Product Info

pH WatchDogä  Overview

The typical pH runoff from readymix concrete plants is around 12.5, very high on the pH scale.  Acids, by definition are low on the pH  scale, and are used to neutralize high pH water. 

The pH WatchDogä was developed by EcoDepot, LLC and utilizes a dry acid, Sodium Bisulfate [SBS], as theactive treatment chemical.  SBS wasselected as the chemical of choice because it is: 

•   only activated when placed in solution
•   can be safely rinsed from the skin if contact is made
•   is low cost
•   safe to store
•   non-hazardous

The discharge water to be treatedtypically is pre-treated for suspended solids.This is usually accomplished by utilizing some form of settling basinsor pits. Flocculants are also able to be utilized to acheive settling in certain cases.

The pH WatchDogä has a sensing probe connected to a pH controller. The probe sends a signal to a  submerged pump when the pH of the discharge water is higher than the preset limit.  The high pH water is then directed to the system mixing tank, where the dry acid has become soluble.  This acid then neutralizes the discharge water. The treated water is distributed back to the basin or pit and the system automatically shuts off when the probe senses that the water is neutralized to within the preset limit.

When the pH WatchDogä is installed to treat the final pit or basin in the settling system, it has no problems with calcium carbonate falling out of suspension. If this occurs, monthly maintenance of the pit will allow for removal of this material along with other fine sediments found in the discharge water.

Volumes of treated water vary which each site. Typical plant operations may have between one and five acres of drainage directed to a specific low area.  The design of the settling pits or basins must be based on the drainage area determined by surveying the site.  Plant water and truck wash water discharge also vary with each plant as well.  This discharge is the most critical as it occurs during dry weather periods, and is generally continuous during the busy hours of the production day.  To date the pH WatchDogä has easily handled dry and wet weather discharge peak volumes.  In most cases, storm events in excess of ½” have little impact on pH reduction requirements, as the rainwater acts as a neutralizing agent.  In the event that volumes are excessive for a standard pH WatchDogä, a larger acid mixing tank and pump can be designed to meet the specific need.  In certain cases, drainage areas necessitate multiple treatment systems as water is captured from in several low areas on-site.