Removal of steroid estrogens in carbonaceous and nitrifying activated sludge processes

This is the post-print version of the final paper published in Chemosphere. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.A carbonaceous (heterotrophic) activated sludge process (ASP), nitrifying ASP and a nitrifying/denitrifying ASP have been studied to examine the role of process type in steroid estrogen removal. Biodegradation efficiencies for total steroid estrogens (ΣEST) of 80 and 91% were recorded for the nitrifying/denitrifying ASP and nitrifying ASP respectively. Total estrogen biodegradation (ΣEST) was only 51% at the carbonaceous ASP, however, the extent of biodegradation in the absence of nitrification clearly indicates the important role of heterotrophs in steroid estrogen removal. The low removal efficiency did not correlate with biomass activity for which the ASPcarbonaceous recorded 80 μg kg−1 biomass d−1 compared to 61 and 15 μg kg−1 biomass d−1 at the ASPnitrifying and ASPnitrifying/denitrifying respectively. This finding was explained by a moderate correlation (r2 = 0.55) between total estrogen loading (ΣEST mg m−3 d−1) and biomass activity (μg ΣEST degraded kg−1 d−1) and has established the impact of loading on steroid estrogen removal at full-scale. At higher solids retention time (SRT), steroid estrogen biodegradation of >80% was observed, as has previously been reported. It is postulated that hydraulic retention time (HRT) is as important as SRT as this governs both reaction time and loading. This observation is based on the high specific estrogen activity determined at the ASPcarbonaceous plant, the significance of estrogen loading and the positive linear correlation between SRT and HRT.Public Utilities Board of Singapore, Anglian Water Ltd., Severn Trent Water Ltd., Thames Water Utilities Ltd., United Utilities Plc., and Yorkshire Water Services Ltd

Soil ozonation as a sustainable alternative to methyl bromide fumigation and synthetic pesticides

ABSTRACT The goal of this dissertation was to investigate the potentials of ozone as a sustainable alternative to the soil fumigant methyl bromide and to synthetic pesticides. Three pathogens were selected for this research, given their economic importance, and the spectrum variety that they represent: Phytoparasitic nematodes, important pests that cause severe crop yield losses; Phytophthora sojae, a predominant soybean pathogen that causes root and stem rot, and pre- and post-emergence damping-off of soybean; and Fusarium oxysporum, which causes Fusarium wilt, an economically important disease in hydroponic systems. Soil samples that were naturally infested with nematodes were treated with different levels of gaseous ozone at 21 ºC and 5 ºC. A medium level of ozonation (2.1 g O3 kg-1 for 10 min at a rate of ozonation 0.21 g O3 kg-1min-1) and low temperature (5 ºC) resulted in 96% nematode inhibition. Regression analysis showed that nematode viability was a function of the level of ozonation (P = 5.1E-07) and the soil temperature (P = 4.4E-08; Adjusted R-square = 0.65). Assays of artificially inoculated soil samples with P. sojae were treated with different doses of gaseous ozone. This study showed that a dosage of 0.47 g O3/kg soil, totally prevented root and stem rot disease symptoms caused by P. sojae. Samples of conidial suspensions of F. oxysporum were treated with incremental doses of ozone from either oxygen feed with high gas-phase concentration (GPC) or air feed with low GPC. Trials resulted in non-viability of the pathogen at high ozone GPC with a dose of 0.84 mg O3/L for 3 seconds. The optimal conditions for F. oxysporum treatment with ozone were high GPC (oxygen feed), and low temperature (5 ºC). Given these promising results, and since ozone degenerates quickly to oxygen, the findings of this research clearly indicate that ozone may be an efficient and sustainable alternative to methyl bromide and to: 1. nematicides in the treatment of nematodes in the soil, 2. fungicides in the inhibition of Phytophthora diseases in the soil, and 3. fungicides in the treatment of Fusarium wilt in hydroponic nutrient solutions

Integration of ionic liquid biorefinery with constructed wetland remediation of wastewater

Constructed wetland remediation has significant potential as a low-cost and low-maintenance water treatment technology. The high growth rates and yields of wetland species mean that constructed wetlands can also serve as a source of lignocellulosic biomass, which can be fractionated and processed into a wide range of useful fuels, chemicals, and materials. The work presented in this thesis investigates the potential for the widespread adoption of constructed wetlands for wastewater remediation, and for the valorisation of the generated biomass through an ionic liquid biorefinery. Firstly, this work investigates the effect of varying the degree of substitution of the cation in aqueous alkylammonium hydrogen sulfate ionic liquids. A decreasing degree of substitution was found to significantly enhance solution acidity in a way that differed from addition of excess sulfuric acid. The effects of this acidity were tested for the ionic liquid pretreatment of Miscanthus, through which a promising new pretreatment solvent was identified. Methylbutylammonium hydrogen sulfate produced pulps with purities of up to 94%, in two-thirds of the time of current benchmark ionic liquids. Secondly, a desk study was carried out to quantify the economic potential for wetland remediation, for the removal of organic and nutrient contamination, and for the remediation of Acid Mine Drainage, relative to conventional technologies. Constructed wetlands were found to be comparatively economically favourable at a wide range of conditions, particularly those with lower flow rates and/or contamination. Valorisation of the wetland biomass was found to be able to offset a significant proportion of total costs, but may require mixing with other feedstocks due to areal requirements. Valorisation of wetland feedstocks through ionic liquid pretreatment was then investigated experimentally. Feedstock independence was validated by pretreating 7 common wetland species. Large improvements in digestibility and pulp purity were observed (to around 80% and 70% respectively), with low variability between species. These feedstocks’ high extractives content was found to increase the rate of pseudolignin formation, but this could be avoided through pre-extraction with ethanol and water. Recycling performance was found to decrease with each cycle, although this was offset to a certain degree through biomass pre-extraction and through addition of acid between cycles. Finally, a novel fractionation process was suggested and developed using duckweed as a feedstock, allowing the full range of its promising features to be utilised. Ionic liquid interactions with pure starch were probed, allowing conditions amenable to starch processing to be determined. Pretreatment of duckweed with ionic liquids at mild conditions allowed near-quantitative sugar release to be achieved in 8 hours of hydrolysis, while a protein-enriched post-saccharification residue was also generated.Open Acces

