Zeolite for Marine & Harbor Oil Spill Sorbents

Q: If you scatter natural zeolite directly onto the sea, does it adsorb oil well?

Unmodified clinoptilolite has a hydrophilic (not hydrophobic) surface, so on seawater it competes with water first and its oil sorption performance is limited. Therefore, to use it as a practical oil sorbent, surface modification to make it organophilic with cationic surfactants such as quaternary ammonium, or pretreatment that imparts hydrophobicity by loading it into silicone or polymer foam, is effectively a prerequisite. Szala et al. (2015) and Asgharzadeh et al. (2025) reported that organic / surfactant modification improves the sorption capacity for petroleum compounds, and Anagnostopoulos et al. (2019) reviewed both the applicability and the limits of natural clinoptilolite for crude oil removal from seawater.

Q: Does it replace existing response equipment such as oil booms and sorbent pads?

It is appropriate to understand it as a supplementary material, not a replacement. The realistic position is to block spreading with oil booms, recover thick oil films first with a skimmer, and then finish-treat the residual thin films and the dispersed oil in stagnant harbor waters with a granular sorbent. Being an inorganic mineral, it leaves little combustion residue and allows you to choose recycling, incineration, or landfill routes after recovery, which distinguishes it from polypropylene sorbent pads.

Q: Is it harmful to aquatic ecosystems?

Clinoptilolite is a natural aluminosilicate mineral and non-toxic, and applying it in a recoverable granular form after use can reduce the residual burden. However, for organozeolite modified with surfactants, the aquatic toxicity and desorption behavior of the surfactant used must be verified separately, and the environmental impact should be reviewed in advance together with the application and recovery plan.

Q: Can I receive a sample for testing?

Yes, KMIZEOLITE supports the provision of samples to verify oil sorption capacity and recoverability. On the sample request page, please leave details of the target oil type (crude oil, diesel, bunker C, etc.), the application medium (seawater, brackish water, harbor water), the desired particle size, and whether modification is required.

Marine & Harbor Oil Spills: What Is the Problem

Tanker collisions and groundings, leaks during harbor refueling, ship bilge discharge, and pipeline and storage tank accidents disperse a wide range of oil types such as crude oil, bunker C, diesel, and lubricating oil across the water surface. Oil films spread rapidly on wind and currents and cause direct damage to fisheries resources, aquaculture farms, beaches, and power plant water intakes through surface blockage (impeding oxygen exchange) and adhesion to shorelines and tidal flats. In Korea, the Korea Coast Guard, the Korea Marine Environment Management Corporation (KOEM), port authorities, and response companies activate the response system according to the accident grade.

Response usually proceeds in the order of blocking spreading with oil booms, recovering thick oil films first with a skimmer, and then finishing the hard-to-recover residual thin films and dispersed oil in stagnant waters with a sorbent. In this final stage, the sorbent's oil selectivity (absorbing oil in preference to water), buoyancy and recoverability, and post-use treatment and environmental safety become important selection criteria.

Why Zeolite Is Considered an Oil Sorbent — and the Key Prerequisite

The first point to address is that the surface of unmodified natural clinoptilolite is hydrophilic. Because its framework evolved to favor cation exchange and moisture adsorption, scattering it directly onto seawater draws in water before oil, limiting oil sorption performance. Therefore, to use it meaningfully as an oil sorbent, one of the following hydrophobic / organophilic pretreatments is effectively a prerequisite.

Surfactant modification (organozeolite): coating the surface with cationic surfactants such as quaternary ammonium to impart affinity for organic molecules. Improved sorption capacity for petroleum compounds and VOCs has been reported
Hydrophobic compositing: loading clinoptilolite into silicone or polymer foam to produce recoverable sorbent mats and pillows with buoyancy and water repellency

On this premise, the reason zeolite is considered as a sorbent is the inherent advantages of an inorganic mineral. Uniform micropores of 4.0–7.0 Å and a specific surface area of 40.0 m²/g provide adsorption sites, high thermal stability (700°C) keeps incineration and regeneration routes open after recovery, and unlike polypropylene sorbent pads, the secondary residue burden generated during combustion is small. In addition, as a natural aluminosilicate it is non-toxic, which is advantageous in terms of aquatic ecosystem safety.

