Pharmaceuticals In Wastewater Treatment Plants Research Articles

The fate of diclofenac in anaerobic fermentation of waste activated sludge

Diclofenac (DCF), a nonsteroidal anti-inflammatory drug, is one of the most commonly detected pharmaceuticals in wastewater treatment plants. However, the fate of DCF in waste activated sludge (WAS) anaerobic fermentation has not been well-understood so far. This work therefore aims to comprehensively reveal whether and how DCF is transformed in WAS mesophilic anaerobic fermentation through both experimental investigation and density functional theory (DFT) calculation. Experimental results showed that ∼28.8% and 45.8% of DCF were respectively degraded during the batch and long-term fermentation processes. Based on the detected intermediates and DFT-predicted active sites, three metabolic pathways, i.e., chlorination, hydroxylation, and dichlorination, responsible for DCF transformation were proposed. DFT calculation also showed that the Gibbs free energy (ΔG) of the three transformation pathways was respectively 19.0, −4.3, and −19.3 kcal/mol, suggesting that the latter two reactions (i.e., hydroxylation and dichlorination) were thermodynamically favorable. Illumina MiSeq sequencing analyses revealed that DCF improved the populations of complex organic degradation microbes such as Proteiniclasticum and Tissierellales, which was in accord with the chemical analyses above. This work updates the fundamental understanding of the degradation of DCF in WAS anaerobic fermentation process and enlightens engineers to apply theoretical calculation to the field of sludge treatment or other complex microbial ecosystems.

Characterization of oxaliplatin removal by multispecies bacterial populations in moving bed biofilm and suspended-biomass reactors.

This work aimed to characterize the oxaliplatin removal potential of multispecies microbial populations using the suspended-biomass (SB) and moving bed biofilm (MBB) reactors. Bacterial strains were isolated from pharmaceutical wastewater, their oxaliplatin degrading potential was screened and oxaliplatin removal efficacy in multispecies bacterial populations was investigated using HPLC. Five bacterial strains able to degrade oxaliplatin with an oxaliplatin removal efficacy of 21%-52% were isolated. The synthetic consortium including Xenorhabdus spp., Pantoea agglomerans and Bacillus licheniformis showed the highest potential with an oxaliplatin removal efficacy of 88.6% and 94.0% using the SB and MBB reactors, respectively. Also, the consortium reduced the chemical oxygen demand (COD) by 91.6 and 33% in MBB and SB reactors, respectively. A kinetic study showed a faster oxaliplatin removal in MBB (0.134 kg-1 ) than in the SB reactor (0.101 kg-1 ). Based on the GS/MS analysis, the overall biochemical pathway of oxaliplatin degradation was hypothesized to be initiated through the oxygenation of diamino-dicyclohexan-platinium complex and the cleavage of the aromatic ring. Microbial removal of oxaliplatin using MBB and SB reactors seems to be an efficient and promising approach for oxaliplatin removal in pharmaceutical and hospital wastewater treatment plants. Employing bacterial populations using the MBB reactor is a promising way to treat pharmaceutical wastewater to reduce the discharge of anticancer drugs into the environment.

Occurrence and toxicological assessment of selected active pharmaceutical ingredients in effluents of pharmaceutical manufacturing plants and wastewater treatment plants in Kampala, Uganda

Abstract There is an increasing eco-toxicological risk associated with pharmaceuticals globally. The prevalence of six active pharmaceutical ingredients (APIs) was studied in effluents of three pharmaceutical manufacturing plants (PMPs) and two wastewater treatment plants (WWTPs) in Kampala, Uganda to ascertain the removal potentials for APIs. The APIs include atenolol, losartan, carbamazepine, sulfamethoxazole, clarithromycin, and diclofenac. The APIs were extracted using solid-phase extraction cartridges and concentrations were analyzed using a liquid chromatography-mass spectrometer system. The concentration ranges of the APIs were <limit of detection (LOD), <LOD – 4.75, <LOD – 1.37, <LOD – 1.17, and 0.28–19.55 mgL−1 for losartan, diclofenac, sulfamethoxazole, carbamazepine, and clarithromycin respectively in effluents of WWTPs, whereas in treated wastewater from PMPs concentrations were 0.00, 0.00–0.23, 5.30–7.4, 0.00–0.14, and 0.12–4.53 mgL−1 for losartan, diclofenac, sulfamethoxazole, carbamazepine, and clarithromycin respectively. The API removal efficiency of PMPs was higher than WWTPs with some APIs removed to concentrations of <LOD. The range of hazard quotients (HQs) for APIs was 0.018–0.9775000 with most of the APIs posing remarkably high environmental risks at HQs way greater than 1. Only sulfamethoxazole from the effluents of Lubigi WWTP, Bugolobi WWTP, and PMP C posed low risks with HQs of <1 at 0.018, 0.305, and 0.018 respectively. The high HQs for most APIs imply that immediate recipients are at very high toxicological risks, yet most studies have focused on the final destinations of APIs in environments where toxicological risks are often minimal due to dilution effects.

