Radiation induced decomposition of a refractory cefathiamidine intermediate

Area of Science:

• Environmental Chemistry
• Radiochemistry
• Wastewater Treatment

Background:

• Diisopropylthiourea (DPT) is a persistent intermediate in cephalosporin synthesis wastewater.
• Conventional biological treatments are ineffective due to DPT's antimicrobial properties.

Purpose of the Study:

• To investigate the decomposition of DPT using gamma (γ) irradiation.
• To determine the degradation kinetics and radiation yield (G-value) of DPT.

Main Methods:

• Aqueous solutions of DPT were subjected to γ-irradiation at doses ranging from 150 to 2000 Gy.
• Changes in DPT concentration and UV absorption were monitored.
• Decomposition kinetics and G-values were calculated.

Main Results:

• DPT concentration decreased significantly with increasing absorbed γ-ray doses.
• G-values for DPT decomposition were 1.04 and 0.47 at 150 Gy and 2000 Gy, respectively.
• Degradation efficiency was reduced at higher substrate concentrations and alkaline pH, indicating optimal degradation at lower pH.

Conclusions:

• Gamma irradiation is an effective method for degrading refractory DPT in wastewater.
• Optimizing pH and managing substrate concentration are crucial for efficient γ-induced DPT removal.
• Formation of by-products was indicated by changes in UV absorption spectra.