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 (50–800 mg L^− 1), retention time (2.5–24 h), waveform magnitude (0.1–9.6 V_p − p), adjustable direct current voltage added to offset voltage (0.1–4.9 V), alternating current frequency (10–60 Hz), and waveforms (sinusoidal, square, and ramp) were studied in this work. The results showed that the proposed system removes 800 mg L^− 1 nitrate up to 95% during 6.5 h. Optimum conditions were obtained in the 8 V_p − p using a frequency of 10 Hz 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 15.24 μgTF mg_biomass cm^− 2 d. The maximum bacterial activity was obtained at a voltage of 8 V_p − 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.

在这项研究中，设计了一种微生物电化学系统（MES），以评估在存在布洛芬作为低生物降解性有机碳源的情况下，低频低压交流电对反硝化效果的影响。圆柱形碳布和包含异养和自养细菌财团的不锈钢网状电极安装在设计的实验室规模生物反应器的壁上。入口硝酸盐浓度（50–800 mg L ^{− 1}），保留时间（2.5–24 h），波形幅度（0.1–9.6 V _{p − p）的影响}），可调整的直流电压加到失调电压（0.1-4.9 V），交流电频率（10-60 Hz）和波形（正弦波，方波和斜波）中进行了研究。结果表明，所提出的系统在6.5 h内可去除800 mg L ^-1硝酸盐，去除率高达95％。使用10 Hz正弦波形的频率在8 V _p-p中获得了最佳条件。形态学研究证实当施加交流电时细菌形态发生变化。在不锈钢电极表面形成的生物膜的脱氢酶活性增加到15.24μgTFmg_生物量 cm ^-2  d。在8 V _p-p的电压下可获得最大的细菌活性。实验结果表明，在碳源（如布洛芬）具有低生物降解性的情况下，使用低频-低压交流电的MES是从制药废水中去除硝酸盐的有前途的技术。