing concentration 4mg/L, contact time 1hr and pH equal to 7.

The degradation of synthetic amoxicillin wastewater (SAW) treated with advanced oxidation process (AOP) including UV/O3/H2O2 was investigated in the present study. In order to investigate the impacts of effective factors on the process performance, four variables involving two numerical factors, initial H2O2 concentration, and initial pH, and two categorical factors, ozonation and UV irradiation, were selected. Enhancement of ozonation processes by the addition of H2O2 and different initial pH was also evaluated. The process was modeled and analyzed using response surface methodology (RSM). The region of exploration for the process was taken as the area enclosed by initial H2O2 concentration (0-20 mM) and initial pH (3-11) boundaries. For two categorical factors (ozonation and UV irradiation), the experiments were performed at two levels (with and without application of each factor). Ozone was the most effective factor with a direct effect on the response in this research. The variables had a synergistic impact on the response. Maximum chemical oxygen demand (COD) removal efficiency was obtained at H2O2 concentration 20 mM at initial pH 11. As a result, O3/ H2O2 system at pH 5 showed better performance in terms of BOD5/COD ratio (0.40). From the HPLC chromatograms, complete degradation of amoxicillin (AMX) was achieved. The O3/H2O2 process showed to be more effective in comparison with UV/H2O2 system.

In this research, in order to application of polymeric membrane for high quality treatment of wastewater, the synthesis, characterization, antifouling properties and performance of blended nanofiltration membranes were investigated. The chemical and physical characteristic influence of embedded hydrophilic dendrimer polycitrate-Alumoxane nanoparticles in membranes matrix was investigated by measuring permeability, filtration of fouling agent, water contact angle and the performance was assessed by calculating of Flux recovery ratio (FRR) and pure water flux. Also, to visual evaluation of thick of skin layer and pores shape, scanning electron microscopy (SEM) techniques was applied. The membrane surface hydrophilicity was improved by adding polycitrate-Alumoxane nanoparticles that can be attributed to the presence of hydrophilic functional groups on surface that was confirmed by contact angle experiments. The modified poly ether sulfone (PES) NF membrane revealed high resistance against fouling and high dye removal efficiency compared with that of the pristine PES. The FRR value of the PES membrane was increased from 39 to 98 % by blending 0.5 wt. % hydrophilic dendrimer polycitrate-Alumoxane nanoparticles. Also, Direct red 16 removal percentage was obtained 82 and 99 for unfilled and modified membrane, respectively.