Showing papers in "Desalination and Water Treatment in 2020"
53 citations
TL;DR: In this paper, the authors investigated the adsorptive behavior of Cu, Ni, and Zn ions by Archontophoenix alexandrae in single metal system (SMS), bi-metal system (BMS), and tri-metal systems (TMS).
Abstract: This study focuses on the investigation of adsorptive behavior of Cu, Ni, and Zn ions by Archontophoenix alexandrae in single metal system (SMS), bi-metal system (BMS), and tri-metal system (TMS). This was done through a novel strategy by combining factorial design (FD), response surface methodology (RSM), and mixture design (MD). The adsorption study was carried out as a function of pH, contact time, and biomass dosage and validated through screening design. To improve adsorption capacities of metallic ions, RSM and MD involving central composite design and simplex lattice design were used. The experimental designs demonstrated the maximum adsorption capacity for Cu. The existence of Cu ions suppressed the adsorption of Ni and Zn ions. Langmuir isotherm model and the pseudo-second-order kinetic model best explain the adsorption kinetics of Cu(II), Ni(II), and Zn(II) metal ions on to A. alexandrae. The A. alexandrae could possibly be used as an efficient biosorbent for the removal of toxic pollutants from industrial effluents.
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47 citations
TL;DR: In this paper, the authors investigated the efficiency of the ozonation process with calcium peroxide for the removal of CIP from aqueous solutions and determined the removal efficiency under optimal conditions, that is, pH = 3, CIP concentration = 5 mg/L, concentration of CaO2 = 0.025 mg/l, temperature = 25°C, odometry rate = 1 g/min and contact time = 50 min.
Abstract: Ciprofloxacin (CIP) belongs to the fluoroquinolones group and is widely applied in therapeutics. The presence of fluorine in CIP increases its stability in the environment. Advanced oxidation processes are among the most effective methods used to remove hazardous and resistant pollutants in the environment. This study aimed to determine the efficiency of the ozonation process with calcium peroxide for the removal of CIP from aqueous solutions. The removal efficiency of CIP and chemical oxygen demand under optimal conditions, that is, pH = 3, CIP concentration = 5 mg/L, concentration of CaO2 = 0.025 mg/L, temperature = 25°C, ozonation rate = 1 g/min and contact time = 50 min, was obtained 95.6% and 80.1% as well as 85.4% and 73.6%, in synthetic and simulated wastewater samples (municipal wastewater + CIP), respectively. Thermodynamic studies have shown that CIP decomposition with ozonation and CaO2 is an endothermic process. The kinetics of CIP decomposition followed the pseudo-first-order equation. The use of the ozonation process with calcium peroxide is an efficient method for CIP removal.
46 citations
TL;DR: In this paper, the adsorption kinetics of MG onto adsorbate was strongly represented by a pseudosecondorder kinetic model, with a coefficient of determination 0.9669.
Abstract: The nanoporous material, Mobil Composition of Matter No. 41 (MCM-41), was prepared and characterized in order to adsorb methyl green (MG) dye from artificial wastewater by adsorption method. The MCM-41 was characterized through X-ray diffraction spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller. The preliminary results were examined for adsorbent mesoporous material samples, in order to estimate the best states for the adsorption of the model dye: adsorbent dose (0.00–80.04 g) contact time (8–150 min), temperature (25°C–45°C), and initial concentration of dye (10–50 mg/L) where the removal efficiency of MG dye under optimum conditions was around 99%. The outcomes were elucidating that the adsorption isotherms can be quite befitting by the Temkin model, with a coefficient of determination 0.9669. The adsorption kinetics of MG onto adsorbate was strongly represented by a pseudosecondorder kinetic model.
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36 citations
TL;DR: In this paper, the authors used principal component analysis (PCA) and hierarchical cluster analysis (HCA) to evaluate the appropriateness of the nature of groundwater for domestic and irrigation uses.
