Removal Percentage Research Articles

UiO-66-NDC (1,4-naphthalenedicarboxylic acid): A versatile metal-organic framework-based catalyst for photocatalytic degradation of dye chemicals

Metal-organic frameworks (MOFs) have received significant attention for their use as photocatalysts and photocatalyst supports. These materials have several benefits, including stability, catalyst reusability, tunability, and the capacity for post-reaction separation. Here, the potential applications of UiO-66-NDC as a photocatalyst for the degradation of reactive orange 16 (RO16), methyl orange (MO), and rhodamine B (RhB) were investigated. UiO-66-NDC was chosen for photocatalytic dye degradation due to its large surface area, adjustable characteristics, stability, effective light absorption, capacity for charge separation, and adaptability in design. UiO-66-NDC was synthesized the solvothermal process and its solid-state structure was characterized by solid-state methods, including UV-DRS, FTIR, zeta potential, PXRD and SEM measurements. The photocatalytic studies were performed by subjecting dye solutions with certain concentrations to UVA light irradiation in the presence of UiO-66-NDC. UV–Vis. spectroscopy was used to monitor the degradation process, which made it possible to calculate the degradation rate constants and the percentage of dye removal. The removal efficiency of adsorption, which was also examined, was at a minimum (17 % for RO16, 48 % for MO, and 25 % for RhB). The degradation of the dyes by UiO-66-NDC showed excellent photocatalytic activity, with degradation rates for RO16, MO, and RhB of 91 %, 93 %, and 81 %, respectively (300 mg/L catalyt; 20 ppm dye conc.). It was determined that the optimal concentration of catalyst was 300 mg/L. The reusability of UiO-66-NDC was successfully demonstrated through five successive cycles. The •OH radical was identified as the active species in photocatalysis. It was possible to remove 97 % of RO16, 99 % of MO, and 95 % of RhB at a high starting dye concentration (15 mg/L).

Optimization of anionic dye removal using cross-linked chitosan composite as eco-friendly bio-adsorbent

The environmental impact of wastewater discharged from the textile dyeing industry has a significant challenge and influence on aquatic ecosystems and human health if not properly managed. This study aimed to develop a novel cross-linked chitosan composite, denoted as chitosan/fly ash/polyvinyl alcohol (Ch/FA/PVA), as a bio-adsorbent for removing Congo Red (CR) textile dye from industrial wastewater. The synthesis involved the incorporation of FA into the chitosan matrix at various ratios to optimize the process. A specifically tailored composite, Ch/FA0.75/PVA, exhibited superior performance with a remarkable 99.7% CR removal under optimum conditions: adsorbent dose (0.9 g/l), contact time (50 min), and dye concentration (40 mg/l). The characterization of Ch/FA0.75/PVA through SEM–EDX, BET, FTIR, and pHzpc confirmed its suitability for adsorption. Employing Box–Behnken design and analysis of variance (ANOVA) facilitated the optimization of key adsorption variables. The Freundlich model described the adsorption equilibrium, indicating a maximum adsorption capacity of 263.15 mg/g for CR dye. The pseudo-second-order model demonstrated favorable kinetics. The study was scaled up to the practical application of Ch/FA0.75/PVA in a pilot plant for industrial wastewater treatment, revealing substantial removal percentages for dye, color, COD, BOD5 and TDS. This comprehensive approach highlights the promising efficacy of Ch/FA0.75/PVA in addressing environmental concerns associated with textile dye wastewater.

