Pharmaceuticals In Wastewater Treatment Plants Research Articles

Factors affecting the performance of a pharmaceutical wastewater treatment plant: Characterization of effluent and environmental risk

Pharmaceutical industries produce a huge volume of emerging pollutants (EPs) that pose a threat to the aqueous environment. Biological processes have shown their inefficacy in treating many pharmaceutical products. The study assessed physicochemical parameters, EPs, heavy metals in pharmaceutical industrial wastewater, and the removal efficiency (RE) of an aerobic biological treatment plant. The study also assessed the contamination levels and risk using several indices, such as the Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI), heavy metal pollution index (HPI), heavy metal evaluation index (HEI), and risk quotients index (RQs). The study found that the treated water quality was poor, having antibiotics, nonsteroidal anti-inflammatory drugs, and others, along with several transformation products (TPs) and heavy metals, which were unsafe for consumption with high environmental risk. The analysis results showed that the RE for TSS, BOD5, COD, TDS, and EC were found to be 91.80%, 86.81%, 72.29%, 72.20%, and 65.60%, respectively, where the values of BOD5, COD, NO3−, and PO43− in the effluent were still higher than the permissible limits of the ECR (2023). However, the RE for heavy metals was in the order of Cu (84.62%) > Fe (65.04%) > Mn (63.3%) > Zn (60.58%) > Cd (53.85%) > Ni (54.12%) > Pb (42.42%) > Cr (38%), where Cr and Cd concentrations were still higher than the permissible limit of DoE (2019). The Pearson correlation and PCA suggested that EC, TDS, TSS, DO, BOD5, and COD were the most correlating and contributing variables. This study argued that metal-ligand behaviors mainly affect the removal efficiency of the treatment plant by lowering the removal rate of heavy metals and pharmaceutical products.

Phytotoxicity and genotoxicity assessment of organic and inorganic contaminants detected in pharmaceutical industrial wastewaters using Vigna radiata and Allium cepa

The discharged effluent of pharmaceutical industrial wastewater treatment plants (PIWWTPs) exhibits substantial environmental toxicity due to the intricate combination of organic and inorganic pollutants. This study assessed the phytotoxicity, genotoxicity, and cytotoxicity of untreated and treated pharmaceutical industrial wastewater (PIWW). Most of the physicochemical parameters viz. COD, BOD, EC, sulfide, sulfate, nitrate, phosphate, grease, phenols, and metal concentrations viz. B, Cr, Ca, Cd, Cu, Zn, Pb, Hg, and As in untreated wastewater (UTW) were noted beyond the permissible limit and remained higher in treated wastewater (TW). The findings revealed that the performance of PIWWTP was woefully inadequate. The GC-MS spectra of UTW and TW revealed the presence of various organic contaminants. The toxicological studies showed that the UTW had a high degree of phytotoxicity, which persisted even after the treatment as it inhibited the seed germination in Vigna radiata. The seed germination was inhibited up to 70% and 50% tested at 50% concentration of UTW and TW respectively. Genotoxicity was measured by determining mitotic index and chromosomal aberrations in Allium cepa root apex grown in untreated and treated PIWW. Compared to the negative control, the mitotic index dropped to 85% and 75% at the 50% concentrations of UTW and TW, respectively. Chromosomal aberrations were also found in the cellular mass of root apex growing in both UTW and TW. According to the findings, it is unsafe for the environment to release PIWW that has not been properly treated, as this could pose serious risks to environmental health.

Reduction characteristic of chlorobenzene by a newly isolated Paenarthrobacter ureafaciens LY from a pharmaceutical wastewater treatment plant.

A highly efficient chlorobenzene-degrading strain was isolated from the sludge of a sewage treatment plant associated with a pharmaceutical company. The strain exhibited a similarity of over 99.9% with multiple strains of Paenarthrobacter ureafaciens. Therefore, the strain was suggested to be P. ureafaciens LY. This novel strain exhibited a broad spectrum of pollutant degradation capabilities, effectively degrading chlorobenzene and other organic pollutants, such as 1, 2, 4-trichlorobenzene, phenol, and xylene. Moreover, P. ureafaciens LY co-metabolized mixtures of chlorobenzene with 1, 2, 4-trichlorobenzene or phenol. Evaluation of its degradation efficiency showed that it achieved an impressive degradation rate of 94.78% for chlorobenzene within 8 h. The Haldane-Andrews model was used to describe the growth of P. ureafaciens LY under specific pollutants and its concentrations, revealing a maximum specific growth rate (μmax ) of 0.33 h-1 . The isolation and characterization of P. ureafaciens LY, along with its ability to degrade chlorobenzene, provides valuable insights for the development of efficient and eco-friendly approaches to mitigate chlorobenzene contamination. Additionally, investigation of the degradation performance of the strain in the presence of other pollutants offers important information for understanding the complexities of co-metabolism in mixed-pollutant environments.