Abstract: In southern India, Attur is a major groundwater province with substantial groundwater quality and quantity deficiencies as a result of increasing population density and urbanization. In the present study, 43 bore well locations are identified in the study area to evaluate the appropriateness of the nature of groundwater for domestic and irrigation uses. The study region majorly covered by charnockite, hornblende biotite gneiss, and porphyroclasts bearing mylonites are exposed in the foothill. The dominant ions in groundwater are as follows K+, >Na+, >Mg2+, and >Ca2+ for cation and Cl–, >HCO3, and >SO4 for anions. It’s revealed that groundwater is mainly alkaline and hard in nature for domestic uses. Various irrigation indices have been calculated for the evaluation of groundwater quality parameters for irrigation suitability. The most efficient methods of statistical analysis are principal component analysis (PCA) and hierarchical cluster analysis (HCA) was carried out in the study. It has also been found that, weathering of host rocks and their minerals, agricultural waste, synthetic fertilizers, and anthropogenic activities are strongly influencing the quality of water in study area. The research concluded that, remedial measures such as primary treatment are immediately needed before use for drinking uses.
35 citations
TL;DR: In this paper, an electrocoagulation-flotation (ECF) following sedimentation was applied as a printing and packaging wastewater treatment using four Al electrodes with a parallel monopolar configuration.
Abstract: In this work, electrocoagulation–flotation (ECF) following sedimentation was applied as a printing and packaging wastewater treatment using four Al electrodes with a parallel monopolar configuration. A sedimentation process was applied after the ECF as a post-treatment phase to remove large pollutants. The simultaneous efficacy of the operating parameters initial color content (1,843.44–12,156.56 ADMI), initial pH (3.56–10.44), current density (6.02–22.18 mA/cm2), and treatment time (5.62–74.38 min) on color and chemical oxygen demand (COD) removal efficiencies were evaluated alongside processing costs. Response surface methodology (RSM) and central composite design (CCD) optimized these key parameters to achieve the highest removal efficiencies and lowest operating costs. Based on the results analyzed by RSM-CCD, using initial color content of 5,576.38 ADMI, initial pH of 7.29, the current density of 18.49 mA/cm2, and treatment time of 59.76 min as optimum operational conditions can result in 97.8% and 92.1% for color and COD removal efficiencies, respectively. At these optimum conditions, operating costs (OPCs), including electrodes material and energy consumption, were 0.07 US$/(kg color removed) and 0.4 US$/(kg COD removed). The results confirm ECF-sedimentation as a promising and costeffective tool for the treatment of printing and packaging wastewater.
34 citations
TL;DR: In this article, an experimental study was made on two similar stills with a single slope, size 1 m × 1 m, the first distiller D1 is used as a control and the second distiller had a simple external mirror glued to its backlog.
Abstract: Desalination is now successfully practiced in many countries as drinking water supply has become a growing problem in most parts of the world. Algeria, like the Maghreb countries, has generally adopted two desalination processes (membrane processes and distillation processes which require a phase change, evaporation/condensation), the latter method is subject of our study. An experimental study was made on two similar stills with a single slope, size 1 m × 1 m, the first distiller D1 is used as a control and the second distiller D2 has a simple external mirror glued to its backlog. The same experience has been done in different climates with improvement results ranging from 9% to 21%. In our case, a complete study was concerning the improvement, the efficiency, the investment and finally the error analysis of the instrumentations that have not been done before. We obtained a very interesting improvement which varied between 42% and 45%, the efficiency is 35% and the recovery period of the sum invested is recovered in 23 d, which shows that this technique is more favorable under the climatic conditions of the West Southeast region of Algeria than elsewhere.
TL;DR: In this article, the results showed that electrical conductivity, alkalinity, and arsenic were above the permissible limit of the World Health Organization (WHW) in Rawalpindi and Islamabad.
