COD Removal Efficiency Research Articles

Efficiency of Electrocoagulation for Laboratory Wastewater Treatment Using Aluminum Electrodes

Environmental analysis of waste generated from residual samples in a testing laboratory is necessary to mitigate its impact. This study aims to assess the performance of electrocoagulation (EC) using aluminum (Al) electrodes in reducing Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and pH level in laboratory wastewater. This investigation successfully employed an EC process utilizing Al electrodes in both anode and cathode configurations. The experimental conditions include Voltage (10, and 20 V), contact time (15, 30, 45, and 60 minutes), and the electrode configuration (monopolar and bipolar). The results indicated that a bipolar configuration of Al electrode relatively outperformed a monopolar configuration. Optimal condition was achieved at 20 V, and contact time of 60 minutes. Results showed COD removal efficiency up to 96.15% reducing COD from 627.45 to 24.183 mg/L, TSS removal efficiency up to 92.45%, lowering TSS from 53 to 4 mg/L. While pH increased during the process, it remained within acceptable limits. This substantial reduction in pollutants significantly improved water quality, surpassing regulatory standards. The results suggest that EC is a promising approach for achieving sustainable treatment for laboratory wastewater.

Predicting biomass conversion and COD removal in wastewater treatment by phototrophic bacteria with interpretable machine learning.

Photosynthetic bacteria (PSB) excel in wastewater treatment by removing pollutants and generating biomass but are challenging to optimize due to complex operational and environmental interactions. Neural Ordinary Differential Equations, Elastic Net, Stacking, and Categorical Boosting were applied as artificial intelligence methods to predict chemical oxygen demand (COD) removal efficiency, biomass productivity, biomass yield, and energy yield. Among these, the Stacking model demonstrated superior predictive performance across all targets. Interpretable machine learning methods were employed to identify key features and establish their workable ranges, which included dissolved oxygen (0.3-2.8mgL⁻1), illuminance (2995.3-6000.0 lux), and light energy (20.0-40.0 kWh) for COD removal efficiency; organic loading rate (OLR, 5.7-7.5g COD L⁻1d⁻1), hydraulic retention time (HRT, 0.2-3.2d), and COD concentration (5.3-10.1gL⁻1) for biomass productivity; COD/N ratio (609.0-800.0), OLR (0.1-2.4g COD L⁻1d⁻1), and illuminance (2661-6000 lux) for biomass yield; and pH (6.5-7.9) and HRT (1.2-2.6d) for energy yield. The two-dimensional partial dependence plots revealed that optimal interactions between two key input features resulted in COD removal efficiency >72%, biomass productivity >28gL⁻1d⁻1, biomass yield> 0.96g CODbiomass g CODremoved⁻1, energy yield> 0.49g kWh⁻1. This work advances the understanding of PSB optimization in wastewater treatment through a combination of advanced machine learning and interpretability analysis, offering potential for more efficient resource recovery and process optimization.

Closing the Loop of Biowaste Composting by Anaerobically Co-Digesting Leachate, a By-Product from Composting, with Glycerine

