About multiplex channel, a large number of problems frequently happened in protection cooperating between channel and diplex equipment.
而复用通道中，在保护与通道的配合上屡屡出现问题，通道设备双重化的问题也日趋严重。
2
But there are still much disadvantage in the process whether in the single or diplex sludge system, such as the low NO3- yield and carbon source utilization, NO3- provide and so on.