Treatment System Research Articles

Sustainable treatment scheme for in-situ remediation of contaminated drains using engineered natural systems

Ensuring water security in resource-constrained, densely populated regions is a significant challenge globally. Due to insufficient treatment infrastructure, untreated sewage discharge into drainage channels is prevalent, especially in developing countries. This leads to the pollution of already dwindling water bodies and threatens future water availability. In this context, in-situ treatment within drains using nature-based systems is an attractive option. This study evaluates microbial bioremediation and phytoremediation as engineered natural solutions for in-stream treatment of municipal wastewater. A three-stage treatment system consisting of anoxic biofilm, aerobic biofilm, and hydroponic floating wetlands was adopted. Each stage was optimized for operational parameters through batch and continuous flow studies. The anoxic biofilm system using autoclaved aerated concrete (AAC) as the attachment media, at an optimized hydraulic retention time (HRT) of 2 h, showed the best performance with respect to COD removal. Comparable COD removal was observed in both externally aerated and non-aerated aerobic biofilm systems with coir fibre at 6 h HRT. However, aerated system outperformed non-aerated system at low HRTs. The hydroponic system with Canna indica effectively removed residual ammonia-N with an HRT of 2 h. The sequential continuous flow studies employing the optimized conditions showed significant removals of COD (86%) and ammonia-N (97.6%). The results highlight that locally available materials having a high specific surface area can be used as biofilm supports for COD removal, and floating wetlands employing indigenous macrophytes can be an ideal choice for in-situ nutrient removal. The Life Cycle Assessment (LCA) showed that the developed system did not have direct significant impacts on freshwater eco-toxicity and eutrophication. The proposed hybrid treatment system can be implemented as modular units without major drainage modifications or energy-intensive operations. The study, therefore, finds potential application in densely populated settlements in low-income countries where systematic sewage treatment options remain inadequate.

Hybrid peroxymonosulfate/activated carbon fiber-sequencing batch reactor system for efficient treatment of coking wastewater: Establishment and influential factors

Coking wastewater contains high concentrations of toxic and low biodegradable organics, causing long hydraulic retention times for its biological treatment process. This study developed a pretreatment method for coking wastewater by using activated carbon fiber (ACF) activated peroxymonosulfate (PMS) to improve the treatment performance of subsequent biological post-treatment process, sequencing batch reactor (SBR). The results showed that, after optimization of treatment processes, the removal efficiency of chemical oxygen demand (COD), phenol, and chroma in coking wastewater reached to 76, 98, and 98%, respectively, with a significantly improved biodegradability. Compared with the sole SBR system without any pretreatment that could remove 73% of COD, the ACF/PMS+SBR system removed over 97% of COD in coking wastewater. Moreover, this pretreatment method facilitated the growth of functional bacteria for organics biodegradation, indicating its high potential as a highly efficacious pretreatment strategy to improve the overall treatment efficiency of coking wastewater.

Superior strength and wear resistance of mechanically deformed High-Mn TWIP steel

In the present study, the mechanical and wear behaviour of the surface-mechanically treated high-manganese (high-Mn) twinning-induced plasticity (TWIP) steel were investigated. The TWIP alloy was first designed and fabricated via surface-mechanical attrition treatment (SMAT) system and the mechanical properties including strength, wear behaviour as well as the microstructural evolution were thereafter determined. Transmission electron microscopy (TEM) characterization revealed a typical dislocation as a result of the surface treatment as well as the formation of twin layers with a reduced stacking fault energy (SFE). Due to the ultra-fine grain refinement caused by plastic deformation during surface treatment, a microhardness value of 489 HV can be obtained after treatment. Likewise, the yield strength of the high-Mn TWIP steel could be enhanced from 360 MPa to 813 MPa and a reduction in elongation to failure of about 20 % can be achieved. The wear test showed that the treated TWIP steel possessed a reduced friction coefficient and improved wear resistance at different testing loads, attributed to the nanoscale refinement of grains induced during treatment. The strength, hardness, and wear resistance of the fabricated TWIP alloy improves significantly, thanks to surface treatment by SMAT.

