Industrial operation reduces arsenic with Neo WaterFX.
By now you know that Neo WaterFX is highly efficient and cost-effective for removing phosphorus from wastewater. But how about other pollutants? Could WaterFX help an industrial client with hazardous wastewater?
WaterFX engineers work with client to bench test WaterFX for arsenic removal.
We were contacted by an industrial client who is required to dispose of their wastewater as hazardous waste due to high arsenic concentrations, in the range of 10 – 20 g/L (10,000 mg/L to 20,000 mg/L). To discharge to a combined sewer system, they would have to reduce this by 4 orders of magnitude, to under 1 mg/L.
Bench testing different process scenarios to determine feasibility, dosage, and process method.
WaterFX engineers tested WaterFX on samples of wastewater containing 17.8 g/L (17,800 mg/L) arsenic. They determined that WaterFX does indeed precipitate the arsenic and can achieve an arsenic concentration of < 1mg/L at a dose of 1.1:1 WaterFX to arsenic. Although the precipitation process is slower than with phosphorus, WaterFX was highly effective at arsenic reduction.
As with most precipitation processes, pH is important, and in this case, the best precipitation occurred when the pH was near the neutral range of 7. Several scenarios were evaluated to determine the best process point for doing this pH adjustment – as the WaterFX was being added, or at the end of the WaterFX addition as a final pH adjustment. They established that the most efficient method was to maintain a near-neutral pH throughout the WaterFX addition. This scenario involved adjusting the very acidic water with NaOH before any WaterFX addition, and then adding more NaOH as WaterFX is being added to maintain as close to a 7 pH as possible throughout the process.
Additional studies are continuing to develop methods of reducing other pollutants and restricting discharge.
Unfortunately, arsenic is not the only pollutant restricting discharge to the combined sewer. WaterFX is continuing to work with the client to explore ways to reduce the other pollutants, most notably sulfate, to discharge levels. This must be done in conjunction with WaterFX to evaluate any impacts the addition of other chemicals for sulfate reduction has on the arsenic reduction with WaterFX.
The client looks forward to reducing or eliminating their hazardous wastewater disposal costs through arsenic reduction with WaterFX.
With the arsenic reduction essentially solved, the client is looking forward to finding solutions to the other pollutants that are hindering discharge to the combined sewer. With the help of WaterFX engineers, they are confident that day is not too far away.
Is arsenic an issue in your wastewater? Our engineers can help.
Contact us for a free consultation to see if WaterFX might meet your arsenic reduction needs.
