Wastewater Treatment Methods Research Articles

Waste newspaper activation by sodium phosphate for adsorption dynamics of methylene blue

Abstract This study investigates the potential of using waste newspaper (WN) as an adsorbent for removing methylene blue (MB) dye from water, emphasizing the environmental benefits of repurposing waste materials. Activated carbon (AC) was synthesized from WN using sodium phosphate (NaH2PO4) as the activating agent, which is known for producing high mesopore content and requiring relatively low activation temperatures. The activated carbon’s physicochemical properties were thoroughly characterized using techniques such as FTIR, SEM, and surface area analysis based on the Brunner-Emmett-Teller (BET) theory. The specific surface area of AC was 917 m2/g. Continuous adsorption experiments were conducted to evaluate the efficiency of the synthesized activated carbon in a dynamic flow system. Various operating conditions, including initial dye concentration, influent flow rate, and bed height, were explored to optimize the adsorption process. This study applied the Yoon-Nelson, Thomas, Adams-Bohart and modified Logistic models to analyze the breakthrough curves and predict adsorption capacities. Results demonstrated that the AC exhibited high adsorption capacity (14.7 mg/g), particularly at lower flow rates and higher bed heights. This work offers valuable insights into sustainable wastewater treatment methods, showcasing the effectiveness of using low-cost, waste-derived activated carbon for dye removal in industrial applications.

Exploring Urban Coastal Areas: Investigating the Urban Coastal Areas as a Reservoirs of Antibiotic Resistance Genes★

Antibiotic resistance genes (ARGs) have long served as adaptive defensive mechanisms among bacteria, enabling their survival and propagation in challenging environments. The consequences of inefficient wastewater treatment have culminated the emergence of untreatable and lethal extensively drug-resistant. To understand the relationship between wastewater effluent and marine ecosystems, we conducted a study to monitor the diversity and prevalence of common ARGs in Hong Kong's urban coastal areas at different seasons.Our findings revealed that sul 1 was the most abundant resistance gene, with an average relative abundance of 4.45×10-2 per 16s rRNA gene copy. Moreover, temperature, dissolved oxygen, and salinity were key factors influencing seasonal variations in total ARGs abundance. The influence of environmental factors varied based on ARGs' association with Intl1, with Intl1-associated ARGs strongly correlating with temperature and dissolved oxygen. Notably, despite their abundance, sul1 and mphA exhibited similar correlations with both Intl1 and key environmental factors, suggesting these ARGs share a common dissemination mechanism. Moreover, the robust association between resistance genes and mobile genetic elements (MGE) could potentially act as a valuable indicator for assessing the efficacy of removing ARGs in wastewater treatment methods when operating under carefully optimized environmental parameters.

Spatial Microenvironment Enhanced Photocatalytic Reduction of Uranyl Ions Under Solar Light Irradiation

Photocatalytic reduction of uranyl ions (UO22+) is an environmentally friendly, energy efficient, and highly effective method for uranium-containing wastewater treatment and uranium recovery. Herein, a novel photocatalytic material CH-8@NNFO-4 with abundant oxygen vacancies was synthesize by growing Ca(OH)2 on the surface of Fe doped NaNbO3 in situ. The Ca(OH)2 synergizes with the oxygen vacancies, creating a microenvironment that narrows the bandgap and extends the light response range. At the same time, the Ca-O enhance carrier transport rates and reduce the electron-hole recombination rate. Under solar irradiation, over 93.68% UO22+ is rapidly reduced to insoluble U(IV) without protectants or free radical scavengers, which is sixteen times that of pure NaNbO3, with a theoretical reduction capacity reached to 826.45mg·g⁻1. After five cycles, the removal efficiency remains at 88.77%. The CH-8@NNFO-4 possesses excellent recyclability, acid and alkali resistant, anti-interference of anions and cations and chemical stability, Furthermore, the charge transfer in CH-8@NNFO-4 revealed through DFT calculations, and an enhanced mechanism for the Ca-O synergizes spatial microenvironment photocatalytic reduction of U(VI) was proposed. This work provides a new catalytic reaction design strategy for the efficient reduction of U(VI).