Deciphering the core bacterial community structure and function and their response to environmental factors in activated sludge from pharmaceutical wastewater treatment plants

Pharmaceutical wastewater is recognized for its heightened concentrations of organic pollutants, and biological treatment stands out as an effective technology to remove these organic pollution. Therefore, a comprehensive exploration of core bacterial community compositions, functions, and their responses to environmental factors in pharmaceutical wastewater treatment plants (PWWTPs) is important for understanding the removal mechanism of these organic pollutants. This study comprehensively investigated 36 activated sludge (AS) samples from 15 PWWTPs in China. The results revealed that Proteobacteria (45.41%) was the dominant phylum in AS samples, followed by Bacteroidetes (19.54%) and Chloroflexi (4.13%). While the dominant genera were similar in both aerobic and anaerobic treatment processes, their relative abundances exhibited significant variations. Genera like HA73, Kosmotoga, and Desulfovibrio were more abundant during anaerobic treatment, while Rhodoplanes, Bdellovibrio, and Hyphomicrobium dominated during aerobic treatment. 13 and 10 core operational taxonomic units (OTUs) were identified in aerobic and anaerobic sludge, respectively. Further analysis revealed that core OTUs belonging to genera Kosmotoga, Desulfovibrio, Thauera, Hyphomicrobium, and Chelativorans, were associated with key functions, including sulfur metabolism, methane metabolism, amino acid metabolism, carbohydrate metabolism, toluene degradation, and nitrogen metabolism. Furthermore, this study highlighted the crucial roles of environmental factors, such as COD, NH4+-N, SO42−, and TP, in shaping both the structure and core functions of bacterial communities within AS of PWWTPs. Notably, these factors indirectly affect functional attributes by modulating the bacterial community composition and structure in pharmaceutical wastewater. These findings provide valuable insights for optimizing the efficiency of biochemical treatment processes in PWWTPs.

[Contamination Characteristics，Detection Methods，and Control Methods of Antibiotic Resistance in Pharmaceutical Wastewater].

Pharmaceutical industry wastewater contains a large number of emerging pollutants such as antibiotics， antibiotic resistant bacteria （ARBs）， and antibiotic resistance genes （ARGs）. The present biological water treatment processes cannot effectively remove these pollutants. Eventually， they are discharged into various water bodies or penetrate into soil with the effluent， causing environmental pollution and affecting human health. Therefore， exploring the pollution characteristics of antibiotics， ARBs， and ARGs in pharmaceutical wastewater and knowing the methods to detect and control antibiotic resistance pollution in wastewater are crucial for reducing the contamination of antibiotics and ARGs and assessing the ecological risks of antibiotic resistance. Aiming at the problem of antibiotic resistance pollution in a pharmaceutical wastewater treatment plant （PWWTPs）， the pollution status of antibiotics， ARBs， and ARGs in pharmaceutical wastewater was discussed. Different assessment methods of antibiotic resistance in pharmaceutical wastewater were summarized. Finally， the wastewater treatment technologies commonly used to remove antibiotics and ARGs in PWWTPs were summarized in order to provide a theoretical basis for the ecological risk assessment and scientific control of antibiotics and ARGs in the environment.

Prediction of the removal of solid suspensions and chemical oxygen demand from a pharmaceutical wastewater plant using a neural network approach

This study aimed to model the removal efficiency of chemical oxygen demand (COD) and solid suspension (SS) from a real pharmaceutical wastewater treatment plant (WWTP) using artificial neural network-multilayer perception (ANN-MLP). The ANN model was developed using experimental data which were collected during four years. The input variables of the neural network are water pH, temperature, SS, and COD. The percentages of removal of COD (CODRE) and of SS (SSRE) are considered as output variables. The Levenberg–Marquardt algorithm was utilized to train ANN. It was found that the ANN architecture has two hidden layers with 8 neurons. The results of ANN models were compared with the measured data based on the correlation coefficient (R2) and mean square error (MSE). It was noticed that the best ANN model provides good accurate results with R2 values of 0.9783 for SSRE and 0.9826 for CODRE, and a value of MSE equal to 1.695 10−3. This study may aid the users to adjust operational parameters in recovering COD and SS in the case of the process treatment of industrial effluents.