To achieve the required recycling rates, organic recycling via composting should be widely introduced in Poland for selectively collected biowaste. However, this process not only produces compost but also leachate (LCB), a nitrogen- and organics-rich liquid by-product. So far there has been limited information on the application of anaerobic digestion (AD) for treating LCB, which has fermentative potential. However, for effective methane production (MP) via AD, the ratio of chemical oxygen demand to total Kjeldahl nitrogen (COD/TKN) and pH of LCB are too low; thus, it should be co-digested with other organics-rich waste, e.g., glycerine (G). The present study tested the effect of G content in feedstock (in the range of 3–5% (v/v)) on the effectiveness of co-digestion with LCB, based on MP and the removal of COD. MP was accessed by using an automatic methane potential test system (AMPTS). Regardless of the feedstock composition (LCB, or LCB with G), the efficiency of COD removal was over 91%. Co-digestion not only increased MP by 6–15%, but also the methane content in the biogas by 4–14% compared to LCB only (353 NL/kg CODadded, 55%). MP and COD removal proceeded in two phases. During co-digestion in the 1st phase, volatile fatty acids (VFA) accumulated up to 2800 mg/L and the pH decreased below 6.8. The presence of G altered the shares of individual VFA and promoted the accumulation of propionic acid in contrast to LCB only, where caproic acid predominated. An initial accumulation of propionic acid and acidification in the mixtures decreased the kinetic constants of MP (from 0.79 to 0.54 d−1) and the rate of COD removal (from 2193 to 1603 mg/(L·d)). In the 2nd phase, the pH recovered, VFA concentrations decreased, and MP was no longer limited by these factors. However, it should be noted that excessive amounts of G, especially in reactors with constant feeding, may cause VFA accumulation to a greater extent and create a toxic environment for methanogens, inhibiting biogas production. In contrast, digestion of LCB only may lead to ammonium buildup if the COD/TKN ratio of the feedstock is too low. Despite these limitations, the use of AD in the treatment of LCB as a sustainable “closed-loop nutrient” technology closes the loop in composting of biowaste.

Engineered alginate-polyethyleneimine and sludge-aluminosilicate biochar composites for greywater treatment: Performance evaluation and models for designing pilot-scale systems.

Greywater, originating from kitchen sinks and toilets, constitutes 75-80 % of the domestic wastewater produced in homes and can be reclaimed for non-potable uses. This study synthesized novel sludge-derived aluminosilicates and alginate-polyethyleneimine (PEI) biochar composites. The aluminosilicates offer a sustainable approach to sludge management, while alginate-polyethyleneimine presents a green biochar modification approach. Their performance in fixed bed columns for treating greywater was compared with zinc chloride, calcium alginate, and PEI-biochar composites. The CatBoost machine learning algorithm also predicted contaminant removal efficiency and breakthrough parameters. The morphological and chemical analyses showed that the modification techniques improved the physiochemical properties of the biochar, which in turn influenced contaminant removal efficiency. With its enhanced surface area and pore structure, zinc chloride-biochar demonstrated notable effectiveness in removing organic matter (highest COD removal efficiency 96.1 %). PEI-biochar exhibited a high removal efficiency for nitrates (highest value of 95.5 %), attributed to the positive amine groups. Aluminosilicate-biochar was the most effective at removing ammonium due to its high cation exchange capacity. The CatBoost algorithm successfully stimulated E. coli, total nitrogen, COD removal efficiencies, and breakthrough parameters from greywater using biochar (R2 > 0.7). Future research should conduct a pilot-scale study for this technology, explore the use of modified biochar arranged in multilayers for treating greywater, use of biochar for removing emerging contaminants in greywater, and optimize predictive models for greywater treatment. The insights from our study provide valuable guidance for effective and sustainable greywater treatment.

Membrane Foulant Removal by Ozone-Biocarrier Pretreatment Technology for Industrial Wastewater Reclamation

During wastewater reclamation, organic matter is considered the dominant foulant that shortens the lifetime of ultrafiltration (UF) membranes during operation. Additionally, the mineralization efficiency of organic matter in secondary effluent is typically low due to nonbiodegradable carbon sources. Herein, a combination of ozone and a porous biocarrier reactor was applied as a novel pretreatment system to enhance organic matter removal in the effluent in a lab-scale evaluation and pilot test. The results indicated that 70% of the biopolymer was removed, and the chemical oxygen demand (COD) removal efficiency was 1.8 times higher in this combined process than in the process with a porous biocarrier alone. The UF flux increased by 16% after the combined ozonation and porous biocarrier pretreatment process compared with the process with no pretreatment. Interestingly, the genus Flavobacterium (15.59%), containing biopolymer-degrading bacteria, was observed only in the combined ozone plus porous biocarrier process. Moreover, the results show that biopolymers can be removed through the combined ozone and porous biocarrier process due to partial ozone degradation, confirming that this combined process is one of the better pretreatment procedures for organic matter removal and improves the flux of UF during the wastewater reclamation process.