Adsorptive removal of phosphate and nitrate by layered double hydroxides through the memory effect and in situ synthesis

This research examines the efficacy of layered double hydroxides (LDHs) in removing phosphate and nitrate from wastewater, enhanced by the memory effect and in situsynthesis techniques. LDHs were synthesized hydrothermally, initially creating carbonate-based CO₃–LDHs, which were then converted to chloride-based Cl–LDHs through anion exchange. These LDHs underwent calcination at 300 °C, 400 °C, and 500 °C to optimize their structure for enhanced adsorption capabilities. The synthesized LDHs were thoroughly characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray diffraction (XRD). Adsorption experiments in solutions with pH values between 5, 7, and 9 revealed the adsorption capacities of phosphate and nitrate on the CO₃–LDHs and Cl–LDH, respectively. The results indicated that LDHs calcined at 500 °C showed the highest adsorption performance, achieving maximum capacities of 184 mg/g for phosphate and 70.1 mg/g for nitrate. Kinetic studies confirmed that the adsorption process followed a pseudo-second-order model, demonstrating the effectiveness of the memory effect in enhancing ion exchange. The in situ synthesis of LDHs under controlled conditions significantly improved the removal rates of these anionic contaminants from wastewater, proving the potential of this method for the realistic wastewater treatment.

Treatment methods for sugar rich wastewater: A review

Treatment methods for sugar rich wastewater: A review

Wastewater quality evaluation in terms of wastewater quality index using hybrid constructed wetland for treatment of dairy and municipal wastewater.

The world's most pressing problem is water shortage, which is made worse by fast industrialization and urbanization, especially in places like India where untreated effluent presents serious threats to human health and the environment. In order to treat dairy and municipal wastewater, this study assesses the efficacy of a two-stage hybrid constructed wetland (CW) system. The WWQI is the primary focus of this evaluation over a range of mixing ratios. Before and after treatment, many physicochemical parameters were examined, including pH, total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorus (TP), ammonia nitrogen ( ), and nitrate nitrogen ( ). The hybrid CWs system dramatically lowers pollutant concentrations, according to the results, with combinations containing higher amounts of MWW showing the best results. The WWQI values, which change from "unfit for any uses" in untreated DWW to "excellent" quality in treated MWW, show these advancements. The results highlight the potential of hybrid CWs as an effective and sustainable wastewater treatment method, especially when it comes to maximizing the proportion of dairy to municipal wastewater. This study adds to our knowledge of efficient wastewater treatment techniques and highlights the significance of incorporating eco-friendly technologies to tackle water scarcity issues. PRACTITIONER POINTS: Hybrid Constructed Wetlands (HCWs) are effective in removing TSS, BOD, COD, TP, ammonia nitrogen, and nitrate nitrogen from dairy and municipal wastewater. On the basis of HCWs performance determine the Wastewater Quality Index (WWQI) for four different ratio proportions of dairy and municipal wastewater. This index is more useful for water quality status determination and treated water reuse for various purposes. This also benefits sustainable treatment technology and contributes to achieving SDGs.

Chromatographic mass spectrometric determination of tetracycline antibiotics in water using a single-quadrupole mass analyzer

