Wastewater Treatment Technologies Research Articles

Trace the evolution path of pharmaceutical wastewater treatment technology based on a patent perspective

ABSTRACT This paper discusses the research hotspots and future development trends of pharmaceutical wastewater treatment technology, in order to provide valuable reference and guidance to promote the development of technology. First, the search path counting (SPC) algorithm is utilized to identify the global main path to perform a preliminary analysis of the technology evolution path from a macro perspective. Second, according to the life cycle, S-curve divides the time windows of the temporal themes and uses the Latent Dirichlet Allocation (LDA) modeling to identify the themes under each time window. Then, a visualized Sankey diagram is generated to determine the evolutionary relationship, which can be supplemented with the paths of technological evolution from the micro point of view. Finally, six research hotspots of pharmaceutical wastewater treatment technology were found, which are compounding agents, advanced oxidation technology, nanomaterials, artificial intelligence (AI) technology, membrane pollution prevention, and various combinations of wastewater treatment technology. The study also predicted its future development direction.

Phosphomolybdic acid functionalized nano silica for enhanced anti-biofouling effect in polymer electrolyte membranes for microbial fuel cell application

Microbial fuel cells (MFCs) represent a promising technology for simultaneous electricity generation and wastewater treatment. In this study, a single-chambered MFC was fabricated utilizing a novel polymer electrolyte membrane synthesized from sulfonated polyether ether ketone grafted with styrene sulfonic acid (SPEEK/SSA) as the base polymer, and silica decorated with phosphomolybdic acid (SPMA) as a functionalized nanofiller. Various concentrations of SPMA (2.5 %, 5 %, 7.5 %, and 10 %) were incorporated into the SPEEK/SSA membranes and characterized physicochemically. The SPEEK/SSA membrane with 5 wt% SPMA demonstrated the highest proton conductivity (3.75×10−2 S cm−1) and ion exchange capacity (1.68 meq g−1). This PEM also exhibited superior tensile strength (20 MPa) and excellent chemical durability, as evidenced by Fenton's reagent test. Performance evaluation revealed that this membrane achieved a maximum power density of 196.6 mW m−2 at a maximum of 180 mA m−2 current density. Additionally, antibiofouling tests indicated that the 5 % SPMA-incorporated membrane possessed significant antibacterial properties against both gram-positive and gram-negative bacteria and exhibited high biofilm inhibition. The wastewater treatment efficacy of the MFC with the 5 % SPMA membrane was confirmed by a chemical oxygen demand (COD) removal efficiency of 81.49 %, indicating its potential for effective wastewater treatment. Phylogenetic analysis through 16S rRNA sequencing identified major bacterial phyla including Proteobacteria, Bacteroidetes, Chloroflexi, and Firmicutes, with predominant genera such as Pseudomonas and Acidovorax. This study emphasises the potential of nanocomposite membranes to enhance the performance and durability of MFCs while mitigating biofouling, thereby paving the way for future research and development in this field.

Life Cycle Impact Assessment (LCIA), A Decision Making Approach in Waste Water Treatment Plant: A Case Study

Environmental foot print of a waste water treatment plant is an important criterion to assess the performance of treatment unit. The novel waste water treatment technology was used to clean waste water up to a certain limit. Therefore, in whole process, beginning from electricity production to final disposal of water these treatment technologies can affect our environment. This environmental foot print can be determined by using CML 2000 guideline. In final performance of a waste water treatment plant environmental ill effects should also be incorporated instead of only using treatment efficiency, CML 2000 gives environmental performance. In this study four waste water treatment technologies namely Activated Sludge Process, up flow Anaerobic Sludge Blanket, Membrane Biofilm Bioreactor, Fluidized Aerobic Bed were taken. The environmental performance of all these novel technologies was assessed on the basis of eutrophication, global warming potential and removal efficiency, characterization factors are normalized by using CML 2000 guideline. The maximum and minimum results of Acidification was obtained as 0.2215 & 0.0569 in UASB and FAB respectively. The maximum and minimum results of Eutrophication was attained as 0.564 & 0.055 in MBBR and ASP respectively.

