Application of Citrus sinensis Solid Waste as a Pseudo-Catalyst for Free Cyanide Conversion under Alkaline Conditions

Abstract

In this study, Citrus sinensis (C. sinensis) solid waste was used to catalyze the conversion of free cyanide (F-CN) under alkaline conditions; conditions which represent most industrial wastewater containing F-CN. Acid hydrolysis of the solid waste increased the catalytic conversion of F-CN by 3.86 compared to the unhydrolysed solid waste. The conversion of F-CN using unhydrolysed and hydrolysed solid waste increased linearly with an increase in pH and temperature. The maximum catalytic conversion of a 100 mg F-CN/L solution containing 0.1% (w/v) of unhydrolysed and hydrolysed C. sinensis solid waste was 17.82% and 62.48%, respectively, at a pH of 12 and a temperature of 50 °C. The catalytic process was largely dependent on the availability of activated hydroxyl groups in the solid waste. As most wastewater contains heavy metals, it was determined that the presence of metallic species (Ni, Zn, and Cu) reduced the conversion of F-CN as the metallic ions attached to the hydroxyl groups. The observed reduction was 26.35% when 10 mg/L of heavy metals were present in the F-CN solution containing the hydrolysed solid waste at a pH of 12 and 40 °C.

Performance of Fusarium oxysporum EKT01/02 isolate in cyanide biodegradation system

“…and bacterial species such as Bacillus sp. and Pseudomonas sp., amongst others, have been found to utilise cyanide as a nitrogen source and/or carbon source, which generally results in the production of ammonium-nitrogen      [7][8][9][10].…”

Thermodynamic Data of Fusarium oxysporum Grown on Different Substrates in Gold Mine Wastewater

“…and Fusarium sp. [6,7] have all shown proficiency in utilising cyanide as a carbon and/or nitrogen source. These organisms were grown on whey, coconut shell, Citrus sinensis, and Beta vulgaris, showing the feasibility of the application of Data 2017, 2,24 agro-waste as a nutrient source for microbial proliferation in cyanide-containing wastewater.…”

Potential of indigenous bacteria to remove cyanide with variations of contact time and temperature

“…[8] are several bacteria that can remove cyanide. And there are also several types of fungi that can remove cyanide such as Fusarium oxysporum [9] dan Citrus sinensin [10].…”