Pharmaceuticals and personal care products (PPCPs) are widely used throughout the world. PPCPs are emerging as pollutants of concern and may pose a risk in the future to drinking water supplies. Two such compounds are sulfamethoxazole (SMXL) and fluoxetine (FLX). These ionizable compounds are not readily removed from water by conventional water treatment technologies. Powdered activated carbon (PAC) is a useful material for removing contaminants from water and is currently used in many water treatment applications. PACs may carry either a net positive or negative surface charge depending on the pH of solution. This study examined the hypothesis that the electrostatic interactions between three PACs’ surface charges and the charges of sulfamethoxazole’s and fluoxetine’s ionizable functional groups would lead to greater sorption efficiency than non-electrostatic interactions alone. Samples containing SMXL or FLX, were treated with varying doses of PAC, and mixed for three hours. The pH of samples were adjusted between experiments to determine if interaction between the polar contaminants and charged surface of PAC significantly impacted removal of the contaminant from solution. Analysis of the treated samples showed the effects of pH and varying PACs on the removal of SMXL and FLX from solution. It was observed that pH of the solution did play a significant role in the removal of contaminant in a number of the experiments, but that under other conditions where greater removal was anticipated based on predicted electrostatic interactions, it did not. These conditions included pH conditions where the contaminant existed predominantly in a negatively charged form. While not the initial focus of this study, it was observed that pore size distribution of the PACs may play a more significant role in the removal of ionizable compounds, especially in the case of fluoxetine, than electrostatic interactions.

Anthropogenic activities such as uranium mining and milling, nuclear weapons production, and nuclear reprocessing have left a legacy of groundwater and soil contaminated with uranium that needs to be addressed. Therefore, developing new remediation technologies to sequester uranium in situ is crucial. The objective of the study was to determine if low-cost commercially available unrefined humic substances, such as Huma-K, can be used to facilitate uranium sorption to minerals in soil and sediment. Sediments from the saturated zone beneath the F-Area seepage basins at the Savannah River Site (SRS) in South Carolina were used for the present study. The SRS site is analogous to many contaminated locations where groundwater acidity enhances uranium and other contaminants mobility. First, a variety of techniques were applied to characterize Huma-K and SRS sediment. Characterization studies showed that Huma-K possesses functional groups that have an acidic nature such as carboxyl and phenol groups. For SRS sediment, a mineral composition of mainly quartz (93.2%), kaolinite (5.1%), and goethite (1.1%) was identified. Second, the interactions between Huma-K and SRS sediment were investigated through batch experiments. Sorption, homogeneous precipitation, and surfaced-induced precipitation were observed to be enhanced at pH 4. However, Huma-K removal from solution decreased with an increase of pH. The sorption behavior was not able to be described by any of the models employed (pseudo-first, pseudo-second, Langmuir, and Freundlich). Third, the interactions between uranium and SRS sediment with and without Huma-K amendment were investigated. In acidic conditions (pH 3-5), the sorption capacity of SRS sediment amended with Huma-K was significantly increased compared to plain sediment. At circumneutral conditions, uranium removal from solution decreased for SRS sediment amended with Huma-K, compared with plain sediments, likely as a result of the formation of aqueous uranium-humic complexes. In summary, the results from the present study suggest that Huma-K, and likely other unrefined humate products, has the characteristics and effects necessary to be suitable for subsurface injection to remediate uranium in acidic groundwater conditions. The treatment zone will persist as long as the pH does not increase sufficiently to cause soil-bound Huma-K to be released, remobilizing uranium.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第23525号 / 農博第2472号 / 新制||農||1087(附属図書館) / 学位論文||R3||N5356(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 梅村 研二, 教授 矢野 浩之, 教授 仲村 匡司 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

High nitrogen and phosphorus content in storm water runoff has affected groundwater, springs and surface water by impacting ecosystem integrity and human health. Nitrate may be toxic and can cause human health problem such as methemoglobinemia, liver damage and even cancers. Phosphorus may trigger the eutrophication issues in fresh water bodies, which could result in toxic algae and eventually endanger the source of drinking waters. Sorption media with mixes of some recycled materials, such as sawdust and tire crumb, combined with sand/silt and limestone, becomes appealing for nutrient removal in environmental management. This paper presented is a specific type of functionalized filtration media, Langmuir and Freundlich isotherms with reaction kinetics for nutrient removal using a suite of batch tests represented. Pollutants of concern include ammonia, nitrite, nitrate, orthophosphate and total dissolved phosphorus. Application potential in storm water management facilities, such as dry ponds, is emphasized in terms of life expectancy and reaction kinetics. As compared to the natural soil that is selected as the control case in the column test, our green sorption media mixture is proved relatively effective in terms of removing most of the target pollutants under various influent waste loads.

Increasing population across the globe paved the way for rapid growth in industrialization. Pharmaceuticals, automotive, textiles, agriculture, electronics, electrical and many other industries discharge different types of heavy metals, dyes and organic contaminants into ground water. These discharges are released into lakes and rivers without prior treatment causing huge environmental impact to the environment. Among different remediation techniques, adsorption was considered the most promising method because of its low-cost and high efficiency. Biomass is considered as the most practical and renewable source for production of bio products and biofuels. Biomass is also used for carbon sequestration and as an essential element to produce hydrochar and biochar which are considered as the 21st century black gold. Hydrochar and biochar can be used as an excellent low-cost adsorbent for the removal of heavy metals, dyes and organic contaminants from water. This dissertation work focuses on, firstly, development of novel oxone treated hydrochar as an adsorbent for the efficient removal of Pb(II) and Methylene Blue (MB) from aqueous solutions. Secondly, preparing novel ozone oxidized hydrochar treated with polyethyleneimine for removal of Remzol Brilliant Blue (RBB) and Remzol Reactive Black (RRB) dyes from aqueous solutions. Thirdly, producing high-performance CO2 activated biochar as an adsorbent for efficient removal of Aniline from aqueous solution. All prepared hydrochar and biochar adsorbents were characterized by SEM, TGA, FTIR, Elemental analysis, conductometric titration, and N2 adsorption-desorption isothermal analyses (BET and BJH). The adsorption capacities were determined by Atomic absorption spectrometry (AAS) and Ultraviolet–visible spectroscopy (UV-VIS) respectively. The adsorption capacity of each prepared biochar or hydrochar was determined and both kinetic and isothermal studies were performed. The optimal preparation conditions and adsorption parameters were determined for each adsorbent.

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