01. The pipeline of the new device contains oily substances and residues from welding pipelines, and the dust is not cleaned before installing the membrane;
02. The design of the pretreatment device is unreasonable;
03. The amount of added chemicals is wrong or the equipment is malfunctioning;
04. Human error in operation;
05. No low-pressure flushing or flushing conditions are not controlled correctly when stopping operation;
06. The source or quality of water supply changes.