Introduction. Antibiotics and other pharmaceuticals are increasingly detected in surface groundwater, and drinking water, raising concerns about their potential adverse impacts on ecosystems and human health. Standard wastewater treatment methods often fail to effectively remove these compounds, particularly small organic molecules like tetracycline antibiotics, leading to their persistence in the environment. To address this issue, continuous monitoring and surveillance are necessary, including regular analysis of wastewater. Modern analytical methods, such as high-performance liquid chromatography coupled with mass spectrometric detection (HPLC-MS), allow detecting trace concentrations. This work presents a new method for qualitative and quantitative analysis using a quadrupole mass analyzer, which can serve as an alternative to tandem mass spectrometry. Materials and methods. Tetracycline antibiotics (oxytetracycline, tetracycline, chlortetracycline, and doxycycline) in aquatic environments were detercted using selected ion monitoring (HPLC-MS) and selected reaction monitoring through tandem mass spectrometry (HPLC-MS/MS). Results. There have been established chromatographic and mass spectrometric criteria for the identification of tetracyclines, determining key operating parameters for the quadrupole, such as selected ion scanning based on mass-to-charge ratio (m/z), signal registration time, and duration. The developed method for analyzing tetracyclines using a quadrupole mass analyzer demonstrates analytical characteristics comparable to tandem mass spectrometry based on a triple quadrupole mass analyzer. The method was validated on a quadrupole mass analyzer during the analysis of water samples from natural sources (drinking water, centralized water supply, and treated wastewater). In this analytical approach, the sample preparation process was simplified, allowing for the assessment of antibiotic content in samples without the need for labour-intensive solid-phase extraction and concentration, starting from 1 ng/ml and above ( for various types of water mactrices). Limitations. In this study, only the intact forms of tetracyclines were identified. Separate investigations into the detection of their chemical transformation products and epimerization were not conducted. The presented approach can be applied for analyzing wastewater and assessing the quality of its treatment, where the concentration of tetracycline antibiotics as micro-pollutants may exceed 10 ng/ml. Conclusion. The proposed analytical method using a single quadrupole mass analyzer can serve as an alternative to the more expensive tandem mass spectrometer, both in terms of acquisition cost and maintenance. Key analytical characteristics that are important for environmental monitoring, such as selectivity and sensitivity, can be enhanced by optimizing the selected ion scanning mode. This was successfully demonstrated in the analysis of tetracyclines in aquatic environments. This approach could serve as a foundation for developing methodologies for detecting pharmaceutical compounds in environmental water samples using a quadrupole mass spectrometer.

Removal of Phosphorus from Water onto Marsh Clam Shell to Predict Contour for Removal Efficiency and Mass of Adsorbent

Anthropogenic activities have resulted in considerable water quality degradation in water sources due to a common problem of the excessive nutrient content (phosphorus) in receiving water, resulting in eutrophication. Even though various wastewater treatment methods have been applied, focusing on phosphorus removal through biological, physical, and chemical treatment, there is still a need to identify the eco-friendly method using the adsorption process and verify the theoretical and experimental data via kinetic and isotherm models. Hence, this study investigates phosphorus removal efficiency from water onto raw marsh clam shells and verifies the experimental and theoretical data with kinetic and isotherm studies. The variable of this study used different masses (2, 4, 6, 8, 10 g) of adsorbents with particle sizes from 1.18 mm to 2.36 mm to remove phosphorus from an aqueous solution (5 mg/L). The physicalchemical properties of adsorbents were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray Fluorescence (EDXRF), and Fourier Transform Infrared Spectroscopy (FTIR) to support the experimental data and identify the possibility of phosphorus adsorption. The batch experiment data obtained were verified using the kinetic (pseudo-first-order and pseudo-second-order) and isotherm (Langmuir and Freundlich) models. The experiments showed that the best contact time for all masses was 1440 min and the best adsorbent dose was 10 g with 78.0%removal. By comparing the two adsorption isotherm models, the study finds that the adsorption isotherm fits the Langmuir isotherm model with a correlation coefficient, R<sup>2</sup> of 0.9006. The novel use of adsorbent marsh clam shell as a potential adsorbent in the application of future water treatment technologies.

An evolutionary game theory analysis on the environmental impact of discharging Fukushima's nuclear wastewater: International stakeholders and strategic dynamics.

