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Response surface methodology (RSM) and its application for optimization of ammonium ions removal from aqueous solutions by pumice as a natural and low cost adsorbent

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Moradi M. , Fazlzadehdavil M. , Pirsaheb M. , Mansouri Y. , Khosravi T. , Sharafi K.

2016

tom Vol. 42, no. 2

33--43

This research was conducted to study the adsorption of ammonium ions onto pumice as a natural and low-cost adsorbent. The physico-chemical properties of the pumice granular were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Modeling and optimization of a NH4+ sorption process was accomplished by varying four independent parameters (pumice dosage, initial ammonium ion concentration, mixing rate and contact time) using a central composite design (CCD) under response surface methodology (RSM). The optimum conditions for maximum removal of NH4+ (70.3%) were found to be 100 g, 20 mg/l, 300 rpm and 180 min, for pumice dosage, initial NH4+ ion concentration, mixing rate and contact time. It was found that the NH4+ adsorption on the pumice granular was dependent on adsorbent dosage and initial ammonium ion concentration. NH4+ was increased due to decrease the initial concentration of NH4 and increase the contact time, mixing rate and amount of adsorbent.

A survey on nitrogen and phosphor compound variation processes in wastewater stabilization ponds

100%

Pirsaheb M. , Fazlzadehdavil M. , Hazrati S. , Sharafi K. , Khodadadi T. , Safari Y.

Polish Journal of Environmental Studies

2014

tom 23

nr 3

Being economical has increased utilization of stabilization ponds to remove different contaminants from wastewater in proper weather conditions. Our current study investigates variations of nitrogen and phosphorous compound concentrations in effluent of wastewater stabilization ponds. 60 samples were taken from raw wastewater, anaerobic pond (AP) effluent, primary and secondary facultative ponds (PFP and SFP), and effluent of final ponds in weekly intervals for 3 months. Samples were examined based on standard methods (20th edition) for the examination of water and wastewater. Nitrogen kjeldahl removal output due to the AP, PFP, SFP, and the whole system were 20.6±4.9, 6.6±3.4, 13.4±9.5, and 47.7±9.1%, respectively. Nitrite removal output due to the PFP, SFP, and the whole system were 30.1±8.8, 36.3±9.8, and 58.8±5.2%, respectively. Respective values for phosphor removal output in AP and SFP, and the whole system were 21.8±10.3%, 13.3±10.1%, and 20.9±17.1%. However, nitrite concentrations in all samples from AP effluent and phosphor levels in all samples from PFP effluent increased compared with those of influent. The results showed that AP plays an important role in removal of organic nitrogen and phosphorous compounds. While the whole system output in nitrogen compound removal was 58.8±5.2%, phosphor removal output showed low efficiency (20.9±17.1%). Increasing the number of complete ponds is suggested for increasing phosphor removal efficiency.