An intelligent MRI assisted diagnosis and treatment system for osteosarcoma based on super-resolution

AbstractMagnetic resonance imaging (MRI) examinations are a routine part of the cancer treatment process. In developing countries, disease diagnosis is often time-consuming and associated with serious prognostic problems. Moreover, MRI is characterized by high noise and low resolution. This creates difficulties in automatic segmentation of the lesion region, leading to a decrease in the segmentation performance of the model. This paper proposes a deep convolutional neural network osteosarcoma image segmentation system based on noise reduction and super-resolution reconstruction, which is the first time to introduce super-resolution methods in the task of osteosarcoma MRI image segmentation, effectively improving the Model generalization performance. We first refined the initial osteosarcoma dataset using a Differential Activation Filter, separating those image data that had little effect on model training. At the same time, we carry out rough initial denoising of the image. Then, an improved information multi-distillation network based on adaptive cropping is proposed to reconstruct the original image and improve the resolution of the image. Finally, a high-resolution network is used to segment the image, and the segmentation boundary is optimized to provide a reference for doctors. Experimental results show that this algorithm has a stronger segmentation effect and anti-noise ability than existing methods. Code: https://github.com/GFF1228/NSRDN.

Treatment efficiency and recovery in sand filters for on-site wastewater treatment: Column studies and reactive modelling

This study examined the adsorption capacity and treatment efficiency of sand filters in on-site treatment systems for cold climate regions. The effects of different operating conditions, porosity and kinetics parameters were investigated in column experiments and COMSOL Multiphysics® modelling, to comprehensively reveal the mechanisms and optimize treatment efficiency of nitrogen (N) and phosphorus (P) removal in a field tidal flow constructed wetland (TFCW), treating effluent from a package treatment plant with P filter material. The results from column experiments with sand showed that Total-P adsorption rate was dependent on feed water quality (Septic tank >0.77 ± 0.06 g kg−1; Biotreatment >0.41 ± 0.07 g kg−1; Reactive material Polonite® <0.18 ± 0.07 g kg−1). In the field TFCW trial, Total-P adsorption in the top layer (>1.42 ± 0.55 g kg−1) and middle layer (>1.06 ± 0.51 g kg−1) was twice that in laboratory columns, due to strong interaction with the air-water interface and use of fluctuated domestic wastewater solutions. The breakthrough curve (BTCs) of the coarse sand matched the physical behaviour of tracer electrical conductivity (EC) in effluent from the sand column experiments. The modelling results demonstrated that high filter porosity and low hydraulic load were significant factors for optimal removal of NH4–N, Total-N, PO4–P, Total- P in the top layer (>99.95 ± 0.03 %, 44.37 ± 28.75%, 70.89 ± 28.30%, 76.18 ± 20.3%), middle layer (>98.94 ± 1.77%, 18.23 ± 23.04%, 76.62 ± 28.73%, 65.40 ± 31.85%) and deep layer (>99.99 ± 0.02%, 65.50 ± 20.64%, 75.53 ± 23.16%, 41.54 ± 28.81%) in the TFCW system, respectively. The results show that on-site wastewater treatment in cold climate TFCW can be applied as a technology to polish effluent from a three-step pretreatment system. However, hydraulic optimization is an important factor for the design of the TFCW to receive a successful long-term operating system.

Optimization of the stowage of fishing discards: Innovations in trawlers in the Gulf of Cadiz (SW Iberian Peninsula)

Discards in commercial fisheries are a common practice that generates negative impacts on fish resources and the environment. This study addresses the challenge of stowing discards in trawlers operating in the Gulf of Cadiz, with the aim of complying with landing regulations and ensuring the safety of fishing operations. The fleet was classified into three groups based on the length (m), power (kW), and tonnage (GT) of the vessels. Through port visits, efficient discard stowage designs were proposed. A SWOT analysis was conducted to assess discard management, leading to proposals based on decision matrices and the establishment of strategies for their management. Subsequently, stowage solutions were proposed for both new and existing vessels, with alternatives such as trays, boxes, and containers, with the optimal solution determined for each vessel type. This study highlights the complexity of discard management on vessels, considering their individual characteristics. Additionally, discard stowage alternatives based on the size and volume of catches are proposed, which could facilitate their handling. Finally, the need to implement a discard treatment system at the fish market is emphasized to achieve comprehensive management of discarded catches.