On August 24, 2023, Japan controversially decided to discharge nuclear wastewater from the Fukushima Daiichi Nuclear Power Plant into the ocean, initiating intense domestic and global debates. This study employs a mixed-method approach, integrating quantitative evolutionary game theory and qualitative data analysis to explore the strategic dynamics among Japan, other nations, and the Japan Fisheries Association regarding this decision. The data includes international environmental reports and economic statistics, served as the basis for simulating decision-making processes under various legal, economic, and environmental pressures. The evolutionary game theory model is used to predict and analyze three evolutionarily stable strategies (ESS), detailing the transition from the initiation to cessation of wastewater discharge. These strategies highlight the necessity for international cooperation, rigorous scientific research, public education, and effective wastewater treatment methods. This study aims to provide both a theoretical framework and practical guidance to foster a global consensus on nuclear wastewater management, which is vital for marine conservation and sustainable development.

Evaluation of Electro-chemical Methods in Wastewater Treatment of Wheat Starch Industry

Evaluation of Electro-chemical Methods in Wastewater Treatment of Wheat Starch Industry

Optimizing papermaking wastewater treatment by predicting effluent quality with node-level capsule graph neural networks.

Papermaking wastewater consists of a sizable amount of industrial wastewater; hence, real-time access to precise and trustworthy effluent indices is crucial. Because wastewater treatment processes are complicated, nonlinear, and time-varying, it is essential to adequately monitor critical quality indices, especially chemical oxygen demand (COD). Traditional models for predicting COD often struggle with sensitivity to parameter tuning and lack interpretability, underscoring the need for improvement in industrial wastewater treatment. In this manuscript, an optimized papermaking wastewater treatment method is proposed that predicts effluent quality using node-level capsule graph neural networks (PWWT-PEQ-NLCGNN). To improve the accuracy of predicting important effluent COD quality indices, the NLCGNN weight parameters are optimized using the hermit crab optimization (HCO) algorithm. The performance of the proposed PWWT-PEQ-NLCGNN technique demonstrated improvements over existing techniques. Specifically, the proposed strategy achieved 30.53%, 23.34%, and 32.64% higher accuracy; 20.53%, 25.34%, and 29.64% higher precision; and 20.53%, 25.34%, and 29.64% higher sensitivity compared to the water quality prediction model using Gaussian process regression based on deep learning for carbon neutrality in papermaking wastewater treatment system (WQP-GPR-DL-CLPWWTS), the prediction of effluent quality in papermaking wastewater treatment processes using dynamic kernel-based extreme learning machine (POEQ-PWWTP-DKBELM), and the quality-related monitoring of papermaking wastewater treatment processes using dynamic multi-block partial least squares (QRM-PWWTP-DMPLS). These results highlight the potential of the PWWT-PEQ-NLCGNN method for enabling timely and accurate monitoring of wastewater treatment processes.

Recent Advances of Using Polymer Nanocomposites For the Removal of Heavy Metal Ions From Waste Water: A Review

A major factor in the development of modern environmental engineering is the necessity of treating water pollutants. The effective removal of metallic ions of wastewater systems, using adsorption techniques, different adsorbents have been widely utilized; among these adsorbents, polymer-based composites have garnered a lot of interest due to their characteristics of environmental harmlessness and degradability. By combining the best features of both polymer and nanocomposites can offer improved chemical, physical, mechanical, and compatibility over single polymers. The review underscores the importance of polymer-based nanocomposites in offering inventive wastewater treatment methods. A thorough examination of current research and obstacles in the field of developing nanotechnology highlights these materials' ability to address the intricate problem of heavy metal ion contamination. The removal of heavy metal ions from various wastewater sources can be accomplished sustainably and effectively by integrating nanocomposites, with an emphasis on their design and manufacture. The investigation of new advances in polymer nanocomposites for the removal of heavy metal ions lays the groundwork for further study and creativity in this crucial area of environmental engineering. Using the adaptability of polymers and the special qualities of nanomaterials, this strategy develops cutting-edge solutions to deal with the intricate problems brought on by heavy metal ion pollution. Through a focus on accuracy in the design and manufacturing of these nanocomposites, scientists and industry professionals can create materials that are specialised, effective, and can make a substantial contribution to the development of wastewater treatment systems. The purpose of this research is recent analyses and challenges in the field of nanotechnology development. The data presented in this analysis will be helpful for future efforts to design and produce polymer-based Nanocomposites for the removal of a wide range of heavy metal ions

