Municipal Treatment Plant Research Articles

A fast start-up of the organotrophic anammox process inoculated with constructed wetland sediment

Organotrophic anaerobic ammonium oxidation (anammox) bacteria can utilize small volatile fatty acids with nitrate as electron acceptors with less energy consumption and no biomass production. To achieve a faster and stable start-up of organotrophic anammox process, in this study, the growth of organotrophic anammox bacteria seeded from hybrid constructed wetland (CW) sediment under different TOC/TN ratios and different chloramphenicol concentrations were investigated. The incubation study was conducted at the TOC/TN ratio = 0.0375–0.1 or 0.1–0.2 for the period of over five months by using serum bottles. The anammox bacteria revealed a higher activity when the TOC/TN ratio was 0.1, with the removal efficiency of NH4+-N (60–80%) and NO2−-N (~100%). The relative abundances of anammox in the incubated CW sediment were about 30% higher in comparison with the municipal waste water treatment plant sludge, suggesting the CW sediment could be a viable source for the enrichment of organotrophic anammox bacteria. On the contrary, the continuous addition of 50 mg/L chloramphenicol completely inhibited the anammox activity in our study. Following the results of the batch tests, Candidatus Brocadia caroliniensis was successfully enriched with the CW sediment in an auto-controlled SBR for the period of 40 days.

Removal efficiencies of top-used pharmaceuticals at sewage treatment plants with various technologies

The presence of pharmaceuticals in wastewater and the environment has attracted growing public concern. Although studies have been performed to detect pharmaceuticals in wastewater effluents, little research has been conducted to assess the efficiency of pharmaceutical removal using different treatment technologies. To assess the removal efficiencies of pharmaceuticals in wastewater, samples from 22 municipal treatment plants in Nova Scotia and New Brunswick were analyzed for 12 commonly used pharmaceuticals and 2 primary metabolites. The medians of removal efficiencies for 9 technologies: aerated lagoon, extended aeration, facultative lagoon, membrane bioreactor, modified secondary, oxidation ditch, primary treatment, rotating biological contactor, and sequencing batch reactor technologies, were determined to be 98.0%, 96.4%, 98.2%, 99.8%, 68.4%, 99.0%, 3.0%, 81.3%, and 98.3%, respectively. The medians of removal efficiencies of individual pharmaceuticals were found from -14.4% to 100%. Primary treatment showed significant differences comparing to other treatment technologies. Very strong correlations of removal efficiencies were found between acetaminophen and warfarin, between cotinine and warfarin, between cotinine and paraxanthine, and between ramipril and atorvastatin. In general, there was no strong correlation of removal between pharmaceuticals and total organic waste load or total suspended solids.

Linking chemical exposure to lipid homeostasis: A municipal waste water treatment plant influent is obesogenic for zebrafish larvae

Obesity, a risk factor for the development of type-2 diabetes, hypertension, cardiovascular disease, hepatic steatosis and some cancers, has been ranked in the top 10 health risk in the world by the World Health Organization. Despite the growing body of literature evidencing an association between the obesity epidemic and specific chemical exposure across a wide range of animal taxa, very few studies assessed the effects of chemical mixtures and environmental samples on lipid homeostasis. Additionally, the mode of action of several chemicals reported to alter lipid homeostasis is still poorly understood. Aiming to fill some of these gaps, we combined an in vivo assay with the model species zebrafish (Danio rerio) to screen lipid accumulation and evaluate expression changes of key genes involved in lipid homeostasis, alongside with an in vitro transactivation assay using human and zebrafish nuclear receptors, retinoid X receptor α and peroxisome proliferator-activated receptor γ. Zebrafish larvae were exposed from 4 th day post-fertilization until the end of the experiment (day 18), to six different treatments: experimental control, solvent control, tributyltin at 100 ng/L Sn and 200 ng/L Sn (positive control), and wastewater treatment plant influent at 1.25% and 2.5%. Exposure to tributyltin and to 2.5% influent led to a significant accumulation of lipids, with white adipose tissue deposits concentrating in the perivisceral area. The highest in vitro tested influent concentration (10%) was able to significantly transactivate the human heterodimer PPARγ/RXRα, thus suggesting the presence in the influent of HsPPARγ/RXRα agonists.Our results demonstrate, for the first time, the ability of complex environmental samples from a municipal waste water treatment plant influent to induce lipid accumulation in zebrafish larvae.