Novel Zeolite 5Å-Co-Fe based catalytic ozonation process for the efficient degradation of Oxytetracycline in veterinary pharmaceutical wastewater

Public health and the aquatic environment face significant threats from pollution originating from pharmaceutical wastewater (PhWW) containing stubborn antibiotics. Conventional treatment methods fail to fully eradicate these antibiotics and other contaminants such as COD and BOD5 due to the complex organic compound mixtures present in PhWW. Additionally, PhWW exhibits low biodegradability and high toxicity, mainly due to the persistence of antibiotics. This pressing issue has prompted the scientific community to seek more effective and cost-efficient treatment solutions for detoxifying PhWW. Hence, this study explores the catalytic efficiency of zeolite 5 Å (Z5Å) coated with cobalt and iron (Z5Å-Co-Fe) for the abatement of one of the most persistent organic pollutants oxytetracycline (OTC) as a target pollutant. The synthesized catalyst is assessed using various analytical techniques such as FTIR, SEM, and EDX analysis. Results show that the heterogeneous catalytic ozonation using cobalt and iron-loaded zeolite (Z5Å-Co-Fe/O3) achieves OTC removal rates of 8%, 67%, and 95% through adsorption, ozonation (O3), and Z5Å-Co-Fe/O3 processes, respectively, at pH 6, 1.6 mg/min of O3flow and 15 min of treatment time. Moreover, the Z5Å-Co-Fe/O3 process demonstrates higher cost-effectiveness compared to other methods, and electrical energy per order (EEO) of 1.47 USD and 1.62 kWh per cubic meter of PhWW respectively. Additionally, it enhances the biodegradability of PhWW from 0.30 to 0.51, making it more suitable for further secondary treatment. Furthermore, Z5Å-Co-Fe/O3 treated PhWW meets National Environmental Quality Standards (NEQS) and holds promise as a pretreatment option for industrial-scale conventional treatment systems. Therefore, it is concluded that the Z5Å-Co-Fe/O3 process was found to be highly efficient for the degradation of OTC in real PhWW matrix and it may help to achieve UN sustainable development goals (SDGs)

The use of dimethyl ether (DME) solution in compression ignition engine

The development of compression ignition combustion engines is focused on meeting many challenges, mainly related to growing ecological requirements. Currently, however, due to technological barriers, meeting them is very difficult and requires the use of additional exhaust gas treatment systems. The use of injection of a diesel and gas solution seems to be very promising. The article presents the results of engine tests involving the use of a solution of diesel fuel and dimethyl ether. The tests were performed on a single-cylinder research engine equipped with a common rail fuel system. The obtained results suggest that the use of the solution has a positive effect on the process of creating the fuel-air mixture, resulting in a reduction in the concentration of HC and CO, while increasing the share of NOx, suggesting an improvement in the combustion process, as evidenced by the limiting injection dose.

MHD Casson ternary hybrid nanofluid flow through a vertical porous plate with thermal radiation: A finite difference approach

AbstractThis entire study aims to investigate the impacts of linear thermal radiation and MHD Casson ternary hybrid nanofluid flows over a vertical porous plate for comparison of nanofluid, hybrid, and tri‐hybrid nanofluids with Newtonian and non‐Newtonian fluids. We used a ternary hybrid nanofluid, Blood contains three types of oxides and metals: spherical ferric oxide (Fe3O4), platelet‐shaped zinc (Zn), and cylindrically‐shaped gold (Au) nanoparticles. The coupled nonlinear dual partial differential equations (PDEs) are turned into PDEs using nondimensional quantities. The Finite Difference Method (FDM) and the Perturbation Method are then used to solve the PDEs. The impacts of different parameters on temperature, velocity, Nusselt number, and Skin friction profiles have been discussed. The increase in viscosity occurs because an increase in Gr also causes an increase in the velocity field for nanofluid, hybrid, and tri‐hybrid nanofluids. A tri‐hybrid nanofluids performs better among the three, such as nanofluid, hybrids and tri‐hybrid nanofluids. As the volume fractions (Fe3O4) increase, the temperature increase for both Newtonian and non‐Newtonian fluids. The increase in temperature is due to the thermal conductivity of nanoparticles, which is enhanced by growth estimates of the nanoparticle volume fraction. The high temperature of the fluid is observed for large estimates of nanoparticle volume fraction. An increase gold (Au) also increases the temperature for shapes (cylinder, platelet, and spherical). A spherical shape performs better among the three, such as cylinder, platelet, and spherical. In this model, biomedical applications such as antiviral and therapeutic, treatment of the COVID‐19 virus, cancer treatment, and anticancer medication delivery systems.