Potential for nutrients reuse, carbon sequestration, and CO2 emissions reduction in the practice of domestic and industrial wastewater recycling into agricultural soils: A review

This review assesses the feasibility of reusing treated wastewater for irrigation in agricultural soils as a strategy for nutrients recycling and mitigation of CO2 emissions. Through a literature review, it was examined wastewater sources enriched with carbon and nutrients, including municipal wastewater and associated sludge, vinasse, swine wastewater, as well as wastewater from the food industry and paper and pulp production. The review also explores the dynamics of organic matter within the soil, discussing the aspects related to its potential conversion to CO2 or long-term storage. It was found that industrial wastewaters, owing to their higher organic matter and recalcitrance, exhibit greater potential for carbon storage. However, the presence of pollutants in wastewater necessitates careful consideration, particularly concerning their impact on soil quality. Toxic metals, microplastics, and organic compounds emerged as significant contaminants that could accumulate in the soil, posing risks to ecosystem health. To mitigate the environmental impacts, it was evaluated various wastewater treatment technologies and their associated carbon emissions. While advanced treatments may effectively reduce the contaminant load and mitigate soil impacts, their adoption is often associated with an increase in CO2 emissions. Membrane bioreactors, microfiltration, ultrafiltration, and up-flow anaerobic sludge blanket reactors were identified as promising technologies with lower carbon footprints. Looking ahead, future research should aim to enhance the understanding of carbon dynamics in soil and validate the environmental impacts of treated wastewater disposal. Despite remaining uncertainties, the literature indicates a positive outlook for wastewater recycling in soil, offering a viable strategy for carbon storage and mitigation of greenhouse gas emissions.

Semi-IPN polysaccharide-based hydrogels for effective removal of heavy metal ions and dyes from wastewater: a comprehensive investigation of performance and adsorption mechanism.

The escalating issue of environmental pollutants necessitates efficient, sustainable, and innovative wastewater treatment technologies. This review comprehensively analyzes the mechanisms and isotherms underlying the adsorption processes of semi-interpenetrating polymer network (semi-IPN) polysaccharide-based hydrogels to remove heavy metal ions and dyes from wastewater. Polysaccharides are extensively utilized in hydrogel synthesis due to their biocompatibility, cost-effectiveness, and non-toxic nature. The synthesis of these hydrogels as semi-IPNs enhances their mechanical and structural robustness and adsorption capacity. This review explores the key parameters affecting adsorption performance, including pH, temperature, contact time, and adsorbent dosage. Findings highlight that semi-IPN polysaccharide-based hydrogels exhibit remarkable adsorption capabilities through electrostatic interactions, ion exchange, and surface complexation. Furthermore, this review highlights the distinct advantages of semi-IPNs over other polymer networks. Semi-IPNs offer improved mechanical stability, higher adsorption efficiencies, and better reusability, making them a promising solution for wastewater treatment. Detailed isotherm models, including Langmuir and Freundlich isotherms, were studied to understand these hydrogels' adsorption behavior and capacity for different pollutants. This study highlights the potential of semi-IPN polysaccharide-based hydrogels as effective adsorbents forheavy metals and dyes and as a promising solution for mitigating environmental pollution. The insights provided herein contribute to developing advanced materials forenvironmental remediation, aligning with global sustainability goals, and advancing wastewater treatment technology.

Insights into the role of electrochemical stimulation on sulfur-driven biodegradation of antibiotics in wastewater treatment

