Recycling and reuse of polyurethane mattresses for recovering oils spilled in seawater

ROCHA, KESLEI ROSENDO DA; CHIAVONE-FILHO, OSVALDO; OLIVEIRA, HUMBERTO NEVES MAIA DE

doi:10.1590/0001-3765202520250053

Tabla de contenido Anterior Actual Siguiente

Tabla de contenido

CHEMICAL SCIENCES • An. Acad. Bras. Ciênc. 97 (4) • 2025 • https://doi.org/10.1590/0001-3765202520250053 linkcopy

Recycling and reuse of polyurethane mattresses for recovering oils spilled in seawater

Authorship SCIMAGO INSTITUTIONS RANKINGS

In this work, polyurethane foams from post-consumer mattresses were recycled through surface modifications and reused to recover oils spilled in seawater. The surface modifications included grafting zinc oxide followed by coating with hexadecanoic acid, which enhanced the foams’ hydrophobicity and oil affinity. Sorption tests simulating oil spills were conducted on three systems involving seawater and oil (diesel, S46 lubricating, or 20W40 engine). The modifications led to increased oil sorption capacity, achieving up to 950% in the seawater-20W40 engine oil system. Additionally, the modification reduced the seawater sorption by up to 72% in the seawater-diesel system. The findings indicated that viscosity significantly affects mass transport between the adsorbate and adsorbent. Verhuls’ kinetic model was the best fit for the sorption of diesel, S46 lubricating, and 20W40 engine oil (R² = 0.99). The pseudo-second-order model was also suitable for diesel and S46 lubricating oil (R² > 0.98). The desorption kinetics and reuse tests demonstrated that the foams effectively retained over 83% of absorbed oil after 30 minutes in suspension and maintained this capacity for over 50 cycles. This study highlights the successful application of one residue as an effective agent for the removal of another, demonstrating its potential for sustainable remediation strategies.

Key words
Oil spill; Reuse of polymers; Solid waste management; Surface modification

Kinetic Model	Sorption rate	Sorption capacity	Parameters
Equation 1 Pseudo-First Order (Lagergren)	$\frac{d q_{t}}{d t} = k_{1} (q_{e} - q_{t})$	$q_{t} = q_{e} (1 - e^{- k_{1} t})$	k₁ (g·g^-1·s^-1) Qe (g·g^-1)
Equation 2 Pseudo-Second Order (Ho & McKay)	$\frac{d q_{t}}{d t} = k_{2} (q_{e} - q_{t})^{2}$	$q_{t} = \frac{k_{2} q_{e}^{2} t}{1 + k_{2} q_{e} t}$	k₂ (g·g^-1·s^-1) Qe (g·g^-1)
Equation 3 Chemisorption (Elovich)	$\frac{d q_{t}}{d t} = α e^{- β q_{t}}$	$q_{t} = \frac{1}{β} \ln (1 + α β t)$	α (g·g^-1·s^-1) β (g·g^-1)
Equation 4 Intraparticle diffusion (Weber & Morris)	-	$q_{t} = K_{d} t^{0.5} + C$	k_d (g·g^-1·s-0.5) C (g·g^-1)
Equation 5 Logistic (Verhulst)	$\frac{d q_{t}}{d t} = c q_{t} (1 - \frac{q_{t}}{a})$	$q_{t} = \frac{a}{1 + b e^{- c t}}$	a (g·g^-1); b c (s1)

	Un-PC	ZnO/HA-PC
Volume (L)	6.71·10-3 ± < 0.001	7.31·10-3 ± < 0.001
Density (g·L-1)	22.00 ± 0.50	25.00 ± 1.00
Porosity (%)	68.87 ± 11.65	92.32 ± 3.43

Parameters	Seawater
Temperature (°C)	24.00 ± 1.00
pH	8.30 ± 0.11
Turbidity (NTU)	17.20 ± 0.09
Conductivity (mS·cm-1)	45.32 ± 1.12
Salinity (‰)	38.00 ± 1.00
Density (g·L-1)	1018 ± 2.00

Oil	Temperature¹ (°C)	Kinematic viscosity² (cSt)	Kinematic viscosity³ 40 °C (cSt)	Density4 (g·L-1)
Diesel	23.00 ± 1.00	5.02 ± 0.08	4.00 ± 0.15	839.00 ± 15.00
S46 lubricating	23.00 ± 1.00	97.00 ± 0.18	46.00 ± 0.10	858.00 ± 07.00
20W40 engine	23.00 ± 1.00	372.00 ± 0.88	120.00 ± 1.02	886.00 ± 12.00