Fate and Proliferation of Vancomycin Resistance Genes in Two Typical Pharmaceutical Wastewater Treatment Plants

The emergence of vancomycin-resistant Enterococcus (VRE) and vancomycin resistance genes (VRGs) complicates the application of vancomycin, which is a last-line agent for human infectious diseases, and pharmaceutical wastewater treatment plants (PWWTPs) are widely thought to be important sources of corresponding antibiotic resistance genes (ARGs). In this study, two VRGs (vanA and vanB) were evaluated in two PWWTPs using quantitative polymerase chain reaction (qPCR) analysis to characterize the occurrence and fate of VRGs. The VRG concentration tended to decrease throughout all processing stages, while anaerobic treatment promoted the propagation of antibiotic-resistant bacteria and led to an increase in VRG abundance. Finally, the absolute concentrations of vanA and vanB exceeded 104 copies/mL in the effluents, and a significant amount of VRGs was transferred to sludge at 1.68 × 1017 copies/d. Redundancy analysis demonstrated that the relative abundance of ARGs was significantly correlated with the concentrations of vancomycin and COD. Furthermore, the relative abundance of vanA was increased in wastewater with multiple antibiotics, while the relative abundance of vanB only increased in the presence of vancomycin. This observation implied different intrinsic resistance mechanisms for different VRG subtypes. Overall, in this report, we describe the first comprehensive study on the fate and behavior of VRGs with different physicochemical or biochemical treatments and different antibiotic selection pressures in PWWTPs; this report provides important references for the environmental spread of VRGs.

Occurrence and removal prediction of pharmaceuticals positively correlated with antibiotic resistance genes in wastewater treatment processes

Wastewater treatment plants (WWTPs) are important source of pharmaceuticals in the environment, identifying their relationship with antibiotic resistance genes (ARGs) and removal behavior is important for risk control. In this study, the correlations of common pharmaceuticals (including antibiotics and non-antibiotics) and ARGs both in wastewater and sludge were investigated, and machine learning was applied to predict the removal efficiencies of typical pharmaceuticals positively correlated with ARGs. Among the 23 kinds of target pharmaceuticals, both antibiotics and non-antibiotics were found to be positive with typical ARGs in wastewater (e.g. correlation coefficients between caffeine and blaTEM, aadD and qnrS were 0.738, 0.609, 0.936, p < 0.01) but negative in sludge (e.g. correlation coefficients between ofloxacin and tetO, tetW and qnrS were −0.922, −0.933 and −0.902, p < 0.01), indicating the high risk of pharmaceuticals in wastewater promoting ARG spread. Furthermore, based on pharmaceutical removal efficiencies in different wastewater treatment processes in this and previous studies, the removal efficiencies of typical pharmaceuticals highly correlated with ARGs were well predicted through process operation parameters and wastewater characteristics by Random Forest model. HRT and temperature were identified as the most important explanatory variables. This study could provide comprehensive references for controlling pharmaceuticals in WWTPs.

Combining large-scale investigation and quantum chemical calculation of pharmaceuticals: Spatiotemporal patterns of occurrence and structural insights into removal

