Are you sure of your 500 ppm H2S. This will make a very corrosive gas/solution when mixed with water. I had all sorts of trouble when H2S levels were above 100 ppm with a Dual Fuel Diesel Engine with valves pipework and gas compressors failing due to this problem.
Sewage is treated as water for the purpose of calculating head loss in pipes.
Sludges are non-newtonian fluids and follow a completely different set of rules
A close coupled pump with a mag coupling has to be the best of both worlds. If the motor fails you remove the motor and leave the pump where it is and the motor is always going to be aligned properly.
I have used mag couplings before but not at this shaft power so I am unable to comment on...
The power absorbed as reported by the pump mnufacturer on its rating plate would normally exclude the shaft losses from motor to pump. It is also unlikely that the rating would include the efficiency of the motor. This means that power absorbed by the pump is nett of all external loses.
Since...
Depends on the protection device. The better the protective device the greater the impedance can be - but ideally you want the impedance to be as low as possible so that you get maximum benefit from the protective device.
The only method I know is to use a standby generator with auto changeover contactor.
The use of actuated valves would not solve your problem as any restriction on flow into the pumping station will just cause the incoming sewer to back and then flood out through the lower manholes on the...
I have not had great success with sludge density meters but the ones that did work more often than most were manufactured by Mobrey a UK company I think.
I did try to get a client to use nucleonic type but there are usually very large regulatory problems associated with this type of density meter.