The presence of antibiotics in wastewater poses significant threat to our ecosystems and health. Traditional biological wastewater treatment technologies have several limitations in treating antibiotic-contaminated wastewaters, such as low removal efficiency and poor process resilience. Here, a novel electrochemical-coupled sulfur-mediated biological system was developed for treating wastewater co-contaminated with several antibiotics (e.g., ciprofloxacin (CIP), sulfamethoxazole (SMX), chloramphenicol (CAP)). Superior removal of CIP, SMX, and CAP with efficiencies ranging from 40.6 ± 2.6 % to 98.4 ± 1.6 % was achieved at high concentrations of 1000 μg/L in the electrochemical-coupled sulfur-mediated biological system, whereas the efficiencies ranged from 30.4 ± 2.3 % to 98.2 ± 1.4 % in the control system (without electrochemical stimulation). The biodegradation rates of CIP, SMX, and CAP increased by 1.5∼1.9-folds under electrochemical stimulation compared to the control. The insights into the role of electrochemical stimulation for multiple antibiotics biodegradation enhancement was elucidated through a combination of metagenomic and electrochemical analyses. Results showed that sustained electrochemical stimulation significantly enriched the sulfate-reducing and electroactive bacteria (e.g., Desulfobulbus, Longilinea, and Lentimicrobiumin on biocathode and Geobactor on bioanode), and boosted the secretion of electron transport mediators (e.g., cytochrome c and extracellular polymeric substances), which facilitated the microbial extracellular electron transfer processes and subsequent antibiotics removal in the sulfur-mediated biological system. Furthermore, under electrochemical stimulation, functional genes associated with sulfur and carbon metabolism and electron transfer were more abundant, and the microbial metabolic processes were enhanced, contributing to antibiotics biodegradation. Our study for the first time demonstrated that the synergistic effects of electrochemical-coupled sulfur-mediated biological system was capable of overcoming the limitations of conventional biological treatment processes. This study shed light on the mechanism of enhanced antibiotics biodegradation via electrochemical stimulation, which could be employed in sulfur-mediated bioprocess for treating antibiotic-contaminated wastewaters.

Efficient treatment of polyacrylamide wastewater by cascade heterogeneous Fenton and magnetic flocculation process

A large quantity of polyacrylamide containing wastewater is generated during polymer flooding every year and it poses great threats to the environment. As highly efficient technology for polyacrylamide wastewater treatment with potential for engineering application is rare, magnetic flocculation represents a promising alternative. It usually takes minutes for complete sedimentation to occur. However, we found in experiments that viscosity reduction in advance was essential to improve the performance of magnetic flocculation. So, a cascade of heterogeneous Fenton and magnetic flocculation process was proposed. Effect of Fe3O4 dosage, flocculants type and dosage, flocculation pH, stirring conditions and flocculation methods on the removal efficiency of PAM was investigated. The cascade process turned out to be one of the most efficient technologies and achieved 92% PAM removal rate in the shortest time (45 min) for 500 mg/L of PAM when Fe3O4 dosage was 1.5 g/L, AlCl3 dosage was 100 mg/L and flocculation pH was 8.0 under optimized stirring conditions. Nano-Fe3O4 exhibited good stability after at least 3 successive runs. The water quality of polymer flooding wastewater from Nanyang Oilfield reached the required standards for reinjection after treatment by the cascade process. The study provides a new and highly efficient technology for PAM wastewater treatment with promising potential for engineering application.

Construction of heterojunction superparamagnetic Cd0.5Ag0.5Fe2O4 nanocomposite photocatalyst for simulated textile effluent oxidation

Abstract Significant attempts have been recently made regarding nanomaterials due to their several environmental applications especially in wastewater treatment technologies. Among the available nanoparticles, ferrite based substances are gaining a special interest since their superior characteristics such as their magnetic nature, high adsorption capacity and large specific surface area. In this regard, Cd0.5Ag0.5Fe2O4 was prepared using the green simple co-precipitation route. Then, the sample is characterized via Scanning Electron Microscopy (SEM) that proved the produced material’s surface morphology. The substance is then employed as a catalyst source for Fenton reaction to oxidize textile effluent solution containing Rhodamine B (Rh-B 6G) dye. The oxidation experiment conducted under ultraviolet (UV) light with the ferrite-based Fenton catalyst supplemented with hydrogen peroxide showed an exceptional removal rate of up to 94% removals. Notably, the oxidation system is significantly impacted by the operational variables. The oxidation efficiency of the dye was maximized at pH 3.0 and 50 mg/L and 1600 mg/L for ferrite-based Fenton catalyst and H2O2, respectively. The impacts of the operational factors, i.e. initial pH value, initial dye concentration, catalyst, and H2O2 concentrations were also investigated. This perspective introduces the role of a superparamagnetic material to be a recyclable sustained catalyst.