Demineralisation of Municipal Biowaste Hydrolysates

AbstractThis work reports the demineralisation of soluble biorganic hyrolysates (SBOs) obtained from three materials sampled from a municipal biowaste treatment plant. The SBOs contain mineral and organic matter. They are promising bio‐based multipurpose products due to their properties as biosurfactants, chemicals for the manufacture of plastics, and fertilizers for plant growth. Demineralisation of SBOs was carried out by HCl ion exchange and HF washing to assess its effect on the pristine product chemical composition and properties. The demineralized products (SBOs‐DM) were characterized by elemental analysis, potentiometric titration, 13C‐NMR spectroscopy and surface tension measurements. They were compared with pristine SBOs. The following results were obtained: ash content 0.2‐1.1% in SBOs‐DM vs. 15–28% in pristine SBOs; lower aliphatic/aromatic C ratio in SBOs‐DM (0.8‐2.0) than in pristine SBOs (1.3‐3.4); higher critical (mineral free) micellar concentration for SBOs‐DM (1‐2.7 g L−1) than for pristine SBOs (1‐2.3 g L−1). The potential applications of SBOs‐DM and pristine SBOs are discussed.

Assessing the organic fraction of municipal solid wastes for the production of lactic acid

With an estimated yearly production of about 140 Mt in the EU, conventionally, the organic fraction of municipal solid wastes (OFMSW) has been disposed in landfills with negative environmental effects. Nonetheless, the chemical composition of this residue make it a substrate with great bioconversion potential. In this study, OFMSW from Spanish municipal treatment plants, were evaluated for the production of LA. Samples were identified according to the sorting mechanisms employed for their collection in: (A) separately collected, (B) non-separately collected and (C) separately collected+paper/cardboard. Enzymatic hydrolysis was used to produce hydrolysates A, B and C accordingly. Hydrolysate A showed the highest total sugars and glucose content with values of 70 and 55 g·L−1, respectively. Following the characterisation, a screening showed that growth of B. coagulans was possible in all three hydrolysates. Furthermore, lab scale fermentations showed that LA final concentrations could reach around 60 g·L−1, with yields from total sugars of above 0.60 g·g−1. A technical scale fermentation of the hydrolysate A resulted in a final LA concentration of 60.7 g·L−1, a yield of 0.71 g·g−1 with a productivity of 2.68 g·L−1·h−1. Overall, it was estimated that 0.23 g of LA could be produced from one g of dry OFMSW.

Gestión y manejo de las aguas residuales no domésticas en la ciudad turística de La Libertad, El Salvador. Desafíos para alcanzar un desarrollo sostenible

