Disposal Characteristics Of Spent Caustics

            The disposal of Spent Caustics is based on many characteristics, but mostly reflects the concentrations based on analytical results, specific contaminants, and the assessment of odors and toxicity experienced in the downstream waste treatment processes.

            The list below shows typical  analytical results form earlier spent caustics that can be expected with any spent caustic matrix today.  A current characterization is required to initially forecast the treatment and disposal of any spent caustic encountered today.

• COD (Chemical Oxygen Demand)
• Typically 10,000 to 100,000 mg/L
• Low: 3,000 mg/L
• High: 200,000 mg/L

 
• BOD (Biochemical Oxygen Demand)
• Typically 5,000 to 50,000 mg/L
• Low: 1,000
• High: 100,000 mg/L

 
• TOC (Total Organic Carbon)
• Typically: 1,000 to 5,000 mg/L
• Low: 300 mg/L
• High: 10,000 mg/L

 
• Sulfides
• Typically: 5,000 to 35,000 mg/L
• Low: 500 mg/L
• High: 84,000 mg/L  (saturated at higher temperature)
  

 
• Acid Oils (when above detection limit 0.5% v/v )
• Typically: 0.5 to 8 % v/v
• Low: 0.5 % v/v
• High: 34 % v/v

 
• Phenol
• Typically: 0 to 2,500 mg/L
• Low: below detection limit 0.5 mg/L (BDL)
• High: 80,000 mg/L

 
• Cresols (ortho, meta, para substutions, combined)
• Typically: 0 to 2,500 mg/L
• Low: BDL 0.5 mg/L
• High: 80,000 mg/L

 
• Naphthenates
• Typically: 100 to 2,000 mg/L
• Low: BDL 0.5 mg/L
• High: 5,000 mg/L

 
• Transient Noxious Odors
• Above TLV (Threshold Limit Values)

 
• Volatiles (Specific EPA 129 Priority Pollutants by GC/MS)
  
• Typically: 50 to 1,000 mg/L
• Lowest: 100 mg/L
• Highest: 5,000 mg/L

 
• Semi-Volatiles (Specific EPA 129 Priority Pollutants by GC/MS)
• Typically: 500 to 2,500 mg/L
• Lowest: 100 mg/L
• Highest: 80,000 mg/L

 
• Heavy Metals (Specific typically looking for Co, Ni, Se, Cu, Zn, Cr, Fe)
• Typically: BDL to 5 mg/L
• Lowest: BDL
• Highest: 500 mg/L

 
• Caustic Value (Free residual NaOH)
• Typically: 3 to 8 % w/w
• Lowest: 0.5% w/w
• Highest: 22% w/w