11 research outputs found
Effects Of Hydrophobe Contents Of Amphiphilic Polyelectrolytes On Flocs Size And Removal Efficiency Of NOM From Waters
Polymer-based coagulants, such as amphiphilic polyelectrolytes, are used for water treatment in two distinct ways, as coagulant aids and as primary coagulants. In the latter role, polymers have a number of advantages over inorganic coagulants, notably the smaller volume of sludge produced and reduced sludge management costs. This study examines the impact of molecular structure of novel amphiphilic polyelectrolytes on floc size and size distribution determined by dynamic light scattering. These parameters are related to hydrophobe contents and charge of the polyelectrolyte. These characteristics are also related to the removal efficiency of natural organic matter (NOM). It is expected that a much lower amount of polymer is sufficient when amphiphilic polyelectrolytes are used as primary coagulants/flocculants in treating waters contaminated with NOM. The smaller polymer amount may result in lesser treatment costs as well as yielding a much lower sludge volume. Dynamic light scattering and UV absorbance results confirmed an optimum polymer dose of 0.3ppm with up to 5% hydrophobe contents. The polymer hydrophobe contents were directly related to the system performance and NOM removal efficiency. The pH of the solution was virtually unaffected
Corrosion properties of duplex treated Ti-6Al-4V alloy in chloride media using electrochemical and positron annihilation spectroscopy techniques
Probabilistic Study on the Geotechnical Behavior of Fiber Reinforced Soil
Expansive soils which are considered extremely problematic due to their potential to create swell and shrinkage-related distresses. In order to satisfy the geotechnical requirements, these soils are fiber reinforced to sustain dynamic loads as a subgrade material. Polypropylene fiber materials when amended with soil medium, have proven functionality in the long run. Usually, a binder is required to ensure proper bonding between discrete/random fiber elements and the clay particulates. In the current study, lime is a proposed binder and its dosage is fixed at 6% satisfying initial lime consumption and optimum lime requirements. Two types of fiber materials (Fiber Cast® and Fiber Mesh®) at varying dosages (0.2, 0.4, and 0.6% by weight of soil) and having different lengths (6 and 12 mm) are considered for the present study and its inclusion effect on the hydraulic conductivity, unconfined compression strength behavior and California bearing ratio behavior has been studied. The focus of this paper is in determining the optimum fiber reinforcement parameters (fiber type, length, dosage, etc.) for the stabilization of selected expansive Al-Ghat soil. Probabilistic analysis has been performed to correlate the targeted properties with aspect parameters (i.e., dosage and length) for fiber-reinforced soil. In addition to this, reliability analysis has been performed to examine the applicability of this fiber-reinforced soil in municipal solid waste (MSW) landfills for waste containment. The probabilistic analysis revealed that both aspect parameters play a crucial role in fiber-reinforced soils. Further, it is concluded that the target reliability approach (TRA) gives a valuable insight with regards to choosing optimum aspect parameters for effective soil stabilization practice