Esta investigación tuvo como objetivo caracterizar la gestión municipal de las aguas residuales no domésticas, generadas por el sector comercial y de servicios de la ciudad de La Libertad en El Salvador; lo que permitió identificar los desafíos para alcanzar un desarrollo sostenible.
 Para desarrollar esta investigación se consultaron fuentes secundarias y se realizaron entrevistas semiestructuradas al personal técnico, y político de la Alcaldía Municipal.
 La ciudad de La Libertad es emblemática del turismo nacional costero; sin embargo, presenta serios problemas ambientales: el 28% de los negocios son generadores de aguas residuales no domésticas; el sistema de alcantarillado es obsoleto, con una cobertura del 61,7%; mientas que la planta de tratamiento municipal se encuentra en malas condiciones, con una eficiencia depurativa del 50%. Fruto de la mala gestión de las aguas residuales y de los residuos sólidos, se producen colapsos tanto en el sistema de alcantarillado como de las aguas lluvias de la ciudad.
 Todo esto genera deterioro en la imagen de la ciudad, mayor insalubridad, contaminación de ríos, quebradas y playas; dificultando el desarrollo turístico sostenible. Aunque la municipalidad tiene conciencia de la problemática, por el momento no cuenta con estrategias e instrumentos necesarios para hacer una gestión integral de las aguas residuales.
 El ordenamiento territorial, la mejora de equipamiento e infraestructura sanitaria, la educación ambiental y el fortalecimiento de las capacidades locales para la aplicación de la legislación ambiental municipal, son desafíos claros para lograr el desarrollo sostenible de la ciudad.

Genomic surveillance of Escherichia coli in municipal wastewater treatment plants as an indicator of clinically relevant pathogens and their resistance genes.

We examined whether genomic surveillance of Escherichia coli in wastewater could capture the dominant E. coli lineages associated with bloodstream infection and livestock in the East of England, together with the antibiotic-resistance genes circulating in the wider E. coli population. Treated and untreated wastewater was taken from 20 municipal treatment plants in the East of England, half in direct receipt of acute hospital waste. All samples were culture positive for E. coli, and all but one were positive for extended-spectrum β-lactamase (ESBL)-producing E. coli. The most stringent wastewater treatment (tertiary including UV light) did not eradicate ESBL-E. coli in 2/3 cases. We sequenced 388 E. coli (192 ESBL, 196 non-ESBL). Multilocus sequence type (ST) diversity was similar between plants in direct receipt of hospital waste versus the remainder (93 vs 95 STs, respectively). We compared the genomes of wastewater E. coli with isolates from bloodstream infection (n=437), and livestock farms and retail meat (n=431) in the East of England. A total of 19/20 wastewater plants contained one or more of the three most common STs associated with bloodstream infection (ST131, ST73, ST95), and 14/20 contained the most common livestock ST (ST10). In an analysis of 1254 genomes (2 cryptic E. coli were excluded), wastewater isolates were distributed across the phylogeny and intermixed with isolates from humans and livestock. Ten blaCTX-M elements were identified in E. coli isolated from wastewater, together with a further 47 genes encoding resistance to the major antibiotic drug groups. Genes encoding resistance to colistin and the carbapenems were not detected. Genomic surveillance of E. coli in wastewater could be used to monitor new and circulating lineages and resistance determinants of public-health importance.

Efficiency of Microalgae Scenedesmus in the Removal of Nitrogen from Municipal Wastewaters

Background: Due to the high content of nitrogen in the municipal wastewaters, this study evaluated the efficiency of Scenedesmus as an important microalgae in the removal of nitrate from wastewaters and its application as an appropriate culture medium. As algae have high resistance to temperature and pH changes, they can absorb low concentrations of nutrients and need simple low-cost technology. Through photosynthesis, microalgae effectively stabilize carbon dioxide at a low cost, and the oxygen produced by the photosynthesis process can reduce the biochemical oxygen demand (BOD) of wastewaters. Methods: In this research, the chemical oxygen demand (COD), BOD, pH, total nitrogen (TN), and microalgae density were measured in the samples within 14 days after sampling from the inlet and outlet of municipal wastewaters treatment plant. Results: The results showed that nitrogen removal rate from the wastewaters at the laboratory conditions was 93% in the inlet and 85% in the outlet, which are higher in efficiency than those provided by other treatment processes. Conclusion: The microalgae can be used for the removal of nitrate and the production of algae biomass in municipal wastewaters processes before entering the natural environment.