Evaluation of the aerobic process performance for treating tannery effluent in the fungicide presence and ammoniacal nitrogen high concentration

Leather processing is characterized by the generation of effluents with a high concentration of ammonia nitrogen (N-NH4+) and the presence of fungicides. This study evaluated the interference of these two constituents on the removal of chemical oxygen demand (COD) and N-NH4+. To this end, an aerated reactor operating in a batch system was used. The effects of cycle time, fungicide volume, and initial N-NH4+ concentration on COD and N-NH4+ removal was evaluated using a Centralized Rotational Composite Design. The highest COD removal (45.45%) occurred under the conditions of 72 h, 0.55 mL of fungicide, and 62.5 mg L-1 of N-NH4+, and the lowest removal (8.24%) occurred under the conditions of 24 h, 0.28 mL of fungicide and 84.8 mg L-1 of N-NH4+. The highest removal of N-NH4+ (38.49%) occurred under the conditions of 42 h, 0.55 mL of fungicide, and 62.5 mg L-1 of N-NH4+, and the lowest removal (4.26%) occurred under the conditions of 24.1 h, 0.82 mL of fungicide and 84.8 mg L-1 of N-NH4+. Through statistical analysis, it was possible to obtain mathematical models for the two response variables, which satisfactorily described the removal efficiency of COD and N-NH4+, and through the desirability analysis, it was possible to optimize the treatment process operation with a cycle time of 58.15h, with the addition of 0.62 mL of fungicide and 57.91 mg L-1 of ammoniacal nitrogen. Although the removal of N-NH4+ via nitrification is an efficient technique in industrial effluent treatment, the results obtained in this work indicate that the removal of N-NH4+ was significantly affected by the presence of the fungicide. Keywords: biological treatment, chemical oxygen demand, DCCR, TCMTB.

Preparation of Fe3O4/C Composite Material from Red Mud for the Degradation of Acid Orange 7.

This study presents a novel Fe3O4/C composite material synthesized from red mud through a process of magnetic roasting and separation. The research explores the impact of Fe3O4/C dosages, sodium persulfate (PS) concentrations, and initial solution pH on the chemical oxygen demand (COD) removal efficiency using Acid Orange 7 as a model pollutant. Optimal conditions were identified as 3 g/L Fe3O4/C, 20 mM PS, and an initial pH of 2, achieving a 94.11% COD removal efficiency within 30 min. X-ray diffraction and photoelectron spectroscopy analyses confirmed that the magnetization roasting process effectively transformed red mud's ferric oxide (Fe2O3) into magnetite (Fe3O4). Concurrently, Fe3O4 interacted with residual carbon to form the Fe3O4/C composite. This composite demonstrated superior catalytic performance, along with excellent recyclability and reusability.

Simultaneous nutrient-abundant hydroponic wastewater treatment, direct carbon capture, and bioenergy harvesting using microalgae–microbial fuel cells

Hydroponics has increasingly been recognized as an important agricultural method due to its stable crop yields under rapidly changing environmental conditions. However, the efficient treatment of nutrient-rich hydroponic wastewater remains a major challenge. This study investigates the effect of anodic pH on the performance of microalgae–microbial fuel cells (mMFCs), focusing on bioelectricity generation, photosynthetic oxygen supply, nutrient removal and recovery, and carbon capture. The mMFC system achieved a maximum power density of 122.5mW/m², a chemical oxygen demand removal efficiency of 93.7%, and an anode-side total nitrogen removal efficiency of 27.5% at an acidic anodic pH. In addition, the cathode chamber had a total ammonium nitrogen removal efficiency of 22.6%, which was ascribed to a combination of ammonium migration and subsequent nitrogen assimilation, and a phosphate removal efficiency of 100%, likely due to microalgal uptake and adsorption. The mMFC also effectively captured CO2 with an algal biomass yield of 0.01379g·L-1·d-1 and a CO₂ fixation rate of 0.02528g·L-1·d-1. These findings provide insights into the optimization of mMFCs as a sustainable solution for managing nutrient-rich hydroponic wastewater, contributing to energy-efficient and resource-recovering wastewater treatment technologies.