Highly efficient adsorption of aqueous heavy metals by Co-derived metal-organic framework. Synergistic mechanism for enhanced water purification

This study opens up exciting possibilities for the application of Co-MOF, a Metal-Organic Framework ([Co(5-NH2-bdc)(bpy)0.5(H2O)]3·2H2O), in the efficient removal of heavy metals (Pb2+, Hg2+, Cd2+, Cu2+) from water. The removal mechanism combines ion exchange and adsorption, influenced by the ionic radius of the metal ions. Langmuir's model determined maximum adsorption capacities (Qm), showing a proportional increase with the ionic radius of heavy metals: 75.47 mg/g (Cu2+), 344.82 mg/g (Cd2+), 485 mg/g (Hg2+), and 526.31 mg/g (Pb2+). Free Gibbs energy, inversely proportional to the metal's ionic radius, was determined as −36.43 kKj/mol (Cu2+), −28.67 Kj/mol (Cd2+), −24.13 Kj/mol (Pb2+), and −21.67 Kj/mol (Hg2+). The pseudo-second-order mechanism explained heavy metal removal, except for Cu2+, due to continuous ion exchange. Reutilization experiments showed a decrement in efficacy in the second cycle. Filtration experiments demonstrated a lower removal percentage (close to 60 %) and confirmed the competitive activity of Co-MOF compared to other MOFs, particularly in Cd2+ removal, with superior rate constants and maximum adsorption capacities.

Valorization of fruit and vegetable waste in a novel three-stage hybrid anaerobic digester for enhanced biogas production: Performance study and microbial community analysis

The study proposes the performance of a three-stage hybrid mesophilic anaerobic digester comprising a suspended-growth hydrolytic reactor, a hybrid (suspended-growth + attached-growth) acidogenic down-flow reactor, and a hybrid methanogenic up-flow reactor, for enhanced biogas production. Commingled fruit and vegetable waste (FVW) – shredded to sizes 1 – 4 mm – plus 2.5 L of tap water served as the feedstock in 8 different batch combinations, where the weight of the waste was increased from 3.5 to 7 kg. Decoupling the three major anaerobic steps ensured desirable working pH ranges for the hydrolytic (4.02 – 6.79), the acidogenic (5.69 – 6.62), and the methanogenic stages (6.94 – 7.7). Triplicate studies of each batch type vis-à-vis all three stages were performed. The highest cumulative soluble chemical oxygen demand percentage removal of 96.3 % was noticed in the case of batch run 5. The maximum biogas yield of 781.8 ml/g CODremoved was corresponding to batch 7, with 6.5 kg FVW, whereas the lowest biogas yield, 735.8 ml/g CODremoved, was corresponding to batch 1. The produced biogas from the methanogenic digester was of high quality (≤ 0.01 % H2S) and constituted 58–62 % CH4 and 6–7 % H2. Microbial community analysis confirmed the presence of pertinent bacterial and archaeal groups, such as Firmicutes, Proteobacteria, Spirochaetes, and Methanothrix, including key homoacetogenic genera, such as Acetobacterium Woodii, Desulfotomaculum, and Desulfitobacterium.

Synthesis and characterization of mesoporous caged silica for efficient adsorption of methylene blue from aqueous solution

Addressing the challenge of removing dyes from textile industry wastewater is crucial for wastewater treatment. Adsorption, utilizing suitable materials, emerges as a promising solution. This work introduces caged silica as an effective adsorption material for wastewater treatment in the textile industry. The proposed caged silica was synthesized via the hard template synthesis method, commonly used in various applications such as catalysts and wastewater treatment. Caged silica exhibited an amorphous structure with notable BET surface area (448m2/g), pore volume (0.325cm3/g), and average pore size (2.4nm), confirmed through detailed characterization. Evaluation of its adsorption capacity for methylene blue (MB) revealed an impressive removal efficiency of approximately 95% within the initial 20 min. The adsorption process followed the pseudo-second-order model and adhered more closely to the Freundlich isotherm model than the Langmuir model. Additionally, the study investigates the effects of pH, percent removal efficiency, cyclic stability, and initial MB concentration on the adsorption procedure. Consequently, the synthesized caged silica stands out as a promising mesoporous material for efficiently removing MB from aqueous solutions, offering practical application potential in wastewater treatment.

Impacts of Deicer Salt on Water Quality Performance of Stormwater Bioretention Systems with Varied Vegetation and Hydrology.

