可见光驱动微生物光电化学池处理剩余污泥同步产氢

氢气是一种理想的清洁能源.太阳能驱动的微生物光电化学池(Microbial photoelectrochemical cell, MPEC)因可同时实现废物处理与自发产氢而受到人们的关注.本文以剩余污泥为底物,构建了一种由无定型硫化钼改性硅纳米线(MoS_3/SiNWs)光阴极和生物阳极组成的MPEC系统,研究了3组MPEC在不同的酸性阴极液pH和外加电压条件下的产氢及污泥减量效果.研究结果表明,MPEC在阴极液pH为1和3的条件下均能在无外加电压下自发产氢;pH=1的MPEC-1实验中平均产氢速率为(0.66±0.02) mL·h~(-1),约是pH=3的MPEC-2实验平均产氢速率的1.5倍,但阴极过酸的条件限制了其实际应用; pH为3、外加0.2 V电压的MPEC-3与MPEC-2相比,产氢周期由15 h增加到40 h,平均产氢速率由(0.44±0.05) mL·h~(-1)提高到(0.52±0.04) mL·h~(-1),污泥TCOD、SCOD、TSS、VSS的降解率分别可达53.96%、70.18%、38.21%和61.76%.可见本文构建的MPEC系统是一种有前景的利用太阳能进行废物处理和资源化的新技术.

Visible light-driven microbial photoelectrochemical cell for sludge reduction and hydrogen generation

Hydrogen is an ideal clean energy resource. Microbial photoelectrochemical cell (MPEC) which can realize simultaneous wastes treatment and hydrogen generation has attracted great attention in recent years. In this study, we constructed a MPEC system consisting of a molybdenum sulfide modified silicon nanowire (MoS₃/SiNWs) photocathode and a biocatalytic anode. Residual sludge was used as the substrate. Three experiments were carried out to study the effects of acidic catholyte pH and external voltage on hydrogen production and sludge reduction. The results show that MPEC system could generate hydrogen spontaneously at pH 1 &3 without external voltage. under pH 1 in MPEC-1, the average hydrogen production rate was (0.66±0.02) mL·h^-1, which was approximately 1.5 times of that under pH 3 in MPEC-2. However, the extreme acidic conditions of catholyte limited its application. Compared with MPEC-2, by adding an additional voltage of 0.2 V at pH=3, the hydrogen production period prolonged from 15 h to 40 h, and the average hydrogen production rate increased from (0.44±0.05) mL·h^-1 to (0.52±0.04) mL·h^-1 in MPEC-3.The degradation efficiencies of TCOD, SCOD, TSS and VSS of the residual sludge reached 53.96%, 70.18%, 38.21% and 61.76%, respectively. It can be concluded that the MPEC system constructed in this study is a promising new technology for waste treatment and resource utilization.