Fate of nanoparticles during alum and ferric coagulation monitored using single particle ICP-MS.

In this study, aluminum sulfate, ferric sulfate, ferric chloride, and poly(diallyldimethylammonium chloride) (pDADMAC) coagulation removal of citrate-stabilized silver and gold nanoparticles (NPs) and uncoated titanium dioxide, cerium dioxide, and zinc oxide NPs was investigated using a single particle (SP) ICP-MS direct monitoring technique. Zone 2 (charge neutralization) coagulation was performed in river water and more commonly used Zone 4 (sweep floc) coagulation was performed in both river and lake water with environmentally relevant concentrations of selected NPs added. SP-ICP-MS was used to detect NP and dissolved species, characterize the size distribution, and quantify particle concentration as well as dissolved species before and after treatments.

Evaluation of thirteen haloacetic acids and ten trihalomethanes formation by peracetic acid and chlorine drinking water disinfection.

Free chlorine is a commonly used disinfectant in drinking water treatment. However, disinfection by-products (DBPs) are formed during water disinfection. Haloacetic acids (HAAs) and trihalomethanes (THMs) are two major groups of DBPs.

Effect of oxidant demand on the release and degradation of microcystin-LR from Microcystis aeruginosa during oxidation.

In this research, the release and degradation of intracellular microcystin-LR (MC-LR) due to oxidation of Microcystis aeruginosa (M. aeruginosa) was examined kinetically. Brief exposure to free chlorine with no measureable oxidant exposure was demonstrated to be sufficient to induce rapid release of intracellular MC-LR from M.

Detection of zinc oxide and cerium dioxide nanoparticles during drinking water treatment by rapid single particle ICP-MS methods.

Nanoparticles (NPs) entering water systems are an emerging concern as NPs are more frequently manufactured and used. Single particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) methods were validated to detect Zn- and Ce-containing NPs in surface and drinking water using a short dwell time of 0.1 ms or lower, ensuring precision in single particle detection while eliminating the need for sample preparation.

Single particle ICP-MS characterization of titanium dioxide, silver, and gold nanoparticles during drinking water treatment.

One of the most direct means for human exposure to nanoparticles (NPs) released into the environment is drinking water. Therefore, it is critical to understand the occurrence and fate of NPs in drinking water systems. The objectives of this study were to develop rapid and reliable analytical methods and apply them to investigate the fate and transportation of NPs during drinking water treatments.

Chlorination and chloramination of bisphenol A, bisphenol F, and bisphenol A diglycidyl ether in drinking water.

Bisphenol A (BPA), bisphenol F (BPF), and bisphenol A diglycidyl ether (BADGE) are common components of epoxy coatings used in food packaging and in drinking water distribution systems. Thus, leachates from the epoxy may be exposed to the disinfectants free chlorine (Cl2/HOCl/OCl(-)) and monochloramine (MCA, NH2Cl). Bisphenols are known endocrine disrupting chemicals (EDC) with estrogenic activity.

Oxidative removal of selected endocrine-disruptors and pharmaceuticals in drinking water treatment systems, and identification of degradation products of triclosan.

The potential occurrences of endocrine-disrupting compounds (EDCs), as well as pharmaceuticals, are considered to be emerging environmental problems due to their persistence and continuous input into the aquatic ecosystem, even at only trace concentrations. This study systematically investigated the oxidative removal of eight specially selected ECDs and pharmaceuticals by comparing their relative reactivity as a function of different oxidative treatment processes (i.e.

Comparative mobility of sulfonamides and bromide tracer in three soils.

In animal agriculture, sulfonamides are one of the routinely used groups of antimicrobials for therapeutic and sub-therapeutic purposes. It is observed that, the animals when administered the antimicrobials, often do not completely metabolize them; and excrete the partially metabolized forms into the environment. Due to the continued use of antimicrobials and disposal of untreated waste, widespread occurrence of partially metabolized antimicrobials in aquatic and terrestrial environments has been reported in various scientific journals.

Oxidation kinetics of two pesticides in natural waters by ozonation and ozone combined with hydrogen peroxide.