Innovative grey water treatment using eco-friendly bio-photocatalyst AgCuFe2O4@chitosan in the presence of synergistic effects of persulfate activation: optimization and mechanisms.

In this study, AgCuFe2O4@Chitosan bio-photocatalyst was synthesized to make the most of environmental benignity and chemical stability for advanced greywater applications. The photocatalyst was evaluated under UV irradiation by synergistic activation of persulfate. FESEM, EDS-Mapping, and BET analyses showed quasi-spherical nanoparticles with a homogeneous size distribution, homogenous elements dispersion, and 15.305m2/g surface area. XRD analysis confirmed that Ag and Cu were effectively incorporated into the chitosan matrix, which increased its crystallinity and stability. The photocatalyst showed a good magnetic property with an Ms. value equal to 17.13emu/g, which helped in its easy retrieval and reuse. The TGA analysis demonstrated that the bio-composite had high thermal stability up to 600°C. The optimal treatment conditions were a pH of 3, 2mM persulfate, and 0.8g/L photocatalyst dosage, where COD removal efficiencies were 82.9% and 73.7%, for synthetic and natural greywater, correspondingly. During the degradation process, greywater followed a pseudo-first-order kinetic model, where both sulfate and hydroxyl radicals played key roles in the elimination of COD. Moreover, the bio-photocatalyst was very reusable up to more than a few runs of treatment cycles with very good performance, underpinning the possible applications in the greywater treatment process in a sustainable manner.

Sustainable utilization of plastic-derived graphene for tetracycline wastewater treatment and its recycling for biogas and biochar production

While several studies have used plastic-derived graphene (PDG) for antibiotics adsorption from wastewater, there is a research gap in finding an environmental-friendly and technically feasible approach for the recycling of exhausted adsorbent. Hence, this study focuses on the utilization of PDG as an adsorbent for tetracycline removal from aqueous solutions, followed by the valorization of spent PDG for dual biogas and biochar production. In the first experiment, a tetracycline removal efficiency of 75.61 % was obtained under the optimum condition of PDG dosage = 0.03 mg/mL, initial concentration = 5.20 ppm, 77.0 min-adsorption time, and acidic pH. Supplementing the regenerated PDG to the anaerobic digestion of sludge and ethanol exhibited bio-CH4 yield and chemical oxygen demand (COD) removal efficiency of 200.60±9.40 mL/g COD and 57.11±3.01 %, respectively. The recycling of anaerobic digestate by pyrolysis showed a biochar yield of 0.58±0.09 g/g, with a high carbon content of 55.34 % w/w. The scalability of this adsorption/digestion/pyrolysis approach for managing 1 kg PDG could be economically feasible with a payback period of 5.02 years, NPV = 297.62 USD, and internal rate of return = 10 %. This project showed less detrimental impacts on the environment, regarding the life cycle assessment (LCA) impact categories related to terrestrial ecosystem and resource recovery.

Effective organic matter removal via bio-adsorption prior to anammox process and utilization of carbon-rich sludge.

Excessive organic matter in the anaerobic ammonia oxidation (Anammox) leads to the growth of a large number of heterotrophic bacteria, which disrupts the anaerobic ammonia oxidation. The adsorption-anaerobic ammonia oxidation process can effectively reduce excessive organic matter, capturing it instead of consuming it, which is a sustainable development technology. In this study, utilizing the excellent adsorption performance of aerobic granular sludge (AGS), an adsorption-regeneration process was employed to remove organic matter at the front end of the Anammox process through bio-adsorption in an artificial simulated domestic sewage environment, and it was successfully used for denitrification. Stirring rate is a key factor affecting sludge granulation. As a parallel experiment of sludge granulation, two Sequencing Batch Reactors (SBRs) (R1 and R2) were operated simultaneously at different stirring rates. After 153 days, the particle size of the two reactors was analyzed, revealing that the proportion of particles larger than 200μm was over 50%, and granular sludge was successfully formed in both reactors. Long-term operational results indicate that at a temperature of 16.5±1°C, varying initial pH levels (6.5, 6.7, 7.2, and 8.5) significantly affect the removal efficiency of chemical oxygen demand (COD). COD is rapidly adsorbed and removed within a short period. Among the tested initial pH values, a pH of 6.7 yielded the best total chemical oxygen demand (tCOD) removal efficiency, achieving up to 95%. Additionally, the study examined the effects of different carbon sources on denitrification, revealing that under carbon-rich conditions, the denitrification rate was highest, reaching 1.44mgN/(g VSS·h). Compared to endogenous denitrification, the denitrification rate increased by 40%, and the nitrate (NO₃⁻-N) removal efficiency reached 100%.