Sodium chloride (NaCl) deicers contaminate bioretention and influence effluent water quality, the effects of which are not yet fully understood. We tested this by constructing 48 mesocosms in a greenhouse, each having Panicum virgatum, Eutrochium purpureum, or no vegetation; having an internal water storage (IWS) zone or not; and being exposed to high or low NaCl doses in the late winters of 2022 and 2023. Synthetic stormwater was applied and effluent was monitored through May 2023 with an end-of-experiment analysis of soil and plant biomass for nitrogen, phosphorus, copper, zinc, and total suspended solids (TSS). Average effluent loads increased in spring, after NaCl application, for total phosphorus (+61%), copper (+61%), zinc (+88%), and TSS (+66%). These four analytes recovered by summer, with average annual percent removals >85%. Vegetation and IWS reduced annual phosphorus (by -33 and -70%, respectively) and copper (by -24 and -40%) loads, while higher NaCl concentrations increased annual phosphorus (+107%), copper (+22%), and TSS (+51%) loads. Nitrogen removal was not linked with NaCl but was dependent upon the presence of IWS or vegetation. Post-NaCl effluent spikes pose seasonal risks to aquatic ecosystems, emphasizing the need for active maintenance, redundant removal mechanisms, and minimized exposure to NaCl.

Composite of activated carbon-hydroxyapatite from corn (Zea mays L.) cob and catfish (Pangasius sp.) bones with H3PO4 activation for methylene blue dye adsorption

Methylene blue (MB) is a synthetic dye in wastewater that causes serious environmental problems due to its toxicity, carcinogenicity, and resistance to environmental degradation. To overcome this problem, activated carbon (AC) from corncob waste and natural Hydroxyapatite (HAp) from catfish bone were synthesized to generate a simple, cost-effective, and efficient composite adsorbent for removing MB dye in wastewater. The performance of the AC/HAp composite adsorbent was assessed under varying conditions, including initial dye concentration, contact time, adsorbent dosage, pH, and reusability. The scanning electron microscope (SEM) morphology and BET results showed that the composite had an irregular shape, with a specific surface area of 419.02 m2/g. The results showed that the isotherm model followed the Langmuir model with an adsorption capacity of 109.90 mg/g. Reusing the composite adsorbent after 3 cycles resulted in an insignificant decrease in the MB removal percentage from 73.52 % to 55.32 % at an initial dye concentration of 200 mg/L. Ion exchange, hydrogen bonding, Lewis acid-base interaction, electrostatic interaction, and π–π bond interactions were several adsorption mechanisms. Based on these findings, the composite had the potential to be an MB adsorbent by enhancing agricultural and aquaculture waste value and supporting the implementation of a circular economy and net zero carbon in Indonesia.

Simultaneous removal of Ni2+ and Congo red from wastewater by crystalline nanocellulose - Modified coal bionanocomposites: Continuous adsorption study with mathematical modeling

Due to ultra-fast technological improvement and rapid urbanization nowadays, industries have generated a huge amount of wastewater that is discharged directly into the environment. Resulting in harsh damage to ecology and public safety/security by contaminating the ground/surface water sources. Therefore, it is very crucial to purify this wastewater before discharging/reusing. This study will be devoted to the latest enhancements along with the new route of production of the multifunctional Crystalline Nanocellulose-Modified Bituminous Coal (CNC-MC) bionanocomposites. Besides these, the significant implementation of the fabricated CNC-MC bionanosorbents for the simultaneous removal of Ni2+ and Congo red (CR) from bulk-scale industrial wastewater has been stated. Conversely, influential parameters like inlet concentration (25–45 ppm), flow rate (3–5 mL/min), and adsorbent bed height (0.2–0.8 cm) were explored. The bionanosorbents were characterized by using some state-of-the-art equipment such as FTIR-ATR, XRD, BET, FESEM, and TGA analysis, while the water samples were analyzed by AAS and UV-NIR techniques. Results suggested that the fabricated CNC-MC bionanocomposites possessed a considerable amount of active binding sites/functional groups, showed high thermal stability up to 700°C, and had a high crystallinity index (around 92.41 ± 0.009%). They revealed a noteworthy honeycomb-like mesoporous microstructure with a significant specific surface area. Due to these outstanding features, this multifunctional bionanosorbents has exhibited sensational adsorption performance. Meanwhile, the maximum removal efficiency and percentage were observed at approximately 328.7 and 478.3 mg/g, as well as around 67.95 and 76.65% for Ni2+ and CR. The experimental data was evaluated by three well-known column models, namely the Thomas, Adam-Bohart, and Yoon-Nelson models, and respectable agreement was found. That is similarly appropriate for the justification of the experimental breakthrough curve by supporting the Langmuir isotherm and 2nd-order reversible reaction kinetics. Hence, this novel CNC-MC bionanosorbent could be beneficially used to purify industrial wastewater in an economical and eco-friendly way for sustainable environmental safety.