This study investigated the spatiotemporal distribution of 17 pharmaceuticals in wastewater treatment plants (WWTPs) from 17 provinces across China, and explored structural insights into their removal in full-scale wastewater treatment processes by quantum chemistry. Briefly, 10 pharmaceuticals were detected in above 85 % of samples, of which ibuprofen and sulfamethoxazole dominated with concentrations up to the μg/L level. Seasonally, concentrations of psychoactive drugs (PDs) were 1.3–2.6 times higher in summer than in other seasons. Spatially, higher average concentrations were detected in northern WWTPs, and regions with similar economic levels exhibited similar contamination patterns. Pharmaceutical removal in WWTPs ranged from 41.4 % (carbamazepine) to 87.2 % (sulfamethizole), with the secondary treatment segment, especially aerobic treatment units, maintaining an important position. Molecular structural mechanisms behind these removal performances were further revealed. Firstly, we demonstrated a significant association of pharmaceutical overall removal with electrophilicity index (ωcubic) as well as the lowest unoccupied molecular orbital energy (ELUMO). Highly electrophilic pharmaceuticals may persist in WWTPs and their sensitivity to electron exchange reactions accounted for the discrepant removal. In terms of treatment segments, pharmaceuticals with reaction sites masked in molecular structure, such as ibuprofen and venlafaxine, showed a propensity for tertiary treatment suitability. Furthermore, enzymes of aerobic units exhibited excellent docking affinity to pharmaceutical molecules with an average affinity of −7.2 kcal/mol, and hydrogen-bond interactions played an important factor in promoting biodegradation. Our results emphasize the necessity of assessing pharmaceutical contamination on a larger spatiotemporal scale. Moreover, the structural insights into removal phenomena offer scientific molecular-level justification for the design and optimization of pharmaceutical treatment technologies in WWTPs.

Process design for removal of pharmaceuticals in wastewater treatment plants based on predicted no effect concentration (PNEC)

Increasing concern on water contamination by micropollutants like pharmaceuticals fuels the development and implementation of technologies to remove micropollutants from municipal wastewater treatment plants (WWTP). However, often the targets and criteria for process design of such technologies are not clarified. This study was conducted to test whether predicted no-effect concentrations (PNEC) can be used as a design parameter for advanced treatment technologies to achieve pharmaceutical levels in WWTP effluents. This goal is consistent with environmental requirements, currently being discussed both by the Danish authorities and the European goals on zero emissions as documented in the draft of the Urban Wastewater Directive. The effluent of a conventional activated sludge WWTP was treated by ozonation and granular activated carbon (GAC) and monitored for 50 pharmaceuticals and iodinated X-ray contrast media, as well as 23 transformation products. Treatment with GAC alone initially achieved concentrations below PNEC for all targeted compounds, but after treating 3,000 – 5,000 bed volumes, the removal for several compounds decreased and the effluent concentrations for clarithromycin and venlafaxine were no longer below PNEC. Ozonation alone effectively reduced the concentrations of most of the compounds with standard ozone dosing of 0.5 mg O3/mg DOC. However, ozonation was unable to remove bicalutamide and oxazepam to reach target concentrations. The operation of both technologies in combination achieved concentrations of all measured pharmaceuticals below the PNEC (even with ozone concentrations of below 0.5 mg O3/mg DOC). Nonetheless, this study suggests that proper steering of WWTP design via the PNEC values alone is obstructed by lack of reliable primal PNEC data and absence of PNEC references for emerging pollutants and potential biologically active transformation products.

Investigating the Potential of Greener-Porous Graphene for the Treatment of Organic Pollutants in Wastewater

Pharmaceuticals have emerged as a new class of ecological pollutants and have majorly contributed to harmful effects on the environment and human health. The presence of these pharmaceuticals in wastewater treatment plants, ground, and seawater has been reported widely. Organic dyes and other organic contaminants which are being considered as emerging contaminants are now in the race among the top organic pollutants that need effective treatment. Removal of these contaminants via green adsorbents has become an essential requirement towards a green and cleaner environment. Herein, we report the efficacy of the novel greener porous graphene obtained via the near-green synthesis method as an adsorbent material for treating seven organic pollutants: Methyl orange, Methyl red, Rhodamine-B, Ciprofloxacin, Atenolol, Ibuprofen, and Carbamazepine. Batch tests were conducted to investigate the effect of adsorption time and varying adsorbent dosages. The obtained greener porous graphene showed fast kinetics, which was determined to be guided by pseudo second-order kinetics and the maximum pollutant removal efficiency (&gt;80%) was seen at a high adsorbent dosage (2 mL injected from a 5 g/L solution). Furthermore, the nonlinear adsorption modeling confirmed that the greener porous graphene followed the Langmuir model for the dye rhodamine-B sorption and the Freundlich model for all the other six contaminants. This greener porous graphene can be considered an effective adsorbent for the removal of organic pollutants in wastewater.

Sol-Gel Synthesis of New TiO2 Ball/Activated Carbon Photocatalyst and Its Application for Degradation of Three Hormones: 17α-EthinylEstradiol, Estrone, and β-Estradiol.