Abstract: Safe drinking water is the basic human right in any region of the world. With increasing population and anthropogenic activities, this basic entity is in danger. This situation is more worsen in developing countries where no monitoring and maintenance is being followed. The present study is based on the monitoring of filtration plants for drinking water in two populated cities of Pakistan to determine the water quality status. Drinking water samples from Rawalpindi (n = 53) and Islamabad (n = 32) were taken from filtration plants installed by Capital Development Authority (CDA) in Islamabad and Water and Sanitation Agency (WASA) in Rawalpindi Pakistan. Physio-chemical parameters metals were analyzed using the standard procedures and multivariate indices and health risks were calculated. The results showed that electrical conductivity, alkalinity, and arsenic were above the permissible limit of the World Health Organization. 32 out of 53 samples in Rawalpindi while 26 out of 32 samples in Islamabad were found under poor water quality category with water quality index (WQI) > 100. Hazard index of arsenic was found <1 in adults (9.80E+01 and 7.03E+01) and children (1.48E+02 and 1.06E+02) at Rawalpindi and Islamabad respectively. Especially, children are found more prone to health hazards. Microbiological (bacteriological) components were incorporated to check the health risks due to water contamination. Proper management should be taken for the sustainability of limited underground water. This study will provide basic information regarding water quality in two large cities in a developing country of Pakistan.
TL;DR: In this article, the photocatalytic degradation of Metronidazole (MNZ) using copper oxide nanoparticles (CuO-NPs) activated by H2O2 in the presence of UV irradiation was evaluated.
Abstract: Metronidazole (MNZ) has identified as a remarkable environmental pollutant since it is highly consumed and is resistant to biological degradation. This study was accomplished to assess the photocatalytic degradation of MNZ in aqueous media using copper oxide nanoparticles (CuO-NPs) activated by H2O2 in the presence of UV irradiation (UV/H2O2/CuO-NPs process). For this purpose, the laboratory-scale experiments were carried out in the 2.5 L batch reactor. The effect of operational parameters, that is, initial pH (3–11), the concentration of MNZ (25–100 mg/L), the concentration of H2O2 (10–40 mg/L), the concentration of CuO-NPs (2–8 mg/L), and reaction time (0–60 min) were also assessed. The results of this study clarified that under optimum conditions (pH = 3, H2O2 = 10 mg/L, [MNZ]0 = 50 mg/L, CuO-NPs = 8 mg/L, and reaction time = 60 min), the removal efficiencies of MNZ, chemical oxygen demand (COD), and total organic carbon (TOC) using the UV/H2O2/CuO-NPs process were 98.36%, 73.0%, and 56.52%, respectively. According to the results, by increasing reaction time from 0 to 60 min, the AOS in the effluent was increased from 1.39 to 2.38, and the COD/TOC ratio was decreased from 1.74 to 0.8. The results related to parameters of the kinetics showed that the removal of MNZ antibiotic using the studied system conforms to the pseudo-first-order kinetics (R2 = 0.983), and kinetics rate constant (k) was 0.0624 min–1. This study provides UV/H2O2/CuO-NPs process as an innovative method to degrade the MNZ antibiotic and enhance its biodegradability. We concluded that the studied process can be used as an effective and eco-friendly method in the removal of MNZ antibiotics.
TL;DR: In this paper, ultrasonic assisted Spirulina platensis (UASP) algal powder was used for the adsorption of Naphthol green-B (NGB) dye within environmental conditions.
Abstract: The usage of ultrasonic-assisted Spirulina platensis (UASP) algal powder for the adsorption of Naphthol green-B (NGB) dye was analyzed within environmental conditions. The batch removal investigations were done with various operational conditions including UASP dose, contact time, initial NGB dye concentration and the NGB solution pH to eliminate NGB dye molecules in the aqueous solution. The optimal working conditions for the removal of NGB dye by UASP was showed that contact time (60 min), dose (3 g/L), initial NGB dye concentration (100 mg/L), pH (3), and temperature (30°C). The dye removal data were inspected by utilizing four adsorption isotherm models like Langmuir, Freundlich, Toth, and Hill isotherm models. The experimental data generated best fits within the following isotherm order: Freundlich > Hill > Toth > Langmuir isotherm model. The maximum monolayer adsorption capacity was 137.9 mg/g. The pseudo-first-order, secondorder kinetic, and intraparticle diffusion models were probed and the outcomes show that the pseudo-first-order fitted with the adsorption of NGB dye molecules by UASP. Thermodynamic parameters like ΔG°, ΔH°, and ΔS° were determined and the results prove that the NGB adsorption was exothermic, spontaneous, and feasible. The results specify that the UASP has actually been utilized as an inexpensive biosorbent for the removal of NBG dye from aqueous solution.
