Conventional Treatment Processes Research Articles

Treatment of antibiotic-containing wastewater with self-suspended algae-bacteria symbiotic particles: Removal performance and reciprocal mechanism

Emerging contaminants such as antibiotics in wastewater have posed a challenge on conventional biological treatment processes. Algae-bacteria symbiotic mode could improve the performance of biological treatment processes. Self-suspended algae-bacteria symbiotic particles (ABSPs) were prepared with Chlorella vulgaris and Bacillus subtilis using the sol-gel method and hollow glass microspheres in this study. The removal effect of nitrogen and phosphorus as well as the feedback mechanism of ABSPs under tetracycline stress were investigated through three-cycles wastewater treatment experiments. The antioxidant enzyme activity and phycosphere extracellular polymeric substance (EPS) content were identified as well. The results indicated that the removal rates of NH4+-N, TP, COD, and tetracycline in the ABSPs group finally reached 96.18%, 95.44%, 81.36%, and 74.20%, respectively, which were higher than the single algae group apparently. The phycosphere EPS content increased by 20.41% and algae cell structure maintained integrity in ABSPs group as compared with that in single algae group. This study demonstrates that the self-suspended ABSPs can improve contaminants removal performance and alleviate the antioxidant stress response of algae through algal-bacterial reciprocity mechanism.

Ozonation for oxidation and transformation of pharmaceuticals in Arroio Diluvio River in Southern Brazil

ABSTRACT Pharmaceuticals are often found in the water environment and are not completely degraded by conventional treatment processes. There are some techniques, such as advanced oxidative processes (AOPs), which can promote, in addition to the total removal of contaminants, their mineralization, transforming them into CO2 and water. Thus, the objective of this work was to evaluate the mineralization capacity of the emerging pollutants caffeine and ampicillin, present in a real aqueous matrix, through ozonation. Factorial planning was carried out by Central Composite Design (CCD) under the Response Surface Methodology (RSM). Water samples were collected from Arroio Dilúvio, a river that cuts through the city of Porto Alegre (RS – Brazil), which receives domestic, hospital, and industrial effluents in nature. The experiments were conducted from the analysis of the influence of pH, time, and ozone flow rate variables. The ozonation system consisted of an oxygen concentrator, an ozone generator, and a gas washer bottle. With removals of caffeine and ampicillin around 100 and 99.7%, respectively, a mineralization of 30.8% was also obtained under conditions of pH 8, with an applied ozone dosage of 830 mg.L−1. In this process, the gas phase concentration was at 16.7 mg.L−1 when applied to 200 mL sample for 10 minutes and ozone flow rate of 1 L.min−1. A linear relationship was observed between the real and predicted values, and it has been shown that the relationship of the residual plot confirmed a sufficient approximation of the method for the optimization process. Finally, the desirability function showed adequate operating conditions for the mineralization of compounds by ozonation. Therefore, it is considered that this technique is effective for the mineralization of the pharmaceuticals studied, and can be applied as a way of treating a contaminated real matrix.

Integrating bioelectrochemical system with aerobic bioreactor for organics removal and caustic recovery from alkaline saline wastewater

Bioelectrochemical systems (BES) are increasingly being explored as an auxiliary unit process to enhance conventional waste treatment processes. This study proposed and validated the application of a dual-chamber bioelectrochemical cell as an add-on unit for an aerobic bioreactor to facilitate reagent-free pH-correction, organics removal and caustic recovery from an alkaline and saline wastewater. The process was continuously fed (hydraulic retention time (HRT) of 6 h) with a saline (25 g NaCl/L) and alkaline (pH 13) influent containing oxalate (25 mM) and acetate (25 mM) as the target organic impurities present in alumina refinery wastewater. Results suggested that the BES concurrently removed the majority of the influent organics and reduced the pH to a suitable range (9–9.5) for the aerobic bioreactor to further remove the residual organics. Compared to the aerobic bioreactor, the BES enabled a faster removal of oxalate (242 ± 27 vs. 100 ± 9.5 mg/L.h), whereas similar removal rates (93 ± 16 vs. 114 ± 23 mg/L.h, respectively) were recorded for acetate. Increasing catholyte HRT from 6 to 24 h increased the caustic strength from 0.22% to 0.86%. The BES enabled caustic production at an electrical energy demand of 0.47 kWh/kg-caustic, which is a fraction (22%) of the electrical energy requirement for caustic production using conventional chlor-alkali processes. The proposed application of BES holds promise to improve environmental sustainability of industries in managing organic impurities in alkaline and saline waste streams.

