جستجوی مقالات مرتبط با کلیدواژه "پساب صنعتی" در نشریات گروه "عمران"

In the present study, the removal of heavy metals (in the case of cobalt removal) from contaminated water using Fe3O4 magnetic nanoparticles and the effects of pH factors, time, cobalt concentration and temperature on cobalt removal were investigated and to describe the data obtained Langmuir and Freundlich equilibrium isotherms have been used for absorption experiments. The experiments were designed with the Taguchi method in the Coalition software, which uses a partial factorial method. Nanoparticles are synthesized by co-operation in the laboratory, and then experiments are performed on four levels of each factor on a simulated solution containing cobalt, and the results are analyzed with the aid of the Coalytic software using the Taguchi standard analysis method. The highest cobalt adsorption rate is 81%, pH is equal to 9, 15 minutes, initial concentration of cobalt is 7 mg / l, and 60 ° C. Also, according to the analysis, the optimum conditions in pH state are 9, the remaining 10 minutes, the initial concentration of cobalt is 25 mg / L, and 20 ° C. The rate of yield in cobalt adsorption is expected to be 383/86 percent. At the end, the result of the experiment under optimal conditions on real industrial waste water contains 36 mg / l of cobalt 60 with an absorption rate of 6.7%, which is 17.1%, due to changes in experimental and actual conditions. The data obtained from adsorption isotherms are consistent with the two models and are more fitted to the Freundlich model.

The present study was conducted to compare the efficiency of normal and modified UASB reactor for the treatment of dairy wastewater. To conduct research, two reactor units with a height of 120 cm and a volume of 48 liters have been used on a laboratory scale and a tank septic tank and an additional sludge blanket have been used to optimize the UASB reactor. Initial inoculation of the reactor was carried out using sewage treatment sludge (active sludge method) slaughterhouse, along with fresh cow discharges and feeding using dry milk. The research lasted for fourteen periods for 154 days, the first period for 30 days including the design and construction of the reactor, the second period for 40 days including starting, forming granules and measuring PH, the third period for 40 days including the continuation of the process The formation of granules and sludge blankets, pH measurements, and preliminary analysis of the removal efficiency of COD and the fourth period for 44 days include the continuation of granulation sludge measurement, PH and the evaluation of COD removal efficiency. The organic loading during four periods was 5.2-11.4 kgCOD/m3.day, and the reactor temperature was in the second to third period in the mesophilic temperature range and during the fourth period at the mesophilic and psychrophilic temperature range. The retention time in the studied period is 24 hours. The output COD yields four to for normal reactor 75-60% and a modified reactor of 94-60%.

Ion flotation includes removing of ions from solution by adding chemical reagents such as collectors in the presence of air bubbles. In this study, removal of Zn(II) cations was studied from low concentration synthetic wastewater by ion flotation. Sodium dodecyl sulfate (SDS) and ethylhexadecyldimethylammonium bromide (EHDABr) were used as collectors and methyl isobutyl carbonyl (MIBC) and Dowfroth250 as frothers. To investigate the effective parameters, the experimental design was performed supporting by DX7 software. Two-level factorial method was used. Sixteen experiments including 6-level variables were designed. The tests were conducted in Hallimond tube. The results showed that the optimal conditions for the removal of Zn(II) ions were: pH=3, SDS= 300 ppm, Dowfroth250= 90 ppm and air flow rate= 1.8 ml/min. Optimal results were evaluated in a mechanical flotation cell. In optimal condition, recovery of Zn(II) ions and water were more than 92% and 8.65% after 10 min, respectively. This study showed that the use of ion flotation is a very effective method for Zn(II) ions removal from industrial wastewaters.