Santoro Carlo, Babanova Sofia, Erable Benjamin, Schuler Andrew, Atanassov Plamen
Department of Chemical & Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico, Albuquerque, NM 87131, USA; Department of Civil Engineering, Center for Emerging Energy Technologies (CEET), University of New Mexico, Albuquerque, NM 87131, USA.
Department of Chemical & Biological Engineering, Center for Micro-Engineered Materials (CMEM), University of New Mexico, Albuquerque, NM 87131, USA.
Bioelectrochemistry. 2016 Apr;108:1-7. doi: 10.1016/j.bioelechem.2015.10.005. Epub 2015 Oct 28.
The performance of bilirubin oxidase (BOx) based air breathing cathode was constantly monitored over 45 days. The effect of electrolyte composition on the cathode oxygen reduction reaction (ORR) output was investigated. Particularly, deactivation of the electrocatalytic activity of the enzyme in phosphate buffer saline (PBS) solution and in activated sludge (AS) was evaluated. The greatest drop in current density was observed during the first 3 days of constant operation with a decrease of ~60 μA cm(-2) day(-1). The rate of decrease slowed to ~10 μA cm(-2) day(-1) (day 3 to 9) and then to ~1.5 μA cm(-2)day(-1) thereafter (day 9 to 45). Despite the constant decrease in output, the BOx cathode generated residual current after 45 days operations with an open circuit potential (OCP) of 475 mV vs. Ag/AgCl. Enzyme deactivation was also studied in AS to simulate an environment close to the real waste operation with pollutants, solid particles and bacteria. The presence of low-molecular weight soluble contaminants was identified as the main reason for an immediate enzymatic deactivation within few hours of cathode operation. The presence of solid particles and bacteria does not affect the natural degradation of the enzyme.
基于胆红素氧化酶（BOx）的空气呼吸阴极的性能在45天内持续监测。研究了电解质组成对阴极氧还原反应（ORR）输出的影响。特别地，评估了酶在磷酸盐缓冲盐水（PBS）溶液和活性污泥（AS）中的电催化活性失活情况。在连续运行的前3天观察到电流密度下降最大，下降速率约为60 μA cm⁻²·天⁻¹。下降速率在第3天至第9天减缓至约10 μA cm⁻²·天⁻¹，此后（第9天至第45天）降至约1.5 μA cm⁻²·天⁻¹。尽管输出持续下降，但BOx阴极在45天运行后仍产生残余电流，相对于Ag/AgCl的开路电位（OCP）为475 mV。还在活性污泥中研究了酶失活情况，以模拟接近真实废物处理运行的环境，其中含有污染物、固体颗粒和细菌。低分子量可溶性污染物的存在被确定为阴极运行后几小时内酶立即失活的主要原因。固体颗粒和细菌的存在并不影响酶的自然降解。
