An investigation of remediation and recovery of oil spill and toxic heavy metal from maritime pollution by a new absorbent material

Figures & data

Table 1. Properties of rice straw, husk, and bagasse.

Properties	Rice straw	Husk	Bagasse
Cellulose, % mass	54–61	36–46	41–53
Hemicellulose, % mass	19–23	16–21	19–27
Lignin, % mass	15–18	24–31	17–23
Others, % mass	3–7	5–11	4–8
Density, kg/m^3	29	32	31

Figure 1. SEM of bagasse (a), husk (b), and rice straw (c).

Figure 2. SEM of pristine PU.

Figure 3. New absorbent based on PU and rice straw.

Figure 4. SEM of absorbent based on PU and rice straw.

Table 2. Density of absorbent based on PU and rice straw.

Absorbent	Pristine PU	S1	S2	S3	S4
Density (kg/m^3)	38	29.5	28.4	28.9	27.7

Table 3. Physical properties of oil samples.

		Oil samples
Properties	Unit	Crude oil	Fuel oil	Diesel oil	Kerosene
Density, ρ	kg/m^3	937	890	850	810
Kinematic viscosity, KV	cSt	32	18	4.0	3.0
Surface tension, σ	N/m	0.317	0.288	0.260	0.225

Figure 5. Measurement method of oil and heavy metal ion absorption capacity.

Figure 6. Contact angle (θ) between oil phase and the surface of absorbent.

Figure 7. ΔP as a function of pore diameters and contact angles.

Figure 8. The dependence of OAC and water uptake on the rice straw mass and size.

Table 4. Oil removal efficiency (ORE) of as-fabricated absorbent samples

	ORE (%)
Absorbent samples	Crude oil	Fuel oil (FO)	Diesel oil (DO)	Kerosene
S1	0.459	0.417	0.378	0.339
S2	0.870	0.843	0.815	0.790
S3	0.864	0.832	0.726	0.676
S4	0.548	0.494	0.395	0.358
PU	0.725	0.683	0.637	0.597
Rice straw	0.741	0.681	0.561	0.475

Figure 9. The dependence of the ORE on time.

Figure 10. The absorbed metal concentrations Cd²⁺, Pb²⁺_, Hg²⁺ for S2 and S3 samples.