Waste Management & Research: The Journal for a Sustainable Circular Economy, 2017
Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfac... more Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in ...
Modeling trihalomethane formation in drinking water after alum coagulation or activated carbon ad... more Modeling trihalomethane formation in drinking water after alum coagulation or activated carbon adsorption
PDFTech ReportBDV31-977-48Base course (Pavements)Concrete aggregatesLaboratory testsLeachateLiter... more PDFTech ReportBDV31-977-48Base course (Pavements)Concrete aggregatesLaboratory testsLeachateLiterature reviewspH valueRecycled materialsRoad constructionWaste productsUnited StatesFloridaFlorida. Dept. of Transportation. Research CenterTownsend, TimothyUniversity of FloridaFlorida. Dept. of TransportationRuelke, TimUS Transportation CollectionUniversity of Florida researchers studied the possibleimpact of recycled concrete aggregate (RCA) used inroadway base layers on the acid/base balance of thesubsurface environment. They also examined a relatedissue: management of concrete grinding residuals thatresult from grooving and grinding operations on Portlandcement concrete pavements
Abstract Recycled concrete aggregate (RCA) is widely used as a replacement for natural aggregates... more Abstract Recycled concrete aggregate (RCA) is widely used as a replacement for natural aggregates in road base construction worldwide. Still, there are concerns that the high pH of RCA leachate may cause accelerated corrosion of metallic-coated (aluminum or galvanized) steel culverts placed in the underlying soil. Carbonation from CO2 produced in the soil by organic matter (OM) has been considered as a potential mechanism to attenuate RCA leachate pH to below aggressive conditions (pH
This article describes the overall development, including formulation and calibration, of linear ... more This article describes the overall development, including formulation and calibration, of linear and nonlinear multiple regression models for predicting total trihalomethane formation potential and kinetics during the chlorination of natural waters. The rationale behind each model formulation is discussed, and statistics relating to the calibration of each model are presented. The testing and attempted validation of these models are also addressed. Each model is subjected to a sensitivity analysis and a validation analysis using data derived from the literature.
ABSTRACT Thesis (Ph. D. - Civil Engineering and Engineering Mechanics)--University of Arizona, 19... more ABSTRACT Thesis (Ph. D. - Civil Engineering and Engineering Mechanics)--University of Arizona, 1985. Includes bibliographical references (p. 216-224). Photocopy.
ABSTRACT Water drawn from the Biscayne Aquifer, an extensively used potable water supply source i... more ABSTRACT Water drawn from the Biscayne Aquifer, an extensively used potable water supply source in Florida, was used to study the effect of the bromide ion on haloacetic acid (HAA) formation during chlorination. The source water contained an ambient bromide ion concentration (160 mu g/L) and a substantial concentration of natural organic matter (nonpurgeable organic carbon = 10.9 mg/L). A systematic evaluation, encompassing a range of bromide ion concentration spikes, and reaction times at fixed pH, chlorine dose, and temperature conditions, was conducted. Two chlorinated HAAs (dichloroacetic acid and trichloroacetic acid), two brominated HAAs (dibromoacetic acid and tribromoacetic acid), and three mixed HAAs (bromochloroacetic acid, bromodichloroacetic acid, and dibromochloroacetic acid) were found. Monobromoacetic acid and monochloroacetic acid were below detection limits in all of the chlorinated samples. In contrast to the findings of previous studies, the molar yield of HAAs increased as the initial bromide ion concentration increased. Concentrations of total HAAs, brominated, and mixed HAAs increased substantially, while chlorinated HAAs decreased slightly, with the addition of the bromide ion.
ABSTRACT Ozone represents a potential oxidant for controlling trihalomethanes (THMs) during water... more ABSTRACT Ozone represents a potential oxidant for controlling trihalomethanes (THMs) during water treatment. The results presented herein indicate that partial oxidation of THM precursors by ozone produces by‐products which are lesa reactive in forming THMs upon chlorination. It is demonstrated that surrogate parameters such as nonvolatile total organic carbon, UV absorbance, and fluorescence are capable of monitoring the performance of the ozonation process in reducing the THM formation potential of waters containing THM precursors.
ABSTRACT Alum coagulation and activated carbon adsorption are effective water treatment processes... more ABSTRACT Alum coagulation and activated carbon adsorption are effective water treatment processes for removing trihalomethane precursors. Nonpurgeable organic carbon (NPOC), UV absorbance, and fluorescence can serve as surrogate parameters for predicting the trihalomethane formation potential (THMFP) of a water source from its untreated state through various degrees of treataent by these processes. Multiplicative parameters such as the product of UV absorbance and NPOC can also function as effective surrogates.
There are over 100 models that have been developed for predicting trihalomethanes (THMs), haloace... more There are over 100 models that have been developed for predicting trihalomethanes (THMs), haloacetic acids (HAAs), bromate, and unregulated disinfection byproducts (DBPs). Until now no publication has evaluated the variability of previous THM and HAA models using a common data set. In this article, the standard error (SE), Marquardt's percent standard deviation (MPSD), and linear coefficient of determination (R(2)) were used to analyze the variability of 87 models from 23 different publications. The most robust models were capable of predicting THM4 with an SE of 48 μg L(-1) and HAA6 with an SE of 15 μg L(-1), both achieving R(2) > 0.90. The majority of models were formulated for THM4. There is a lack of published models evaluating total HAAs, individual THM and HAA species, bromate, and unregulated DBPs.
