Abstract:
Sustainability and life-cycle concerns about the conventional activated sludge (CAS) process for wastewater treatment have been driving the development of energy-efficient, greener alternatives. Feasibility of an algal-based wastewater treatment (A-WWT) system has been demonstrated recently as a possible alternative, capable of simultaneous nutrient and energy recovery. This study compared capabilities of the A-WWT and CAS systems in removing organic micropollutants (OMP). Initial assessments based on surrogate organic measures and fluorescence excitation-emission matrix (FEEM) scans revealed that the A-WWT system achieved higher removals of organics than the CAS system. However, effluents of both systems contained residual organic matter, necessitating further OMP assessment for a rigorous comparison. A novel ultrahigh-performance liquid chromatography- Fourier transform mass spectrometry (UPLC-FTMS)-based non-targeted screening approach was adopted here for residual OMP analysis. This approach confirmed that the A-WWT system resulted in better OMP removal, eliminating 329 compounds and partially reducing 472 compounds, compared to 206 eliminations and 410 partial reductions by the CAS system. Mass spectra signal corresponding to some OMPs increased with treatment while some transformation products were observed following treatment. Higher OMP reduction in the A-WWT system with concurrent reductions of biodegradable carbon, nutrients, and pathogens in a single-step while producing energy and nutrient rich algal biomass underscore its potential as a greener alternative for wastewater treatment.
摘要:
对传统活性污泥(CAS)废水处理工艺的可持续性和生命周期的关注一直推动着节能、更环保的替代品。藻类废水处理(A-WWT)系统的可行性最近已被证明是一种可能的替代方案,能够同时恢复营养和能量。这项研究比较了A-WWT和CAS系统去除有机微污染物(OMP)的能力。基于替代有机测量和荧光激发发射矩阵(FEEM)扫描的初步评估表明,A-WWT系统比CAS系统实现了更高的有机物去除量。然而,两个系统的流出物都含有残留的有机物,需要进一步评估OMP以进行严格的比较。本文采用基于超高效液相色谱-傅里叶变换质谱(UPLC-FTMS)的非靶向筛选方法进行残留OMP分析。这种方法证实了A-WWT系统可以更好地去除OMP,消除329种化合物,部分减少472种化合物,相比之下,CAS系统取消了206项,部分减少了410项。对应于一些OMP的质谱信号随着处理而增加,而在处理后观察到一些转化产物。A-WWT系统中的OMP减少量较高,同时减少了可生物降解的碳,营养素,和病原体在一个步骤,同时产生能量和营养丰富的藻类生物质强调了其作为废水处理的绿色替代品的潜力。