Clinical analysis of 80 patients with oblique vaginal septum syndrome

Objective: To investigate the clinical features, diagnosis and treatment of oblique vaginal septum syndrome (OVSS). Methods: The clinical data of 80 patients with OVSS admitted to The Second Hospital of Hebei Medical University from July 2005 to July 2023 were retrospectively analyzed. According to the classification system of OVSS proposed by Female Genital Anomalies Study Group, Chinese Obstetricians and Gynecologists Association in 2021, the patients were divided into four groups. The clinical manifestations, accompanied urinary system abnormalities, diagnosis and treatment methods and treatment outcomes were observed. Results: According to the above classification system, among the 80 patients with OVSS, 35 patients (44%, 35/80) were categorized as type Ⅰ, 33 patients (41%, 33/80) were categorized as type Ⅱ, 2 patients (3%, 2/80) were categorized as type Ⅲ and 10 patients (13%, 10/80) were categorized as type Ⅳ. The main onset symptom of patients was periodic abdominal pain (70%, 56/80), vaginal bleeding (20%, 16/80), dysuria or fecal impaction (15%, 12/80), vaginal mucopurulent discharge (10%, 8/80). The morbidity of combined urinary system abnormalities was 88% (70/80), and the most common urinary system abnormality was ipsilateral renal agenesis (81%, 65/80). Bilateral kidneys were normal in 13% (10/80) patients, and 6% (5/80) were combined with other urinary system abnormalities. A total of 74 patients underwent vaginal oblique septectomy or septum excision. Five of the 10 patients with type Ⅳ underwent hysterectomy on the cervical atresia side, 4 patients received hysteroscopy combined with cervicoplasty+oblique septotomy or septum excision, and one patient selected delayed menstruation. Two patients underwent laparoscopic resection of the dysplasia kidney and ectopic ureter which opening to the vagina. Eleven patients with endometriosis cyst, hydrosalpinx or empyema underwent laparoscopic surgery. Conclusions: The main symptom of type Ⅰ and Ⅳ patients is abdominal pain, while the main symptom of type Ⅱ and Ⅲ patients is bleeding. Magnetic resonance imaging (MRI) has advantages in the evaluation of complex OVSS, and MRI is recommended before operation to exclude other axial reproductive tract dysplasia and complex urinary system dysplasia. If there is leakage of urine, vaginal discharge or complex deformity, it is necessary to multidisciplinary discussion and formulate a reasonable surgical plan. The first treatment is related to the prognosis of patients especially children, and should be highly valued.

Metagenomic profiling of antibiotic resistance genes/bacteria removal in urban water: Algal-bacterial consortium treatment system

Antibiotic resistance genes (ARGs) have exhibited significant ecological concerns, especially in the urban water that are closely associated with human health. In this study, with presence of exogenous Chlorella vulgaris-Bacillus licheniformis consortium, most of the typical ARGs and MGEs were removed. Furthermore, the relative abundance of potential ARGs hosts has generally decreased by 1–4 orders of magnitude, revealing the role of algal-bacterial consortium in cutting the spread of ARGs in urban water. While some of ARGs such as macB increased, which may be due to the negative impact of algicidal bacteria and algal viruses in urban water on exogenous C. vulgaris and the suppression of exogenous B. licheniformis by indigenous microorganisms. A new algal-bacterial interaction might form between C. vulgaris and indigenous microorganisms. The interplay between C. vulgaris and bacteria has a significant impact on the fate of ARGs removal in urban water.

