scholarly journals Induction of microbial oxidative stress as a new strategy to enhance the enzymatic degradation of organic micropollutants in wastewater

2019 ◽  
Author(s):  
Amrita Bains ◽  
Octavio Perez-Garcia ◽  
Gavin Lear ◽  
David Greenwood ◽  
Simon Swift ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Wastewater Treatment ◽  
Oxygen Supply ◽  
Cytochromes P450 ◽  
Treatment Plant ◽  
Dairy Farm ◽  
Organic Micropollutants ◽  
Aquatic Life ◽  
Incomplete Removal ◽  
New Strategy

Organic micropollutants (OMPs) are pervasive anthropogenic contaminants of fresh and marine waters with known potential to adversely affect aquatic life (e.g. endocrine disruption). Their ubiquitous environmental occurrence is primarily attributed to wastewater treatment plant discharges following their incomplete removal by common biological treatment processes. This study assesses a new strategy for promoting the degradation of six model OMPs (i.e. sulfamethoxazole, carbamazepine, tylosin, atrazine, naproxen and ibuprofen) by stimulating microbial oxidoreductase production to counter the effects of oxidative stress caused by oxygen perturbation. Microbial cultures from dairy farm wastewater were exposed to a cyclical ON-OFF perturbations of oxygen supply, ranging from 0.16 to 2 cycles per hour (i.e. 2, 1, 0.5, 0.25 and 0.16 cycles/hour), in laboratory bioreactors. The activity and relative abundances of microbial oxidoreductases (such as peroxidases, cytochromes P450) were upregulated by oxygen perturbation. In comparison to controls subjected to constant oxygen levels, OMP concentrations in perturbed cultures decreased by 70±9% (mean ± SD). A distance-based linear model confirmed strong positive correlations between the relative abundance of the bacterial families, Rhodocyclaceae, Syntrophaceae and Syntrophobacteraceae, and oxygen perturbations. Our results confirm that intentional perturbation of oxygen supply to induce microbial oxidative stress can improve OMP removal efficiencies in wastewater treatment bioreactors.

Determination and occurrence of organic micropollutants in reverse osmosis treatment for advanced water reuse

2012 ◽  
Vol 66 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Veronica Gomez ◽  
Katariina Majamaa ◽  
Eva Pocurull ◽  
Francesc Borrull
Keyword(s):  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Water Reuse ◽  
Treatment Plant ◽  
Organic Micropollutants ◽  
Wastewater Reclamation ◽  
North East ◽  
Incomplete Removal ◽  
Wide Range ◽  
Ro Membrane

The growing demand on water resources has increased the interest in wastewater reclamation for multiple end-use applications such as indirect and direct potable reuse. In these applications, the removal of organic micropollutants is of a greater concern than in conventional wastewater treatment. This article presents a collection of data of trace organic micropollutants in an urban wastewater treatment plant (WWTP) in North East Spain using reverse osmosis (RO) membrane treatment. The RO rejection values of the organic molecules studied with a wide range of solute size and hydrophobicity were determined. Several chromatographic methods monitoring different endocrine disrupting chemicals (EDCs), pharmaceuticals and personal care products (PPCPs) were used. Results indicated that secondary effluents from this Spanish WWTP contained most of the studied organic compounds indicating incomplete removal of organics in the conventional treatment of the plant. However, the rejection of most micropollutants was high for all three RO membrane types (low energy, high rejection, fouling resistant) tested. It was observed that some selected micropollutants were less efficiently removed (e.g. the small and polar and the more hydrophobic) and the molecular weight and membrane material influenced removal efficiencies.

scholarly journals Energy Effectiveness of Direct UV and UV/H2O2Treatment of Estrogenic Chemicals in Biologically Treated Sewage

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kamilla M. S. Hansen ◽  
Henrik R. Andersen
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Effectiveness ◽  
Treatment Plant ◽  
High Sensitivity ◽  
Electrical Energy ◽  
Continuous Exposure ◽  
Aquatic Life ◽  
Treated Sewage ◽  
Estrogenic Chemicals

Continuous exposure of aquatic life to estrogenic chemicals via wastewater treatment plant effluents has in recent years received considerable attention due to the high sensitivity of oviparous animals to disturbances of estrogen-controlled physiology. The removal efficiency by direct UV and the UV/H2O2treatment was investigated in biologically treated sewage for most of the estrogenic compounds reported in wastewater. The investigated compounds included parabens, industrial phenols, sunscreen chemicals, and steroid estrogens. Treatment experiments were performed in a flow through setup. The effect of different concentrations of H2O2and different UV doses was investigated for all compounds in an effluent from a biological wastewater treatment plant. Removal effectiveness increased with H2O2concentration until 60 mg/L. The treatment effectiveness was reported as the electrical energy consumed per unit volume of water treated required for 90% removal of the investigated compound. It was found that the removal of all the compounds was dependent on the UV dose for both treatment methods. The required energy for 90% removal of the compounds was between 28 kWh/m3(butylparaben) and 1.2 kWh/m3(estrone) for the UV treatment. In comparison, the UV/H2O2treatment required between 8.7 kWh/m3for bisphenol A and benzophenone-7 and 1.8 kWh/m3for ethinylestradiol.

scholarly journals Assessment of the fate of organic micropollutants in novel wastewater treatment plant configurations through an empirical mechanistic model