Algal removal from raw water by electro-flotation

In order to reduce the influence of algae on the conventional treatment process of the water plant, the electro-flotation process was used to test the raw water of a lake-type reservoir. After raw water with cyanobacteria as the dominant algae is treated by the best electro-flotation process, the average removal rate of algal density can reach 99.1%. The effects of current density, residence time, and electrode spacing on the algal removal efficiency of the electro-floating process were investigated by orthogonal experiments. The order of influence was current density > residence time > electrode spacing. Considering economics, the optimal process conditions were as follows: the current density was 5 mA/cm2, the dwell time was 6 min, and electrode spacing was 10 mm.

Microplastics in different water samples (seawater, freshwater, and wastewater): Methodology approach for characterization using micro-FTIR spectroscopy

Microplastics of millimeter dimensions have been widely investigated in environmental compartments and today, studies are mainly focused on particles of smaller dimensions (< 500 µm). However, as there are no relevant standards or policies for the preparation and analysis of complex water samples containing such particles, the results may be questionable. Therefore, a methodological approach for 10 µm to 500 µm microplastic analysis was developed using μ-FTIR spectroscopy coupled with the siMPle analytical software. This was undertaken on different water samples (sea, fresh, and wastewater) taking into consideration rinsing water, digestion protocols, collection of microplastics, and sample characteristics. Ultrapure water was the optimal rinsing water and ethanol was also proposed with a mandatory previous filtration. Although water quality could give some guidelines for the selection of digestion protocols, it is not the only decisive factor. The methodology approach by μ-FTIR spectroscopy was finally assessed to be effective and reliable. This improved quantitative and qualitative analytical methodology for microplastic detection can then be used to assess the removal efficiency of conventional and membrane treatment processes in different water treatment plants.

The Elimination of Pharmaceutical Agents with Microbiological Treatment from Municipal Sewage

Pharmaceutical agents accumulate in wastewater after consumption, but the conventional sewage treatment process is unable to remove them completely. The occurrence of certain compounds in the environment brings forth serious problems even at low concentrations. In this study, the microbiological elimination ability of four non-steroidal anti-inflammatory drugs (NSAIDs)—ibuprofen, naproxen, ketoprofen and diclofenac—were investigated under laboratory, pilot and plant conditions. Mixed cultures from environmental matrices presumably have the ability to reduce the concentration of target agents effectively. According to our analytical measurements, certain mixed cultures gained from natural habitats were even capable of reducing the amount of diclofenac efficiently, after being enriched to a 109 colony-forming unit—CFU/mL scale, and inoculated in adequate quantity. Target NSAIDs were detected at µg/L levels in both influents and effluents from wastewater treatment plants (WWTPs). The results showed that inoculated conventional activated sludge sewage treatment technologies have high efficiency for removing ibuprofen, ketoprofen and naproxen. The diclofenac-specific bacteria mix exhibited mild but positive removal efficiency compared to the control plant. This removal ability is also influenced by the hydraulic retention time (HRT).

MOF‐Heterostructure‐Mediated pH‐Responsive Adsorptive Removal of Ciprofloxacin: A Step towards Pharmaceutical Wastewater Treatment

AbstractOne of the biggest challenges of the modern world is the antibiotic pollution in the water resources owing to the lack of effective removal techniques in the conventional wastewater treatment processes. Importantly, very few commercially available adsorbents are at the same time porous, magnetic, and have the capacity to bind and remove particular antibiotic classes from the slurries in a selective manner. Herein we report CNS@ZIF67 heterostructure derived adsorbent for the pH‐dependent removal of ciprofloxacin (CIP). The materials can be synthesized via a simple two‐step wet chemical method followed by annealing in a controlled atmosphere. The material demonstrates an attractive surface‐to‐mass ratio of 203.02 m2 g−1. We have performed a detailed time dependent adsorption study indicating a high removal efficiency of 96% within 2 h. Experimental adsorption data matches the Langmuir isotherm model and the kinetics follows pseudo‐second‐order reaction kinetics suggesting a chemisorption pathway of adsorption kinetics. The adsorbent has an interesting pH dependent adsorption behavior towards CIP. The adsorbent has also demonstrated its value in being reusable for four cycles of adsorption and desorption without significantly changing the removal efficiency.

