Asedimentation basin is used to remove suspended solids from a wastewater. the rate of flow of wastewater into the tank is 10 l/s, and the influent concentration of suspended solids is 200 mg/l. the removal efficiency of the settling tank for suspended solids is 60%. calculate the amount of suspended solids (sludge) accumulating in the sludge zone each day. you may assume that the amount of water withdrawn when pumping out the sludge from the sludge zone is very small compared to the inflow of wastewater to the tank and can therefore be ignored.

Which of the following controllers anticipates the future from the slope of errors over time? a)-proportional b)-on/off c)-integral d)-derivative.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?

Apure substance is a)-mixture of various chemical elements or compounds b)-substance that has a fixed chemical composition throughout c)-mixture that is homogeneous (such as air) d)-all the answers