In this study, a packed bed was used to remove pathogenic bacteria from synthetic contaminated water. Two types of packing material substrates, sand and zeolite, were used. These substrates were coated with silver nanoparticles (AgNPs), which were prepared by decomposition of Ag ions from AgNO3 solution. The prepared coated packings were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy and transmission electron microscopy. The packed column consisted of a PVC cylinder of 2 cm diameter and 20 cm in length. The column was packed with silver nanoparticlecoated substrates (sand or zeolite) at a depth of 10 cm. Four types of bacteria were studied: Escherichia coli, Shigella dysenteriae, Pseudomonas aeruginosa and Vibrio cholera. The parameters studied were feed inlet flow rate (1.5, 2, 3 and 4 L/h) and AgNO3 concentration (0.02, 0.04, 0.07 and 0.1 mM), which were used to coat the packing substrates. The best results for removal efficiency of bacteria were obtained at the feed flow rate of 1.5 L/h with AgNO3 concentration 0.1 mM. Likewise, the percent of bacterial removal from contaminated water was found to be 99% for V. cholera, 93.7% for E. coli, 85% for S. dysenteriae and 77.5% for P. aeruginosa
Cadmium is one of the heavy metal found in the wastewater of many industries. The electrocoagulation offers many advantages for the removal of cadmium over other methods. So the removal of cadmium from wastewater by using electrocoagulation was studied to investigate the effect of operating parameters on the removal efficiency. The studied parameters were the initial pH, initial concentration, and applied voltage. The study experiments were conducted in a batch reactor with with two pairs of aluminum electrodes with dimension and 2mm in thick with 1.5 cm space between them. The optimum removal was obtained at pH =7, initial concentration = 50 mg/L, and applied voltage = 20 V and it was 90%.
Three types of extracts ( aquatic, alcoholic, and oily ) were prepared from the fruits of coconuts, and a series of chemical tests were conducted in addition to the use of the FTIR equipment to determine the active locations in the prepared extracts. The results indicated the presence of active compounds (tannins, saponins, flavonoids, turbines and steroids) in the extracts prepared from the fruits of coconuts, also the antimicrobial capability of these extracts were tested on pathogenic bacteria isolated from wounds and burns infections cases. The results proved that the concentration 80 mg/ml of the aquatic extract is the minimum inhibitory concentration for the microbes: Proteus vulgaris and Pseudomonas fluorescence, while the
... Show MoreIn this study, the adsorption of Zn (NO3)2 is carried out by using surfaces of malvaparviflora. The validity of the adsorption is evaluated by using atomic absorption Spectrophotometry through determination the amount of adsorbed Zn (NO3)2. Various parameters such as PH, adsorbent weight and contact time are studied in terms of their effect on the reaction progress. Furthermore, Lagergren’s equation is used to determine adsorption kinetics. It is observed that high removal of Zn (NO3)2 is obtained at PH=2. High removal of Zn (NO3)2 is at the time equivalent of 60 min and reaches equilibrium,where 0.25gm is the best weight of adsorbant . For kinetics the reaction onto malvaparviflora follows pseudo first order Lagergren’s equation.
Granular carbon can be used after conventional filtration of suspended matter or, as a combination of filtration - adsorption medium. The choice of equipment depends on the severity of the organic removal problem, the availability of existing equipment, and the desired improvement of adsorption condition.
Design calculations on dechlorination by granular - carbon filters considering the effects of flow rate, pH , contact time, head loss and bed expansion in backwashing , particle size, and physical characteristics were considered assuming the absence of bacteria or any organic interface .