Academically as well, Szala et al. (2015, Fuel Processing Technology) summarized that organically modified zeolites can be used in the cleanup of petroleum compound spills (DOI:10.1016/j.fuproc.2016.04.015), and Asgharzadeh et al. (2025, MethodsX) reported that clinoptilolite modified with a cationic surfactant is effective for the adsorption of volatile organic compounds derived from kerosene (DOI:10.1016/j.mex.2025.103200). Anagnostopoulos et al. (2019, Natural Resources) reviewed both the applicability and the limits of natural clinoptilolite for crude oil removal from seawater (DOI:10.4236/nr.2019.1010020).

KMIZEOLITE Key Properties

Item	Value
Clinoptilolite purity	97%
Cation exchange capacity (CEC)	1.6–2.0 meq/g
Specific surface area	40.0 m²/g
Pore diameter	4.0–7.0 Å
pH stability range	3.0–10.0
Hardness	4.0–5.0 Mohs
Thermal stability	700°C
Specific gravity	1.89
Bulk density	45–54 lbs/ft³
Certifications	OMRI KMI-10365, FDA GRAS (21 CFR 182.2729), TSCA, EN-71-3

Note: the CEC and pore properties above are based on unmodified natural clinoptilolite and do not guarantee oil sorption performance itself. Since actual oil sorption capacity is determined by the modification method and oil type, oil sorption capacity and recovery rate testing with the target oil type is recommended before adoption.

Oil Spill Response Application Examples (Focused on Supplementary Response Sorbents)

Below are representative scenarios in which clinoptilolite (including modified and composited forms) is considered as a supplementary sorbent in marine and harbor oil spill response. All applications are positioned at the finishing stage, on the premise of primary response equipment such as oil booms and skimmers.

Residual thin film recovery: scatter buoyant granular or mat-type sorbents onto the thin oil film remaining after primary skimmer recovery and recover them with nets or skimmers
Stagnant harbor water treatment: spread sorbent in areas with weak flow where oil stagnates, such as quays and wharves, to recover adhered oil
Drain and catch basin packed beds: place granular packed cartridges in harbor stormwater and wash water discharge paths to delay or block oil discharge
Sorbent boom and pillow filler: fill into hydrophobic foam or nonwoven fabric to produce floating sorbent pillows for early-stage deployment and recovery operations
Pilot application: use small samples to pre-verify oil sorption capacity and recovery rate for the target oil type (crude oil, diesel, bunker C)

Recommended Particle Sizes and Product Specifications

For operations where the material is scattered on the water surface and then recovered, Coarse to Medium Granule with good buoyancy and recoverability is considered, while for drain and catch basin packed beds, Fine to Medium Granule, which balances water permeability and adsorption area, is considered. Fine powder has a large adsorption area but carries a risk of dispersion in water and difficult recovery, so it is not recommended for marine surface application. Refer to the table below to select the product group that matches your operating method.

Product group	Mesh	Particle size	Typical use
Powder	100 mesh or finer	<150μm	Pozzolan, feed, powder adsorption
Fine Granule	30×50 mesh	0.3–0.6mm	Water treatment, filtration, soil
Medium Granule	14×40 mesh	0.4–1.4mm	Filter beds, bedding, litter
Coarse Granule	8×14 mesh	1.4–2.4mm	Pools, de-icing, large-scale filtration
Extra Coarse	4×8 mesh	2.4–4.8mm	Packed beds, air scrubbers

→ View products by mesh size · Product selection guide by use

Pilot Testing and Field Evaluation Points

When applying a zeolite sorbent to marine and harbor oil spill response, the following items must be confirmed together.