TL;DR: In this article, bioadsorbent powder of Solamen Vaillanti snail shell was used to remove lead, cobalt, and copper ions from synthetic and industrial wastewater, and the effect of different parameters such as pH, contact time, temperature, initial concentration of metal ions, and adsorbent dosage on the removal efficiency of lead and cobalt ions was investigated.
Abstract: In this study, bioadsorbent powder of Solamen Vaillanti snail shell was used to remove lead, cobalt, and copper ions from synthetic and industrial wastewater. To do this, bioadsorbent powder was first prepared by the calcination of shellfish skin, and the physical properties of the bioadsorbent before and after the adsorption process were then studied using Brunauer–Emmett–Teller, scanning electron microscopy, Fourier-transform infrared spectroscopy, and energy dispersive X-ray analysis techniques. Also, the effect of different parameters such as pH, contact time, temperature, the initial concentration of metal ions, and adsorbent dosage on the removal efficiency of lead, cobalt and copper ions was investigated. The best adsorption efficiency was determined as pH 6 for cobalt and pH 5 for lead and copper, the temperature of 25°C, the contact time of 60 min, initial ion concentration 10 mg L–1, and adsorbent dosage of 2 g L–1. The maximum removal efficiencies of lead, cobalt, and copper ions were 94.4%, 96.5%, and 96.7%, respectively. Also, the maximum adsorption efficiency of lead, cobalt, and copper ions from industrial wastewater was obtained 85%, 81%, and 91%, respectively. The equilibrium behavior of the adsorption process indicated that the adsorption process follows the Langmuir isotherm model. Also, the pseudo-second-order kinetic model could better describe the kinetic behavior of the adsorption process. According to the Langmuir model, the highest adsorption capacity of lead, cobalt, and copper were obtained 26.04, 29.41 and 33.55 mg g–1, respectively. The values of the thermodynamic parameters also showed that the adsorption process was feasible, spontaneous, and exothermic.
TL;DR: In this paper, the soybean leaves were modified by acetic acid (AA) to improve the adsorption capacity of RR195 dye removal from aqueous solutions, and the results showed that AA-SL was a low-cost material that has the potential to be used as a new alternative adorbent for the removal of reactive red color.
Abstract: This study aims mainly to use the soybean leaves (SL), agricultural wastes, as a new low-cost adsorbent for Reactive Red 195 (RR195) dye removal from aqueous solutions. The dried SL was chemically modified by acetic acid (AA) to improve its adsorption capacity. The adsorbent (AA-SL) was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The effects of operational parameters such as contact time, pH, adsorbent dose, initial dye concentration, and temperature were investigated in batch experiments. Adsorption kinetics, isotherm, and thermodynamic of AA-SL have been studied. The AA-SL structure was found to be irregular and porous. FTIR revealed that the surface of AA-SL was abundant in various functional groups. The solution pH strongly affects RR195 removal efficiency. The highest removal efficiency equal to 97.8% was achieved using a solution pH equal to 1 at 50°C. The removal efficiency was increased by increasing the solution temperature. The adsorption of RR195 was decreased from 15.32 to 2.29 mg g–1 with increasing the adsorbent dose from 0.25 to 3 g L–1, respectively. Increasing initial dye concentration from 5 to 40 mg L–1 resulted in increasing the adsorption capacity from 2.2 to 9.2 mg g–1, respectively and decreasing the removal rate from 88% to 45.8%, respectively. The adsorption of RR195 onto AA-SL obeyed Langmuir (R2 = 0.998) and D–R (R2 = 0.967) models with a theoretical maximum adsorption capacity of about 12 mg g–1 at 50°C. The experimental data fitted very well with the pseudo-second-order kinetic (R2 = 0.991). Thermodynamic studies indicated that the reaction is irreversible and endothermic adsorption. AA-SL, as a low-cost material has the potential to be used as a new alternative adsorbent for the removal of RR195 dye from aqueous solutions.