Microalgal cultivation on digestate: Process efficiency and economics

This study aims at evaluating the process efficiency of an outdoor pilot-scale microalgae-based wastewater treatment system. Experimental results from two monitoring campaigns were analysed, showing that the system removed on average 85.1 % and 36.2 % of the influent ammoniacal nitrogen and orthophosphate, respectively, with an associated algal productivity of 9.5 g TSS·m−2·d-1. Based on pilot-scale results, a comprehensive techno-economic assessment was performed, allowing to calculate a biomass production cost of 4.3 €·kg TSS-1 and a wastewater treatment cost of 2.7 €·m−3 (corresponding to a nitrogen removal cost of 12.5 €·kg N−1). These costs turned out to be comparable with conventional wastewater treatment processes, thus recognizing the potential of microalgae cultivation on wastewaters as feasible alternative to conventional energy-demanding bioremediation systems and to expensive algal cultivation processes. A sensitivity and scenario analysis indicated that, under the most optimistic condition (20 % increase in the productivity, and 20 % OPEX and CAPEX reduction), biomass production and nitrogen removal costs could be further reduced of approximately 44 %.

A comparative study of the mechanical properties of sol-gel derived hydroxyapatite produced from a novel mixture of two natural biowastes for biomedical applications

In this work, hydroxyapatite (HAp) was produced in a cost-effective and environmentally friendly manner from bovine and catfish bones. Carbonization and calcination were used to deproteinize the bones before converting the bones into HAp via the conventional thermal treatment process in a muffle furnace. The sol-gel synthesis process was used to ensure homogeneity of the powder mixtures after the thermal treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and mechanical measurements were used to characterize the powders in terms of their phase composition, purity, crystallinity, mechanical properties, and wear rates. Also, the specific surface area and the volume of samples were calculated. Sample B25/C75 (HAp from bovine and catfish bones, respectively- 25/75%) had the highest hardness value of 0.54 GPa, while B50/C50 and B75/C25 had equal hardness values of 0.47 GPa. From the data obtained, the micro-hardness for all the samples is within the range reported for hard tissue engineering. The sample B50/C50, on the other hand, had the highest compressive strength of 1.75 MPa. The sample B50/C50 was observed to have a lower wear rate under dynamic loading, while B100 had the highest wear rate.

Electrochemical Advanced Oxidation Processes Using Diamond Technology: A Critical Review

Re-evaluation of conventional wastewater treatment processes is of paramount importance to improve the overall quality of our aquatic environment. Electrochemical Advanced Oxidation Processes (EAOPs) are the most promising alternative methods with application in wastewater treatment facilities since in situ electrogenerated oxidant agents degrade and mineralize a wide range of water pollutants. Boron-doped diamond (BDD) technology has proven its excellency in the anodic oxidation (AO) of different pollutants. In this work, we describe the use of a systematic literature review (SLR) methodology and a bibliometric analysis tool for the assessment of a representative sample of work (hundreds of publications) concerning the synergism between AO using BDD technology and other oxidation methods. One section of the discussion relates to different techniques used to enhance the AO performance of BDD technology, namely persulfate radicals or ozone and photoelectrocatalysis, whereas the second one considers Fenton-based reactions. A standard synergism effect occurs between AO using BDD technology and the add-ons or the Fenton-based methods, resulting in the enhancement of the degradation and mineralization efficiencies. The future of EAOPs using BDD technology must include renewable energy sources to self-sustain the overall process, and further research on the subject is mandatory to enable the effective acceptance and application of such processes in wastewater remediation facilities.

Membrane techniques for removal detergents and petroleum products from carwash effluents: a review

One of the most significant urban services is the carwash, which generates large amounts of wastewater containing a variety of pollutants, including sand, gravel, suspended solids, surfactants, oil products, diesel cleaners, etc., that may cause environmental pollution when transferred to the sewage system without any treatment. The effective treatment is crucial to prevent environmental pollution as well as to recycle the water source. Contaminants are removed from carwash effluent using a variety of treatment technologies. This review focuses on identifying and comparing efficiency of using advanced commercial and modified membrane filtration techniques, meeting discharge standard regulations, to treat carwash impurities, especially detergents/surfactants (anionic surfactant) and petroleum products (oil/grease). The results of this review indicate that ultrafiltration membrane (UF) is the most common membrane filtration technology for carwash wastewater treatment. Additionally, the adoption of traditional pre-treatment processes may be advantageous before utilization of membrane process for treating carwash wastewater; although conventional treatment processes can produce a high quality of effluent, they are less effective than membrane systems.

