Abstract: This study evaluated the ability of Chlorella vulgaris, a freshwater microalgae species, to remove nutrients from raw municipal wastewater. The wastewater was collected from the initial sedimentation-stage discharge of the treatment plant and used to cultivate the microalgae in both a shaker-incubator and a photobioreactor. The results showed that the microalgae effectively reduced the nitrate, nitrite, phosphate, and ammonium ion concentrations in the wastewater by over 90%. Phosphate removal was particularly efficient in the photobioreactor, with a removal rate of 91%, while the shaker- incubator had a removal rate of 44%. In addition to removing nutrients, the microalgae were also able to significantly reduce the wastewater’s chemical oxygen demand (COD), with a reduction of over 90% from 264 to 23.1 mg/l. The microalgae also had a symbiotic effect on the bacterial colonies present in the wastewater, reducing their numbers by 99% while allowing the microalgae to thrive. The final biomass concentration in the photobioreactor was 2.03 g/l, a higher value compared to similar studies. These results demonstrate the potential of Chlorella vulgaris and other microalgae species for use in wastewater treatment systems.
Abstract: Antibiotics are generally applied for the treatment of infections in human and animals due to its economic values, easy accessibility and its potency. The use of veterinary pharmaceuticals such as antibiotics for the treatment of various infections in aquaculture cannot be overemphasized; the discharge of the aquaculture effluent without necessary remediation techniques leads to toxicity of the ecosystem. In this work, zinc oxide hexagonal-nanorods was synthesized via precipitation method and calcined at 5000C in a muffle furnace for the catalytic degradation of ciprofloxacin (CIP) formulated aquaculture effluent. The characterization of nano-sized ZnO (n-ZnO) were conducted by using scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) surface area determination. The SEMmicrograph depict both hexagonal and rod-like structures. The TEM micrograph subjected to image j. software showed an average particle size of 42.69 nm. The weight percent of the elements from the EDS followed the trend Zn>O>C>Cl. The sharp peak of Zn-O band was observed around 463.12 cm-1. The results from the XRD showed that pure n-ZnO was achieved at a temperature of 5000C with a BET surface area of 8.3 m2/g, pore volume of 0.072 cm3/g and pore size of 184.77 A0. The percentage COD removal of CIP formulated aquaculture effluent followed the trend 42.8%, 73.9% and 94.8% for ultrasound (US), US/n-ZnO and US/n-ZnO/H2O2 systems.A US/n-ZnO/H2O2system showed the highest removal efficiency of CIP from aquaculture effluent from the experiment. The kinetics best fit pseudo-second-order while the mechanism of degradation follows Langmuir-Hinshelwood model for the US/n-ZnO/H2O2system.Hence, the utilization of US/n-ZnO/H2O2for the degradation of CIP formulated aquaculture effluent has proven to be a sustainable system as the technique is dependable, faster, less-tedious and no generation of additional waste.
Abstract: A cavity-bubble oxidation reactor was used to study the degradation of patent blue v. The generation of cavity-bubbles by glass balls and flow-rate-induced jet were the degradation mechanisms used in this reactor. Initially, basic operating parameters were optimised by varying the initial concentration (10–40 ppm) and solution pH 2–12. The extent of degradation (22.6%) at 20 ppm was reduced to 11.4% when the initial concentration was increased to 40 ppm. Following that, combined treatment strategies for process intensification of the degradation process were investigated. It was found that lower initial concentrations and acidic conditions favoured the degradation of patent blue v. Under the optimal conditions of a concentration of 20 ppm and a pH of 2, the combined effect of the cavity-bubble oxidation reactor and chemical oxidation processes, such as hydrogen peroxide, gave a 95.38% extent of degradation at optimum H2O2 loading (2.5 g/L), which was 4.5 times greater than that obtained using cavity bubble oxidation reactors alone. The highest degree of degradation (98.48%) was achieved with a cavity-bubble oxidation reactor coupled with an optimum loading of the Fenton reagent (0.125 g/L FeSO4 and 2.5 g/L hydrogen peroxide). With the exception of the Fenton process, the kinetic analysis revealed that the degradation of patent blue v followed first-order reaction kinetics in all cases.
Abstract: This study investigated the performance and adsorption properties of paclitaxel and gemcitabine from industrial sewage by adsorbent of multi-magnetic carbon nanotubes. For this purpose, the first multi-walled carbon nanotubes were become magnetic by the Co-sedimentation method. Their characteristics have been determined by scanning electron microscopy analysis of field emission, transmission electron microscopy, energy dispersive x ray, X-ray diffraction as well as vibration sample magnetometer. Analyzes showed that iron oxide nanoparticles were incorporated well without destroying the structure of the nanotubes. Also, the effect of pH solution and adsorbent dosage on the adsorption of drugs was examined. According to the results, the pH of 7 and adsorbent dosage of 200 mg/L were found to be the optimal conditions for the process. Comparing The results of removal performance of paclitaxel and gemcitabine contaminants from drug sewage showed that multi-magnetic carbon wall nanotubes are more efficient in removing paclitaxel with 58% than gemcitabine with 26 %. Studies on the reaction kinetics and adsorption isotherms were performed on two contaminants. The results obtained from the fitting of the curve showed that the kinetics reaction of the drugs is of the second-order and is consistent with the Langmuir isotherm. Finally, the reusability and stability of the adsorbent was investigated, with only 8% and 5% (paclitaxel and gemcitabine respectively) reduction detected after 5 cycles.
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