persulfaat

Persulfaat, also known as persulfate ions (S2O8^2−), are powerful oxidizing agents commonly used in chemical synthesis, analytical chemistry, and environmental applications. The persulfate ion consists of two sulfate (SO4^2−) groups bonded through a peroxide linkage (–O–O–), giving it a highly reactive structure that readily generates sulfate radicals (SO4•−) when activated by heat, transition metals, or light. These radicals are among the strongest oxidants in aqueous solution, with a standard reduction potential of +2.5 V versus the standard hydrogen electrode.

Persulfates are commercially available as compounds such as sodium persulfate (Na2S2O8) and potassium persulfate (K2S2O8), which are white crystalline solids soluble in water and often used as initiators in polymerization processes, for example in the polymerisation of methacrylic acid or styrene. In analytical chemistry, persulfates serve as titrants in redox titration, oxidising agents in destruction of organic dyes, and oxidants in the determination of trace metals by spectrophotometry.

In environmental remediation, persulfate activation is employed to degrade organic contaminants in groundwater and soil. The generated sulfate radicals attack hydrophobic organic compounds, converting them into less harmful or more biodegradable products. The activation methods include addition of transition metal salts (e.g., Fe^2+ or Mn^2+), alkaline conditions, or exposure to UV radiation.

While persulfates are highly effective oxidants, they also pose safety risks, as they can corrode metal equipment, provoke violent reactions with certain organic materials, and pose health hazards through skin and eye irritation. Proper handling procedures, personal protective equipment, and storage under controlled conditions are essential.