BASF unveils strategy to reduce carbon intensity

For successful implementation of sustainability in industry robust assessments of products and processes are necessary that quantify environmental aspects under consideration of costs. The sustainability needs of companies vary greatly according to region, sector and stakeholder. BASF has developed a toolbox for eco-efficiency assessments that addresses the broad range of in-house and external needs, allowing flexibility while ensuring that relevant and sufficient environmental impact is covered to support decision-making based on quantified sustainability assessments. The toolbox is based on standard practices for life cycle assessment to support strategic decisions, product development and marketing. Environmental impact assessment follows ISO 14040 and 14044. Impacts are aggregated to an overall environmental impact. Life cycle costs are similarly determined and may be combined with environmental impact to an overall Eco-Efficiency Portfolio and Eco-Efficiency Index. The relevance check ensures inclusion of main impact categories and coverage of sufficient environmental impacts. A peer-reviewed case study on the treatment of flowback from fracturing operations demonstrates the applicability of the Eco-Efficiency Analysis. Deposition of flowback in existing hydrocarbon-containing reservoirs was compared with treatment in preparation for disposal to a municipal waste water treatment plant. The Reservoir option is more eco-efficient both at low and high flowback volumes. Disadvantages of the waste water treatment option include the greenhouse gas emissions associated with the high energy needed for the removal of dissolved solids from the flowback. The relevance check shows that climate change is the dominant environmental impact, but photochemical ozone formation, acidification, freshwater eutrophication, human toxicity and resource depletion (mineral & fossil) are significant as well.

The Effect of Hydrolysis on Properties of Soot and Tar During the Pyrolysis of Sewage Sludge

In this study, we evaluate the effect of hydrolysis treatment on the properties of tar and soot produced during the pyrolysis of sewage sludge at different operating temperatures (500–800 °C). The pyrolysis experiments were performed in a two-stage tubular fixed-bed reactor at atmospheric pressure. Raw sludge and hydrolysis-treated sludge (at pressure of 0.4 MPa and temperature 200 °C) samples were collected from local municipal sewage sludge treatment plant. The tar and soot samples obtained from pyrolysis at different temperatures were characterized by gas chromatography–mass spectrometry and scanning electron microscopy with energy dispersive X-ray spectroscopy, respectively. The results showed that increase in the pyrolysis temperature decreases the tar and soot yield for both raw and hydrolysis-treated sludge. The minimum tar yield was achieved with hydrolysis-treated sludge at 800 °C. The soot from raw sludge pyrolysis was of greater yield at high temperature than hydrolysis-treated sludge pyrolysis. The tar from pyrolysis of hydrolysis-treated sludge had more aliphatic character as compared to raw sewage sludge. The formation of heavy polycyclic aromatic hydrocarbons during pyrolysis of hydrolysis-treated sludge was lower at high temperatures than that of raw sludge. The aromatic hydrocarbons yield of hydrolysis-treated sludge was higher as compared to raw sludge at 800 °C.

Analysis of Selected Endocrine Disrupters Fraction Including Bisphenols Extracted from Daily Products, Food Packaging and Treated Wastewater Using Optimized Solid-Phase Extraction and Temperature-Dependent Inclusion Chromatography.