Electro-nitrification coupled with biological denitrification achieves efficient nitrogen removal from rare earth mine ammonia-nitrate wastewater

Nowadays, ammonia-nitrate wastewater has been posed serious environmental hazards. Electrochemical ammonia oxidation (AOR) technology with environmentally friendly and easy-to-operate features has attracted much attention. In this work, a novel anode catalytic electrode (Ni1Cu1Fe0.5-S/Ti) is prepared by a one-step electrodeposition method for electro-nitrification, and coupled a biological denitrification device for the treatment of real ammonia-nitrate wastewater. The unique three-dimensional layered spherical structure of Ni1Cu1Fe0.5-S/Ti electrode has been verified through physical characterization, and electrochemical tests demonstrated that Ni1Cu1Fe0.5-S/Ti electrode gained an excellent current density of 54.48 mA·cm−2 toward to AOR at 0.65 V vs. Hg/HgO as well as good stability for four times repeated electro-nitrification experiments. The optimal experimental operating conditions were obtained by changing electrode spacing, initial NH4+-N concentration, current density and flow rate. Consequently, 97.7 % total nitrogen (TN) removal efficiency of real wastewater is achieved through electro-nitrification coupled with biological denitrification, providing a new perspective technology for ammonia-nitrate wastewater treatment.

Performance Evaluation of Advanced Wastewater Treatment Technologies in Herbal Processing and Extraction Industry

"Due to enormous quantities with hazards and complexity in nature is a big challenge for effective treatment of wastewater from pharmaceutical processes including herbal extraction through conventional methods of distillation. The situation is further aggravated in countries facing high rising population, urbanization, and industrialization resulting in the generation of industrial wastes. The study has been carried out in the herbal extraction industry by conducting stage-wise sampling of ETP based on the conventional method and further coupled with ozonation as an advanced treatment to comply with regulatory standards. Additionally, the same process was studied that implementing the best available technology (BAT) by providing ETP with advanced technology modules such as MBR (membrane bioreactor) + RO + O3 has not only resulted in compliance with standards but also reuse of treated wastewater into the process and utilities has been proved to be techno-economically a viable and sustainable option. Modifying existing aeration tanks and advanced oxidation through ozone injection post-biological treatment has resulted in COD and BOD reduction of 96.42% and 99.0% respectively. Whereas in the case of MBR + RO + O3, the values of pH, BOD, COD, TSS, and sulfide have been observed as 8.32, 2.0 mg.L-1, 14.0 mg.L-1, 1.0 mg.L-1 and 0.0 mg.L-1 respectively and 98% recovery of treated effluent, thus saving 44 KL.day-1 of freshwater resulting into significant financial benefits of Rupees 12.59 acs annually, which otherwise was outsourced through tankers."

Life Cycle Assessment of Industrial Wastewater Treatment Trains

AbstractAlternative technologies to granular activated carbon (GAC) are of interest to improve the sustainability and reduce the cost of munitions wastewater treatment. Research efforts have highlighted GAC alternatives, yet few reports of environmental and economic impacts associated with these technologies are available. Herein, a life cycle assessment (LCA) aids in assessment of environmental impacts associated with six munitions wastewater treatment configurations—specifically GAC, compared to five configurations that include combinations of ion exchange (IX), reverse osmosis (RO), aerobic granular reactors (AGR), UV/H2O2, and ozone technologies. The LCA compares environmental impacts generated by treating 1 m3 of munitions wastewater, impacts by life cycle stage, and effects of IX, RO, and GAC replacement frequency. Results show that IX resin pairs with AGR (for flow‐through treatment) and ozone (for IX regenerant treatment) generated 22 ± 18% less impact than GAC in nine of ten environmental impact categories during production, transportation, and disposal. Treatment trains with ozone or AGR produce 35% less environmental impact than those with UV/H2O2. Production and use stages generate more environmental impacts than transportation and disposal stages for most treatment technologies. This LCA provides insights into the sustainability of six munition wastewater treatment technologies and identifies areas where treatment sustainability can be improved.