Aquaculture Wastewater Treatment by Constructed Wetlands Planted with Anthurium Plants (Anthurium andraeanum)

Aquaculture wastewater often has high content of organic matter and nutrients (nitrogen, phosphorus). Along with the rapid development of the aquaculture industry is the problem of water pollution, eutrophication... because of untreated wastewater. Among current wastewater treatment methods, constructed wetland technology is an environmentally friendly wastewater treatment solution, providing high treatment efficiency and low cost. In this study, constructed wetland systems planted with anthurium plants (Anthurium andraeanum) at laboratory-scale were established to treat shrimp farming wastewater in Quang Ninh. The results showed that after 15 experimental days, the wetland system planted with anthurium plants on gravel and coconut fiber materials had organic matter (COD) removal efficiency, ammonium (NH4+-N) and phosphate (PO43--P) removal efficiency of 87.5%, 76% and 44.1%, respectively. The wetland system planted with anthurium plants on gravel had organic matter (COD) removal efficiency, NH4+-N and PO43--P removal efficiency of 75.7%, 46.7%, and 40.6%, respectively. Meanwhile, the COD removal efficiency, NH4+-N and PO43--P removal efficiencies in the control system were only 15.8%, 12.6% and 19.4%, respectively. The research results show the ability of constructed wetland systems planted with anthurium plants to treat aquaculture wastewater.

The symbiotic system between Tribonema sp. and aerobic denitrifying phosphorus accumulating bacteria: A promising method for wastewater treatment

To enhance the wastewater treatment performance of the microalgae-bacteria symbiotic system and simplify the wastewater treatment process, a strain of aerobic denitrifying phosphorus accumulating (ADPA) bacteria with simultaneous nitrification, denitrification and phosphorus removal function was isolated in this study. The strain was identified as Pseudomonas sp. Subsequently, a co-culture system of Tribonema sp. and Pseudomonas sp. (T + P) was established. Compared to the Tribonema sp.-activated sludge (T + AS), activated sludge (AS), and Pseudomonas sp. (P) groups, the T + P group exhibited excellent nitrogen and phosphorus removal efficiency. The removal efficiencies of phosphate (PO43−-P), ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3−-N) and total nitrogen (TN) at 36 h were 67.69 %, 76.93 %, 95.76 % and 84.87 %, respectively. Meanwhile, T + P group had the highest total biomass and lipid content, which could reach 0.67 g·L−1 and 25.44 % in 108 h. The addition of Tribonema sp. significantly contributed to reducing total organic carbon (TOC) and inorganic carbon (IC) concentrations. This Tribonema sp.-Pseudomonas sp. symbiotic system has proven to be a promising and efficient new method for wastewater treatment, potentially addressing the limitations of traditional activated sludge processes.

Comparative life cycle assessment of traditional and emerging methods for high concentration organic wastewater treatment.