The aim of this research is to demonstrate the concept and ability for the fast and preliminary screening of complex food and environmental samples for the presence of endocrine disrupters fractions, consisting of low-molecular mass micropollutants, particularly various bisphenols (A, B, C, E, F, S, Z, AF, AP, BP and FL). The developed analytical protocol for this research requires two main steps: (i) optimized solid phase extraction (SPE) for selective isolation, purification and pre-concentration of target fraction, and (ii) selective temperature-dependent inclusion chromatography for samples analysis via a HPLC-UV-VisDAD system using isocratic elution and internal standard quantification approach. The chromatographic experiment revealed that both β-CD and its hydroxypropyl derivative strongly interact with selected bisphenols. This is in contrast to the steroids and PAHs molecules investigated previously, where a strong interaction with β-cyclodextrin was observed. Integrated areas derived from acquired chromatographic profiles for each individual sample were used as the simple classification variable enabling samples comparison. We demonstrated that the proposed analytical protocol allows for fast estimation of EDC fractions in various daily use products, food and environmental samples. The materials of interest were selected due to the presence in surface water ecosystems of their residues, and finally, in raw wastewater including rice bags, plastic bags, cloths, sanitary towels, fish baits and various plastic foils from food products. Treated sewage water released directly to the environment from a municipal treatment plant (Jamno, Koszalin) was also investigated. It has been demonstrated that a whole range of low-molecular mass compounds, which may be detected using UV-Vis detector, can easily be emitted from various in daily use products. The presence of micropollutants in treated wastewater, water ecosystems and plastic waste utilization via technological wastewater treatment processes must be addressed, especially in terms of microplastic-based pollutants acting as endocrine disrupters. It is hoped that the proposed simple analytical protocol will be useful for fast sample classification or selection prior to advanced targeted analysis involving the more accurate quantification of specific analytes using e.g., mass spectrometry detectors.

Detection of vancomycin-resistant Enterococcus faecium hospital-adapted lineages in municipal wastewater treatment plants indicates widespread distribution and release into the environment.

Vancomycin-resistant Enterococcus faecium (VREfm) is a leading cause of healthcare-associated infection. Reservoirs of VREfm are largely assumed to be nosocomial although there is a paucity of data on alternative sources. Here, we describe an integrated epidemiological and genomic analysis of E. faecium associated with bloodstream infection and isolated from wastewater. Treated and untreated wastewater from 20 municipal treatment plants in the East of England, United Kingdom was obtained and cultured to isolate E. faecium, ampicillin-resistant E. faecium (AREfm), and VREfm. VREfm was isolated from all 20 treatment plants and was released into the environment by 17/20 plants, the exceptions using terminal ultraviolet light disinfection. Median log10 counts of AREfm and VREfm in untreated wastewater from 10 plants in direct receipt of hospital sewage were significantly higher than 10 plants that were not. We sequenced and compared the genomes of 423 isolates from wastewater with 187 isolates associated with bloodstream infection at five hospitals in the East of England. Among 481 E. faecium isolates belonging to the hospital-adapted clade, we observed genetic intermixing between wastewater and bloodstream infection, with highly related isolates shared between a major teaching hospital in the East of England and 9/20 plants. We detected 28 antibiotic resistance genes in the hospital-adapted clade, of which 23 were represented in bloodstream, hospital sewage, and municipal wastewater isolates. We conclude that our findings are consistent with widespread distribution of hospital-adapted VREfm beyond acute healthcare settings with extensive release of VREfm into the environment in the East of England.

Promoting circular economy in the surroundings of an organic fraction of municipal solid waste anaerobic digestion treatment plant: Biogas production impact and economic factors

The Anaerobic Digestion and Composting Plant of the Vallès Oriental Waste Treatment Centre processes source-selected organic fraction of municipal solid wastes generated in its surrounding area. To promote Circular Economy between Municipal Solid Waste and industrial waste management systems, the Treatment Centre is looking for complementary wastes to be valorised through co-digestion with its main substrate. The study includes waste characterization and a complete treatment cost analysis, that jointly with the biogas potential and the mass balance of the Plant allows to calculate the price of each waste to be treated in the Plant. Up to 13 industrial wastes have been characterised for its biogas potential and its treatment cost calculated. Treatment prices ranged between 83 and 51 € t−1.