Fate evaluation of pharmaceuticals in solid and liquid phases at biological process of full-scale municipal wastewater treatment plants

In the last few decades, pharmaceuticals have saved millions of lives. However, their overconsumption is causing several negative impacts on human and wildlife endocrine systems. To date, numerous studies have investigated the occurrence and fate of pharmaceutical in municipal wastewater treatment plants (WWTPs). However, efforts to understand the removal mechanism of pharmaceuticals in WWTPs by simultaneously investigating pharmaceuticals in liquid and solid phases are limited. In this study, a simultaneous assessment of pharmaceuticals in liquid and solid phases was performed using samples collected from biological processes of three municipal WWTPs that adopted different treatment configurations. Among the three WWTPs, noticeable mitigation of macrolide antibiotics was observed in WWTP_A, which adopted membrane bioreactor. 12 pharmaceuticals, which showed positive removal in all sampling campaigns, were selected to evaluate the removal mechanism. The removal of acetylsalicylic acid, ciprofloxacin, ibuprofen, and ofloxacin by sorption in each WWTP seems to be acceptable as per the calculated sorption coefficient (Kd) value and qualitative detection. However, it is inadequate to only evaluate using the Kd values of acetaminophen, caffeine, and cefradine of WWTP_B owing to their lower qualitative detection in the solid phase. Interestingly, the calculated biodegradation constant value of ciprofloxacin (0.41–5.07 L/gMLSS·d) (mitigation pathway of electrostatic interaction) in the anaerobic reactor of WWTP_A was similar to that of caffeine (0.84–5.20 L/gMLSS·d) indicating a high biodegradability in wastewater treatment. Therefore, the simultaneous analysis of both liquid and solid phases provides valuable information for the detailed evaluation of the fate of pharmaceuticals in biological processes of municipal WWTPs.

Occurrence, source apportionment and source-specific risk assessment of antibiotics in a typical tributary of the Yellow River basin

The spatial distributions, sources, and source-specific risk apportionments of 26 antibiotics (5 categories) in the Fenhe River basin were determined based on sample data. The results showed that antibiotics were widely distributed in the surface water. There were significant differences between the different types of antibiotics, and the highest mean concentration was that of the sulfonamide category (33.74 ng/L), accounting for 36% of the total antibiotic concentration. Spatially, all antibiotics were mainly detected in the middle and downstream areas. The ecological risk assessment results showed that the significant risk rate of antibiotics accounted for 70% and was mainly distributed in the downstream area; however, the risks differed between the 5 categories. Quinolone antibiotics exhibited the highest significant risk rate, reaching 100%. The ecological risk associated with sulfamethoxazole was the highest among all detected antibiotics. The following five main factors influenced the antibiotic concentrations: aquaculture, pharmaceutical wastewater, livestock discharges, domestic sewage, and sewage treatment plants. Among these, pharmaceutical wastewater sources contributed the most (35%) to the total antibiotic concentration, and were distributed throughout the river. Although livestock discharges were not the main reason for the high level of ecological risk, these discharges were highest at certain sites in the midstream region. Different pollution sources posed different levels of ecological risk to the Fenhe River basin, the highest of which was pharmaceutical wastewater with a significant risk rate of 58%.

