A large Midwestern Engine Manufacturer requires wastewater treatment of spent cleaners for process steps. Oil and grease loading is in both emulsified and insoluble forms.Read the full post
Sludge Reduction with OMEGA BP-4145
An electroplating job shop was unhappy with their waste treatment operation. The volume of sludge generated to gain compliance was costly and an operational problem for the plant. Business was very good and the plant was operating at peak capacity.
The volume of sludge generated began to exceed the clarification equipment design. Solids carryover was a frequent problem, and compliance with discharge metals of Copper, Nickel, and Chrome was now a major concern.
An alternate treatment approach was required to meet the operational demands of the plant as well as keep the facility in compliance for all regulated discharge metals.
The existing wastewater treatment program utilized both ferrous sulfate and calcium chloride to condition the waste water solids. The volume of these inorganic coagulants required to ensure metals compliance was excessive. The dual clarifier assembly was operating with a sludge bed only one foot away from the water discharge weir. Any flow variations to the clarifiers caused a sludge bed upset, with significant carryover across the discharge weir.
COVENTYA Water Care Action Plan
The facility survey review identified the need to replace the existing treatment program. The following steps were taken:
- All wastewater sources were investigated. Chrome reduction and cyanide destruction were checked for maximum efficiency without excessive bisulfite (chrome reduction) and chlorine (cyanide oxidation) demand.
- Treatability studies utilizing COVENTYA Water Care products were performed on the wastewater solutions from chrome, cyanide, acid, and alkaline waste sources.
- Chemical demand ratios were compared for the Water Care program vs. the existing treatment program.
- It was determined that the application of OMEGA BP-4145, a specialty aluminum sulfate / cationic polymer blend could replace both the ferrous sulfate and the calcium chloride. Bench studies indicated metals compliance could be accomplished, while, at the same time, reducing sludge volume by 66%.
COVENTYA Water Care Program
The acidic wastewater source was identified as the major component of suspended metals. The coagulant / cationic polymer blend OMEGA BP-4145 highly reactive at solids charge neutralization at low pH levels.
To the acidic (pH of 2.0) wastewater holding tank, OMEGA BP-4145 was dosed at a 500 ppm demand. A de-stabilized and neutral colloidal -micro floc is formed as OMEGA BP-4145 reacts with this waste source.
The elimination of the inorganic coagulants of ferrous sulfate and calcium chloride provides for a 66% reduction in solids loading to the treatment system.
Upon final pH neutralization with sodium hydroxide, to a pH of 9.5 SU, in the secondary reaction tank, all ionic charges are conditioned.
At the clarifier floc tank, OMEGA AP-2140, a concentrated, hydrated anionic polymer, is added to agglomerate the waste solids into a large dewatered macro floc. The clarifier solids loading was reduced by 66%,as the improved program floc formation quickly settles in the clarifier. A clear supernatant is discharged at the overflow weir.
The effluent metals of concern: Copper – Nickel – Chrome, are now all below 0.5 ppm in discharge concentration.
COVENTYA Water Care Program Evaluation
The COVENTYA Water Care program provides the following benefits to this facility:
- Plant wastewater solids treatment capacity was increased by 66%. This reduction in solids burden on the clarifier provides for consistent compliance with metals discharge criteria.
- The manpower labor factor in the wastewater plant was reduced due to the decreased burden of coagulant chemical handling and sludge generation handling.
- Filter press equipment operation was reduced by 50%. This reduction increased emergency sludge holding capacity and improved much needed air pressure and capacity on alternate shifts.
- A significant cost savings was realized by the 66% reduction in hazardous waste generation and disposal costs.