TL;DR: In this paper, a novel hybrid nanocomposite adsorbent was prepared by encapsulation of multi-walled carbon nano-tubes within polyvinyl alcohol/chitosan hydrogel (Cs/MWCNT/PVA) and crosslinked with glu-taraldehyde.
Abstract: A novel hybrid nanocomposite adsorbent was prepared by encapsulation of multi-walled carbon nano-tubes within polyvinyl alcohol/chitosan hydrogel (Cs/MWCNT/PVA) and cross-linked with glu-taraldehyde. The chemical reactions between the components affected the position and intensities of the infrared bands. This nanocomposite has excellent Cr6+ ions adsorption efficiency. The optimal conditions of the process as a function of the solution pH, contact time, ionic strength, and sorbent weight were investigated. The batch equilibrium experiments revealed that the most suitable pH for chromium adsorption was at 1.5. The maximum adsorption capacity for the hydrogel was 217.4 mg g–1 as estimated by the Langmuir model. Other isotherm models, such as Freundlich and Temkin, were used to analyze the experimental data and the models’ parameters were evaluated. The pseudo-first and second-order, Elovich, intraparticle diffusion, and film diffusion kinetic models were also inves-tigated. The obtained results enabled to estimate the possibility to use the Cs/MWCNT/PVA hydrogel in the removal of Cr6+ ions from wastewater by adsorption. (Less)
TL;DR: In this article, a study was conducted to evaluate the quantity and quality of wastewater generated by industrial and municipal effluent and its treatment efficiency in a semi-arid city Faisalabad, Pakistan.
Abstract: Increased population growth, better living standards and improved economic activity put the upward burden on the world’s inadequate water resources. A study was conducted to evaluate the quantity and quality of wastewater generated by industrial and municipal effluent and its treatment efficiency in a semi-arid city Faisalabad, Pakistan. Samples from industries (n = 60) and sewage water (n = 30) were collected and evaluated for different quality parameters. Physio-chemical including pH, total dissolved solids, suspended solids, biochemical oxygen demand (BOD) and chemical oxygen demand (COD), total coliform and heavy metals including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were analyzed. Emphasis was made on metal contamination by multivariate indexes including metal pollution index (MPI), degree of contamination (CD) and pollution load of drains. Aquatic macrophytes (Typha latifolia, Brachiaria mutica, Poa annua) were collected from anaerobic ponds of the Chokera wastewater plant. Results showed that all the parameters were higher than the upper limit of Punjab Environmental Quality Standards (PEQs) set by the Environmental Protection Agency (EPA) Pakistan. MPI was found high in textile industrial effluents (MPI > 1,000). The degree of contamination was very high than the maximum contamination level (≥ 3) in industrial effluent (33.85) followed by sewage effluent (14.05). Pollution load was calculated which showed the high BOD (119.34 ton/d) and COD (376.41 ton/d) load in Pharang drain due to excessive discharge of industrial effluent. Treatment efficiency at Chokera wastewater ponds was higher (60%) in summers as compared to winters and through the phytoremediation process. Typha latifolia found a most suited plant with a high accumulation coefficient value for metals uptake. Parameters after treatment were still above the PEQs. So, these ponds need to be monitored quarterly for maintenance. The possible environmental benefits can be obtained by introducing such plants in wastewater drains and effluent treatment plants to enhance its efficiency. However, there should be a strict policy to be implemented for the control of industrial discharge by government agencies.
TL;DR: In this article, the removal of amoxicillin using a photocatalysis/ozonation process for treating pharmaceutical wastewater loaded with this type of refractory pollutants was carried out using different pH values (3-11), catalyst dosages (250-750 mg/L), and reaction times (30-90 min), at an ozonation rate of 200 mg/h.