AUTOMATED EFFLUENT TREATMENT SYSTEM

This paper introduces the Programmable Logic Controller (PLC) Based Automated Effluent Treatment System as an innovative solution for efficiently managing industrial effluents. The system employs sophisticated technology, including PLCs and various sensors, to automate and optimize the treatment process. Specifically designed for industries like electroplating, where water contamination is prevalent, the system effectively monitors and controls water levels, temperature, gas presence, and pH levels to ensure the safe disposal of effluent. Through a detailed exploration of its components and functionalities, this paper demonstrates how the PLC-based system enhances efficiency, reliability, and environmental sustainability in industrial wastewater treatment. Key Words: Programmable Logic Controller, Automation, Effluent treatment plant, Environment safety, Sewage, Chemicals.

ROOT ZONE TECHNOLOGY FOR WASTE WATER TREATMENT

In India, the primary cause of surface and ground water pollution is the discharge of untreated sewage, according to a 2007 study by the Central Pollution Control Board. In India, there is a significant delay between the generation and treatment of household wastewater. India's insufficient treatment capacity is not the only issue; there are also sewage treatment plants that exist, but they are not being maintained or operated. Because of poor design, inadequate maintenance, unreliable electricity supplies, absentee staff, and incompetent management, the majority of government-owned sewage treatment plants remain closed for the most part of the year. Usually, the wastewater produced in these places evaporates or percolates into the soil. Uncollected waste builds up in urban areas, releasing pollutants that seep into surface and groundwater and creating unsanitary conditions. Furthermore, industrialists prefer not to treat the waste produced and instead to dump it untreated into rivers in the areas where these treatment plants are located because the cost of treatment is so high.The Root Zone Treatment System (RZTS), sometimes referred to as the reed bed system or the constructed wetland system, is a sealed filter bed that is planted with vegetation that can grow in wetlands and is made up of a sand, gravel, and soil system, sometimes with a cohesive element. The wastewater flows through the filter bed, where biodegradation of the wastewater occurs, after the coarse and floating material has been removed. Complex physical, chemical, and biological processes that are the outcome of the interaction of wastewater, wetland plants, filter bed material, and microorganisms define the functional mechanisms in the soil matrix that are in charge of the mineralization of biodegradable matter.

#1561 A tool for the “screening” of the dialysis facilities environmental impact

Abstract Background and Aims The great number of resources needed for hemodialysis treatment can be a limiting factor in the perspective of access to care, especially in developing Countries, and may have a negative impact on the environment. The aim of the study was to develop a questionnaire that is easy and informative of the ecologic impact (energy costs and waste production) of a single dialysis center. The questionnaire's goal is to highlight potentially modifiable factors that are responsible of the ecologic footprint of dialysis. Method A team of 8 people, 3 nephrologists, 3 representatives of dialytic equipment companies and 2 of water treatment systems, developed the questionnaire. The items have been decided after two meetings in person. The completed questionnaire included 49 items divided into three sections, exploring the organization techniques of the dialysis center, its consumption and its water treatment system's characteristics. The questionnaire was then submitted to 11 dialysis centers and made available from 30 September 2022 to 1 February 2023, and included data collected in May 2022. An investigator assisted within filling in the form and collecting feedback on the comprehension of the questions and on any problems that may have surfaced during the compilation of the questionnaire. Results The questionnaires were completed by the center's managers who, unanimously, thought that the form was easily understandable and without significant problems during the compilation. The data collected evidenced that there is almost no real knowledge of the center's consumptions and that also many data about power and water consumption and of waste production are ignored and are therefore missing. No center is fueled by renewable energies. Data refers to a total of 10337 dialysis treatments, with an average 940 treatments per center. Electrical consumption and waste production are in line with the literature, with an average of 13 KwH and 1,9 kg consumption per treatment, respectively. The average water consumption in our sample (550 L per treatment) seems to be higher than expected. Standard dialysate flow was greater than or equal to 500 ml/min in both HD and HDF, except in two centers. Five centers had a water treatment system which is more than eight years old. Average values of each center are reported in the Table 1. Conclusion Our questionnaire appears to be an easily fillable option to carry out consumption “screenings” of each dialysis center. The form could also prove itself useful for a large-scale investigation, to collect an adequate amount of data and to conduct a thorough research to highlight critical issues that could affect the center's consumption. A wider spread of this questionnaire could improve the awareness of nephrologists about their dialysis structure's consumption, taking part in the cultural revolution which is needed to develop a “greener” nephrology.