Modeling risk attributes of wastewater treatment plant violations of total ammonia nitrogen discharge limits in the United States

A performance-based modeling framework is developed to estimate three attributes of the risk of Total Ammonia Nitrogen (TAN) permit limit violations: probability, magnitude and frequency of violations. Discharge Monthly Report data from a sample of 106 US municipal treatment plants for the period of 2004–2008 is used for the analysis. A Generalized Linear Model regression produces estimates for the probability and frequency of TAN discharge violations, using logistic and Poisson distributions, respectively. The expected magnitude of violations is modeled as a non-stationary Generalized Pareto Distribution (GPD), using Extreme Value Theory. Regression covariates are plant inflow, fractional use of design hydraulic capacity, seasonality and previous month’s performance. The logistic regression model of the probability of a TAN violation has a median Brier Skill Score of 0.25, while the Poisson regression model of violation frequency has a median of 65% correct prediction in validation. The GPD model has equivalent model and empirical quantiles. Model predictions of probability and frequency are combined to obtain two composite risk indices—the Estimated Violation Index (EVI), which is the product of the average probabilities of violation and frequency at each location, and the Estimated Severity Index (ESI) which is the product of the EVI and the predicted 2-year return value of discharge TAN concentrations above the regulatory limit. Spatial maps of ESI and EVI provide visual guides for regulatory agencies to identify risks and prioritize compliance and enforcement efforts.

Metabolic response of bacteria to elevated concentrations of glyphosate-based herbicide

Glyphosate-based herbicides (GBHs) are the most widespread commonly used broad-spectrum herbicides that contaminate soils and waters, are toxic to bacteria, plants and animals, and have been classified as ‘probably carcinogenic to humans’ by the International Agency for Research on Cancer in 2015. Particular soil bacteria and fungi can degrade GBHs, hence, search for new GBH-degrading strains or microbial consortia, effective under specific growth conditions and local environment, seems to be a promising solution for bio-remediation of glyphosate-contaminated environment. Consequently, there is a need for rapid and informative methods to evaluate the GBH-induced changes of the metabolic pathways in cells, that may serve as indicators of GBH-degrading potential.Three new GBH-degrading bacterial strains, Pseudomonas sp., Actinobacteria and Serratia sp. were isolated from sludge of municipal waste water treatment plant (Daugavgriva, Riga, Latvia), agricultural soil and plant tissue, respectively. This study examined the response of these isolates to elevated concentrations of glyphosate (GLP) (100 and 500 mg/L) in GBH Klinik® 360 SL. The GBH-induced shift of metabolic activity in cells of Pseudomonas sp. was shown by tests on EcoPlates™. Fourier transform infrared (FTIR) spectroscopy analyses were used to evaluate the metabolomic response of bacteria to elevated concentrations of GBH in the growth environment. The spectra of Pseudomonas sp. and Serratia sp., incubated with and without GBH, were similar, thus indicating their GBH-resistance. The absorption at 1736 cm−1, assigned to ester carbonyl stretch vibrations, was detected in spectra of all three bacteria. The highest ester content was detected in Actinobacteria grown in medium with 1.0% molasses and 100 or 500 mg/L GLP in GBH Klinik®. An increase of cellular amounts of esters, either those of phospholipids or poly-β-hydroxybutyrates, indicates degradation of GLP. Therefore, monitoring the ester carbonyl stretch vibration band in FTIR spectra of bacterial biomass may speed up the search GBH-degrading strains. Microbiological tests and cell metabolic response studies by FTIR spectroscopy showed that the three new isolates of Pseudomonas sp., Actinobacteria and Serratia sp. were resistant to elevated concentrations of GBH Klinik® in growth environment and exhibited the potential for GBH degradation.

