An eco-friendly approach to separate emulsified oil from water using all natural materials of chitosan and beach sand

An eco-friendly approach was proposed to remove emulsified oil from water using entirely natural materials: chitosan and beach sand. The findings indicate this new approach achieved an oil removal efficiency of up to 94%, accompanied by a six-fold reduction in the settling period from 90 to 15 min. Consequently, the shorter sedimentation period contributes to a decrease in capital expenditure (CAPEX) compared to conventional large sedimentation tanks or expensive air flotation equipment. Furthermore, the generated sludge is anticipated to be non-toxic due to the utilization of natural materials such as chitosan and beach sand. Given its simplicity and eco-friendliness, this approach holds promise as an alternative to conventional industrial methods for treating oily wastewater. • Eco-friendly oily wastewater treatment with chitosan and beach sand. • 100 mg/L chitosan and 500 mg/L beach sand (100 μm) form high-density flocs. • High oil removal efficiency of up to 94 % was achieved. • By reducing settling time to 15 min, capital costs are lowered. • Natural materials ensure environmentally safe sludge disposal. Oil-contaminated water from oil and gas exploration remains the industry’s primary waste stream. The common method of using chemical coagulation/flocculation followed by air flotation has drawbacks such as generating non-biodegradable and toxic sludge and high operational costs. This study presents an eco-friendly alternative utilizing chitosan and beach sand to remove emulsified oil from water. Chitosan acts as a biodegradable flocculant, while beach sand aids in high-density floc formation and accelerates settling velocity. This approach achieved up to 94 % oil removal efficiency and reduced settling time from 90 to 15 min by using 100 mg/L chitosan and 500 mg/L beach sand with a particle size distribution of 50–100 μm. Shorter settling time reduces capital expenditure compared to conventional methods. Additionally, using natural materials like chitosan and beach sand minimizes toxic sludge generation. This eco-friendly approach offers a promising alternative to conventional methods for treating oily wastewater.