“…Antibacterial activity has formerly been evaluated in the widespread range in the molluscan species such as oyster, mussel sea hare, etc. The searching principium for drugs from the marine environment is that marine animals and plants have a constant competition for reproduction, space, predation, etc (44,45). Although, most of the agents isolated from the marine sources, shows antimicrobial activities but they were not strong enough to compete with all classical antimicrobials obtained from the other microorganisms.…”
Background: The presence of medicines in the environment is considered as a serious threat to the human health. The entrance of these substances into the water sources causes soil pollution, which eventually leads to the environmental pollution and it creates some problems for the public health. Also, increasing antibiotic resistant bacteria has attracted the attention of researchers to the use of natural resources such as marine products, for producing new antibiotics. The aim of this study was to evaluate antimicrobial activities of powdered cuttlebone against Klebsiella oxytoca, Staphylococcus aureus, and Aspergillus flavus. Methods: At first, cuttlebones were washed, dried, and powdered. Then, the powdered cuttlebone was characterized. In the next step, its antimicrobial activities were evaluated using agar well diffusion technique, and minimum inhibitory concentration (MIC) was calculated. Results: The powdered cuttlebone was found to be effective against K. oxytoca (24 mm, MIC: 10-1 mg/mL), but no antimicrobial response was found against S. aureus. Also, the powdered cuttlebone antifungal activity and MIC against A. flavus were recorded 23 mm and 10-1 mg/mL, respectively. Conclusion: The obtained results suggest antimicrobial activities of powdered cuttlebone, which are concentration dependent. Furthermore, cuttlebone can be used as an accessible natural source to provide novel, low cost, and safe antimicrobial agents.
“…Antibacterial activity has formerly been evaluated in the widespread range in the molluscan species such as oyster, mussel sea hare, etc. The searching principium for drugs from the marine environment is that marine animals and plants have a constant competition for reproduction, space, predation, etc (44,45). Although, most of the agents isolated from the marine sources, shows antimicrobial activities but they were not strong enough to compete with all classical antimicrobials obtained from the other microorganisms.…”
Background: The presence of medicines in the environment is considered as a serious threat to the human health. The entrance of these substances into the water sources causes soil pollution, which eventually leads to the environmental pollution and it creates some problems for the public health. Also, increasing antibiotic resistant bacteria has attracted the attention of researchers to the use of natural resources such as marine products, for producing new antibiotics. The aim of this study was to evaluate antimicrobial activities of powdered cuttlebone against Klebsiella oxytoca, Staphylococcus aureus, and Aspergillus flavus. Methods: At first, cuttlebones were washed, dried, and powdered. Then, the powdered cuttlebone was characterized. In the next step, its antimicrobial activities were evaluated using agar well diffusion technique, and minimum inhibitory concentration (MIC) was calculated. Results: The powdered cuttlebone was found to be effective against K. oxytoca (24 mm, MIC: 10-1 mg/mL), but no antimicrobial response was found against S. aureus. Also, the powdered cuttlebone antifungal activity and MIC against A. flavus were recorded 23 mm and 10-1 mg/mL, respectively. Conclusion: The obtained results suggest antimicrobial activities of powdered cuttlebone, which are concentration dependent. Furthermore, cuttlebone can be used as an accessible natural source to provide novel, low cost, and safe antimicrobial agents.
“…If the lnC 0 /C t graph versus reaction time is a straight line, the graph slope indicates the rate constant (k) (12,27,28). From the slope of the graph, the rate of the photocatalytic degradation of metronidazole was determined (27,(29)(30)(31).…”
Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.
“…Eventually, the precursor was immobilized on 3 pieces of flat and rough stone 3 in 20 cm and in order to calcination it was placed in an electric furnace (BADi) for 1 hour at 850 °C ( Fig. 1 ) [19] . Fig.…”
Section: Zno Nanoparticles Synthesis and Characterizationmentioning
confidence: 99%
“…Hence, removal of azo dyes from textile industry wastewater is so necessary. Lately, a lot of physical, chemical and biological methods [5 , 6] such as adsorption [7] , [8] , [9] , [10] , [11] , [12] , [13] , electrocoagulation [14] , [15] , [16] , [17] , activated sludge [18] , photochemical [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] ), oxidation [30] , [31] , [32] , [33] , [34] , trickling filter [35] and membrane processes [36] have used for the azo dyes, organic and inorganic pollutants removal from the environment. However, these methods have some problems [23] such as the toxics production expensive facilities and high maintenance and operation costs.…”
Azo dyes are the largest group of synthetic organic dyes which containing the linkage C—N
N—C and used in various industries such as textile industries leather articles, and some foods. Azo dyes are resistant compounds against the biodegradation processes. The purpose of this research was hybrid UV/COP advanced oxidation process using ZnO as a catalyst immobilized on a stone surface for degradation of acid red 18 (AR18) Dye. In the hybrid process using some parameters such as the dye initial concentration, pH, contact time and catalyst concentration, the process efficiency was investigated. In order to the dye removal, the sole ozonation process (SOP), catalytic ozonation process (COP) and photocatalytic process (UV/ZnO) were used. The ZnO nanoparticles were characterized by XRD, SEM and TEM analyses. The maximum dye removal was achieved 97% at the dye initial concentration 25 mg/L, catalyst concentration 3 g/L, contact time 40 min and pH 5. As a real sample, the Yazdbaf textile factory wastewater was selected. After that, the physicochemical quality was evaluated. As well as, in the optimal conditions, the AR18 dye removal efficiency was achieved 65%. The kinetic results demonstrated that the degradation reaction was fitted by
pseudo
-first-order kinetic. The UV/COP hybrid process had high efficiency for removal of resistant dyes from the textile wastewater.
Advantages of this technique were as follows:
ZnO nanoparticles were synthesized as catalyst by thermal method and were immobilized on the stones.
pH changes had no significant effect on the removal efficiency.
In the kinetic studies, the decomposition reaction followed
pseudo
-first order kinetic.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