Ethanol fermentation of tapioca wastewater in anaerobic baffled reactor: Performance evaluation and microbial community analysis.

Anaerobic treatment of tapioca wastewater has a long processing time. This study aims to evaluate ethanol fermentation as an effective treatment of tapioca wastewater. Simulated tapioca wastewater with an average chemical oxygen demand (COD) of 6900 mg L-1 was treated in a four-column anaerobic baffled reactor for 300 d. Ethanol production was achieved, however it was inconsistent. Ethanol cycles lasted 10-15 d, with a maximum yield of 51.0 ± 2.2 mg COD L-1. With each decline in ethanol production, glycerol formation increased, peaking at 10.3 ± 1.7 mg COD L-1. COD removal efficiency reached 93 %, resulted from biomass formation and sedimentation. Microbial analysis revealed that, during ethanol production, Clostridium sensu stricto 11 and Ethanoligenens were the predominant bacteria, whereas Sordariomycetes, Debaryomycetaceae, and Pichia dominated the fungal community. Meanwhile, Helotiales was prevalent during glycerol formation. Understanding the dynamics of microbial shifts could be key to optimizing ethanol fermentation in future processes.

Anaerobic Biohythane Production in an Internal Two-Stage Bioreactor: Kitchen Waste Concentration Optimization

An internal two-stage bioreactor constructed with a hydrogen chamber and a methane chamber with a working volume of 300 mL and 4700 mL, respectively, was operated using various kitchen waste (KW) concentrations from 10 to 80 g COD/L with a hydraulic retention time of 2 days to characterize the biomethane production performance. The results showed that daily biohythane production exhibited a similar increasing trend at KW concentrations of 10 to 40 g COD/L. The peak biomethane production was 2481 mL/day at a KW concentration of 40 g COD/L. The KW concentration could also affect the COD, carbohydrate, lipid, and protein removal efficiencies. These removal efficiencies were somehow dependent on the KW concentration, with two notable KW concentration groups of 10–20 g COD/L and 40–80 g COD/L. After 80 days of cultivation, Firmicutes dominated the hydrogen chamber, and Methanobacteriaceae and Methanomicrobiaceae dominated the methane chamber. This study presents the optimal KW concentration for high biohythane production efficiency in a novel internal two-stage bioreactor and reveals the dominant microorganisms in its microbial community.

EFFECT OF LOCALLY ISOLATED <i>SCENEDESMUS</i> SP. TN1 ON BIOMASS PRODUCTION AND NUTRIENT REMOVAL FROM COOKING COCOON WASTEWATER: EFFECTS OF INITIAL ALGAL CELL DENSITY AND TEMPERATURE

Scenedesmus sp. TN1, a local freshwater microalga, was cultivated in cooking cocoon wastewater. The effects of initial algal cell density and temperature on microalgae growth and the removal of total nitrogen (T-N), total phosphorus (T-P), and chemical oxygen demand (COD) were studied. The initial algal cell densities were 5, 10, 15, and 20 mg/l. The experimental temperatures varied from 20 °C to 30 °C. The growth rate increased with the increase in initial algal cell density up to 15 mg/l and was statistically stable thereafter. A similar trend of total nitrogen, total phosphorus, and COD removal efficiency was observed. The optimum temperature for microalgae growth and nutrient removal was 30 °C. After 9 days of cultivation, Scenedesmus sp. TN1 exhibited nutrient removal efficiencies of 88.28%, 82.91%, 92.01%, and 89.16% for T-N, T-P, biological oxygen demand (BOD5), and COD, respectively. The maximum biomass production and nutrient removal efficiencies of Scenedesmus sp. TN1 were observed at cultivation conditions of 15 mg/l initial algal cell density at 30 °C. This study compiled information on the cultivation conditions for cooking cocoon wastewater treatment practices.