BASF adopts new strategy to accelerate growth

For successful implementation of sustainability in industry robust assessments of products and processes are necessary that quantify environmental aspects under consideration of costs. The sustainability needs of companies vary greatly according to region, sector and stakeholder. BASF has developed a toolbox for eco-efficiency assessments that addresses the broad range of in-house and external needs, allowing flexibility while ensuring that relevant and sufficient environmental impact is covered to support decision-making based on quantified sustainability assessments. The toolbox is based on standard practices for life cycle assessment to support strategic decisions, product development and marketing. Environmental impact assessment follows ISO 14040 and 14044. Impacts are aggregated to an overall environmental impact. Life cycle costs are similarly determined and may be combined with environmental impact to an overall Eco-Efficiency Portfolio and Eco-Efficiency Index. The relevance check ensures inclusion of main impact categories and coverage of sufficient environmental impacts. A peer-reviewed case study on the treatment of flowback from fracturing operations demonstrates the applicability of the Eco-Efficiency Analysis. Deposition of flowback in existing hydrocarbon-containing reservoirs was compared with treatment in preparation for disposal to a municipal waste water treatment plant. The Reservoir option is more eco-efficient both at low and high flowback volumes. Disadvantages of the waste water treatment option include the greenhouse gas emissions associated with the high energy needed for the removal of dissolved solids from the flowback. The relevance check shows that climate change is the dominant environmental impact, but photochemical ozone formation, acidification, freshwater eutrophication, human toxicity and resource depletion (mineral & fossil) are significant as well.

Parasitological contamination with eggs Ascaris spp., Trichuris spp. and Toxocara spp. of dehydrated municipal sewage sludge in Poland

The objective of the present study was to evaluate the contamination of sewage sludge produced by municipal waste treatment plants in Poland by viable eggs of intestinal parasites of the genera Ascaris, Toxocara and Trichuris (ATT). Ninety-two municipal, mechanical-biological sewage treatment plants located within Poland were selected. These plants belonged to types of agglomerations: group 0 (large), group 1 (medium), group 2 (smaller) and group 3 (small). Samples were collected at the final stage of sewage treatment after the addition of flocculent to sludge, followed by dehydration. The samples were examined by a method adjusted to examine sewage sludge dehydrated using polyelectrolytes. The viability of the isolated eggs was evaluated based on incubation in a moist chamber. Live eggs of intestinal nematodes were found in 99% of samples. Most samples were contaminated by the eggs of Ascaris spp. (95%) and Toxocara spp. (96%). However, Trichuris spp. eggs were detected in 60% of samples. The mean number of eggs in 1 kg of dry mass (eggs/kg d.m.) was 5600 for Ascaris, 3700 for Toxocara and 1100 for Trichuris. The highest number of ATT eggs was detected in samples from sewage treatment plants located in south-eastern and central Poland. The highest number of ATT eggs was found in sewage sludge produced in large sewage treatment plants (agglomeration Groups 0 and 1), with mean values of 15,000 and 8900 eggs/kg d.m. The present study is the first parasitological investigation conducted on a large number of samples (92 samples) taken from various types of municipal sewage treatment plants located throughout Poland (16 regions) after the common introduction of polyelectrolytes during sewage sludge dehydration. The results of this study indicate that sludge produced in municipal sewage treatment plants is highly contaminated with parasite eggs.

Viability of the Use of Leachates from a Mechanical Biological Municipal Solid Waste Treatment Plant as Fertilizers

The main environmental issue associated with compost production is the production of a liquid leachate. Leachate from municipal wastes contains carbon, nitrogen, phosphorus, potassium and trace elements that can be used as nutrients by plants. The advantages of the use of organic wastes such as compost leachate as fertilizers are evident. Their use would reduce the consumption of commercial fertilizers, which need, with their production, high cost and energy. This work aims to determine the physical and chemical properties of a specific leachate with a variable composition, collected from the composting line of a mechanical and biological treatment facility. The goal is to assess if the leachates can be used as a potential source for fertilizers, and thus develop and design a sequence of processes which could effectively convert the leachates to commercial fertilizers according to the requirements of the proposal of regulation of the European Parliament of 2016 for fertilizers. Preliminary results show that the leachate samples qualitatively meet the requirements established for the composition of commercial fertilizers, especially organo-mineral fertilizers. Furthermore, there is no production cost of leachate as a raw material. The results show that the leachate is characterized by manageable concentrations of heavy metals which can be removed by adsorption processes, and it presents suitable amounts of organic carbon after a water removal procedure. However, the establishment of the conditions for suitable conversion processes are still under investigation considering the high composition variability due to factors like storage and environmental conditions.