Two traditional methods, including incineration and the sequencing batch reactor activated sludge process (SBR), and two emerging methods, including supercritical water oxidation (SCWO), catalytic wet oxidation (CWO) combined with SBR (CWO-SBR), for high concentration organic wastewater treatment were compared from the view of environmental impact. The printing ink wastewater generated from the surface treatment of electronic products was selected as the typical wastewater and diluted to various concentrations for sensitivity analysis. Simapro 9.3 software was selected to explore the environmental impacts of the four processes with Traci impact assessment method and Ecoinvent 3.8 database. Moreover, two tools including the total environmental impact and comprehensive competitiveness were used for quantitative comparison. The total environmental impacts for the incineration and SCWO processes gradually decrease with increasing chemical oxygen demand (COD) concentration for more steam output and less fuel and electricity consumptions, but opposite trends appear for the CWO-SBR and SBR processes, indicating higher COD concentrations exhibit smaller environmental impacts for the incineration and SCWO processes. The incineration and SBR processes have the slightest and highest total environmental impacts of 0.030 and 1.117 at the base case of COD=234,000mg/L, respectively. The trends of the comprehensive indexes for the four processes with increasing COD concentration are similar to those of the total environmental impacts. The SCWO process has the highest comprehensive index of 0.956 at the base case, followed by the incineration, CWO-SBR, and SBR processes, with values of 0.783, 0.460, and 0.158, respectively.

Alum sludge-driven electro-phytoremediation in constructed wetlands: a novel approach for sustainable nutrient removal.

In addition to their advantages as promising methods for wastewater treatment, CWs exhibit poor performance in terms of N and P removal efficiency in the effluent of wastewater treatment plants. By focusing on this issue, we designed CWs integrated with a biochar-doped activated carbon cloth (ACC) electrode and alum sludge from water treatment plants as a substrate to achieve concomitant organic matter and nutrient removal efficiency. Compared with the use of one layer of alum sludge in CWs (CWs-C3) with ACC electrodes inserted in two layers, which uses one layer of alum sludge, a significant improvement in removal efficiency was achieved (96% for COD; 89% for TN; and 77% for TP). The findings revealed that the application of potential accompanied by the insertion of a cathode ACC electrode into the first layer of alum sludge was beneficial for completing nitrification and facilitating denitrification in the cathode and anode regions, respectively, resulting in increased removal of organic matter and nutrients. Further evaluation revealed that the TN-TP synergetic removal mechanism was influenced by the use of Fe2+ as an electron donor and as a driving force for the development of autotrophic denitrifying bacteria to increase nitrate reduction. Additionally, the formation of FePO4 and AlPO4 and their adsorption through the interaction of FeOOH and AlOOH with phosphate constitute the main removal mechanism for TP in wastewater. Another reason for the increased removal efficiency in the CW-C3 reactor was the greater abundance and microbial diversity effectuated by the application of potential in the anode and cathode regions. In summary, a promising strategy for simultaneously promoting organic matter and nutrients and utilizing CWs on a large scale and in practical applications was proposed.

Emerging organic micropollutants as serious environmental problem: A comprehensive review.

The escalating problem of environmental pollution can be attributed to the accelerated pace of global development, which often prioritizes human needs over planetary health. Despite huge global attempts endeavours to mitigate legacy pollutants, the uninterrupted introduction of novel substances such as the emerging organic micropollutants (EOMs) represents a significant menace to the natural environment and all forms of life on the earth. The widespread occurrence of EOMs in water and wastewater is a consequence of both their growing consumption as well as the limitations of the conventional wastewater treatment methods containing such pollutants resulting in deterioration of water quality and its supplies as well as this is a significant challenge for researchers and the scientific community alike. EOMs possibility to bioaccumulate, their toxic properties, resistance to degradation, and the limitations of conventional wastewater treatment methods for quantitative removal of EOMs at low concentrations give a significant environmental risk. These compounds are not commonly monitored, which exacerbates further the problem. Therefore the wide knowledge concerning EOMs properties, their occurrence as well as awareness about their migration in the environment and harmful effects is also extremely important. Therefore the EOMs characterization of various types, their classification and sources, concentrations in the aquatic systems and wastewaters, existing regulatory guidelines and their impacts on the environment and human health are thoroughly vetted in this review. Although the full extent of EOMs' effects on aquatic ecosystems and human health is still in the process of investigations, there are evident indications of their potential acute and chronic impacts, which warrant urgent attention. In practical terms the results of the research presented in this paper will help to fill the knowledge gaps concerning EOMs as a serious problem and to raise public awareness of actions to move to sustainable pollution management practices to protect our planet for future generations are vital.

