Investigating the potential of using tannery process solid hair waste for spent engine and vegetable oils removal from water and toxicity assessment using maize

Abstract

Contamination of water and soils by oil is becoming one of the most dangerous pollution problem to handle due to oil toxicity to aquatic organisms, degradation of soil quality and effect on human health. Unfortunately, industrial development, increase population and human activities have increased different types of oil discharges into the soils and water sources. This aim of this study was to investigate the efficiency of cattle hair waste in removing spent engine and vegetable oils from wastewater using different process conditions, and the toxicity of water containing oil and when treated on maize germination evaluated. The equilibrium removal time is 10 minutes for both oils with 100% removal at 50 g/L initial oil concentration. Cattle hair is a good oil adsorbent with adsorption capacities of 52.20 g/g for vegetable oil and 28.49 g/g for spent engine oil. Temperature increase reduces oil removal from 100% at 25–30 °C to 93% at 60oc for spent engine oil and from 100% at 25 °C to 85% at 60 °C for vegetable oil. The removal of vegetable oil is reduced from 100% in the absence of NaCl to 10% at 10000 mg/L NaCl meanwhile there is a negligible effect of NaCl presence on spent engine oil removal. Untreated water containing spent engine oil reduced maize seed germination by about 70% compared to 45% for vegetable oil. These values reduced respectively to 17% for spent engine oil and 11% for vegetable oil when oil wastewater is treated. The fact that just 10 minutes was required to have a 100% removal, and with removal capacities of 52.20 g/g for vegetable oil and 28.49 g/g for spent engine oil shows cattle hair can be effectively applied in removing spent engine and vegetable oils from wastewater in a low cost process, with a positive effect on environmental and human safety.

Keywords

• Oil
• Wastewater
• Cattle hair
• Toxicity
• Maize