Pharmaceuticals in Wastewater Treatment Plants: A Systematic Review on the Substances of Greatest Concern Responsible for the Development of Antimicrobial Resistance

In recent years, there is a growing concern about the alarming spread of antimicrobial resistance (AMR) in different environments. Increasingly, many species of bacteria, fungi and viruses are becoming immune to the most commonly used pharmaceuticals. One of the causes of the development of the resistance is the persistence of these drugs, excreted by humans, in municipal and hospital wastewater (WW). Consequently, wastewater treatment plants (WWTPs) are a primary source of antimicrobial resistance genes as novel pollutants. This systematic review sought to examine the relevant literature on pharmaceutical residues (PRs) responsible for AMR in municipal and hospital WW in order to propose a classification of the PRs of greatest concern and provide an updated source for AMR management in WWTPs. Among 546 studies collected from four databases, 18 were included in the present review. The internal and external validity of each study was assessed, and the risk of bias was evaluated on a 20-parameter basis. Results were combined in a narrative synthesis discussing influent and effluent PR concentrations at 88 WWTPs, seasonal variations, differences between hospital and municipal WW, environmental risk assessment values of antimicrobial substances and treatment facilities removal efficiencies. Among the 45 PRs responsible for AMR evaluated in this study, the antibiotics ciprofloxacin, clarithromycin, erythromycin, metronidazole, ofloxacin, sulfamethoxazole and trimethoprim constitute a considerable risk in terms of ubiquitous distribution, worrying concentrations, risk quotient values and resistance to removal treatments. Gaps in knowledge, data and information reported in this review will provide a valuable source for managing AMR in WWTPs.

Evaluation of residual antimicrobial activity and acute toxicity during the degradation of gatifloxacin by ozonation

The concerns regarding the occurrence of pharmaceuticals in wastewater treatment plants have increased in the last decades. Gatifloxacin (GAT), the fourth generation of fluoroquinolones, has been widely used to treat both Gram-positive and Gram-negative bacteria and has a limited metabolization. The present study aimed to evaluate ozonation as a technique to degrade GAT. An exchange A UHPLC-MS/MS by an UHPLC-MS/MS method was used to quantify the residual of GAT and to assess its degradation products. The removal efficiency was higher under alkaline conditions (pH = 10), reaching up to 99% of GAT after 4 min. It was also observed that the first ozone attack on the GAT molecule was through the carboxylic group. In contrast, under acid conditions (pH = 3), the ozone attack was first to the piperazinyl ring. The antimicrobial activity was evaluated using Escherichia coli and Bacillus subtilis as test organisms, and it was observed that the residual activity reduced most under alkaline conditions. In contrast, the best condition to remove the residual toxicity evaluated for the marine bacteria V. fischeri was the acidic one. Due to this, ozonation seemed to be an exciting process to remove GAT in aqueous media.

A pilot experiment to assess the efficiency of pharmaceutical plant wastewater treatment and the decreasing effluent toxicity to periphytic biofilms

Pharmaceutical industry effluents are complex and highly variable in time. Assessing the efficiency of a pharmaceutical industry wastewater treatment plant (WWTP) and the resulting decrease in effluent toxicity and ecological risk is thus not straightforward. We set up an original in situ pilot directly connected to a pharmaceutical WWTP to monitor the chronic toxicity of successive effluents using natural periphytic biofilms. Their structural and functional responses to effluent exposure were assessed by combining (i) a molecular approach to characterize the bacterial and diatom diversity and (ii) functional measurements of photosynthetic and enzyme activities. Effluent contamination by pharmaceuticals strongly decreased after the quaternary treatment (activated carbon). Most of the structural biological characteristics improved with cumulative WWTP treatment (bacterial diversity, microbial genetic structure, and biological diatom index), showing community recovery along the treatment process. However, functional parameters did not show clear links with treatment steps, suggesting that microbial activities were not solely driven by pharmaceuticals produced during the experimental period. Operationally, this type of pilot system offers a useful tool for biomonitoring approaches and offers new approaches for industrial managers to assess the ecological risk of production effluents in receiving water.

Removal of pharmaceuticals by ammonia oxidizers during nitrification.