Evaluation of the efficiency of shell powder as a natural adsorbent for the adsorption of chromium in aqueous solutions: kinetic and thermodynamic approach and modeling of adsorption isotherms

Water pollution by heavy metals such as chromium is a major environmental issue requiring effective remediation solutions. In this study, shellfish powder was used as a natural material to adsorb chromium (III) from aqueous solutions. The results show that shellfish have a significant adsorption capacity, indicating their effectiveness under a variety of conditions. Adsorption kinetics tests showed that the adsorption mechanism followed a pseudo-second-order kinetic model. In addition, thermodynamic parameters show that the adsorption process is a beneficial, spontaneous and endothermic phenomenon. Isotherm models such as Langmuir, Freundlich and Temkin were applied to analyze adsorption behavior. This research could contribute to the development of more sustainable wastewater treatment methods, incorporating natural materials into remediation strategies.

Research on Energy Savings through Floating DO Measuring Device in SBR Wastewater Treatment Method

Objectives : The objective of this study is to propose an optimal operational control method to ensure stable effluent water quality and reduce treatment costs in the SBR(Sequencing Batch Reactor) wastewater treatment process. In particular, the study aims to maintain the dissolved oxygen(DO) concentration required for microorganisms while reducing power costs associated with excessive aeration.Methods : To address issues with conventional fixed DO sensors, such as scum formation, inaccuracies caused by bubbles and strong flow velocities during aeration, and reduced reliability due to fluctuating water levels, a floating DO sensor was introduced to measure DO concentrations in real-time. Based on these real-time measurements, the optimal DO concentration required for microbial activity was calculated, and a system was designed to automatically control the airflow rate set value(SV) of the turbo blower.Results and Discussion : The application of a single-variable DO control method effectively reduced the power consumption required for aeration in the SBR aeration tank. This approach prevented energy waste caused by excessive aeration while maintaining the appropriate DO concentration needed for microbial activity. These results demonstrate that the proposed method improves the reliability and efficiency of the system.Conclusion : The real-time DO control method using a floating DO sensor enables energy savings and ensures stable effluent water quality in the SBR process. The proposed method overcomes the limitations of conventional fixed DO sensors, contributing to reduced power costs and improved process efficiency.

PRODUCTION OF NANOCELLULOSE FOR WATER PURIFICATION FROM DYES

In the context of increasing industrial pollution and insufficient efficiency of traditional wastewater treatment methods, the issue of finding environmentally friendly and effective sorbents is particularly acute. Industrial dyes entering reservoirs change their color, are toxic and can pose a serious threat to human health and the ecosystem. The main difficulty lies in the fact that many dyes are resistant to biodegradation, which complicates their removal by standard cleaning methods. One of the promising materials that can solve this problem is nanocellulose, which has unique properties: high specific surface area, biocompatibility and biodegradability. Obtained from renewable sources, nanocellulose can become the basis for environmentally friendly water treatment systems. This study is aimed at studying the adsorption characteristics of nanocellulose synthesized from microcrystalline cellulose in relation to two stable water – soluble dyes – methylene blue and bengal rose. The results showed that nanocellulose effectively adsorbs methylene blue, reaching a sorption capacity of 35.87 mg/g, whereas for Bengal rose the adsorption capacity was 26.11 mg/g, which is explained by the difference in the types of interactions: chemical and physical adsorption. The methods of IR spectroscopy and X-ray diffractometry confirmed the structural changes that occurred during the synthesis of nanocellulose, which had a positive effect on its sorption characteristics. Morphological studies using optical and scanning electron microscopes have also demonstrated a high degree of dispersion and a developed porous structure of nanocellulose, which is important for improving its adsorption properties.