The oxidation of bromoxynil and trifluralin was investigated using ozone (O(3)) and O(3) combined with hydrogen peroxide (H(2)O(2)) in natural waters using batch reactors. The results indicated that these pesticides could not be completely degraded during ozonation, achieving degradation levels lower than 50%. An enhancement of the level of degradation was observed using O(3)/H(2)O(2) process.

Investigation of pharmaceuticals in Missouri natural and drinking water using high performance liquid chromatography-tandem mass spectrometry.

A comprehensive method has been developed and validated in two different water matrices for the analysis of 16 pharmaceutical compounds using solid phase extraction (SPE) of water samples, followed by liquid chromatography coupled with tandem mass spectrometry. These 16 compounds include antibiotics, hormones, analgesics, stimulants, antiepileptics, and X-ray contrast media. Method detection limits (MDLs) that were determined in both reagent water and municipal tap water ranged from 0.

Oxidative removal and kinetics of fipronil in various oxidation systems for drinking water treatment.

Fipronil, a pesticide gaining wide usage, was oxidized with common drinking water treatment disinfectants and oxidants; with a degradate identified using liquid chromatography-mass spectrometry. Oxidants investigated were free chlorine (HOCl/OCl(-)), monochloramine (ClNH(2)), chlorine dioxide (ClO(2)), and permanganate (MnO(4)(-)) at pH 6.6 and 8.

Assessment of metal contaminations leaching out from recycling plastic bottles upon treatments.

Background, Aims, And Scope: Heavy metal contaminants in environment, especially in drinking water, are always of great concern due to their health impact. Due to the use of heavy metals as catalysts during plastic syntheses, particularly antimony, human exposure to metal release from plastic bottles has been a serious concern in recent years. The aim and scope of this study were to assess metal contaminations leaching out from a series of recycling plastic bottles upon treatments.

Simultaneous screening of herbicide degradation byproducts in water treatment plants using high performance liquid chromatography-tandem mass spectrometry.

Currently, herbicides are widely used in various combinations at many stages of cultivation and during postharvest storage. There are increasing concerns about the public health impact of herbicide degradation byproducts that may be present in water bodies used either as drinking water or for recreational purposes. This work investigated the sulfonic acid and oxanilic acid degradation products of metolachlor, alachlor, acetochlor, and propachlor in a variety of water bodies.

Effects of oxidative and physical treatments on inactivation of Cylindrospermopsis raciborskii and removal of cylindrospermopsin.

The presence of toxic cyanobacterial blooms (or blue-green algae) in water bodies used either as drinking water or for recreational purposes may present serious health risks for the human population. In this study, the removal of the chemical toxin, cylindrospermopsin, via free chlorine, chlorine dioxide, monochloramine, permanganate, ozone, and UV irradiation was studied. Ozone and free chlorine were found to be highly effective for cylindrospermopsion removal while the other disinfectants were ineffective.

Effects of ionic strength, temperature, and pH on degradation of selected antibiotics.

Aqueous degradation rates, which include hydrolysis and epimerization, for chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin A (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.

Diversity of tet resistance genes in tetracycline-resistant bacteria isolated from a swine lagoon with low antibiotic impact.

Tetracycline resistance has been extensively studied and shown to be widespread. A number of previous studies have clearly demonstrated that a variety of tetracycline resistance genes are present in swine fecal material, treatment lagoons, and the environments surrounding concentrated animal feeding operations (CAFOs). The diversity of tetracycline resistance within a swine lagoon located at a CAFO that used only bacitricin methylene disalicylate as an antibiotic was evaluated by screening 85 tetracycline-resistant isolates for the presence of 18 different genes by performing PCR with primers that target tetracycline efflux genes of Gram-negative bacteria and ribosomal protection proteins.

Removal of estrogenic activity of natural and synthetic hormones from a municipal wastewater: efficiency of horseradish peroxidase and laccase from Trametes versicolor.

