Civil & Environmental Engineering Department, University of California, Irvine, CA 92697-2175, USA.
Inyokern Community Services District, 1429 Broadway, Inyokern, CA 93527, USA.
J Environ Manage. 2018 Jan 1;205:125-133. doi: 10.1016/j.jenvman.2017.09.049. Epub 2017 Sep 30.
Mixing is the driver for the energy footprint of water resource recovery in lagoons. With the availability of solar-powered equipment, one potential measure to decrease the environmental impacts of treatment is to transition to an off-the-grid treatment. We studied the comparative scenarios of an existing grid-powered mixer and a solar-powered mixer. Testing was conducted to monitor the water quality, and to guarantee that the effluent concentrations were maintained equally between the two scenarios. Meanwhile, the energy consumption was recorded with the electrical energy monitor by the wastewater treatment utility, and the carbon emission changes were calculated using the emission intensity of the power utility. The results show that after the replacement, both energy usage and energy costs were significantly reduced, with the energy usage having decreased by 70% and its cost by 47%. Additionally, carbon-equivalent emission from electricity importation dropped by 64%, with an effect on the overall carbon emissions (i.e., including all other contributions from the process) decreasing from 3.8% to 1.5%.
混合是影响塘污水处理能源足迹的主要因素。随着太阳能设备的普及，减少处理过程对环境影响的一种潜在措施是转向离网处理。我们研究了现有电网混合器和太阳能混合器的对比方案。通过测试监测水质，以确保两种方案的出水浓度保持一致。同时，用废水处理厂的电能监测器记录能源消耗，利用电力供应商的排放强度计算碳排放量变化。结果表明，更换后，能源使用量和能源成本都显著降低，能源使用量减少了 70%，成本降低了 47%。此外，电力进口的碳当量排放量下降了 64%，对整体碳排放（即包括该过程的所有其他贡献）的影响从 3.8%降至 1.5%。
