Reducing Turbidity of Construction Site Runoff Via Coagulation with Polyacrylamide and Chitosan - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Reducing Turbidity of Construction Site Runoff Via Coagulation with Polyacrylamide and Chitosan write by David Robert Rounce. This book was released on 2012. Reducing Turbidity of Construction Site Runoff Via Coagulation with Polyacrylamide and Chitosan available in PDF, EPUB and Kindle. The U.S. Environmental Protection Agency is in the process of developing a nationwide standard for turbidity in construction site runoff. It is widely expected that this standard cannot be met with conventional erosion and sediment control measures; consequently, innovative practices for managing sediment on construction sites must be developed. The objective of this research was to develop an understanding of how soil characteristics and polymer properties affect the amount of turbidity reduction that can be achieved through flocculation. The polymers used were PAMs, a proprietary product, and chitosan. The charge density of the PAMs ranged from 0% to 50% and the molecular weights ranged from 0.2 to 14 Mg/mol. A protocol for creating modified synthetic stormwater runoff for soil samples was developed and used on soils from seven construction sites. Particle size distributions were used to compare the modified synthetic stormwater runoff with grab samples of stormwater from one site and showed the synthetic runoff was representative of the actual runoff. Flocculation tests were performed on the synthetic runoffs with PAM and chitosan doses from 0.03 to 10 mg/L. The non-ionic PAM, proprietary product, and chitosan were found to be the most effective at reducing the turbidity of all the synthetic runoff below 200 NTU. The high molecular weight anionic PAMs were effective on only two of the seven synthetic runoff samples. Hardness tests were performed indicating interparticle bridging to be the bonding mechanism of the PAM. Electrophoretic mobility tests were performed on two of the soil suspensions and indicated the bonding mechanism of PAM to be interparticle bridging, and the bonding mechanism of chitosan to be a combination of charge neutralization and interparticle bridging. Tests showed as the charge density of the PAM increased, their effectiveness decreased.
Factors Affecting Turbidity Reduction in Stormwater Runoff from South Dakota Construction Sites Using Polyacrylamide
Factors Affecting Turbidity Reduction in Stormwater Runoff from South Dakota Construction Sites Using Polyacrylamide - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Factors Affecting Turbidity Reduction in Stormwater Runoff from South Dakota Construction Sites Using Polyacrylamide write by Jacob Humburg. This book was released on 2015. Factors Affecting Turbidity Reduction in Stormwater Runoff from South Dakota Construction Sites Using Polyacrylamide available in PDF, EPUB and Kindle.
Development of Best Management Practices for Turbidity Control During Rainfall Events at Highway Construction Sites Using Polyacrylamide
Development of Best Management Practices for Turbidity Control During Rainfall Events at Highway Construction Sites Using Polyacrylamide - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Development of Best Management Practices for Turbidity Control During Rainfall Events at Highway Construction Sites Using Polyacrylamide write by Joanne Kelly Johnson. This book was released on 2015. Development of Best Management Practices for Turbidity Control During Rainfall Events at Highway Construction Sites Using Polyacrylamide available in PDF, EPUB and Kindle. In 2009, the United States Environmental Protection Agency (EPA) promulgated a national turbidity standard for runoff water leaving highway construction sites at 280 nephelometric turbidity units (NTU). Meeting this standard can be challenging as turbidities of runoff waters can exceed 15,000 NTU. The objective of this research was to assess polyacrylamide (PAM), a coagulant aid used in water treatment, to help meet the EPA turbidity regulation. Twelve commercially available PAM types were studied, selected on the basis of charge type (cationic, nonionic, anionic), charge density (0-100%), and molecular weight (0.1-28 Mg mol-1). Jar tests were conducted with runoff waters from AHTD construction sites and synthetically made formulations of tap water blended with bentonite, illite, kaolinite, and Arkansas Red Dirt. Jar tests were completed at PAM doses between 0.5-20 mg L-1 and the turbidity of the supernatant was measured following a quiescent settling period. Results showed that anionic PAMs with low charge densities were most effective at reducing supernatant turbidities, likely due to enhanced interparticle bridging. Hydraulic flocculation tests were done with two PAM types in lab-scale continuous flow reactors and at a controlled field site. It was concluded that anionic PAMs at a dose of 10 mg L-1 provided adequate turbidity reduction and that channel baffling induced hydraulic flocculation and further reduced effluent turbidities.