Abstract: Concerns about environmental pollution from antibiotics such as amoxicillin have received increasing attention. These compounds should be eliminated from discharged effluents to avoid their possible negative effects on humans and animals, as well as on the environment. Recently, advanced oxidation techniques have been used to remove antibiotics. This work aims to study the removal of amoxicillin using a photocatalysis/ozonation process for treating pharmaceutical wastewater loaded with this type of refractory pollutants. The removal process was carried out using different pH values (3–11), catalyst dosages (250–750 mg/L), and reaction times (30–90 min), at an ozonation rate of 200 mg/h. Statistical analysis indicated that a quadratic model was suitable for modeling amoxicillin degradation by the photocatalytic process and that all studied parameters had statistically significant critical levels. Under optimum conditions (pH 11, a catalyst dose of 500 mg/L, and a reaction time of 90 min), the amoxicillin degradation efficiency of the photocatalytic process was 78.7%. The results of the photocatalysis/ozonation process indicated that after 90 min of ozone injection, an amoxicillin degradation efficiency of 98.7% was obtained. Therefore, it was concluded that the combined ozonation process and photocatalytic process could be used to remove amoxicillin effectively.
TL;DR: In this paper, the authors compared the efficiency of the activated carbon coated with the zinc oxide (ZnO) nanoparticles prepared by walnut shell in removing two dyes from aqueous environments.
Abstract: Dyes considered as a main environmental pollutant are present in various effluents released from different industries like textiles. Dyes cause problems such as reduced light penetration, allergies, and cancer when they are entered into the environment. The purpose of this study was to compare the efficiency of the activated carbon coated with the zinc oxide (ZnO) nanoparticles prepared by walnut shell in removing two dyes from aqueous environments. The study used a floating method to prepare the AC-ZnO composite. The composite structure and morphology were studied using Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller (BET), X-ray diffraction and field emission scanning electron microscopy techniques. The results confirmed the accuracy of the composite structure. Moreover, the study examined reaction time, solution pH, composite volume, and initial dye concentration and AC-ZnO composite recovery. The removal efficiencies under the optimal conditions for Reactive Blue 19 (RB-19) and Reactive Black-5 (RB-5) (dye concentrations 100 mg L–1, composite dose 1.5 g L–1, reaction time 45 min and pH 3) were 97.36% and 73.36%, respectively. The results of the experimental data were fitted well to the Langmuir isotherm, indicating monolayer adsorption of both metal ions onto the AC-ZnO composite and an estimated adsorptive capacity of 71.42 (RB-5) and 94.33 mg g–1 (RB-19). However, the kinetic data agreed well with the pseudo-second-order model. The SBET and total pure volume for the AC-ZnO composite and AC were 728.17 m2 g–1, 687.95 m2 g–1 and 0.684 cm3 g–1, 0.612 cm3 g–1, respectively. It can be concluded that AC-ZnO composite as an effective and environmentally friendly adsorbent had a high ability in removing dye from aqueous solutions.
TL;DR: In this article, the capacities of these composite materials for Ni2+, Cd2+, Co2+, Pb2+, Zn2+, and Cu2+ were studied and the data revealed that the capacity of MgSi is higher that obtained P(AM-AN) by 0.6 value, and lower for [P(AM)-AN)-MgSi by 1.32 value.
Abstract: Chemically stable magneso-silicate (MgSi), polyacrylamide acrylonitrile P(AM-AN), and polyacrylamide acrylonitrile magneso-silicate [P(AM-AN)-MgSi] comparing with other ion exchangers ware synthesized at different radiation doses. The capacities of these composite materials for Ni2+, Cd2+, Co2+, Pb2+, Zn2+, and Cu2+ were studied and the data revealed that the capacity of MgSi is higher that obtained P(AM-AN) by 0.6 value, and lower for [P(AM-AN)-MgSi] by 1.32 value. Distribution coefficients in HNO3 show separation potentiality of prepared composites for studied cations and Cd2+ have higher separation factor to MgSi and P(AM-AN), while Pb2+ has higher separation factor to [P(AM-AN)-MgSi].
TL;DR: In this paper, the Feammox process was successfully developed in a biofilm reactor using sponge iron as a Fe source feeding ammonium-containing aerobic water, which demonstrated an average NH4 oxidation efficiency and rate of 42.3% and 32.2% respectively.