Waste Management & Research: The Journal for a Sustainable Circular Economy, 2017
Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfac... more Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in ...
Modeling trihalomethane formation in drinking water after alum coagulation or activated carbon ad... more Modeling trihalomethane formation in drinking water after alum coagulation or activated carbon adsorption
PDFTech ReportBDV31-977-48Base course (Pavements)Concrete aggregatesLaboratory testsLeachateLiter... more PDFTech ReportBDV31-977-48Base course (Pavements)Concrete aggregatesLaboratory testsLeachateLiterature reviewspH valueRecycled materialsRoad constructionWaste productsUnited StatesFloridaFlorida. Dept. of Transportation. Research CenterTownsend, TimothyUniversity of FloridaFlorida. Dept. of TransportationRuelke, TimUS Transportation CollectionUniversity of Florida researchers studied the possibleimpact of recycled concrete aggregate (RCA) used inroadway base layers on the acid/base balance of thesubsurface environment. They also examined a relatedissue: management of concrete grinding residuals thatresult from grooving and grinding operations on Portlandcement concrete pavements
Abstract Recycled concrete aggregate (RCA) is widely used as a replacement for natural aggregates... more Abstract Recycled concrete aggregate (RCA) is widely used as a replacement for natural aggregates in road base construction worldwide. Still, there are concerns that the high pH of RCA leachate may cause accelerated corrosion of metallic-coated (aluminum or galvanized) steel culverts placed in the underlying soil. Carbonation from CO2 produced in the soil by organic matter (OM) has been considered as a potential mechanism to attenuate RCA leachate pH to below aggressive conditions (pH
This article describes the overall development, including formulation and calibration, of linear ... more This article describes the overall development, including formulation and calibration, of linear and nonlinear multiple regression models for predicting total trihalomethane formation potential and kinetics during the chlorination of natural waters. The rationale behind each model formulation is discussed, and statistics relating to the calibration of each model are presented. The testing and attempted validation of these models are also addressed. Each model is subjected to a sensitivity analysis and a validation analysis using data derived from the literature.
ABSTRACT Thesis (Ph. D. - Civil Engineering and Engineering Mechanics)--University of Arizona, 19... more ABSTRACT Thesis (Ph. D. - Civil Engineering and Engineering Mechanics)--University of Arizona, 1985. Includes bibliographical references (p. 216-224). Photocopy.
ABSTRACT Water drawn from the Biscayne Aquifer, an extensively used potable water supply source i... more ABSTRACT Water drawn from the Biscayne Aquifer, an extensively used potable water supply source in Florida, was used to study the effect of the bromide ion on haloacetic acid (HAA) formation during chlorination. The source water contained an ambient bromide ion concentration (160 mu g/L) and a substantial concentration of natural organic matter (nonpurgeable organic carbon = 10.9 mg/L). A systematic evaluation, encompassing a range of bromide ion concentration spikes, and reaction times at fixed pH, chlorine dose, and temperature conditions, was conducted. Two chlorinated HAAs (dichloroacetic acid and trichloroacetic acid), two brominated HAAs (dibromoacetic acid and tribromoacetic acid), and three mixed HAAs (bromochloroacetic acid, bromodichloroacetic acid, and dibromochloroacetic acid) were found. Monobromoacetic acid and monochloroacetic acid were below detection limits in all of the chlorinated samples. In contrast to the findings of previous studies, the molar yield of HAAs increased as the initial bromide ion concentration increased. Concentrations of total HAAs, brominated, and mixed HAAs increased substantially, while chlorinated HAAs decreased slightly, with the addition of the bromide ion.
ABSTRACT Ozone represents a potential oxidant for controlling trihalomethanes (THMs) during water... more ABSTRACT Ozone represents a potential oxidant for controlling trihalomethanes (THMs) during water treatment. The results presented herein indicate that partial oxidation of THM precursors by ozone produces by‐products which are lesa reactive in forming THMs upon chlorination. It is demonstrated that surrogate parameters such as nonvolatile total organic carbon, UV absorbance, and fluorescence are capable of monitoring the performance of the ozonation process in reducing the THM formation potential of waters containing THM precursors.
ABSTRACT Alum coagulation and activated carbon adsorption are effective water treatment processes... more ABSTRACT Alum coagulation and activated carbon adsorption are effective water treatment processes for removing trihalomethane precursors. Nonpurgeable organic carbon (NPOC), UV absorbance, and fluorescence can serve as surrogate parameters for predicting the trihalomethane formation potential (THMFP) of a water source from its untreated state through various degrees of treataent by these processes. Multiplicative parameters such as the product of UV absorbance and NPOC can also function as effective surrogates.
There are over 100 models that have been developed for predicting trihalomethanes (THMs), haloace... more There are over 100 models that have been developed for predicting trihalomethanes (THMs), haloacetic acids (HAAs), bromate, and unregulated disinfection byproducts (DBPs). Until now no publication has evaluated the variability of previous THM and HAA models using a common data set. In this article, the standard error (SE), Marquardt's percent standard deviation (MPSD), and linear coefficient of determination (R(2)) were used to analyze the variability of 87 models from 23 different publications. The most robust models were capable of predicting THM4 with an SE of 48 μg L(-1) and HAA6 with an SE of 15 μg L(-1), both achieving R(2) > 0.90. The majority of models were formulated for THM4. There is a lack of published models evaluating total HAAs, individual THM and HAA species, bromate, and unregulated DBPs.
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