Phytoremediation potential of Duranta erecta in cascade hydroponics for effective domestic wastewater treatment

Discharging untreated wastewater into natural water systems poses significant risks to public health, economies, and ecological stability worldwide. This study addresses these effects by investigating the phytoremediation potential of Duranta Erecta in cascade hydroponics for treating domestic wastewater. It centers on the removal of dissolved and suspended solids as well as organic matter, representing a groundbreaking effort in this domain. It involved two experimental setups: one integrating Duranta Erecta with media (gravel (EXU-1) and polyester sponge (EXU-2)), and a control setup ((gravel (COU-1) and polyester sponge (COU-2))) using only media. Each configuration consisted of three bioreactors designed to treat wastewater from Kilinto prison camp. Four hydraulic retention times (HRTs) were tested, with the 7-day HRT emerging as the most effective compared to the 1, 3, and 5-day intervals. At the 7-day HRT, experimental units one and two demonstrated substantial reductions in pollutants: suspended solids (96.50 % & 89.3 %), turbidity (94.3 % & 87.2 %), dissolved solids (49.5 % & 45.15 %), biological oxygen demand (94.57 % & 89.78 %), and chemical oxygen demand (95.44 % & 90.65 %). Statistical analysis confirmed these reductions as statistically significant (P < 0.05). These findings highlight Duranta Erecta cascade hydroponics as a promising decentralized wastewater treatment technology, particularly suitable for developing countries like Ethiopia.

Long-term operation of a full-scale membrane bioreactor for industrial wastewater treatment using polyvinyl fluoride hollow fiber membranes: A systematic evaluation during 18-year operation

A membrane bioreactor (MBR) is a robust, high-performance technology for wastewater treatment that has been commercialized and disseminated worldwide since 1990. Despite broad implementation of this technology in the wastewater sector, ultralong operation beyond the membrane lifetime has rarely been reported. Therefore, the objectives of this study were to investigate (1) the effectiveness of a manually-operated feedback strategy to prevent membrane biofouling by dosing with sodium hypochlorite and oxalic acid and (2) the organic carbon removal of industrial wastewater treated by a full-scale MBR system in a chemical plant. The manually-operated feedback strategy consisted of monitoring the transmembrane pressure (TMP) by a test module in a bench-scale MBR to detect an inflection point, that is, the point (15 kPa) at which the TMP switched from growing gradually to exponentially in time. Biocake formation became noticeable at the inflection point, suggesting the TMP at which the membrane should be chemically washed to prevent severe biofouling. A full-scale MBR system was installed with a polyvinylidene fluoride (PVDF) membrane for organic carbon removal. The membrane was washed with 3000 mg/L of sodium hypochlorite and 1 wt% oxalic acid when the TMP reached 15 kPa during operation. The MBR was successfully operated for over 18 years without the PVDF membrane being damaged or compromised by biofouling. Characterization of the foulants on the membrane surface revealed that membrane washing removed inorganic (calcium and iron) and organic (acid amides and polysaccharides) foulants, plausibly by the action of oxalic acid and sodium hypochlorite, respectively. Installing a robust PVDF membrane and performing chemical washing at an inflection point in the TMP dynamics enabled ultralong MBR operation beyond the regular membrane lifetime. The implementation of the advocated strategy paves the way for the low CO2 footprint operation of a PVDF MBR, which does not require frequent membrane replacement and laborious membrane ex-situ cleaning.

Recent Advancements in Water Waste Water Treatment Technologies

Recent Advancements in Water Waste Water Treatment Technologies

Recent Advances in Magnetic Feˣ⁺/TiO₂ Microfibers for Wastewater Treatment as Climate Change Mitigation