Abstract: Anoxic ferric iron-dependent ammonium oxidation (Feammox) is a novel biological nitrogen removal process that oxidizes ammonium to NO2, NO3 or N2 using ferric iron as the electron acceptor. In this study, the Feammox process was successfully developed in a biofilm reactor using sponge iron as a Fe source feeding ammonium-containing aerobic water. The results showed that NH4 was oxidized to NO3 by Feammox. During 300 d of operation, the bioreactor demonstrated an average NH4 oxidation efficiency and rate of 42.3% and 32.2 mg N L–1 d–1, respectively. Sponge iron was oxidized to ferric by dissolved oxygen (DO) in the influent and provided ferric and anaerobic conditions for Feammox. Only a small proportion of the generated NO3 was reduced to N2 by nitrate-dependent Fe(II) oxidation causing nitrogen removal in the Feammox biofilm reactor. A distinct inhibition of Feammox was observed when DO increase to 1.0 mg L–1. Microbiological composition analysis of the Feammox biomass showed that the dominant iron-reducing bacteria were Geobacter spp., Fervidicella, and Geothrix, which may contribute to Feammox. This study provides information on the process development of Feammox.
TL;DR: In this article, the surface charge of the individual CdS NPs, AgBr NPs and the resulted coupled CCAN system was estimated at 6.3, 4.6, and 5.6.
Abstract: As synthesized coupled CdS-AgBr nanoparticles (NPs) (CCAN) were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence and ultraviolet-visible diffuse reflectance spectroscopy techniques. The surface charge of the individual CdS NPs, AgBr NPs and the resulted coupled CdS-AgBr system was estimated at 6.3, 4.6, and 5.6, respectively. Then, the photocatalytic activity of the individual and the coupled systems was tested towards decolorization of methylene blue (MB) in aqueous solution and about 39%, 60%, and 80% of MB molecules were respectively decolorized by CdS NPs, AgBr NPs, and CdS-AgBr CCAN during 30 min photocatalytic decolorization experiments. Change in a mole ratio of the involved semiconductors of the coupled system changed the photo decolorization activity and the best response was obtained for the catalyst with a mole ratio of 1:4 CdS:AgBr. Kinetic of the process was followed and the results showed that the Langmuir-Hinshelwood model can model the process and a relatively fast reaction with a rate constant about 3.49 × 10–2 min–1 was distinguished. Mineralization extent of MB aqueous solution during the decolorization experiments was followed by chemical oxygen demand (COD) technique and the results showed that the initial COD value of 1,280 mg O2 L–1 was decreased to 640 and 480 mg O2 L–1 after 30 and 60 min of decolorization of MB solution. The catalyst retained its initial activity during 4 successive reusing runs.
TL;DR: In this paper, the impact of nanomaterial composition (i.e., sizes, structure, and shapes) on membrane possessions and desalination operations was investigated. And the results showed that the merging of AgNPs produced membrane of enhanced filtration performances (Ag/PSf/PA) than pure thin-film composite membrane (PSf-PA).
Abstract: In this work, silver nanoparticles (AgNPs) were produced by soil isolated fungus Eurotium cristatum extract and thin-film nanocomposite (Ag/PSf/PA) membrane was built-up (by adding different concentrations of AgNPs into the polysulfone support layer) to look into the impacts of nanomaterial composition (i.e., sizes, structure, and shapes) on membrane possessions and desalination operations. The desalination consequences exposed that the merging of AgNPs produced membrane of enhanced filtration performances (Ag/PSf/PA) than pure thin film composite membrane (PSf/PA). In contrast to the PSf/PA membrane, the Ag/PSf/PA membrane possesses better water flux (32 vs. 16.5 L/m2 h) and advanced NaCl rejection (91.7% vs. 89%). Moreover, scanning electron microscopy analysis outcomes reveal that the enlargement of gram-negative (Escherichia coli) and gram-positive (Listeria sp.) were greatly inhibited on the Ag/PSf/PA nanocomposite membrane, representing the sure thing of silver nanoparticles. This analysis offers enormous potential for promising use as a new form of anti-biofouling membrane.