Question

1. the following steps are part of the treatment process for municipal wastewater. place them in the sequency in which they occur.

a) clean water is returned to the river or lake.
b) wastewater from homes and businesses is sent to the treatment plant through underground pipes.
c) in the aeration tanks, microorganisms digest organic waste.
d) a coarse screen removes large debris such as toys, false teeth, and rags.
e) settling tanks separate the floaters and the sinkers. the remaining liquid is sent to the aeration tanks.
f) liquid from the secondary tanks can contain harmful microorganisms, so it is usually disinfected with chlorine.

Explanation:

Step1: Wastewater collection

Wastewater from homes and businesses is sent to the treatment plant through underground pipes (b).

Step2: Primary treatment

A coarse screen removes large debris such as toys, false teeth, and rags (d). Then settling tanks separate the floaters and the sinkers. The remaining liquid is sent to the aeration tanks (e).

Step3: Secondary treatment

In the aeration tanks, microorganisms digest organic waste (c). Liquid from the secondary tanks can contain harmful microorganisms, so it is usually disinfected with chlorine (f).

Step4: Final discharge

Clean water is returned to the river or lake (a).

Answer:

b, d, e, c, f, a