New insights into magnetic fields selective enhancement of ferrate(Ⅵ) combined with hydrogen peroxide for removal of organic pollutants

A magnetic field (MF) was applied to selectively enhance the generation of reactive species in a ferrate (Fe(VI)) water treatment system, effectively mitigating the limitations associated with the selective oxidation of Fe(VI) for organic matter. An MF was introduced into Fe(VI) and Fe(VI)/H2O2 systems, and a significant difference was observed in its enhancement of the removalefficiency of different types of contaminants. The results of radical scavenging experiments, high-valent Fe inhibition experiments, and methyl phenyl sulfoxide (PMSO) chemical probe experiments indicated that the MF promoted the production of Fe(V)/Fe(IV) in the Fe(VI) system and ·O2– in the Fe(VI)/H2O2 system, which modulated the generation of active species. Subsequently, by monitoring the change in product quantities during the decomposition of Fe(VI) and considering the theory of paramagnetism, it was hypothesized that the MF weakened the pathways for further self-reduction of Fe(V)/Fe(IV) in the Fe(VI) system and strengthened these pathways in the Fe(VI)/H2O2 system: Fe(IV) → Fe(III) → ·O2−. Furthermore, the systems enhanced by the MF were more resistant to partial anions and environmental interference in water quality experiments. This suggested that the MF modulation method may have significant potential for practical applications.

Overheating fault traceback of Regenerative thermal oxidizer in Multi-Source waste gas treatment system via dynamic cumulative correlation analysis

Regenerative thermal oxidizers (RTO) are commonly used in the pharmaceutical and chemical industries to treat emissions of volatile organic compounds but are prone to overheating risks stemming from variations in the flow and concentration of exhausted gases from diverse workshops. This paper proposes a dynamic analysis method based on correlation between various sensor-point data to determine the cause of the RTO overheating in such a multi-source waste gas treatment system. This method continuously adjusts the length of the data in the correlation analysis to comprehensively capture the dynamic changing characteristics of the data. And a strategy for the accumulation of association degrees is introduced to reveal long-standing potential causal relationships. The effectiveness of proposed method was validated in an industrial exhaust gas treatment system of a pharmaceutical company with over 1000 sensor points. The fault diagnosis results are consistent with those of the actual on-site investigation in 5 real cases. Our proposed method can provide relatively accurate results within 2–3 h, much faster than the manual investigation of the workers (2 days on average). Moreover, compared to traditional static correlation analysis methods, our method can narrow down the investigation scope by more than 5 times. This study provides a practical and effective method for tracing the source of anomalies in complex dynamic systems, and also contributes to the safe and stable operation of chemical engineering systems.

Synergistic promotion of microalgal growth and copper removal from synthetic wastewater by nanoscale zero-valent iron particles.

The increasing concentrations of heavy metals in livestock wastewater pose a serious threat to the environmental safety and human health, limiting its resource utilisation. In the present study, microalgae and nanoscale zero-valent iron were selected to construct a coupled system for copper-containing wastewater treatment. The addition of 50 mg·L-1 nanoscale zero-valent iron (50 nm) was the optimal value for the experiment, which could significantly increase the biomass of microalgae. In addition, nanoscale zero-valent iron stimulated microalgal secretion of extracellular polymeric substances, increasing the contents of binding sites, organic ligands, and functional groups on the microalgal surfaces and ultimately promoting the settling of microalgae and binding of heavy metals. The coupled system could quickly adapt to copper-containing wastewater of 10 mg·L-1, and the copper removal rate reached 94.99%. Adsorption and uptake by organisms, together with the contribution of zero-valent iron nanoparticles, are the major copper removal pathways. Overall, this work offers a novel technical solution for enhanced treatment of copper-containing livestock wastewater, which will help improve the efficiency and quality of wastewater treatment.