Confirm the modification prerequisite: unmodified clinoptilolite is hydrophilic, so as-is oil sorption performance is weak. Fix whether organophilic modification (surfactant) or hydrophobic compositing will be used as the very first design variable
Oil sorption capacity testing by oil type and medium: compare oil sorption capacity (g oil / g sorbent) and water absorption interference in batch tests for oil types with different viscosity and volatility, such as crude oil, diesel, and bunker C, and for seawater and brackish water media
Buoyancy and recoverability: after scattering, the material must float without sinking to be recoverable. Check the buoyancy persistence and skimmer / net recovery rate for each particle size and composited form
Modifier safety: for organozeolite, separately evaluate the aquatic toxicity and desorption behavior of the surfactant used, and check the risk of residue and re-leaching
Post-use treatment route: determine in advance the incineration, regeneration, or landfill route and the waste classification for the recovered oil-saturated sorbent
Regulations and approvals: review compliance with the criteria for response materials and chemicals under the Marine Environment Management Act and with the operating procedures of the responsible agencies (Coast Guard, KOEM, port authorities). Professional response and environmental review must precede application

Meanwhile, regarding the hydrophobic compositing route, Fidan et al. (2022, Journal of Applied Polymer Science) reported the oil sorption capacity of clinoptilolite-filled silicone composite foam, presenting an application direction as a recoverable composite material rather than the mineral alone (DOI:10.1002/app.52637).

→ View TDS (Technical Data Sheet) · View MSDS (Safety Data Sheet)

Marine & Harbor Oil Spill Sorbent FAQ

If you scatter natural zeolite directly onto the sea, does it adsorb oil well?

Unmodified clinoptilolite has a hydrophilic (not hydrophobic) surface, so on seawater it competes with water first and its oil sorption performance is limited. Therefore, to use it as a practical oil sorbent, surface modification to make it organophilic with cationic surfactants such as quaternary ammonium, or pretreatment that imparts hydrophobicity by loading it into silicone or polymer foam, is effectively a prerequisite. Szala et al. (2015) and Asgharzadeh et al. (2025) reported that organic / surfactant modification improves the sorption capacity for petroleum compounds, and Anagnostopoulos et al. (2019) reviewed both the applicability and the limits of natural clinoptilolite for crude oil removal from seawater.

Does it replace existing response equipment such as oil booms and sorbent pads?

It is appropriate to understand it as a supplementary material, not a replacement. The realistic position is to block spreading with oil booms, recover thick oil films first with a skimmer, and then finish-treat the residual thin films and the dispersed oil in stagnant harbor waters with a granular sorbent. Being an inorganic mineral, it leaves little combustion residue and allows you to choose recycling, incineration, or landfill routes after recovery, which distinguishes it from polypropylene sorbent pads.

Is it harmful to aquatic ecosystems?

Clinoptilolite is a natural aluminosilicate mineral and non-toxic, and applying it in a recoverable granular form after use can reduce the residual burden. However, for organozeolite modified with surfactants, the aquatic toxicity and desorption behavior of the surfactant used must be verified separately, and the environmental impact should be reviewed in advance together with the application and recovery plan.

Which particle size (mesh) is suitable?

For operations where the material is scattered on the water surface and then recovered with skimmers or nets, Coarse to Medium Granule (8×14 to 14×40 mesh) with good buoyancy and recoverability is generally considered, while Fine to Medium Granule is considered for pass-through treatment in packed beds at harbor drains and catch basins. Fine powder has a large adsorption area but carries a risk of dispersion in water and difficult recovery, so it is not recommended for marine surface application.

Can I receive a sample for testing?

Yes, KMIZEOLITE supports the provision of samples to verify oil sorption capacity and recoverability. On the sample request page, please leave details of the target oil type (crude oil, diesel, bunker C, etc.), the application medium (seawater, brackish water, harbor water), the desired particle size, and whether modification is required.

Inquiries and Sample Requests

If you are considering applying zeolite in the marine and harbor oil spill sorbent field, please contact us through the channels below.

Notice

Whether the application is suitable may vary depending on field conditions, regulations, and test results. Before actual application, testing and review suited to the field conditions must always be carried out first. It is appropriate to understand zeolite not as an all-purpose solution in this field, but as a sorbent material that supplements primary response such as oil booms and skimmers.