Techno-economic assessment of a novel algal-membrane system versus conventional wastewater treatment and advanced potable reuse processes: Part II

This study developed a comprehensive techno-economic assessment (TEA) framework to evaluate an innovative algae resource recovery and near zero-liquid discharge potable reuse system (i.e., the main system) in comparison with a conventional potable water reuse system (i.e., the benchmark system). The TEA study aims to estimate the levelized costs of water of individual units and integrated processes including secondary wastewater treatment, advanced water purification for potable reuse, and sludge treatment. This would provide decision-makers valuable information regarding the capital and operational costs of the innovative main system versus a typical potable water reuse treatment train, along with possible routes of cost optimization and improvements for the design of full-scale facilities. The main system consists of (i) a novel algal-based wastewater treatment coupled with a dual forward osmosis and seawater reverse osmosis (Algal FO-SWRO) membranes system for potable water reuse and hydrothermal liquefaction (HTL) to produce bioenergy and subsequent nutrients extraction from the harvested algal biomass. The benchmark system includes (ii) an advanced water purification facility (AWPF) that consists of a conventional activated sludge biological treatment (CAS), microfiltration (MF), brackish water reverse osmosis (BWRO), ultraviolet/advanced oxidation process (UV-AOP), and granular activated carbon (GAC), with anaerobic digestion for sludge treatment. Capital expenditures (CAPEX) and operational expenditures (OPEX) were calculated for each unit of both systems (i.e., sub-systems). Based on a 76% overall water recovery designed for the benchmark system, the water cost was estimated at $2.03/m3. The highest costs in the benchmark system were found on the CAS and the anaerobic digester, with the UV-AOP combined with GAC for hydrogen peroxide (H2O2) quenching as the driving factor in the increased costs of the system. The cost of the main system, based on an overall 88% water recovery, was estimated to be $1.97/m3, with costs mostly driven by the FO and SWRO membranes. With further cost reduction and optimization for FO membranes such as membrane cost, water recovery, and flux, the main system can provide a much more economically viable alternative in its application than a typical benchmark system.

Ibuprofen removal from synthetic effluents using Electrocoagulation-Peroxidation (ECP).

Concerning water resources, several ordinances and legislation determine standards and conditions for the discharge of effluents into water bodies. However, several contaminants are not covered by these guidelines due to little knowledge of their long-term effects and because they are found in low concentrations. These contaminants are called emergent and this category includes drugs, such as anti-inflammatory drugs. The electrocoagulation process associated with advanced oxidation comes up as an alternative to conventional effluent treatment processes, and the objective of this study was to evaluate this process using scrap iron as sacrificial electrodes in the treatment of synthetic effluents containing ibuprofen. High-performance liquid chromatography was used to quantify the drug in synthetic effluents. The Central Rotational Composite Design 24 was used in an experimental design, considering independent variables the concentration of contaminants, applied current, the concentration of the primary oxidizing agent H2O2, and the reaction time. The optimized conditions determined by statistical analysis were drug concentration of 5mg L-1, H2O2 concentration of 200mg L-1, current of 5 A, and 150min. The removals obtained under these conditions were higher than 92% in the aqueous phase, showing that electrocoagulation peroxidation technique has the potential to treat contaminants such as drugs present in effluents and waters.

Identification and characterization of diverse isomers of per- and polyfluoroalkyl substances in Chinese municipal wastewater

Linear and branched isomers of per- and polyfluoroalkyl substances (PFASs) are simultaneously present in the environment. However, isomer profiles of PFASs in municipal wastewater treatment plants (WWTPs) are still unknown because of the limitations of standards. Here, influent and effluent samples from 148 municipal WWTPs in China were collected. Ion mobility spectrometry was introduced into high-resolution mass spectrometry-based suspect screening methods to identify the target and suspect PFAS isomers. A total of 38 branched isomers of 14 typical PFASs were identified in wastewater samples. Linear PFASs had higher detection rates (22.3%-100%) than branched isomers (2.0%-98%). Compared to the influents, proportions of branched isomers of most PFASs (except for perfluoropentanoic acid and perfluorohexanoic acid) increased in the effluents. The conventional biological treatment processes (such as anaerobic–anoxic–aerobic and oxidation ditch treatments) had poor removal efficiency for linear PFASs (<21.4%) and branched isomers (<13.4%). No difference on removal efficiency among treatment processes was found. Furthermore, isomer composition in the WWTPs showed obvious differences between East China region and other regions, and the usage of short-chain PFASs (perfluorobutanesulfonic acid and perfluorohexanesulfonic acid) may be a key factor for driving this difference. This study sheds lights on the identification and characterization of PFAS isomers in WWTPs, which would be useful for development of monitoring and control strategies of PFASs.