Novel High-Performance Functionalized and Grafted Bio-Based Chitosan Adsorbents for the Efficient and Selective Removal of Toxic Heavy Metals from Contaminated Water.

Novel functionalized and/or grafted crosslinked chitosan adsorbents were synthesized and used to remove several toxic heavy metal ions such as nickel, lead, chromium, and cadmium ions from contaminated water. The chitosan biopolymer was functionalized by maleic anhydride (CS_MA) acting also as a crosslinking agent. Glutaraldehyde-crosslinked chitosan (CS_GA) grafted with poly(methyl methacrylate) (CS_MMA) was also synthesized. The synthesized adsorbents were characterized using a variety of analytical techniques such as SEM, TGA, and FTIR, which confirmed their chemical structures and morphology. The adsorption capacity of the adsorbents was analyzed under various conditions of contact time, adsorbent dose, initial concertation, temperature, and pH and evaluated against those of pure chitosan (CS) and the crosslinked chitosan(CS_GA). The ultimate removal conditions were 0.5 g/100 mL adsorbent dose, an initial metal ion concentration of 50 ppm, a temperature of 45 °C, and pH 9. CS_MMA had the highest removal percentages for all metal ions, ranging from 92% to 94%. The adsorption was demonstrated to fit a pseudo-first-order model that followed a Langmuir adsorption isotherm. The results highlight the capacity of the synthesized polymers to efficiently remove major toxic contaminants at low cost from contaminated water, present especially in low-income areas, without harming the environment.

Removal of thiophene compounds from model fuel with supported copper on active carbon, adsorption kinetics, and isotherms

AbstractIn this study, the adsorption of thiophene compounds (TCs), including thiophene (T), benzothiophene (BT), and dibenzothiophene (DBT), from model fuels was investigated using modified activated carbon (AC). The model fuel, prepared as a single‐solute model at a concentration of 2000 ppm based on a mixture concentration of 3000 ppm, served as the basis for the adsorption experiments. Additionally, an examination of thiophene adsorption from commercial fuels, specifically kerosene, was conducted. Experimental data were used to calculate correlated parameters of adsorption isotherms, kinetic models, and the Fisher factor. The pseudo‐second‐order model demonstrated the best fit to the experimental data. Notably, the adsorbent consisting of 10% Cu+ supported on acid‐washed activated carbon (A1CN10) exhibited the highest adsorption capacity for TCs, achieving removal percentages of 78%, 96%, and 100% for T, BT, and DBT, respectively. Various methods were employed to investigate the physicochemical properties of the adsorbents, including N2 adsorption–desorption surface analysis (BET), scanning electron microscopy (SEM), X‐ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Furthermore, the regeneration of the adsorbent was studied using two techniques: agitation and ultrasound.

