Webster Texas is a suburb of Houston Texas which is the 4th largest metropolitan area in the USA. With close proximity to NASA and the Gulf of Mexico, Webster has a population of 10,680 and over 300 restaurants contributing to their wastewater treatment demands. This provides an ongoing challenge for both maintenance and performance reasons to the existing belt screen technology Webster City WWTP has been using to dewater sludge. Webster is a 3.3MGD Design and 1.4 MGD Actual treatment plant. Webster has also had some significate wear in their Headworks screen system further challenging reliability. Esmil Corp. is a leading producer of equipment for wastewater treatment and sludge dewatering and visited Webster to survey and engineer solutions to their challenges.
Prior the equipment installation Esmil Corp. made full scale excess sludge dewatering pilot test using MDQ-201 screw press. Achieved results were very successful so Esmil Corp. offered MDQ 353 C with other auxiliary equipment including a Polymer Feeder unit, macerator and installation platform with a safety walkway and fences. Also, important factors influencing the choice of Esmil Corp. as a supplier of equipment were the optimal combination of operating costs (polymer consumption, spare parts, energy consumption, labor, etc.), capital costs as well as the guarantees provided.
During the third quarter of 2018, Esmil Corp. shipped and installed an MDQ-354 C Multi-disk Screw Press and New Polymer Feeder unit to replace the aging belt press which was located 32’ above the plant facility in a press house. In addition to a challenging installation location, contractors had removed all of the existing belt press, piping and wiring requiring Esmil Corp. to build a new custom floor base, safety walkway, new plumbing, conduit and wire. In addition, a Macerator to handle and consume errant plastic (think straws) and other foreign materials was installed in line to the existing sludge pump which was reused. We took responsibility for the provided technological solution and its implementation “turnkey”.
Multi-disk screw press Installation Results
Type Of Sludge | Excess activated sludge |
Unit Sludge Supply | 95 gpm 800 lbDS/h |
Operation Time | 8 h/d |
Feed Sludge DS Concentration | 1.5-2% |
Cake DS Concentration | 16% |
Average Polymer Dose | 22lb/ton DS |
Next, Esmil Corp. shipped and installed a new RKE 0809 2.5MGD Rake Bar Screen (slot width – 5/16”) with accompanying Screw Compacting Press (5-7 times compacting volume) and removed the existing worn screen system. The new screen was engineered to fit the existing 24” channel and like the MDQ-354 installation, completely new wire, controls and actuators were supplied and installed.
Both systems are reportedly operating smoothly and efficiently and are tied into the 24-hour SCADA system in the Webster City control center. The installation of the new screen allowed more effective retention of mechanical inclusions, as well as reduced labor requirements.