Advanced solar photo-Fenton-like process with directly growing nano-heterojunctions on graphite fiber felt for phenolic wastewater treatment :Synergistically expand the pH activity range and facilitate the Fe(III)/Fe(II) cycle.

Nanoscale FeWO4/BiVO4 heterojunctions were directly grown on the graphite fiber felt (GF) with good conductivity to construct a FeWO4/BiVO4 @GF solar photo-Fenton like wastewater treatment system. The removal effect of COD from phenolic wastewater and the mechanism of synergistic improvement of wastewater treatment efficiency by this system were investigated. The FeWO4/BiVO4 heterojunction prepared by hydrothermal method exhibited higher photoelectric conversion efficiency and solar light utilization rate, thus endowing FeWO4/BiVO4 with excellent solar-Fenton like reaction activity.The photo-Fenton activity can be maintained well even within the pH range of 2-8. Loading FeWO4/BiVO4 nano-heterojunction on GF helped to increase the contact area between Fenton reagents and wastewater, facilitate the electron transfer on the FeWO4/BiVO4 heterojunction and enable the recovery and reuse of the Fenton reagents.Under solar light radiation, the COD removal efficiency of FeWO4/BiVO4 @GF/H2O2 system in phenolic wastewater was more than 92%. Even after five cycles, the system still exhibited excellent operation stability. FeWO4/BiVO4@GF promoted the conversion and cycling of Fe(III)/Fe(II) by accelerating the separation and transport of photogenerated electrons/holes and increasing the concentration of active species, thereby stimulating excellent solar photo-Fenton like activity.The results are significance to the development of green and efficient photo-Fenton process for advanced treatment of industrial wastewater.

Application of response surface methodology for optimization of phosphate and ammonia removal from domestic wastewater by modified steel slag

Domestic wastewater is one of the significant sources causing phosphorus and nitrogen pollution in natural water. Though steel slags have been applied for the adsorption of phosphate, ammonia, and both in various synthetic and real wastewaters, no report has been found for the application of response surface methodology (RSM) to investigate the main and interaction effects, and optimization of various factors on phosphate and ammonia adsorption by steel slag. The current study aims to evaluate the removal of phosphate and ammonia from domestic wastewater using adsorbents of modified steel slags. Steel slags from two companies were modified, characterized, and preliminarily applied for synthetic wastewater treatment to select the suitable type of steel slag. Optimization experiments were then designed using RSM to find the significant factors, their interactions affecting the treatment processes, and optimum conditions. The results of energy-dispersive X-ray spectroscopy (EDS) and Brunauer–Emmett–Teller (BET) analyses showed that thermal treatment affected the mass percentages of elements and increased the surface areas of the materials. The adsorption kinetics and isotherm studies demonstrated that the phosphate adsorption process followed pseudo-second-order reaction kinetics, and the Langmuir model was appropriate to the present experimental results. The results from RSM suggested that output phosphate concentration was significantly affected by the modified temperature, steel slag dosage, contact time, and the modified temperature-dosage interaction, while the modified temperature and steel slag dosage were significant factors for output ammonia concentration. Validation of the domestic wastewater treatment at the optimum conditions including the modified steel slags at 776°C, contacting time of 15.7 h, and dosage of 0.87 g/L confirmed the high removal efficiency for phosphate (81.7%), while ammonia and COD were eliminated at the efficiencies of 31.6% and 32.7%, respectively. This study hence proposed the application of the modified steel slag as a promising and cheap adsorbent for nutrient removal in domestic wastewater.