Anthropogenic Gadolinium Anomalies in an Alluvial Plain with On-site Wastewater Treatment Systems in Campinas, SP, Brazil

Gadolinium anomalies have become a well-established marker for the pollution caused by wastewater, but there is not yet a standardized method to estimate the anomaly. Here, we compare four different published equations, distinct threshold values and reference normalizing values to estimate Gd anomalies by applying them to the results of a hydrochemical investigation in an alluvial aquifer with on-site sanitation systems. We measured traditional wastewater markers (such as electric conductivity, NO3_N, NH4–N, Cl-) and REE in groundwater samples collected from hand-dug wells in two seasons. The ratios of Gd normalized measured concentrations to Gd normalized geogenic concentrations (GdSN/Gd*) estimated with the various methods ranged from 0.7 to 2.8. It turned out that the choice of the equation and the threshold value can affect the decisions about anthropogenic pollution’s occurrence (or not). The normalizing values did not play a significant role in the decision. Based on measurement uncertainties and on the interpretation of hydrogeological conditions in the study area, a threshold value of 1.3 for defining anthropogenic Gd anomalies was deemed adequate for the study area. The occurrence of Gd anomalies higher than 1.8 in two wells, one in each season, reinforces the hypothesis that the groundwater is contaminated by the on-site sanitation systems in the study area, as intermittent detection of anthropogenic Gd is a characteristic of this pollution source.

Analysis of ammonia-nitrogen removal kinetics by stage in pilot scale vertical flow wetlands treating landfill leachate in series

This study explored the effect stage number and plant type have on ammonia-nitrogen (NH3–N) removal kinetics in a two-stage pilot-scale vertical flow constructed wetland (VFCW) system treating landfill leachate. Half of the VFCW columns were planted with Typha latifolia and the other half Scirpus californicus, and half of the columns were loaded with municipal solid waste landfill leachate (diluted to 1 part leachate to 2 parts total) with the effluent from these columns was collected in two separate barrels. The remaining columns were loaded with the effluent collected from the first columns, creating a two-stage VFCW system with four unique pairs to be tested. The leachate used here experienced no prior pre-treatment, and average influent concentrations of NH3–N for the first- and second-stage VFCWs were 508 and 321 mg L−1, respectively— much higher than many other VFCW treatment systems. Some reduction in chemical oxygen demand was observed, as well as generation of nitrate and nitrite, evidence of nitrification. No apparent correlation between aboveground biomass and removal of NH3–N was observed. Overall removal efficiency of NH3–N through two stages of VFCWs was 53.7% for columns planted with T. latifolia and 58.3% for those planted with S. Californicus. Average NH3–N removal efficiencies for the first stage VFCWs were 32.7% and 34.3%, while those in the second stage were 31.3% and 36.5%; no significant difference was observed between the first and second stage, suggesting that stage number does not have a significant effect on the removal efficiency of NH3–N in the primary treatment of landfill leachate via VFCWs. However, average mass removal rates of NH3–N in the first stage were 166 and 175 mg L−1 d−1; the second stage was significantly lower at 99.4 and 112 mg L−1 d−1, indicating that the first stage removed more pollutants overall.

Artificial intelligence and machine learning for the optimization of pharmaceutical wastewater treatment systems: a review

AbstractThe access to clean and drinkable water is becoming one of the major health issues because most natural waters are now polluted in the context of rapid industrialization and urbanization. Moreover, most pollutants such as antibiotics escape conventional wastewater treatments and are thus discharged in ecosystems, requiring advanced techniques for wastewater treatment. Here we review the use of artificial intelligence and machine learning to optimize pharmaceutical wastewater treatment systems, with focus on water quality, disinfection, renewable energy, biological treatment, blockchain technology, machine learning algorithms, big data, cyber-physical systems, and automated smart grid power distribution networks. Artificial intelligence allows for monitoring contaminants, facilitating data analysis, diagnosing water quality, easing autonomous decision-making, and predicting process parameters. We discuss advances in technical reliability, energy resources and wastewater management, cyber-resilience, security functionalities, and robust multidimensional performance of automated platform and distributed consortium, and stabilization of abnormal fluctuations in water quality parameters.