Computational intelligence for empirical modelling and optimization of methylene blue adsorption phenomena utilizing an activated carbon‐supported [Co(NH3)6]Cl3 complex

AbstractThe study focuses on the efficiency of hexaamminecobalt (III) chloride (HACo, [Co(NH3)6]Cl3) immobilized on activated carbon for removing methylene blue (MB) from water solutions. The primary objective of this study was to assess the sorption performance of HACo immobilized on activated carbon in removing MB from water solutions. Additionally, predictive models were developed to optimize the MB removal percentage. Lastly, the study aimed to determine the optimal conditions for achieving maximum MB removal. Samples were characterized using scanning electron microscopy. Batch sorption experiments were conducted to analyze the impact of MB concentration, adsorbent mass, pH, temperature, and contact time. Predictive models were built using multiple linear regression and neural network techniques, specifically artificial neural networks (ANN) and hybrid ANN–particle swarm optimization (ANN‐PSO). The PSO‐ANN model with a single hidden layer of eight neurons trained using the Levenberg–Marquardt algorithm demonstrated high accuracy in predicting MB removal percentage, with mean absolute percentage error (MAPE) = 0.083788, root mean square error (RMSE) = 0.11441, and R2 = 0.99693. The MB adsorption process followed a mono‐layer with one energy model and a pseudo‐first‐order kinetic model. Optimization using the genetic algorithm revealed that the maximum MB removal percentage of 99.56% is achievable at an MB concentration of 9.36 mg/L, adsorbent mass of 15.72 mg, and temperature of 311.2 K. The study confirms the effectiveness of HACo immobilized on activated carbon for MB removal. The PSO‐ANN predictive model proved superior in accuracy compared to empirical models. Optimization results provide the optimal conditions for maximizing MB removal, offering valuable insights for practical applications.

Bioremediation of Liquid Waste of Olive Presses (Al-Jeft water) by Using the Biomass of the Local Isolate of The Fungus Helvella bachu

The study included investigating the potential of the biomass of the local isolate of the fungus Helvella bachu in bioremediation of the liquid waste of olive presses (Jeft water) at two concentrations of 10%-20%. The mycelium was inoculated on solid media treated with olive press water, with concentrations of 10% and 20%, for several incubation days 2, 4, and 6, respectively. We observed that the diameter of the fungal colony is directly proportional to the increase in the incubation period, as the largest diameter of the fungal colony was 13.56 mm and 11.46 mm after 6 days of incubation at a concentration of 10% and 20% of Jeft water, respectively, compared to the diameter of the fungal colony growing in untreated medium, which it reached 15 mm, while the least diameter of the fungal colony was 6.00 and 5.36 mm at a concentration of 10% and 20% of Jeft water, respectively, after two days of incubation compared to the control sample. As for using liquid media, the results revealed a decrease in the total phenol concentration, reaching 2.14 mg / 100 g after 30 days of treatment with a concentration of 20% of Jeft water, compared to the control treatment of 23.58 mg / 100. The percentage of black color removal was 64.39% at a concentration of 10% and an incubation period of 30 days, while at a concentration of 20%, the percentage of color removal was 49.53% and 42.10% after 30 days of incubation. The biomass of the fungus isolate was able to reduce the chemical oxygen demand in both concentrations of Jeft water used with different responses. The percentage of chemical oxygen requirement was 65.83% at a concentration of 10% of Jeft water after 30 days of treatment, while the percentage of COD was 8.08% at a concentration of 20% for the same incubation period above.

Modification of PVA Nanofiber by Simple Hot Water Treatment and Application on the Removal of Malachite Green Dye From Aqueous Solutions.

In this study, the crosslinking of PVA nanofiber was increased using solvent vapor treatment. Then, Fe3O4 nanoparticles were synthesized by a simple hot water technique and composited with the nanofiber. The study focuses on applying the modified PVA nanofibers to remove malachite green (MG) from water using different pH, contact times, and dye initial concentrations. The surface morphology of the nanofiber was determined using SEM, FTIR, and XRD techniques. SEM showed that the crosslinking was increased, and Fe3O4 nanoparticles appeared as agglomerates on the surface of the nanofiber. The removal percentages at optimal pH and contact time were 99.76%, and 99.5%, respectively. Thereafter, kinetics was studied by the linear pseudo-first order, pseudo-second order, Elovich equation, and Intraparticle diffusion models. Results demonstrated that the adsorption kinetics follow the pseudo-second order. Moreover, the adsorption isotherm was discussed using Langmuir and Freundlich equations. The Langmuir equation best described the adsorption with R2 value of 0.9771, and the maximum removal was 128.205 mg/g. As a result, the MG dye molecules covered the PVA nanofiber/Fe3O4 nanoparticles in a monolayer and homogenous coverage. The results of this study are significant for industries' wastewater treatment as they provide a potential solution for the removal of MG dye from textile, paper, cosmetics, food, and aquaculture industries' wastewater.