Discussion of the Segregation and Low Hardness of Large-Diameter M3 High-Speed Steel Produced by Spray Forming.

As an advanced near-net-shape processing method in which directly preformed, semi-finished products are created from liquid metals, spray forming has become popular in the development and application of new materials and is supporting industrialization. However, as investigated in this work, the problems of segregation and low hardness exist in the actual industrialization process, particularly for large-diameter M3 high-speed steel. It was here found that the annual ring segregation morphologies were mostly distributed from the edge to 1/2R, with a large number of stripes primarily enriched in C, Mo, and Cr elements, and the degree of segregation was mild. The ring segregation was located at the 1/2R position, where the main elemental enrichments were C, W, Mo, Cr, and V, and the segregation degree was severe. The formation of segregation during deposition is described based on an equilibrium solidification model. A slow cooling rate and heat dissipation from the surface to the inside were judged to be the main factors causing segregation and changes in the carbide morphology. In terms of hardness, with the increase in the quenching temperature to 1230 °C, the tempering hardness increased significantly. The analysis shows that a faster cooling rate in the atomization stage caused the solidified droplets to exhibit rapid solidification characteristics, and there was a higher proportion of MC carbide in the deposited billet. MC carbides cannot be fully dissolved using the conventional heat treatment process, which decreases the C, Cr, Mo, and V contents in the solution and, thus, reduces the secondary hardening capability. The findings show that, when the spray forming process is used to prepare large-diameter materials, it should not be considered a rapid solidification technology simply because of its atomization stage. Moreover, more attention should be paid to the influence of microstructure transformation during atomization and deposition.

"Repairing the Heart: Cell Therapy, a Promising Avenue?"

This paper calls for greater deliberate collaboration between basic scientists and engineers to advance our understanding of viral fate in wastewater treatment systems. Despite the fact that conventional treatment technologies and processes efficiently eliminate SARS-CoV-2 from the final effluent, viral retention in the sludge remains a concern.

Single atom catalyst-mediated generation of reactive species in water treatment.

Water is one of the most essential components in the sustainable development goals (SDGs) of the United Nations. With worsening global water scarcity, especially in some developing countries, water reuse is gaining increasing acceptance. A key challenge in water treatment by conventional treatment processes is the difficulty of treating low concentrations of pollutants (micromolar to nanomolar) in the presence of much higher levels of inorganic ions and natural organic matter (NOM) in water (or real water matrices). Advanced oxidation processes (AOPs) have emerged as an attractive treatment technology that generates reactive species with high redox potentials (E0) (e.g., hydroxyl radical (HO˙), singlet oxygen (1O2), sulfate radical (SO4˙-), and high-valent metals like iron(IV) (Fe(IV)), copper(III) (Cu(III)), and cobalt(IV) (Co(IV))). The use of single atom catalysts (SACs) in AOPs and water treatment technologies has appeared only recently. This review introduces the application of SACs in the activation of hydrogen peroxide and persulfate to produce reactive species in treatment processes. A significant part of the review is devoted to the mechanistic aspects of traditional AOPs and their comparison with those triggered by SACs. The radical species, SO4˙- and HO˙, which are produced in both traditional and SACs-activated AOPs, have higher redox potentials than non-radical species, 1O2 and high-valent metal species. However, SO4˙- and HO˙ radicals are non-selective and easily affected by components of water while non-radicals resist the impact of such constituents in water. Significantly, SACs with varying coordination environments and structures can be tuned to exclusively generate non-radical species to treat water with a complex matrix. Almost no influence of chloride, carbonate, phosphate, and NOM was observed on the performance of SACs in treating pollutants in water when nonradical species dominate. Therefore, the appropriately designed SACs represent game-changers in purifying water vs. AOPs with high efficiency and minimal interference from constituents of polluted water to meet the goals of water sustainability.