Biomass-derived 3D hydrogel bioanode forincreasing electron transfer and chemical oxygen demand removal efficiency

Biomass-derived 3D hydrogel bioanode forincreasing electron transfer and chemical oxygen demand removal efficiency

Enhancing synthetic vinasse treatment efficiency using an integrated UASB-Modified Bardenpho Process

Vinasse poses considerable environmental problems due to its complex composition of organic matter, minerals, and toxic compounds. If discharged into the environment without treatment, it can cause adverse impacts on ecosystems. This research investigated the effectiveness of an integrated treatment system involving an upflow anaerobic sludge blanket (UASB) reactor and the modified Bardenpho process (MBP) for purifying synthetic vinasse. The study lasted for 167 days, during which the integrated UASB-MBP system processed untreated synthetic vinasse with organic loading rates (OLR) ranging from 1.6 to 12.5 kgCOD/m3 day. The UASB-MBP system impressively achieved a COD removal efficiency of 99.41%. Removal efficiencies of approximately 98.14, 99.91, and 99.63% were also achieved for total nitrogen (TN), total phosphorus (TP) and total ammonium (NH4+-N), respectively. The final discharge was 51.06 mg/L. The concentrations of NH4+-N and TN in the outflow of the settlement tank were 0.8–1.2 mg/L and 5.1–7.9 mg/L, respectively. Optimal performance was achieved when the HRT and nitrate recycle ratio were 15.5 h and 200%, respectively. The temperature was kept in the mesophilic range (33–35 °C) during the experiments. These results underscores the potential of the integrated UASB reactor and modified Bardenpho process to provide an effective and eco-friendly approach for concurrent removal of COD and nutrients from vinasse treatment, offering broad prospects for implementation in wastewater treatment.

The effectiveness of ozonation treatment in reducing ph, turbidity, bod, cod, and toc in pharmaceutical industrial wastewater

Abstract The pharmaceutical industry’s fabrication of pharmaceutical products releases byproducts that have the potential to negatively impact the environment. Indicators of contaminants include characteristics such as COD, BOD, TOC, pH, and turbidity that are within acceptable standards of excellence. The objective of this study was to look at fluctuations in the concentrations of pharmaceutical wastewater substances parameters before and following treatment with the ozonation method, as well as to assess the ozonation procedure’s performance on pharmaceutical wastewater contaminants parameters. The ozonation methods, which altered the O3 retention period, served as the independent variable in this study. The dependent variables applied were pH optimalization, and the removal efficiency of turbidity, BOD, COD, and TOC. Controlling variables involve the starting pollutant concentration, pressure and temperature levels, and equipment conditions. To determine the ideal time variation for the ozonation process, many variations will be evaluated. However, several parameters (e.g. pH, BOD, and TOC) were not reducing with the designed time variations. Nevertheless, this approach was effective in reducing turbidity levels by 48.5% and COD levels by 55.4% over 15 minutes.

Enhanced hydrolytic acidification with Zero-Valent Iron for efficient treatment of comprehensive wastewater from industrial parks: mechanistic insights and toxicity reduction

In this study, a laboratory-scale zero-valent iron (ZVI)-enhanced hydrolytic acidification system was established to treat the comprehensive wastewater from Nanjing Jiangbei New Material Science Technology Park. Results indicated that the ZVI-enhanced hydrolytic acidification system achieved a maximum COD removal efficiency of 95.0%, surpassing the performance of the system without ZVI by 12.2%. Microbial community analysis revealed the enrichment of electrogenic bacterium Bacteroidetes_vadinHA17 and typical hydrogenotrophic methanogen Methanobacterium due to ZVI addition. High-throughput sequencing combined with PICRUSt2 analysis demonstrated acetate production was promoted, and butyrate and propionate production was inhibited. Additionally, Oxygen Uptake Rate-based toxicity assays revealed the hydrolytic acidification system transitioned the wastewater of three enterprises from low toxicity to non-toxic status and two from high to low toxicity. While the ZVI-enhanced hydrolytic acidification system successfully reduced the toxicity of all highly and low toxic wastewaters to non-toxic levels.