Many approaches have been investigated to eliminate pharmaceuticals in wastewater treatment plants during the last decades. However, a lack of sustainable and efficient solutions exists for the removal of hormones by advanced oxidation processes. The aim of this study was to synthesize and test new photoactive bio composites for the elimination of these molecules in wastewater effluents. The new materials were obtained from the activated carbon (AC) of Arganian spinosa tree nutshells and titanium tetrachloride by the sol gel method. SEM analysis allowed one to confirm the formation of TiO2 particles homogeneously dispersed at the surface of AC with a controlled titanium dioxide mass ratio, a specific TiO2 anatase structure, and a highly specific surface area, evidenced by ATG, XRD, and BET analysis, respectively. The obtained composites were revealed to quantitatively absorb carbamazepine (CBZ), which is used as a referred pharmaceutical, and leading to its total elimination after 40 min under irradiation with the most effective material. TiO2 high content disfavors CBZ adsorption but improves its degradation. In the presence of the composite, three hormones (17α-ethinylestradiol, estrone, and β-estradiol) are partially adsorbed onto the composite and totally degraded after 60 min under UV light exposure. This study constitutes a promising solution for the efficient treatment of wastewater contaminated by hormones.

Study on the removal characteristics and degradation pathways of highly toxic and refractory organic pollutants in real pharmaceutical factory wastewater treated by a pilot-scale integrated process.

Pharmaceutical wastewater frequently contains high levels of toxic pollutants. If they are discharged untreated, they pose a threat to the environment. The traditional activated sludge process and the advanced oxidation process do not sufficiently remove toxic and conventional pollutants from pharmaceutical wastewater treatment plants (PWWTPs). We designed a pilot-scale reaction system to reduce toxic organic pollutants and conventional pollutants from pharmaceutical wastewater during the biochemical reaction stage. This system included a continuous stirred tank reactor (CSTR), microbial electrolysis cells (MECs), an expanded sludge bed reactor (EGSB), and a moving bed biofilm reactor (MBBR). We used this system to further investigate the benzothiazole degradation pathway. The system effectively degraded the toxic pollutants (benzothiazole, pyridine, indole, and quinoline) and the conventional chemicals (COD, NH4 +-N, TN). During the stable operation of the pilot-scale plant, the total removal rates of benzothiazole, indole, pyridine, and quinoline were 97.66, 94.13, 79.69, and 81.34%, respectively. The CSTR and MECs contributed the most to the removal of toxic pollutants, while the EGSB and MBBR contributed less to the removal of the four toxic pollutants. Benzothiazoles can be degraded via two pathways: the benzene ring-opening reaction and the heterocyclic ring-opening reaction. The heterocyclic ring-opening reaction was more important in degrading the benzothiazoles in this study. This study provides feasible design alternatives for PWWTPs to remove both toxic and conventional pollutants at the same time.

Carbon emission reduction mechanism of the pharmaceutical supply chain: Quadrilateral evolutionary game models

The climate crisis and the increasing temperature of the earth have highlighted the need to reduce carbon emissions in supply chains, which has gradually become a global consensus. The focus has often been on traditional carbon emission industries, such as energy and transportation, while the pharmaceutical industry has received little attention. This paper, therefore, aims to fill that research gap by exploring the carbon emission reduction mechanisms of the pharmaceutical supply chain, specifically the role of public participation. We constructed a quadrilateral evolutionary game model, based on evolutionary game theory, consisting of local government, pharmaceutical manufacturers, wastewater treatment plants, and the public. By finding the equilibrium point of the system of replicator dynamics, evolutionary stable strategies are obtained. Our numerical simulation shows the impacts of the principal strategy change and the key variables. This paper also identifies some management implications: 1) When local governments implement a combination policy (carbon subsidies and carbon tax policy), the key is to formulate a subsidy level satisfactory to the four parties. If the subsidy level is in the middle level, the four parties are at their most willing to participate in carbon emission reduction. 2) When local governments implement a single policy (carbon tax policy), the carbon tax rate becomes the key variable. A high level of carbon tax accelerates carbon emission reduction in the pharmaceutical supply chain. 3) No matter what policies local governments implement, the free-rider effect between pharmaceutical manufacturers and wastewater treatment plants always hinders their low-carbon decisions. 4) Public reporting is an effective measure for promoting carbon emission reduction in the pharmaceutical supply chain. When local governments implement a combination policy, it can reduce the cost of reporting and improve the willingness of the public to report. Finally, we put forward suggestions for rationalizing carbon emission reduction.