Identification of β-lactam-resistant coding genes in the treatment plant by activated sludge process

Wastewater treatment plants are the most important release source of antibiotic-resistance genes (ARGs) into the environment. This study aimed to identify β-lactam-resistance genes in Qom province municipal wastewater and also to determine the effect of municipal wastewater treatment plants with different processes on reducing these pollutants. Sampling was performed according to the standard protocol and at constant temperature conditions. Nine genes resistant to the six groups of β-lactam antibiotics were selected, and polymerase chain reaction (PCR) test was performed to identify the presence/absence of ARGs. At the same time, real-time PCR test was also carried out to quantitatively measure three ARGs in wastewater and effluent samples. The obtained results showed that the highest and the lowest removal were related to blanps-1 (90.61%) and blaCTX-M-32 (65.93%), respectively; however, a decreasing trend in these two genes were showed in to blaoxa-1 with an increase in effluent unit (45.12%). The results showed that conventional biological wastewater treatment processes not only have little potential to reduce antibiotic-resistance genes during the treatment process but also these processes sometimes increase resistant genes. The results of the oxa-1 gene in this study are consistent with this trend. In addition, the sludge treatment unit was based on the results of sequencing Salmonella enterica and Klebsiella pneumoniae. Our study suggests that wastewater treatment plants using conventional chlorination do not favor the proliferation of antibiotic resistance bacteria and ARGs during wastewater treatment. Thus, equipping treatment plants with advanced processes will be efficient in reducing bacterial resistance.

Understanding the properties of activated carbon and biochar for the adsorption and removal of cyanotoxins: a systematic review.

Cyanotoxins pose a health threat when present in the drinking water supply since conventional water treatment processes are not effective in removing extracellular metabolites hence, advanced treatment techniques are usually applied. Powdered activated carbon (PAC) is an effective adsorbent for removing toxins. However, since a high volume is necessary, alternative adsorbents have been investigated. Biochar, especially from renewable sources, is a potential adsorbent material that could replace PAC for removing toxins. This paper aimed to investigate which PAC properties play key roles in cyanotoxin adsorption by a systematic review addressing the adsorption of toxins such as microcystins-LR (MC-LR), cylindrospermopsin (CYL), and saxitoxins (STXs). As a result, the review showed that some commonly adopted indices (i.e. total surface area) are not relevant to cyanotoxin adsorption, especially if appraised alone. Along with a multi-barrier approach, PAC has to be applied taking into account the complexity of the water system, which includes a better understanding of the characteristics of the adsorbent, the target toxin, and the aqueous medium. The biochar systematic review showed that no studies have yet been designed specifically for the removal of toxins. Since biochar has not yet been applied to water treatment processes, the knowledge gap is even greater than for PAC.

Micropollutant Removal Efficiency of Advanced Wastewater Treatment Plants: A Systematic Review.

Various review papers have been published regarding the occurrence and fate of micropollutants (MPs). MPs in the aquatic environment are still not well reviewed to generate comprehensive summaries with a special focus on their removal from wastewater using conventional and advanced treatment processes. Therefore, this review aimed to provide a synopsis of the efficiency of the advanced wastewater treatment plants in the removal of MPs. A systematic search of published literature was conducted on the National Library of Medicine (NLM) database, Web of Science, Joanna Briggs Institute (JBI) database, Scopus, and Google Scholar, based on studies with evidence of removal of MPs in the wastewater treatment process. Screening of the published articles was made using pre-specified inclusion and exclusion criteria. Amongst the 1545 studies searched, 21 full-length articles were analyzed that showed 7 treatment options related to the removal of MPs from wastewater. MPs from wastewater effluents were successfully and effectively removed by advanced treatment techniques. Advanced Oxidation Processes (AOPs), membrane processes, and adsorption processes have all been shown to be potential solutions for the removal of MPs in advanced treatment plants (WWTPs). But, there are 2 critical issues associated with the application of the advanced treatment options which are high operational cost and the formation of dangerous by-products and concentrated residues. This study identified that the removal of MPs using WWTPs was commonly incomplete with varying removal efficiency. Therefore, the adaptation and scale-up of the cost-effective and efficient combined wastewater treatment technology are vital to creating an absolute barrier to MPs emissions.