Coconut shell-derived green synthesised carbon nanotubes for clean-up of crude oil spills

Abstract The global economy has led to an increase in oil transportation and exploitation, posing a threat to aquatic and terrestrial ecosystems. Crude oil spilled water purification is a major challenge worldwide. Researchers are focusing on finding adsorbents that improve oil adsorption capability. In the present study the adsorption of crude oil using synthesized carbon nanotubes (CNTs) prepared from coconut shell was investigated by batch adsorption experiments under varying parameters (adsorbent dosage and contact time) after analytical techniques (UV–vis, FTIR and SEM) confirmed the formation of the CNTs. The morphological modification significantly increased the hydrophobicity of the adsorbent, thus creating a synthesized CNTs with a much better adsorption capacity for crude oil removal having a maximum adsorption capacity of 4855.8 mg/g. The experimental results showed that the percentage of crude oil removal increased with an increase in adsorbent dosage and the contact time respectively. According to the correlation coefficient (R 2 = 0.9801) value obtained from the adsorption isotherm investigations, the isotherms were found to fit the Freundlich isotherm somewhat better than the Langmuir isotherm model, which is consistent with the findings reported in the literature. These findings have made the synthesised CNTs an attractive, useful, and environmentally friendly adsorbent for controlling crude oil spill.

Application of natural earth-based materials as adsorbents for the treatment of chromium (VI)-contaminated tannery wastewater: Box-Behnken and fixed-bed column optimization

This study focuses on the application of earth materials (gravel, clay, zeolite, lime rock, sea shell (Diplodonta)) as adsorbents for the removal of chromium (VI) from tannery wastewater. The removal efficiencies and adsorption capacities of chromium (VI) followed this order: pristine lime rock (63.59 %, qe: 65.5 mg/g)> pristine gravel (48.88 % and 50.4 mg/g)> pristine sea shell (39.03 %, qe: 40.2 mg/g)> pristine zeolite (38.5 %, qe: 39.7 mg/g) > pristine clay (33.55 %, qe: 34.5 mg/g). Lime rock and gravel gave the highest chromium (VI) adsorption capacities and hence, were used in subsequent experiments. Employing Box-Behnken design through response surface methodology, gravel exhibited the highest adsorption capacity (40.7 mg/g) at pH 4, and lime rock (56.1 mg/g) at pH 2, with initial chromium (VI) concentration of 150 mg/L and 11-hour contact time. Scanning electron microscopy and Brunauer–Emmett–Teller analysis showed a lack of pores on both adsorbents suggesting electrostatic attraction as the primary removal mechanism. Best-fitted models were Dubinin-Radushkevich and Temkin isotherms for lime rock and gravel, respectively, while pseudo-first-order kinetics suited both. Thermodynamics calculations showed adsorption is exothermic for lime rock and endothermic for gravel. Application of lime rock in fixed-bed column study showed the highest removal percentage and adsorption capacity (16.64 %, qe: 2.3 mg/g). Applying optimum conditions from column study to synthetic tannery wastewater achieved 63.61 % removal and adsorption capacity (qe: 12.7 mg/g) at 150 mg/L initial chromium (VI) concentration. Regeneration of the adsorbents after 3 cycles maintained strong adsorption capacity. The cost-effective, easily-prepared adsorbent underscores its potential for large-scale wastewater treatment.