The Effectiveness of Polyacrylamide in Reducing Turbidity Caused by High Clay Sediment
The Effectiveness of Polyacrylamide in Reducing Turbidity Caused by High Clay Sediment - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook The Effectiveness of Polyacrylamide in Reducing Turbidity Caused by High Clay Sediment write by . This book was released on 2007. The Effectiveness of Polyacrylamide in Reducing Turbidity Caused by High Clay Sediment available in PDF, EPUB and Kindle. Polyacrylamide was studied for its efficacy in reducing turbidity. The purpose of this research was to determine optimum conditions for 10 blends of PAM to reduce turbidity from construction site runoff. The research was based on 10 different PAM blends, researching concentrations (0, 1, 5, 10 ppm), PAM forms (dry granular or solution), mixing powers (80 and 150 rpm), and mixing times (1 and 2 minutes). The research was conducted in a laboratory setting using a PB-700 [trade mark] Standard Jar Tester (Phipps and Bird, Richmond, Virginia) with a clay texture sediment source. The clay-textured sediment source was researched under two sediment-water concentrations of 2,000 and 10,000 parts per million (ppm). For non-polymer control, each sediment concentration was mixed for five minutes to ensure complete mixing. One minute after the cessation of mixing, turbidity measurements were taken on time intervals of 0.5, 2, 5, and 10 minutes. Using these same samples, polyacrylamide was then added to the sediment-water solution. Three replicates of the various treatment conditions, and similar turbidity measurements were then taken. The data showed the most key aspects, on the average at reducing turbidity the greatest, were the dry forms of PAM for the 2,000 ppm sediment-water concentration and the solution forms of PAM for the 10,000 ppm sediment-water concentrations. Turbidity reductions were not as dramatic with the dry form of PAM, at the lower mixing power, with the shorter mixing time, at low PAM concentrations. The data also provided evidence that all PAM blends demonstrate different turbidity reduction under different treatment combinations. This information shows the important issue that PAM is not exactly 100% PAM and each PAM product (blend) are very soil dependent. This key issue needs to be considered when a PAM product is applied in any form or fashion.
Field Implementation of Polyacrylamide for Runoff from Construction Sites
Field Implementation of Polyacrylamide for Runoff from Construction Sites - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Field Implementation of Polyacrylamide for Runoff from Construction Sites write by Rafiqul Islam Chowdhury. This book was released on 2011. Field Implementation of Polyacrylamide for Runoff from Construction Sites available in PDF, EPUB and Kindle. Polyacrylamide (PAM) is often used a part of a treatment train for the treatment of stormwater to reduce its turbidity. This study investigated the application of PAM within various treatment systems for a construction site environment. The general concept is to introduce hydraulic principles when placing PAM blocks within an open channel in order to yield high mixing energies leading to high turbidity removal efficiency. The first part of the study observed energy variation using a hydraulic flume for three dissimilar configurations. The flume was ultimately used to determine which configuration would be most beneficial when transposed into field-scale conditions. Three different configurations were tested in the flume, namely, the Jump configuration, Dispersion configuration and the Staggered configuration. The field-scale testing served as both justification of the findings within the controlled hydraulic flume and comprehension of the elements introduced within the field when attempting to reduce the turbidity of stormwater. As a result, the Dispersion configuration proved to be the most effective when removing turbidity and displayed a greater energy used for mixing within the open channel. Consequently, an analysis aid is developed based on calculations from the results of this study to better serve the sediment control industry when implementing PAM blocks within a treatment system. Recommendations are made for modification and future applications of the research conducted. This innovative approach has great potential for expansion and future applications. Continued research on this topic can expand on key elements such as solubility of the PAM, toxicity of the configuration within the field, and additional configurations that may yield more advantageous energy throughout the open channel.