The adverse effect of pharmaceuticals on ecosystem and human health raises great interest for the removal of pharmaceuticals in wastewater treatment plants (WWTPs). Enhanced removal of pharmaceuticals by ammonia oxidizers (AOs) has been observed during nitrification. This review provides a comprehensive summary on the removal of pharmaceuticals by AOs-ammonia oxidizing bacteria (AOB), ammonia oxidizing archaea (AOA), and complete ammonia oxidizer (comammox) during nitrification in pure ammonia oxidizing culture and mixed microbes systems. The superior removal of pharmaceuticals by AOs in conditions with nitrifying activity compared with the conditions without nitrifying activity was proposed. The contribution of AOs on pharmaceuticals removal in pure and mixed microbe systems was discussed and activated sludge modeling was suggested as the proper measure on assessing the contribution of AOs on the removal of pharmaceuticals in mixed microbe culture. Three transformation processes and the involved reaction types of pharmaceuticals transformation during nitrification were reviewed. The present paper provides a systematical summary on pharmaceuticals removal by different AOs across pure and mixed microbes culture during nitrification, which opens up the opportunity to optimize the wastewater biological treatment systems for enhanced removal of pharmaceuticals. KEY POINTS: • The superior removal of pharmaceuticals by ammonia oxidizers (AOs) was summarized. • The removal contribution of pharmaceuticals attributed by AOs was elucidated. • The transformation processes and reaction types of pharmaceuticals were discussed.

Occurrence and Fate of Psychiatric Pharmaceuticals in Wastewater Treatment Plants in Hong Kong: Enantiomeric Profiling and Preliminary Risk Assessment

Psychiatric pharmaceuticals are receiving widespread attention as emerging contaminants. Wastewater treatment plants (WWTPs) represent primary point sources for pharmaceuticals in the aquatic envir...

Biodegradation of omethoate by Bacillus sp. YB-10: optimization of culture conditions and degradation characteristics

Omethoate is an acute organophosphorus pesticide which is widely used. It presents a high pollution potential and health risk nowadays. In this study, Bacillus sp. YB-10, which was isolated from the activated sludge of a pharmaceutical wastewater treatment plant, was used for degrading omethoate. The culture conditions and degradation characteristics were investigated. Results showed that the Bacillus sp. YB-10 could degrade omethoate through co-metabolism. The optimal carbon and nitrogen sources were glucose and NH4NO3, respectively. Response surface methodology (RSM) results showed that the most appropriate nutrition ratio of C:N:P was 3:1:1 when degrading 1,000 mg/L of omethoate. Omethoate degradation kinetics could be described by a first-order rate equation. The optimal degradation conditions were pH of 7.0, temperature of 30℃, initial bacteria concentration of 0.25%, rotation speed of 150 r/min. Under the optimal conditions, the degradation rate reached 77.24% within 5 d by the Bacillus sp. YB-10 when the initial omethoate concentration was 1,000 mg/L.

Wastewater discharge drives ARGs spread in the coastal area: A case study in Hangzhou Bay, China

The distribution of 14 ARGs, intI1, and 16S rDNA were analysed in 4 wastewater treatment plants (WWTPs), 2 effluent receiving areas (ERAs), and Hangzhou Bay (HZB). The results showed that each integrated WWTP (IWWTP) received higher abundance of ARGs than pharmaceutical WWTPs (PWWTPs), and IWWTPs removed ARGs more efficiently than PWWTPs. The WWTP effluents greatly contributed to the ARGs pollution in the water environments of the ERAs and HZB, and the total abundance of the ARGs displayed a distance decay pattern. In coastal sediments, more ARGs were accumulated in remote sites. The correlation analysis showed that the occurrence of ARGs was more related to 16S rDNA and intI1 in the WWTPs. Three macrolides resistance genes (ermB, mphA, and vatB) had strong correlations with 16S rDNA and intI1 in all the sample groups. Our study clearly reveals the link between land WWTPs discharge and emerging pollution of ARGs in coastal environments.

Metagenomic Analysis of Antibiotic Resistant Bacteria and Resistance Genes in a Pharmaceutical and Chemical Wastewater Treatment Plant