Magnetic bio-composite based on zirconium and chitosan modified activated carbon from peanut husk with enhanced antibacterial and adsorptive potential for alizarin red and congo red in wastewater

Creating new adsorbents is crucial for removing contaminants from water due to increased industrialization, which has worsened water pollution in recent years. In this study, a magnetic biocomposite, Zirconium (Zr)-doped chitosan (CS)-coated iron oxide nanoparticles (Fe3O4-NPs)-peanut husk (PH)-based activated carbon (AC) (Zr-CS/Fe3O4-NPs@PH-AC), was synthesized for efficient removal of alizarin red (AR) and congo red (CR) dyes, alongside antibacterial applications. Characterization via scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis revealed micropores and mesopores development due to chemical activation of PH biomaterial and Fe3O4-NPs addition. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) identified functional groups and structural properties. Vibrating sample magnetometry (VSM) analyzed magnetic properties. Optimal conditions for AR/CR removal were determined, including Zr-CS/Fe3O4-NPs@PH-AC dose, dye dose, contact time, and temperature, achieving maximum removal percentages. Experimentally determined maximum adsorption capacities for AR and CR were 374.3 and 154.1 mg·g−1, respectively. Cytotoxicity studies affirmed the eco-friendly and non-toxic nature of the adsorbent by exhibiting the reduction in the cell viability from 100 % to 88.68 % from the 0 to 200 μg·L−1 respectively. Additionally, the biocomposite exhibited significant antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) due to magnetic NPs. The material in this study shows extreme compatibility for numerous applications.

Nickel augmented biochar for sustaining produced water treatment to decarbonize oil and gas industrial waste using anaerobic-aerobic granular cylindrical periodic discontinuous batch reactors

This study assessed the efficacy of granular cylindrical periodic discontinuous batch reactors (GC-PDBRs) for produced water (PW) treatment by employing eggshell and waste activated sludge (WAS) derived Nickel (Ni) augmented biochar. The synthesized biochar was magnetized to further enhance its contribution towards achieving carbon neutrality due to carbon negative nature, Carbon dioxide (CO2) sorption, and negative priming effects. The GC-PDBR1 and GC-PDBR2 process variables were optimized by the application of central composite design (CCD). This is to maximize the decarbonization rate. Results showed that the systems could reduce total phosphorus (TP) and chemical oxygen demand (COD) by 76–80% and 92–99%, respectively. Optimal organic matter and nutrient removals were achieved at 80% volumetric exchange ratio (VER), 5 min settling time and 3000 mg/L mixed liquor suspended solids (MLSS) concentration with desirability values of 0.811 and 0.954 for GC-PDBR1 and GC-PDBR2, respectively. Employing four distinct models, the biokinetic coefficients of the GC-PDBRs treating PW were calculated. The findings indicated that First order (0.0758–0.5365) and Monod models (0.8652–0.9925) have relatively low R2 values. However, the Grau Second-order model and Modified Stover-Kincannon model have high R2 values. This shows that, the Grau Second Order and Modified Stover-Kincannon models under various VER, settling time, and MLSS circumstances, are more suited to explain the removal of pollutants in the GC-PDBRs. Microbiological evaluation demonstrated that a high VER caused notable rises in the quantity of several microorganisms. Under high biological selective pressure, GC-PDBR2 demonstrated a greater percentage of nitrogen removal via autotrophic denitrification and a greater number of nitrifying bacteria. The overgrowth of bacteria such as Actinobacteriota spp. Bacteroidota spp, Gammaproteobacteria, Desulfuromonas Mesotoga in the phylum, class, and genus, has positively impacted on granule formation and stability. Taken together, our study through the introduction of intermittent aeration GC-PDBR systems with added magnetized waste derived biochar, is an innovative approach for simultaneous aerobic sludge granulation and PW treatment, thereby providing valuable contributions in the journey toward achieving decarbonization, carbon neutrality and sustainable development goals (SDGs).