An enriched ammonia-oxidizing microbiota enables high removal efficiency of ammonia in antibiotic production wastewater

High ammonia concentration hinders the efficient treatment of antibiotic production wastewater (APW). Developing effective ammonia oxidation wastewater treatment strategies is an ideal approach for facilitating APW treatment. Compared with traditional nitrification strategies, the partial nitrification process is more eco-friendly, less energy-intensive, and less excess sludge. The primary limiting factor of the partial nitrification process is increasing ammonia-oxidizing bacteria (AOB) while decreasing nitrite-oxidizing bacteria (NOB). In this study, an efficient AOB microbiota (named AF2) was obtained via enrichment of an aerobic activated sludge (AS0) collected from a pharmaceutical wastewater treatment plant. After a 52-day enrichment of AS0 in 250 mL flasks, the microbiota AE1 with 69.18% Nitrosomonas microorganisms was obtained. Subsequent scaled-up cultivation in a 10 L fermenter led to the AF2 microbiota with 59.22% Nitrosomonas. Low concentration of free ammonia (FA, < 42.01 mg L−1) had a negligible effect on the activity of AF2, and the nitrite-nitrogen accumulation rate (NAR) of AF2 was 98% when FA concentration was 42.01 mg L−1. The specific ammonia oxidation rates (SAORs) at 30 °C and 15 °C were 3.64 kg NH4+-N·kg MLVSS−1·d−1 and 1.43 kg NH4+-N·kg MLVSS−1·d−1 (MLVSS: mixed liquor volatile suspended solids). The SAOR was 0.52 kg NH4+-N·kg MLVSS−1·d−1 when the NaCl concentration was increased from 0 to 20 g L−1, showing that AF2 functioning was stable in a high-level salt environment. The ammonia oxidation performance of AF2 was verified by treating abamectin and lincomycin production wastewater. The NARs of AF2 used for abamectin and lincomycin production wastewater treatment were >90% and the SAORs were 2.39 kg NH4+-N·kg MLVSS−1·d−1 and 0.54 kg NH4+-N·kg MLVSS−1·d−1, respectively, which was higher than the traditional biological denitrification process. In summary, AF2 was effective for APW treatment via enhanced ammonia removal efficiency, demonstrating great potential for future industrial wastewater treatment.

Impacts of dibutyl phthalate on biological municipal wastewater treatment in a pilot-scale A2/O-MBR system

Dibutyl phthalate (DBP) is a typical contaminant in pharmaceutical wastewater with strong bio-depressive properties which potentially affects the operation of municipal wastewater treatment systems. Based on a year-round monitoring of the quality of influent and effluent of a full-scale pharmaceutical wastewater treatment plant in Northeast China, the DBP was found to be the representative pollutant and its concentration in the effluent ranged 4.28 ± 0.93 mg/L. In this study, the negative effects of DBP on a pilot-scale A2/O-MBR system was investigated. When the influent DBP concentration reached 8.0 mg/L, the removals of chemical oxygen demand (COD) and total nitrogen (TN) were significantly inhabited (P < 0.01), with the effluent concentration of 54.7 ± 2.6 mg/L and 22.8 ± 3.7 mg/L, respectively. The analysis of pollutant removal characteristics of each process unit showed that DBP had the most significant effects on the removals of COD and TN in the anoxic tank. The α- and β-diversity in the system decreased significantly when the influent DBP concentration reached 8.0 mg/L. The impacts of DBP on known nitrifying bacteria, such as Nitrospira, and phosphorus accumulating organisms (PAOs), such as Cadidatus Accumulibacter, were not remarkable. Whereas, DBP negatively affected the proliferation of key denitrifying bacteria, represented by Simplicispira, Dechloromonas and Acinetobacter. This study systematically revealed the impacts of DBP on the pollutants removal performance and the bacterial community structure of the biological municipal wastewater treatment process, which would provide insights for understanding the potential impacts of residues in treated pharmaceutical wastewater on biological municipal wastewater treatment.

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 &amp;lt;limit of detection (LOD), &amp;lt;LOD – 4.75, &amp;lt;LOD – 1.37, &amp;lt;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 &amp;lt;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 &amp;lt;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.