Question

1-) What can be occur when the bar spacing is too small and too large? What are important for the operation and maintenance of screens?

2-) what may be happen when the activated sludge system hydraulically overloaded or underloaded? What may be happen when the activated sludge system may be subjected to organic underloading or overloading?

Please explain in detail

#environmental engineering

i ask before but false answers were given do not copy paste other answer please

Answer 1

1 a) #If the bar spacing is too small then there will be cost of the steel over estimated and it is over reiforced.Due to over reinforcement there is failure in concrete. Congestion of reinforcement happen, due to congestion vibration is difficult, improper compaction will occure , honeycombs will happen

# If the bar spacing is too large then it is under estimation. It causes failure of steel reinforcement and due to more spacing bondage between concrete and steel is little bit low.

1b) operation and maintenance of screens are necessary. Screens are used for separating the coarse particles from the waste water in water treatment treatment plant. It is primary treatment method. It is mechanicallly operated or man made . If we do regular maintainance, removal of collected coarse particles can remove, then it is properly working with out breaks. If there is any obstruction in scenns then screens will damge as a result improper screening will happen.

2a) # Activated sludge process is suspended growth method. In this process we are introducind the food to micro organisms . That micro organisms will consume the food . If we over loaded the food then there I exess of food to micro organisms then improper sludge forms. If the food is underloaded then due to shortage of food to micro organisms, F/M ratio will disturb. Below mention some problems

1) F/M ratio will disturb.

2) sludge production rate is fluctuate .

3) organisms growth varies .

4) haudraulic retention time varies .

5) Quality of eflluent is improper .

6) process will be complicated .

7) we should do repeat the process .