2020 ◽  
Vol 716 ◽  
pp. 137079 ◽  
Author(s):  
Anton Taboada-Santos ◽  
Chitta Ranjan Behera ◽  
Gürkan Sin ◽  
Krist V. Gernaey ◽  
Miguel Mauricio-Iglesias ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Mechanistic Model ◽  
Treatment Plant ◽  
Organic Micropollutants

Performance of an Earthworm-Based Biological Wastewater-Treatment Plant for a Dairy Farm: Case Study

2018 ◽  
Vol 144 (1) ◽  
pp. 04017086
Author(s):  
M. Fayzul K. Pasha ◽  
Dilruba Yeasmin ◽  
David Zoldoske ◽  
Bijay Kc ◽  
Jorge Hernandez
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Dairy Farm ◽  
Biological Wastewater Treatment

scholarly journals EVALUATION OF WATER POLLUTION STATUS IN BAHLUI RIVER (IASI TOWN AREA) DUE TO DOMESTIC AND URBAN WASTEWATER TREATMENT ACTIVITIES

2016 ◽  
Vol 21 (4) ◽  
Author(s):  
ZAHARIA CARMEN
Keyword(s):  
Water Pollution ◽  
Wastewater Treatment ◽  
Treatment Plant ◽  
Urban Wastewater ◽  
Aquatic Life ◽  
Pollution Status ◽  
Water Classification ◽  
Control Section ◽  
Urban Wastewater Treatment ◽  
Town Area

This study presents some data about the water pollution status of Bahlui river in Iasi town area (two control sections) mainly due to domestic and urban wastewater treatment activities, considering especially some quality indicators (i.e.<em> </em>nitrogen-based nutrients, total phosphorus and sum organics content) evaluated for 2009-2010. The Bahlui water classification by European standards in Iasi town area corresponds to ‘medium’ (WQI = 53.893 - 64.345). The real water pollution state of Bahlui river (Iasi town area) is estimated by the global pollution index (<em>I<sup>*</sup><sub>GP</sub></em>), and corresponds to values of 2.80-2.929 (Valea Lupului-Iasi control section), and 3.030-3.196 (Holboca control section, i.e. downstream of Dancu wastewater treatment plant). These values are indicating an aquatic environment modified by domestic and urban wastewater treatment activities, generating discomfort effects, or producing stress against aquatic life forms. These data are recommending application of hydro-ameliorative/remediation actions, and permanent control of Bahlui watercourse quality in all existing control sections.

scholarly journals Filling in the Gaps in Metformin Biodegradation: A New Enzyme and a Metabolic Pathway for Guanylurea

2021 ◽  
Author(s):  
Lambros J. Tassoulas ◽  
Ashley Robinson ◽  
Betsy Martinez-Vaz ◽  
Kelly G. Aukema ◽  
Lawrence P. Wackett
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Source ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Metagenomic Sequencing ◽  
Pseudomonas Mendocina ◽  
Sole Nitrogen Source ◽  
Aquatic Life ◽  
Dead End

The widely prescribed pharmaceutical metformin and its main metabolite guanylurea are currently two of the most common contaminants in surface and wastewater. Guanylurea often accumulates and is poorly, if at all, biodegraded in wastewater treatment plants. This study describes Pseudomonas mendocina strain GU isolated from a municipal wastewater treatment plant using guanylurea as its sole nitrogen source. The genome was sequenced with 36-fold coverage and mined to identify guanylurea degradation genes. The gene encoding the enzyme initiating guanylurea metabolism was expressed, the enzyme purified and characterized. Guanylurea hydrolase, a newly described enzyme, was shown to transform guanylurea to one equivalent of ammonia and guanidine. Guanidine also supports growth as a sole nitrogen source. Cell yields from growth on limiting concentrations of guanylurea revealed that metabolism releases all four nitrogen atoms. Genes encoding complete metabolic transformation were identified bioinformatically, defining the pathway as follows: guanylurea to guanidine to carboxyguanidine to allophanate to ammonia and carbon dioxide. The first enzyme, guanylurea hydrolase, is a member of the isochorismatase-like hydrolase protein family that includes biuret hydrolase and triuret hydrolase. Although homologs, the three enzymes show distinct substrate specificities. Pairwise sequence comparisons and the use of sequence similarity networks allowed fine structure discrimination between the three homologous enzymes and provided insights into the evolutionary origins of guanylurea hydrolase. IMPORTANCE Metformin is a pharmaceutical most prescribed for type 2 diabetes and is now being examined for potential benefits to COVID-19 patients. People taking the drug pass it largely unchanged and it subsequently enters wastewater treatment plants. Metformin has been known to be metabolized to guanylurea. The levels of guanylurea often exceed that of metformin, leading to the former being considered a “dead end” metabolite. Metformin and guanylurea are water pollutants of emerging concern as they persist to reach non-target aquatic life and humans, the latter if it remains in treated water. The present study has identified a Pseudomonas mendocina strain that completely degrades guanylurea. The genome was sequenced and the genes involved in guanylurea metabolism were identified in three widely separated genomic regions. This knowledge advances the idea that guanylurea is not a dead end product and will allow for bioinformatic identification of the relevant genes in wastewater treatment plant microbiomes and other environments subjected to metagenomic sequencing.

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