Wastewater treatment plants hold a vast pool of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). The aim of this study is to analyze the ARB and ARGs in a pharmaceutical and chemical wastewater treatment plant using a metagenomic technique. The results of taxonomic annotation revealed that bacteria were the predominant domain. The most abundant phyla and genus was Proteobacteria and Hyphomicrobium, respectively. A total of 74 categories of ARGs were predicted using CARD with the most dominant types being sav 1866, dfrE, and mfd. Furthermore, a network analysis was conducted to investigate the co-occurrence patterns between ARGs and microbial taxa. ARGs were found to be highly connected to microbial taxa at the genus level. With respect to the antibiotic resistance mechanisms, antibiotic-specific efflux pumps appeared to be the most common mechanisms. Among these, resistance-nodulation-cell division (RND) was the major type. The most important functional pathway of this microbial community was metabolic correlation. Interestingly, there were many genes related to human diseases, among which bacterial infectious diseases were the main ones. On the one hand, these data further confirmed that pharmaceutical and chemical wastewater treatment plants are rich in ARB and ARGs. The accumulation of ARGs increases the potential environmental risks, and hence it is necessary to strengthen the active monitoring of ARB and ARGs in pharmaceutical and chemical wastewater treatment plants. On the other hand, research on ARB and ARGs offers important information for the selection of deep processing technology to effectively remove ARB and ARGs.

PHARMACEUTICALS IN WATER CYCLE: A REVIEW ON RISK ASSESSMENT AND WASTEWATER AND SLUDGE TREATMENT

Pharmaceuticals in the environment are considered as emerging contaminants which are particularly persistent and which could represent a threat both for animals and humans following long-term exposure. Pharmaceuticals include, among others, antibiotics, anti-inflammatory drugs, steroid hormones, antidepressants, -blockers and lipid regulators. Excretion from humans is considered the main source of release of such compounds in the environment. The excreted compounds reach wastewater treatment plants (WWTPs), which demonstrated to be generally ineffective in removing emerging contaminants in the absence of advanced treatments. Due to the importance of the topic, which still represents an issue of great concern, this review analyses the scientific literature with the aim of investigating the role of different sources of release, the fate of pharmaceuticals in WWTPs, their typical levels in the aquatic environment, the estimated risk levels for the aquatic fauna and the potential effects on humans. In the last part of this study, different options to effectively reduce the concentrations of pharmaceuticals in effluents from WWTPs are reviewed and discussed, in order to provide environmental agencies and local administrators with an overview of the advanced treatments that are currently available to mitigate the impact of pharmaceuticals in downstream water bodies.

Whole Genome Sequencing of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli Isolated From a Wastewater Treatment Plant in China.

Background and ObjectivesWastewater treatment plants (WWTPs) are one of the major reservoirs for antimicrobial resistant bacteria (ARB) and antimicrobial resistance genes (ARGs) in the environment. Thus, the investigation on ARB and ARGs from WWTPs has attracted increasing attention in recent years. In order to uncover the resistome in a WWTP treating effluents from a pharmaceutical industry in China, the extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains were isolated and their whole genome sequences were obtained and analyzed. Moreover, metagenomic sequencing was applied to give a comprehensive view of antibiotic resistance in this WWTP.Methods18 ESBL-producing E. coli strains were isolated from a WWTP located in Taizhou, China on April, 2017. All strains were sequenced using Illumina HiSeq 2000 sequencer. The whole genome sequences were assembled using SPAdes software and annotated with RAST server. Sequence types (STs), plasmids, ARGs and virulence genes were predicted from the genomes using MLST, Plasmid Finder, ResFinder and Virulence Finder, respectively. Metagenomic DNA of the same sample was extracted and sequenced using Illumina Hiseq X Ten platform. Metagenomic sequences were assembled using SOAPdenovo software.ResultsAll 18 ESBL-producing E. coli strains were resistant to ampicillin, cefazolin, and ceftriaxone. Analysis of their genomes revealed that all strains carried beta-lactamase encoding genes and the most prevalent type was blaCTX–M. Various virulence genes and ARGs confronting resistance to other types of antimicrobial agents were also predicted. Further investigation on the metagenomics data indicated 11 ARGs with high amino acid identities to the known ARGs. Five of these ARGs, aadA1, aac(6′)-lb-cr, flo(R), sul2 and sul1, were also present in the genomes of the ESBL-producing E. coli isolated from the same sample.ConclusionOur study revealed the resistome of a pharmaceutical WWTP by both culture-dependent and metegenomic methods. The existence of ESBL-producing E. coli strains, indicating that pharmaceutical WWTP can play a significant role in the emergence of ARB. The occurrence of ARGs annotated from the metagenomic data suggests that pharmaceutical WWTP can play a significant role in the emergence of ARGs. Our findings highlight the need for strengthening the active surveillance of ARB and ARGs from pharmaceutical industry.