Chemical dyeing and finishing processes used in the clothing and textile industries are among the main contributors that can increase the impact of climate change. Photocatalysis using nanosized titanium dioxide (TiO2) has been continuously developed as a promising technology for purifying dye wastewater into simpler and environmentally friendly components. In addition, the decoration of iron cations (Fe2+) and (Fe3+) increases the reusability of the photocatalyst due to their magnetic properties, which are easy to collect for the recycling process. Magnetic Fex+/TiO2 microfibers have been successfully prepared using a hydrothermal method using titanium dioxide in an alkaline solution. Cations were added into the solution with the different molar ratios of Ti/Fex+ to produce Fe2+/TNW and Fe3+/TNW, respectively. Photocatalysis activity test using magnetic Fex+/TNW was carried out using methylene blue in a reactor equipped with an incandescent bulb lamp representing solar light. The results showed that adding the cations resulted in a new shape of palm tree leaves, like titanate microfibers. Controlling the cation’s molar ratio produces the magnetic Fex+/TNW with a 50-150 µm length. SEM images of each material presented the uniformly elongated shape and aggregated on one side morphology. In addition, paramagnetic properties indicate that magnetic Fex+/TNW can be easily separated from the dispersion in less than 1 minute using an external magnet. A photocatalysis activity test of magnetic Fex+/TNW was performed by calculating the percent degradation of methylene blue with variations in irradiation time in visible light conditions. The result showed the effectiveness of photodegradation of methylene blue was significantly increased in materials with 3.3 molar ratios of both Ti/Fe2+ and Ti/Fe3+ with a percent degradation reaching 79% and 70%, respectively, in 5 hours. In conclusion, magnetic Fex+/TNW is introduced as an alternative dye wastewater treatment technology that has reusable properties and works well on sustainable energy sources of solar light.

Ecotoxicological study of seven pharmaceutically active compounds: Mixture effects and environmental risk assessment

Pharmaceutically active compounds (PhACs) have been detected in several aquatic compartments, which has been of environmental concern since PhACs can cause adverse effects on the aquatic ecosystem at low concentrations. Despite the variety of PhACs detected in surface water, ecotoxicological studies are non-existent for many of them, mainly regarding their mixture. In addition, water bodies can continuously receive the discharge of raw or treated wastewater with micropollutants. Thus, PhACs are subject to mixture and interactions, potentiating or reducing their toxicity. Therefore, the present study evaluated the toxicity on Aliivibrio fischeri of seven PhACs, which still needs to be explored in the literature. The effects were evaluated for the PhACs individually and for their binary and tertiary mixture. Also, the experimental effects were compared with the concentration addition (CA) and independent action (IA) models. Finally, an environmental risk assessment was carried out. Fenofibrate (FEN), loratadine (LOR), and ketoprofen (KET) were the most toxic, with EC50 of 0.32 mg L-1, 6.15 mg L-1 and 36.8 mg L-1, respectively. Synergistic effects were observed for FEN + LOR, KET + LOR, and KET + FEN + LOR, showing that the CA and IA may underestimate the toxicity. Environmental risks for KET concerning algae, and LOR e 17α-ethynylestradiol (EE2) for crustaceans and fish were high for several locations. Besides, high removals by wastewater treatment technologies are required to achieve the concentrations necessary for reducing KET and LOR risk quotients. Thus, this study contributed to a better understanding of the toxic interactions and environmental risks of PhACs.

Enhanced antifouling behavior and phosphorus removal in a gravity-driven electrochemical dynamic membrane bioreactor (EDMBR) process: Performance and mechanisms

Gravity-driven dynamic membrane bioreactor (DMBR) process has emerged as a promising wastewater treatment technology. However, long dynamic membrane (DM) formation time, membrane fouling and low phosphorus removal have limited its widespread application. A novel gravity-driven electro-DMBR (EDMBR) using stainless-steel meshes as the anodic membrane and graphite plates as the cathodes was developed for domestic wastewater treatment, with process performance, DM properties and energy consumption compared with a control DMBR without external voltage applied. Electrostatic adsorption between negatively charged foulants and positively charged anodic membrane shortened DM formation time to less than 4 min. Afterwards, electro-oxidation effect and biodegradation effect resulted from the enrichment of electroactive microorganisms (such as Pseudomonas, Acinetobacter, Exiguobacterium) ensured continuous degradation of attached foulants and maintained a thin and well-structured DM layer, showing higher stable flux and reduced cleaning frequency at the voltage of 1.2 V and 1.6 V compared to the control DMBR. The electro-coagulation (EC) effect originated from iron releasing modified the sludge properties and enhanced phosphorus removal (74 %-87 %). Moreover, the EDMBR with higher permeability and treatment capacity resulted in lower energy consumption (0.41–0.44 kWh/m3) compared to the DMBR (0.50 kWh/m3). The results provide new insights into sustainable operation of the EDMBR process towards lower energy demand and less maintenance requirement.