Simultaneous removal of ammonium, phosphate, and phenol via self-assembled biochar composites CBCZrOFe3O4 and its utilization as soil acidity amelioration

ABSTRACT High concentrations of ammonium, phosphate, and phenol are recognized as water pollutants that contribute to the degradation of soil acidity. In contrast, small quantities of these nutrients are essential for soil nutrient cycling and plant growth. Here, we reported composite materials comprising biochar, chitosan, ZrO, and Fe3O4, which were employed to mitigate ammonium, phosphate, and phenol contamination in water and to lessen soil acidity. Batch adsorption experiments were conducted to assess the efficacy of the adsorbents. Initially, comparative studies on the simultaneous removal of NH4, PO4, and phenol using CB (biochar), CBC (biochar + chitosan), CBCZrO (biochar + chitosan + ZrO), and CBCZrOFe3O4 (biochar + chitosan + ZrO + Fe3O4) were conducted. The results discovered that CBCZrOFe3O4 exhibited the highest removal percentage among the adsorbents (P < 0.05). Adsorption data for CBCZrOFe3O4 were well fitted to the second-order kinetic and Freundlich isotherm models, with maximum adsorption capacities of 112.65 mg/g for NH4, 94.68 mg/g for PO4 and 112.63 mg/g for phenol. Subsequently, the effect of CBCZrOFe3O4-loaded NH4, PO4, and phenol (CBCZrOFe3O4-APP) on soil acidity was studied over a 60-day incubation period. The findings showed no significant changes (P < 0.05) in soil exchangeable acidity, H+, Mg, K, and Na. However, there was a substantial increase in the soil pH, EC, available P, CEC, N-NH4, and N-NO3. A significant reduction was also observed in the available soil exchangeable Al and Fe (P < 0.05). This technique demonstrated multi-functionality in remediating water pollutants and enhancing soil acidity.

Micro plastics removal by Zai water treatment plant, Amman Jordan

Micro-plastics (MPs) concentration, in Zai Water Treatment Plant (WTP) influent, and their removal by the different treatment units have been investigated. Samples were collected from the influent to Zai WTP, and from the effluent of each treatment unit, in December 2022, January, February, May and June of 2023. The samples were sieved at the site using one100 μm, 300 μm and 500 hundred μm sieves. The sieves were rinsed, the rinsed water was collected in 250 ml bottles and brought to the laboratory. The samples were treated and filtered in the Laboratory; two filter papers were prepared for each sample. Filtered samples were tested by Thermo Scientific micro-FTIR spectroscopy, for Microplastic identification, and by fluorescence microscope for MP quantification and morphology. The most frequently identified MPs in the influent were polyester, polyethylene, polypropylene, polystyrene; other MPs were identified at lower frequencies. The results showed that small MPs < 100 μm, in length, were dominant; larger sizes were detected at lower concentrations. The results showed that MPs were removed by the powdered activated carbon unit, coagulation, flocculation followed by sedimentation units, and by the dual media filter. Removal percentages by the different treatment units varied from month to month, which is attributed to the monthly variation in MPs nature and size distribution; variation of MP concentration in the influent; and variation in the operational conditions. Overall MP removal efficiencies were (48, 29, 53, 91, 84) %, for December, January, February, May, and June samples, respectively.

Switching of iron coagulants from steel residue for wastewater treatment

To create raw materials with additional value, a range of raw materials from waste products from the mineral sector can be recycled. At the tertiary step of wastewater treatment, iron solid waste can be converted into inorganic coagulants. Steel waste can be converted into ferric chloride (FC) and poly ferric chloride (PFC), which are crucial for tertiary treatment of sewage water. The variables influencing the amount of FC and PFC were produced as (Fe2O3) were assessed, including pH, contact time, hydrochloric acid concentration %, and HCl flow rate. The generated FC and PFC were characterized using FTIR, XRD, XRF, and SEM as a new material that was later employed to treat wastewater. The highest removal percentage of turbidity, TSS, TOC, and TKN from tertiary treatment of sewage water with FC were, 92.7 %, 97.2 %, 88.2 %, and, 94.4 %, respectively. The highest removal percentage of turbidity, TSS, TOC, and TKN for tertiary treatment of sewage water were, 97.7 %, 98.4 %, 90.5 %, and, 96.8 %, respectively using PFC. In conclusion, FC and PFC made from steel waste should be used more widely in the tertiary treatment of sewage water, surface water, agricultural wastewater treatment since it is an affordable, high-quality coagulant and protection of environment.