Simultaneous removal of antibiotics and antibiotic resistance genes from pharmaceutical wastewater using the combinations of up-flow anaerobic sludge bed, anoxic-oxic tank, and advanced oxidation technologies

Pharmaceutical wastewater often contains high levels of antibiotic residues and serves as an important reservoir for antibiotic resistance genes (ARGs). However, the current pharmaceutical wastewater treatment plants (PWWTPs) were not sufficiently effective in removing antibiotics and ARGs. Here, we designed a lab-scale simulation reactor, including up-flow anaerobic sludge bed (UASB), anoxic-oxic tank (A/O), and four separate advanced oxidation processes (AOPs) i.e., UV, Ozonation, Fenton, and Fenton/UV, to simultaneously remove 18 antibiotics and 10 ARGs from a real pharmaceutical wastewater. The results showed that all antibiotics were fully eliminated through the reactor during 180 d-operation. Among all treatment units, UASB provided the greatest contribution (85.8 ± 16.1%) for the removal of 18 antibiotics. The mass balance results manifested that degradation was a predominant mechanism for the removal of tetracyclines, sulfamethoxazole, and ampicillin (62.5–80.9%), while sorption to sludge (73.9%) was predominant for enrofloxacin removal in UASB. Meanwhile, the substantial decrease of ARG absolute abundance (log reduction by 0.1–3.1 fold) through the whole reactor was observed although the existence of the partial enrichment (1.2–3.8 log units) from the influent to the A/O unit. Fenton/UV combination was the most effective AOP for the removal of ARGs. Finally, the optimum operating conditions for the removal of ARGs using Fenton was also proposed considering the relatively lower cost and high ARG elimination. Overall, this study provides feasible suggestions for the design of real PWWTPs for simultaneous removal of antibiotics and ARGs.

Occurrence of selected pharmaceuticals in wastewater treatment plants of Tuscany: An effect-based approach to evaluate the potential environmental impact.

Municipal wastewaters may pose a risk to the aquatic environment and ultimately to human kind. Their treatment is a fundament step but the actual WWTPs performances cannot be taken for granted, claiming instead for continuous evaluation campaigns. Our waters are indeed threatened by the continuous input of various persistent micropollutants that are part of human daily routine life; the potential effects of their presence in the receiving waters have to be quantified. The present paper reports data of a monitoring campaign focused on nine pharmaceuticals belonging to different therapeutic groups in three WWTPs in Tuscany (Italy). All the three WWTPs use conventional activated sludge process with pre-denitrification and no tertiary treatment. The analytical determination has been achieved through off-line solid phase extraction and analysis in liquid chromatography coupled with mass spectrometry. The overall ecotoxicological effect of effluents was evaluated through a battery of tests using organisms belonging to different trophic levels. All nine pharmaceuticals were detected in the influent of all WWTPs at least in one sampling campaign. The most concentrated compounds were acetaminophen, diclofenac and amoxicillin followed by atenolol, ketoprofen, clarithromycin, carbamazepine, doxycycline and E2; their average concentrations (considering all measurements from all plants) were, respectively: 3914 ± 2620; 2065 ± 739; 2002 ± 2170; 1223 ± 1042; 961 ± 1003; 356 ± 370; 233 ± 100; 196 ± 189; 4 ± 4 ng/L. The highest concentrations were found in the plant that treats urban and hospital wastewaters. Amoxicillin, atenolol and diclofenac were more concentrated in winter than in summer, while ketoprofen, doxycycline and 17-β-estradiol are higher in summer. These results are probably due to the different consumption of each drug during the year, depending on their therapeutic usage. Measured drugs can be divided into three categories: those ones that are generally well removed inside the WWTP (such as acetaminophen, ketoprofen and atenolol), the partly removed ones (doxycycline, clarithromycin and 17-β-estradiol) and the refractory ones to biodegradation during activated sludge process (carbamazepine, diclofenac and amoxicillin). Regarding ecotoxicological assays, the most sensitive organisms were V. fisheri and R. subcapitata, whereas D. magna almost never reacted to the wastewaters. Seasonal variability was not clearly observed among plants and collecting time. The toxicity score evaluated all the results coming from the bioassays battery, indicating that WWTPs treatments always determined a toxicity reduction, even though a residual toxicity was still measured. This observation, together with chemical data, clearly indicate WWTPs as an important source of pharmaceuticals in the Arno river with an important environmental toxicity; therefore, the reduction of pharmaceutical load originated from point source such us WWTPs would ask in the future the adoption of refinery steps in WWTPs able to increase RE of drugs.