Fertilizer Application on Crop Yield

This book is a printed edition of the Special Issue Fertilizer Application on Crop Yield that was published in Agronom

Role of the glycerophosphocholine acyltransferase, Gpc1, in phosphatidylcholine (PC) biosynthesis and remodeling in Saccharomyces cerevisiae

Biomembranes are permeable barriers that enclose the cell and the intracellular organelles in a cell. The selective nature of these robust barriers acts as the first line of defense towards the harsh factors that can compromise cell survival. Biomembranes primarily consist of membrane lipids that are organized into layers to form a dynamic bilayer structure. The dynamic nature of the membrane requires the synchronized modulation of lipid composition through de novo synthesis, degradation, intracellular movement, and remodeling. Phospholipids are the major membrane lipid class, and phosphatidylcholine (PC) is the most abundant phospholipid in most eukaryotic biomembranes. PC is primarily produced via two major pathways: the Kennedy and PE methylation pathways. Through a collaborative project, we have discovered a lipid-modifying enzyme, a glycerophosphocholine acyltransferase, Gpc1, involved in a new pathway for PC biosynthesis and PC remodeling. Here, I have examined this alternative route for PC biosynthesis and remodeling using Saccharomyces cerevisiae (S. cerevisiae) as a model organism. First, I performed in vivo metabolic labeling studies to delineate the role of Gpc1 in the alternative route for PC biosynthesis. I have also determined the apparent molecular weight of this novel Gpc1 protein by constructing a C-terminal epitope tag followed by Western blot analysis. These studies are described in more detail in Chapter two. In the second half of my dissertation, I have examined the physiological function and regulatory aspects of Gpc1. Using LC-MS analysis, I have determined the PC species profile generated via this alternative pathway. Gpc1 was found to be involved in a PC deacylation/reacylation remodeling pathway (PC-DRP) that results in an increase in monounsaturated PC species at the expense of diunsaturated PC species. Here, I report inositol, a phospholipid precursor, as a down-regulator for GPC1 expression. Also, I have identified a phenotype associated with the loss of GPC1. Loss of GPC1 results in decreased cell viability for cells at the stationary phase. These studies are described in detail in Chapter three. Overall, in Chapters two and three, I have identified Gpc1 as a member of PC-DRP, a pathway that increases the saturation state of the PC. This increase may impact on the physiochemical properties of the membrane

Integrating dynamic economic optimization and nonlinear closed-loop GPC: Application to a WWTP

Producción CientíficaIn this paper, a technique that integrates methods of dynamic economic optimization and real-time control by including economic model predictive control and closed-loop predictive control has been developed, using a two-layer structure. The upper layer, which consists of an economic nonlinear MPC (NMPC), makes use of the updated state information to optimize some economic cost indices and calculates in real time the economically optimal trajectories for the process states. The lower layer uses a closed-loop nonlinear GPC (NCLGPC) to calculate the control actions that allow for the outputs of the process to follow the trajectories received from the upper layer. This paper also includes the theoretical demonstration proving that the deviation between the state of the closed-loop system and the economically time varying trajectory provided by the upper layer is bounded, thus guaranteeing stability. The proposed approach is based on the use of nonlinear models to describe all the relevant process dynamics and cover a wide operating range, providing accurate predictions and guaranteeing the performance of the control systems. In particular, the methodology is implemented in the N-Removal process of a WWTP and the results demonstrate that the method is effective and can be used profitably in practical cases such as the chemical, refinery and petrochemical process industries.Ministerio de Economía y Competitividad - (project DPI2015- 67341C21R)Junta de Castilla y Leon y Fondo Europeo de Desarrollo Regional (FEDER) - (grants CLU 2017-09 and UIC 233

Biodegradation of Synthetic Polymers in the Aquatic Environment

Biodegradation of synthetic polymers can be a sophisticated property for intelligent and sustainable products that offer complex benefits for specific applications. There are many entry paths for synthetic polymers that can accumulate in the aqueous and especially marine environment and little is known about their biodegradation especially in the aquatic environment. The difficulties with determining biodegradation in those environments are based on the absence of appropriate methods and also the fact that these environments often prove low biodegradation rates. It is also complicated to detect biodegradation on polymeric substances because of the high molecular weight, water insolubility and difficult molecular structure making it hard to detect biodegradation products. This work provides an overview of the actual status of research and investigates on different methods of biodegradation tests in the aquatic environment with selected synthetic polymers

Biodegradation of Synthetic Polymers in the Aquatic Environment

Biodegradation of synthetic polymers can be a sophisticated property for intelligent and sustainable products that offer complex benefits for specific applications. There are many entry paths for synthetic polymers that can accumulate in the aqueous and especially marine environment and little is known about their biodegradation especially in the aquatic environment. The difficulties with determining biodegradation in those environments are based on the absence of appropriate methods and also the fact that these environments often prove low biodegradation rates. It is also complicated to detect biodegradation on polymeric substances because of the high molecular weight, water insolubility and difficult molecular structure making it hard to detect biodegradation products. This work provides an overview of the actual status of research and investigates on different methods of biodegradation tests in the aquatic environment with selected synthetic polymers