Sorption (g·g^-1)	Seawater		Diesel
	Un-PC	ZnO/HA-PC	Un-PC	ZnO/HA-PC
	15.78a ± 0.51	4.37b ± 0.20	30.44A ± 1.86	25.19B ± 0.99
Sorption (g·g^-1)	Seawater		S46 lubricating oil
	Un-PC	ZnO/HA-PC	Un-PC	ZnO/HA-PC
	4.46b ± 0.22	10.25a ± 0.10	4.26B ± 0.15	23.16A ± 0.19
Sorption (g·g^-1)	Seawater		20W40 engine oil
	Un-PC	ZnO/HA-PC	Un-PC	ZnO/HA-PC
	0.09b ± 0.00	0.45a ± 0.02	1.38B ± 0.04	14.50A ± 0.04

Kinetics	Parameters	Seawater1	Diesel	Seawater2	S46 Lub.	Seawater3	20W40 eng.
Pseudo-First-Order (Lagergren)	k₁ (g·g^-1·s^-1)	0.115	0.105	0.009	0.004	0.070	0.121
	4Q_e(_exp.) (g·g^-1)	4.360	25.086	10.230	24.985	0.458	14.519
	5Q_e(_calc.) (g·g^-1)	4.197	17.943	12.568	15.138	0.586	39.583
	R²	0.977	0.940	0.979	0.830	0.966	0.727
	SSR	0.460	569.823	69.035	1164.741	0.242	7651.029
Pseudo-Second-Order (Ho & McKay)	k₂ (g·g^-1·s^-1)	0.057	0.011	0.010	0.007	0.011	< 0.001
	4Q_e(_exp.) (g·g^-1)	4.360	25.086	10.230	24.985	0.458	14.519
	5Q_e(_calc.) (g·g^-1)	4.667	26.668	11.755	25.561	1.151	718.382
	R²	0.992	0.994	0.975	0.982	0.194	0.000
	SSR	0.952	22.622	3.191	31.768	0.033	69.303
Chemisorption (Elovich)	α (g·g^-1·s^-1)	1.451	8.878	2.352	6.441	0.063	1.870
	β (g·g^-1)	0.915	0.162	0.367	0.164	7.345	0.220
	R²	0.938	0.950	0.983	0.949	0.867	0.837
	SSR	1.182	24.976	3.257	36.044	0.053	73.692
Intraparticle diffusion (Weber & Morris)	k_d (g·g^-1·s-0.5)	0.525	2.971	1.369	2.973	0.071	2.411
	C (g·g^-1)	0.972	5.942	0.937	3.809	-0.051	-2.434
	R²	0.816	0.831	0.939	0.850	0.897	0.890
	SSR	3.797	109.558	7.485	94.908	0.036	43.983
Logistic (Verhulst)	a (g·g^-1)	4.250	24.573	9.987	22.771	0.440	14.279
	b	9.240	5.866	5.945	8.785	19.796	50.300
	c (s1)	0.325	0.267	0.167	0.257	0.190	0.216
	R²	0.999	0.999	0.999	0.998	0.982	0.998
	SSR	0.347	26.159	3.455	9.089	0.004	1.137

Kinetics	Parameters	Diesel	S46 lubricating oil	20W40 engine oil
U t = U L e −kt + U e	U_L (g·g^-1)	0.143	2.532	5.864
	U_e (g·g^-1)	45.045	36.136	29.662
	U_L + U_e (g·g^-1)	45.188	38.668	35.526
	k (s^-1)	0.005	0.015	0.019
	R²	0.979	0.985	0.979
	χ²	1.219·10-4	2.233·10-2	1.655·10-1
R t = R L e −kt + R e	R_L	0.003	0.065	0.159
	R_e	0.996	0.931	0.825
	R_L + R_e	0.999	0.996	0.984
	k (s1)	0.005	0.015	0.019
	R²	0.979	0.985	0.976
	χ²	5.939·10-8	1.498·10-5	1.474·10-4

location_on

Academia Brasileira de Ciências Rua Anfilófio de Carvalho, 29, 3º andar, 20030-060 Rio de Janeiro RJ Brasil, Tel: +55 (21) 2391-7901 - Rio de Janeiro - RJ - Brazil
E-mail: aabc@abc.org.br

rss_feed Acompañe los números de esta revista en su lector de RSS

[tfnI] qt (g·g^-1) is the amount of fluid sorbed at any time t (s); qe (g·g^-1) is the amount of fluid sorbed at equilibrium (after a long period of exposure to the adsorba_te); k1 (g·g^-1·s_-1), k2 (g·g^-1·s_-1), kd (g·g^-1·s-0,5), α (g·g^-1·s^-1), and c (s^-1) are kinetic constants of their respective models and are responsible for the angular coefficient (slope) of the kinetic curves; β (g·g^-1), C (g·g^-1), a (g·g^-1), and b (dimensionless) are constants of their respective models.