Evaluation of a Greenhouse Ecosystem to Treat Craft Beverage Wastewater

An aerated greenhouse ecosystem, often referred to as a Living Machine®, is a technology for biological wastewater treatment within a greenhouse structure that uses plants with their roots submerged in the wastewater. This system has a small footprint relative to traditional onsite wastewater treatment systems and constructed wetland, can treat high-strength wastewater, and can provide a high level of treatment to allow for reuse for purposes such as irrigation, toilet flushing, and landscape irrigation. Synthetic and actual craft beverage wastewaters (wastewater from wineries, breweries, and cideries) were examined for their treatability in bench-scale greenhouse ecosystems. The tested wastewater was high strength with chemical oxygen demands (COD) concentrations of 1120 to 15,000 mg/L, total nitrogen (TN) concentrations of 3 to 45 mg/L, and total phosphorus (TP) concentrations of 2.3 to 90 mg/L. The COD, TN, and TP concentrations after treatment ranged from below 125 to 560 mg/L, 1.5 to 15 mg/L, and below 0.25 to 7.8 mg/L, respectively. The results confirm the ability of the aerated greenhouse ecosystem to be a viable treatment system for craft beverage wastewater and it is estimated to require 54 and 26% lower hydraulic retention time than an aerobic lagoon and a low temperature, constructed wetland, respectively, the types of systems that would likely be used for this type of wastewater for onsite locations.

From Origins to Impacts: A Comprehensive Review of Microplastics in Freshwater Environments

Microplastics are plastic particles of dimensions less than 5mm, increasingly recognized as omnipresent contaminants in freshwater systems. These small particles are sourced from microbeads provided by personal care products, industrial abrasives, and other secondary sources formed by the degradation of larger plastic items. The microplastics are contaminated in freshwater environments through runoff, atmospheric deposition, and the discharge of water treatment processes. The presence of microplastics in freshwater has greater potential to cause harm to aquatic environments and human health. The primary objective of this paper is to identify the microplastic pollution in freshwater resources and classify the sources of this pollution in freshwater resources, including both primary and secondary microplastics, and to evaluate the ecological impact of microplastics and their potential health risks to humans through food chain transfer. This review synthesizes the most recent findings on sources, impacts, and potential mitigation measures of microplastic pollution in freshwater ecosystems to emphasize the attentive work needed urgently in our efforts to conquer the environmental challenge. The mitigation strategies in practice thus focus on policy implementation and correct technology in wastewater treatment, raising public awareness to minimize the use of plastics and encourage good waste management. However, studies with much detail are still required to develop systematic methodologies for microplastic analysis and go far enough to find long-term solutions

Nitrogen-doped iron-manganese porous carbon particle electrodes for electrocatalytic degradation of tetracycline: Interfacial reaction mechanisms

In this study, nitrogen-doped porous carbon-supported iron-manganese microspheres (FeMn@NC-700) were successfully synthesized and employed as three-dimensional particle electrodes (3DPE) for electro-oxidative of tetracycline (TCH) in water. FeMn@NC-700 exhibited stable catalytic activity and effective TCH removal capabilities under complex water quality conditions and varying pH levels. Under optimized conditions, the 3D/FeMn@NC-700 system reduced the TCH concentration from an initial 20 mg/L to 0.96 mg/L within 60 min, achieving a 95.23 %removal efficiency with an energy consumption of only 10.05 kWh/m3. The outstanding electrocatalytic activity of the 3D/FeMn@NC-700 system was attributed to the dynamic redox cycling between the Fe and Mn species on the 3DPE surface. Radical quenching experiments and electron paramagnetic resonance (EPR) analysis identified the predominant role of singlet oxygen (1O2), effectively removing TCH with the assistance of hydroxyl radicals (·OH) and superoxide anions (O2·-). The degradation pathways of major intermediate products of TCH were proposed, along with a toxicity assessment. In conclusion, the 3D/FeMn@NC-700 system represents a reliable and cost-effective technology for TCH wastewater treatment.