Enhancement of Elemental Sulfur Recovery from Wastewater Biogas Using Nickel (II)-(5,10,15,20)-tetrakis-phenylcarboxylporphyrin

Sulfide control is a vital issue affecting the regional air quality and operational safety in sewage treatment processes. The conventional sulfide removal techniques are sophisticated industrial processes which require large operational footprint or are related to hazardous chemicals. In this study, the performance of elemental sulfur recovery from a simple micro-aeration process with metal-TCPP ((5,10,15,20)-tetrakis-p-carboxyphenylporphyrin) was investigated through laboratory experiments. A minimum of fourfold enhancement of elemental sulfur recovery was achieved from sulfide dissolved wastewater with the addition of nickel (II) TCPP, which demonstrated the highest among seven various types of transition metal-porphyrin complexes in the 3d block elements. The optimized reaction conditions resulted in 72.53% sulfur recovery with the addition of only 4.5 ppm nickel into the solution. The catalyst significantly improves the recyclability and life-cycle of the water-based absorbent and provides benefits to odor control and resource recovery.