Maryland landfill utilizes wheel-wash system that reuses and recycles water
A Maryland county landfill required the use of a permanent wheel-wash system for all garbage trucks entering and exiting the facility to prevent “track-out” of mud and dirt onto local roadways. The county chose the MobyDick Tailor Made system because of its performance and reliability. The MobyDick system is tasked with providing 40 to 50 garbage truck wheel-washes per day, with an average flow rate of 3,000 gpm of water required for each wash and a variable duration ranging from 40 seconds to 1 minute per wash. After each wheel wash, the water drains into concrete basins and is then treated to clean the water, allowing the water to then be reused for subsequent washings. The landfill was having difficulties getting the water clean enough for reuse.
The composition of the dirt being washed off the truck wheels was a combination of clay and various sediments. Initially, the retention wash-water was being treated using an anionic synthetic polymer, which was chosen to help remove the contaminants from the water for clarity and reuse in the washing system. Unfortunately, the petroleum-based product created solids that were fairly “sticky” in nature and compromised the mechanical parts of the washing system, including both the augur delivery and the flumes of the wheel-wash system.
Rain for Rent worked with HaloKlear to optimize the MobyDick treatment system to wash the haul-truck wheels and simultaneously clean the wash-water to be continuously reused for additional washes. Cleaning of the water requires removing the dirt or mud track, treating the wash-water to remove the clay and sediment and reusing the water in the wheel-washing machine. Rain for Rent employed the MobyDick Tailor Made wheel-washing system in combination with a retention and treatment basin for the wash-water.
The initial synthetic polymer was not providing the required results, so Rain for Rent decided to employ HaloKlear TW-10, a “hybrid dry polymer” product specially formulated to effectively dewater high-solid wastewater streams. The unique polymer blend is designed to capture and separate sediment, heavy metals and other contaminants from the water. The rapid settling of the captured contaminants allows for easy reuse of cleaned water. TW-10 produces dense floccules with a high shear strength and filterability—perfectly suited for solids dewatering and disposal.
After making adjustments to obtain the optimal dosing rate, the TW-10 product, in conjunction with the Rain for Rent and MobyDick filtration equipment, has proven to provide the perfect solution from both a performance and cost perspective. The post-treatment water is visibly clear, the equipment is no longer being affected by any gumming up of the mechanical parts and the water is being reused and recycled within the wheel-washing system. The initial influent turbidity of the basin was averaging around 86 ntu, and after treatment of the wheel-wash water with the MobyDick system, turbidity measured at 28 ntu at the pump locations.
To learn more, stop by MobyDick (Booth #319) at StormCon 2015 in Austin, Texas.