What issue does the presence of dust from PAC pose for water treatment systems?

The presence of dust from powdered activated carbon (PAC) can indeed cause operational complications in water treatment systems. PAC is used primarily for its adsorption properties, helping to remove contaminants from water. However, when dust is introduced into the system, it can lead to several challenges.

One significant issue is that PAC dust can cause clogging and fouling within systems, particularly in filters and other equipment designed for water purification. This buildup can reduce the efficiency of the treatment process and require more frequent maintenance and cleaning, which can increase operational costs and downtime.

Additionally, the dust may not be fully activated or might settle in unwanted areas, leading to uneven distribution of PAC throughout the treatment process. This can result in suboptimal contact between the carbon and the contaminants, ultimately affecting the effectiveness of the water treatment system.

The other options do not accurately reflect the consequences of PAC dust. While improved water quality, no impact, and enhanced adsorption are desirable characteristics of PAC, the dust specifically compromises these benefits by introducing complications that challenge the efficiency and effectiveness of treatment processes.