Edris Hoseinzadeh

Removal of acid dyes from aqueous solution using potato peel waste biomass: a kinetic and equilibrium study

The goal of this study was to survey the feasibility of the biosorption of two acid dyes (Acid Blue 113 and Acid Black 1) from aqueous solution using biomass prepared from potato peel waste. Adsorption isotherms were constructed and the kinetics of dye adsorption were studied. Langmuir and Freundlich isotherms, pseudo-first-order, and pseudo-second-order kinetic models were studied. The maximum biosorption was observed at a pH of 2 and 3 for Acid Blue 113 and Acid Black 1, respectively. The biosorption of two dyes increased with increasing contact time and reached equilibrium after two hours, approximately. Acid dye removal efficiency decreased with an increase in the initial dye concentration. The sum of squares due to error and the coefficient of determination (R2) analysis showed that the pseudo-second-order kinetic and the Langmuir isotherm model are better fit for the adsorption of Acid Blue 113 and Acid Black 1 on used potato peel waste.

Nitrate removal from pharmaceutical wastewater using microbial electrochemical system supplied through low frequency-low voltage alternating electric current

In this study, a microbial electrochemical system (MES) was designed to evaluate the effects of a low frequency-low voltage alternating electrical current on denitrification efficacy in the presence of ibuprofen as a low biodegradable organic carbon source. Cylindrical carbon cloth and stainless steel mesh electrodes containing a consortium of heterotrophic and autotrophic bacteria were mounted in the wall of the designed laboratory-scale bioreactor. The effects of inlet nitrate concentration (50-800mgL-1), retention time (2.5-24h), waveform magnitude (0.1-9.6Vp-p), adjustable direct current voltage added to offset voltage (0.1-4.9V), alternating current frequency (10-60Hz), and waveforms (sinusoidal, square, and ramp) were studied in this work. The results showed that the proposed system removes 800mgL-1 nitrate up to 95% during 6.5h. Optimum conditions were obtained in the 8Vp-p using a frequency of 10Hz of a sinusoidal waveform. The morphology studies confirmed bacterial morphology change when applying the alternating current. Dehydrogenase activity of biofilms formed on surface of stainless steel electrodes increased to 15.24μgTFmgbiomasscm-2d. The maximum bacterial activity was obtained at a voltage of 8Vp-p. The experimental results revealed that the MES using a low frequency-low voltage alternating electrical current is a promising technique for nitrate removal from pharmaceutical wastewaters in the presence of low biodegradability of carbon sources such as ibuprofen.