Some researches studied the removal of steroid estrogens by enzymatic treatment, however none verified the residual estrogenicity after the enzymatic treatment at environmental conditions. In this study, the residual estrogenic activities of the key natural and synthetic steroid estrogens were investigated following enzymatic treatment with horseradish peroxidase (HRP) and laccase from Trametes versicolor. Synthetic water and municipal wastewater containing environmental concentrations of estrone, 17beta-estradiol, estriol, and 17alpha-ethinylestradiol were treated.

Quantification of steroid sex hormones using solid-phase extraction followed by liquid chromatography-mass spectrometry.

In this study, the occurrence of trace amounts of natural and synthetic steroid estrogens in the aquatic environment was studied using liquid chromatography coupled with electrospray mass spectrometry, following solid-phase extraction (SPE). The SPE was performed with C18 and NH2 cartridges. The first objective was to develop a reliable method for analyzing steroid estrogens (resulting from human and animal excretions) in different matrices.

Laccase-catalyzed conversion of natural and synthetic hormones from a municipal wastewater.

The Trametes versicolor-derived laccase-catalyzed oxidation of natural estrogens (estrone--E1; 17beta-estradiol--E2; and estriol--E3) and a synthetic estrogen (17alpha-ethinylestradiol--EE2) was studied in synthetic water and municipal wastewater to optimize the process for steroid estrogen removal in wastewater. The optimal pH for each studied steroid estrogen oxidation was approximately 6 in synthetic water. This research also focused on the wastewater matrix effect on developed enzymatic treatment.

Oxidation of natural and synthetic hormones by the horseradish peroxidase enzyme in wastewater.

Steroid estrogens, including both natural estrogens (e.g., estrone - E1; 17beta-estradiol - E2; and estriol - E3) and synthetic estrogens (e.

Diffusion of oxygen through activated sludge flocs: experimental measurement, modeling, and implications for simultaneous nitrification and denitrification.

Diffusion of dissolved oxygen through activated sludge flocs was studied, as it represents a potential mechanism for simultaneous nitrification and denitrification in activated sludge systems. Dissolved oxygen profiles through six floc particles collected at different times from a full-scale activated sludge plant demonstrated that that the dissolved oxygen concentration declines through all floc particles. For larger floc particles (2-mm diameter and greater), the dissolved oxygen concentration reached near-zero values at depths depending on process operating conditions.

Effects of sorbate speciation on sorption of selected sulfonamides in three loamy soils.

Sorption of sulfamethazine (SMN) and sulfathiazole (STZ) was investigated in three soils, a North Carolina loamy sand, an Iowa sandy loam, and a Missouri loam, under various pH conditions. A significant increase in the sorption coefficient (KD) was observed in all three soils, as the sulfonamides converted from an anionic form at higher pH to a neutral/cationic form at lower pH. Above pH 7.

Treatment of antibiotics and antibiotic resistant bacteria in swine wastewater with free chlorine.

Recent recognition of the occurrence of antibiotics in the environment has highlighted concerns regarding potential threats of antibiotics to humans and wildlife. Antibiotics are commonly applied to animals to prevent diseases and promote growth, making livestock agriculture a major source of antibiotic pollution. The purpose of our study was to examine chlorination technology as a method for preventing the release of antibiotics as well as antibiotic-resistant bacteria into the environment from concentrated animal feeding operations.

Natural and synthetic hormone removal using the horseradish peroxidase enzyme: temperature and pH effects.

The primary objective of our research was to establish the technical feasibility of using the horseradish peroxidase (HRP) enzyme for natural and synthetic estrogens-estrone (E1), 17beta-estradiol (E2), estriol (E3), and 17alpha-ethinylestradiol (EE2)-removal. The effects of temperature and pH on enzymatic treatment kinetics were investigated. Residual estrogen concentrations were quantified by liquid chromatography, coupled with mass spectrometry analysis.

Disinfection of swine wastewater using chlorine, ultraviolet light and ozone.

Veterinary antibiotics are widely used at concentrated animal feeding operations (CAFOs) to prevent disease and promote growth of livestock. However, the majority of antibiotics are excreted from animals in urine, feces, and manure. Consequently, the lagoons used to store these wastes can act as reservoirs of antibiotics and antibiotic-resistant bacteria.