Influence of operating parameters on the biodegradation of steroid estrogens and nonylphenolic compounds during biological wastewater treatment processes

This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Environmental Science & Technology, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/es901612v.This study investigated operational factors influencing the removal of steroid estrogens and nonylphenolic compounds in two sewage treatment works, one a nitrifying/denitrifying activated sludge plant and the other a nitrifying/denitrifying activated sludge plant with phosphorus removal. Removal efficiencies of >90% for steroid estrogens and for longer chain nonylphenol ethoxylates (NP4−12EO) were observed at both works, which had equal sludge ages of 13 days. However, the biological activity in terms of milligrams of estrogen removed per day per tonne of biomass was found to be 50−60% more efficient in the nitrifying/denitrifying activated sludge works compared to the works which additionally incorporated phosphorus removal. A temperature reduction of 6 °C had no impact on the removal of free estrogens, but removal of the conjugated estrone-3-sulfate was reduced by 20%. The apparent biomass sorption (LogKp) values were greater in the nitrifying/denitrifying works than those in the nitrifying/denitrifying works with phosphorus removal for both steroid estrogens and nonylphenolic compounds possibly indicating a different cell surface structure and therefore microbial population. The difference in biological activity (mg tonne−1 d−1) identified in this study, of up to seven times, suggests that there is the potential for enhancing the removal of estrogens and nonylphenols if more detailed knowledge of the factors responsible for these differences can be identified and maximized, thus potentially improving the quality of receiving waters.Public Utilities Board (Singapore), Anglian Water Ltd, Severn Trent Water Ltd, Thames Water Utilities Ltd, United Utilities 393 Plc and Yorkshire Water Services

Glycosaminoglycans and Sialylated Glycans Sequentially Facilitate Merkel Cell Polyomavirus Infectious Entry

Merkel cell polyomavirus (MCV or MCPyV) appears to be a causal factor in the development of Merkel cell carcinoma, a rare but highly lethal form of skin cancer. Although recent reports indicate that MCV virions are commonly shed from apparently healthy human skin, the precise cellular tropism of the virus in healthy subjects remains unclear. To begin to explore this question, we set out to identify the cellular receptors or co-receptors required for the infectious entry of MCV. Although several previously studied polyomavirus species have been shown to bind to cell surface sialic acid residues associated with glycolipids or glycoproteins, we found that sialylated glycans are not required for initial attachment of MCV virions to cultured human cell lines. Instead, glycosaminoglycans (GAGs), such as heparan sulfate (HS) and chondroitin sulfate (CS), serve as initial attachment receptors during the MCV infectious entry process. Using cell lines deficient in GAG biosynthesis, we found that N-sulfated and/or 6-O-sulfated forms of HS mediate infectious entry of MCV reporter vectors, while CS appears to be dispensable. Intriguingly, although cell lines deficient in sialylated glycans readily bind MCV capsids, the cells are highly resistant to MCV reporter vector-mediated gene transduction. This suggests that sialylated glycans play a post-attachment role in the infectious entry process. Results observed using MCV reporter vectors were confirmed using a novel system for infectious propagation of native MCV virions. Taken together, the findings suggest a model in which MCV infectious entry occurs via initial cell binding mediated primarily by HS, followed by secondary interactions with a sialylated entry co-factor. The study should facilitate the development of inhibitors of MCV infection and help shed light on the infectious entry pathways and cellular tropism of the virus

An overview of chemical additives present in plastics: Migration, release, fate and environmental impact during their use, disposal and recycling

Over the last 60 years plastics production has increased manifold, owing to their inexpensive, multipurpose, durable and lightweight nature. These characteristics have raised the demand for plastic materials that will continue to grow over the coming years. However, with increased plastic materials production, comes increased plastic material wastage creating a number of challenges, as well as opportunities to the waste management industry. The present overview highlights the waste management and pollution challenges, emphasising on the various chemical substances (known as “additives”) contained in all plastic products for enhancing polymer properties and prolonging their life. Despite how useful these additives are in the functionality of polymer products, their potential to contaminate soil, air, water and food is widely documented in literature and described herein. These additives can potentially migrate and undesirably lead to human exposure via e.g. food contact materials, such as packaging. They can, also, be released from plastics during the various recycling and recovery processes and from the products produced from recyclates. Thus, sound recycling has to be performed in such a way as to ensure that emission of substances of high concern and contamination of recycled products is avoided, ensuring environmental and human health protection, at all times

The fate and behavior of octyl- and nonylphenol ethoxylates and their derivatives in three American wastewater treatment plants and the Back River, Maryland

The octyl- and nonylphenol ethoxylates (collectively known as alkylphenol ethoxylates, APEOs) are a family of widely used surfactants in industrial processes and as detergents in both industrial and household applications. After being used, the APEOs are transformed into more toxic and endocrine disrupting products, such as short-chain APEOs, nonylphenol (NP), and octylphenol (OP). The main objective of the present work was to study the fate of the APEOs and transformation products (APEs) in three American wastewater treatment plants (WWTPs) and in Back River, an estuary of the Chesapeake Bay that receives treated effluent from one of the plants. In order to accomplish this, analytical methods were developed based on solid-phase extraction for water, accelerated solvent extraction for solids, and isotope dilution liquid chromatography/tandem mass spectrometry for quantitation. Analysis in the WWTPs showed that influent wastewater had similar APEs concentrations, whereas effluent concentrations were only similar when samples from the same season (fall or winter) were compared, with concentrations being several times higher in winter than in fall. Sorption to particulate was approximately 1.6 times higher for nonylphenolic compounds than for their octylphenolic counterparts, in agreement with their difference in Kow values. Effluent concentrations and APEO removal rates--the latter averaging 99% in summer and 94% in winter for the NPEOs--were strongly correlated to water temperature, and no correlation was found with suspended solids or organic carbon removal. In Back River the most abundant of the APEs were the carboxylated transformation products (APECs, > 95% on mass basis), followed by NP in September and October, and NP1-2EO in March. NP concentrations found, 0.087 - 0.69 μg/L, were below acute toxicity thresholds, and generally below recently proposed water quality criteria by the US EPA. Total NPE concentrations in the Back River seemed to vary in accordance to the concentrations in the WWTP effluent, especially in the case of the APECs. However, a closer analysis of the data suggested that in the fall sampling events, when rain occurred, the ethoxylates present in the particulate matter originated in the river's tributaries rather than the WWTP

A sensitive and robust method for the determination of alkylphenol polyethoxylates and their carboxylic acids and their transformation in a trickling filter wastewater treatment plant.

This paper presents a method for the determination of alkylphenols, alkylphenol polyethoxylates (APEO) and alkylphenol ethoxycarboxylates (APEC) in the aqueous and particulate phase of wastewater samples. Quantification was achieved by liquid chromatography-tandem mass spectrometry. The sensitivity of the method is demonstrated by low detection limits, in the dissolved phase 1.2–9.6 ng l−1 for alkylphenol, AP1–3EO and APEC and 0.1–4.1 ng l−1 for longer chain alkylphenol polyethoxylates. The method detection limit for particulate phase samples ranged from 6 to 60 ng g−1 for AP, AP1–3EO and APEC; with the longer chain APEO being from 0.5 to 20 ng g−1. Matrix effects were noted in complex matrix rich samples. There was a distinct change in the distribution of alkylphenol ethoxylates during biological treatment of the wastewater, with the major biotransformation products observed being carboxylated derivatives at concentrations of up to 1768 ng l−1. Shorter chain APEO were present in higher proportions in the suspended solids, due to their higher affinity to particulate matter compared to the lo