Biotransformation of the Fluorinated Nonsteroidal Anti-Inflammatory Pharmaceutical Flurbiprofen in Activated Sludge Results in Accumulation of a Recalcitrant Fluorinated Aromatic Metabolite.

Flurbiprofen is a fluorinated, nonsteroidal, anti‐inflammatory pharmaceutical with potential application in a wide range of maladies. Currently, there is no information regarding its environmental fate. To address this, flurbiprofen is spiked at 500 and 50 ppm into activated sewage sludge taken from the municipal treatment plant of Ankara, Turkey. Flurbiprofen is partially degraded after 80 days, with removal proportion varying from 33% to 48%. Isolation of organisms able to use flurbiprofen as a sole carbon and energy source is unsuccessful. A transient, acid‐labile yellow coloration appears in supernatants after addition of flurbiprofen. During disappearance, a novel potential metabolite is detected by high‐performance liquid chromatography (HPLC) analyses, a chemical that does not appear in killed controls or in nonflurbiprofen‐amended controls. Mass spectra of the novel chemical obtained at low and high collision energies are consistent with 4‐(1‐carboxyethyl)‐2‐fluorobenzoic acid, suggesting the application of a canonical metabolic paradigm for halogenated biphenyl metabolism by bacteria in which the nonhalogenated ring is metabolized by dioxygenation and metacleavage, leaving the halogenated aromatic ring behind. This metabolite shows no signs of disappearance after the 80‐day monitoring period, implying that the environmental release of flurbiprofen might be of concern.

Sludge footprints of municipal treatment plant for the management of net useful energy generation beyond energy neutrality

The paper devised a unified basis for energy recovery processes in municipal treatment plants based on sludge footprints. Emphasis was placed upon innovative energy recovery technologies to test whether energy neutrality could be sustained or even, net useful energy could be produced. In this context, it evaluated first the energy potential of municipal wastewater treatment plant based on sludge footprints: it adopted a unified perspective where energy recovery was considered as an integral part of energy conservation in sludge. Sludge footprints of different activated sludge configurations were first analyzed based on latest concepts of process stoichiometry and modeling. The performance indicators of process modifications were analyzed and interpreted for energy conservation for a wide range of sludge age between of 0.5–50 d. An influent COD level of 500 mg/L was adopted, also defining all significant COD fractions compatible with related characterization studies. The role of primary sedimentation was accounted for where applicable. Calculations showed that 1259 kcal/m3 (75%) to 379 kcal/m3 (23%) of COD energy could be preserved in sludge as the sludge age was increased between the range of 0.5–50 d. Conventional activated sludge (CAS) conserved around 35–40% energy, corresponding to 600–650 kcal/m3. Primary sedimentation boosted the overall energy conservation to 901–990 kcal/m3, corresponding to 54–59% of the available energy in sewage COD. As expected, energy recovery by means of anaerobic digestion (biogas), remained far below the energy consumption in the treatment plant. This study envisaged syngas production by means of high temperature pyrolysis as a novel alternative instead of sludge digestion. Pyrolysis revealed a potential to yield a net useful energy (positive net energy) of 0.08–0.49 kWh/m3 for systems operated at sludge ages of 2–10 d without primary sedimentation; much higher net useful energies of 0.33–0.59 kWh/m3 could be obtained in systems with primary sedimentation operated at sludge ages 2–14 d. The study provided conclusive evidence that the real problem in establishing energy neutrality in treatment systems was the low energy recovery of the conventional sludge digestion and not the level of energy conservation in the activated sludge process; therefore, the step forward should look for more effective energy recovery processes such as high temperature pyrolysis (syngas generation) or similar novel technologies.