Fate and Occurrence of Pharmaceutically Active Organic Compounds during Typical Pharmaceutical Wastewater Treatment

The chemical composition, distribution, and fate of pharmaceutically active compounds (PhACs) present in typical pharmaceutical wastewater treatment plants were investigated with the aim of effectively removing these pollutants while minimizing waste of resources and energy. The results of this study indicate that the relative content of an organic compound class is unrelated to the number of organic compounds in the influent and effluent, yet it is directly proportional to the pollution contribution in pharmaceutical wastewater. In wastewater influent, the organic compound classes with the highest relative contents and pollution contributions were acids (relative content = 63.65%, contribution to pollution = 67.22%), esters (44.96%, 41.24%), and heterocyclic compounds (30.24%, 35.23%); in wastewater effluent, these classes were organic acids (62.54%, 65.13%), esters (52.66%, 59.02%), and organosilicon compounds (42.46%, 37.45%). The different physicochemical characteristics of these pollutants result in different removal efficiencies. For example, N,N-dimethylformamide, 4-methyloctane, N-ethylmorpholine, and 4-amino-N,N- and N,N-diethylbenzamide are refractory and are not degraded by microorganisms; thus, these compounds are discharged into the aquatic environment. Other organic compound classes including organosilicon compounds, acids, esters, heterocycles, and alcohols are mostly biodegraded, which leads to high concentrations of hydrocarbons in the wastewater effluent. The results of this study provide a foundation for the improvement of pharmaceutical wastewater treatment.

Application of Bioaugmentation to Improve Pharmaceutical Wastewater Treatment Efficiency

Ecological harm and human health risks caused by environmental pollution with active pharmaceutical ingredients (API) nowadays is recognised as issue of growing concern. Widespread presence of human and veterinary API in aquatic environment clearly indicates persistence and low removal efficiency of these compounds at conventional pharmaceutical and municipal wastewater treatment plants (WWTP). Bioaugmentation of activated sludge systems with specialized microorganisms could be a powerful and environmentally friendly tool to enhance the removal efficiency of recalcitrant API. Selection of inoculum strains, that have appropriate enzymatic pathways to metabolise complex molecules of API, belonging to different therapeutic classes, is of great importance. This study evaluated the potential of pure cultures of 10 bacteria, 10 yeasts and 3 filamentous fungi previously isolated from activated sludge of pharmaceutical WWTP to degrade less investigated API – Oxytocin, Zopiclone and Meldonium dihydrate as sole carbon source and in cometabolic manner with presence of skim milk powder as additional nutrient source. Bacteria Sphingobacterium thalpophilum and filamentous fungi Fusarium solani and Fusarium udum showed very high treatment efficiency of all tested API in laboratory-scale bioaugmentation tests and were recognized as culture with high metabolic potential to be used in bioaugmentation for removal of pharmaceutical micropollutants.

Isolation and Characterization of a Bacterial Strain Capable of Efficient Berberine Degradation.

Background: Berberine (BBR) is a pharmaceutical chemical with a broad antibacterial spectrum, and its biological treatment has been of research and practical interest. In this study, a pure bacterial strain B16 was isolated from the activated sludge in a pharmaceutical wastewater treatment plant. The aim of the study is to characterize the properties of the strain B16, especially its BBR degradation capability. Methods: The identification of strain B16 was conducted by visual observation, as well as biochemical and phylogenetic analysis. The degradation kinetics of strain B16 was tentatively described by Haldane model. Results: The strain B16 was 100% determined as a Sphingopyxis sp. The kinetic parameters of BBR degradation by strain B16 were as follows: Vmax 54.73 ± 5.54 mg (g MLSS · h)−1, Km 66.68 ± 8.95 mg L−1, and Ki 43.16 ± 5.92 mg L−1, with an R2 of 0.996. Stain B16 exhibited considerable capability of BBR degradation. BBR of initial concentration 40 mg L−1 could be completely degraded in 48 h under optimal conditions. Conclusions: strain B16 was the first pure culture found with the ability to totally mineralize BBR, indicating the potential of B16 application in real industrial processes.