New technologies reshape water and sand supply for construction and industry

Ultrasonic sea-sand desalination device debuts as river-sand shortages bite construction; South Korea and Oman show different paths to water and CO2 goals

The construction sector is increasingly turning to sea sand as river sand shortages tighten supply. Environmental rules and overextraction have curbed river sand availability, pushing builders to seek alternatives. But sea sand comes with a long-standing hurdle: higher salt content that can corrode the steel rebar in reinforced concrete, weakening structures and raising safety and cost concerns. A wave of new tech is aiming to address this: an ultrasonic washing device developed by the Korea Institute of Ocean Science & Technology (KIOST) promises to desalinate sea sand more efficiently, with less water usage and strict safety standards in mind.

In a shift that mirrors growing demand for sustainable construction materials, the KIOST device is designed to remove salt while conserving water. Traditional desalination methods rinse sand with large amounts of water, using roughly four tons of water per ton of sand. The new process blends sea sand with water at a 1:2 ratio (sand to water) and subjects the mix to ultrasonic waves at 300 W or higher for about three minutes. The technique relies on cavitation-driven washing, strong particle clearance from bubble collapse, improved penetration, and non-contact cleansing using ultrasonic energy, enabling operation even in confined spaces. Tests have shown the method can reduce the salt concentration in sea sand to 0.04% or below, aligning with regulatory targets for aggregate in construction.

The method’s real-world significance lies in giving builders access to sea sand that meets safety thresholds without wasting enormous volumes of water. The Ministry of Land, Infrastructure and Transport in Korea sets a maximum salt content of 0.04% for sea-sand aggregates, a benchmark the KIOST system aims to meet consistently. The research and validation results have been published in Scientific Reports, underscoring a move toward scalable, water-efficient desalination that can support broader use of sea sand in construction. The project’s lead designer, Dr. Gil-Lim Yoon, emphasizes that the ultrasonic approach could help bridge the global river-sand gap while maintaining structural integrity and economic feasibility.

Beyond the technical feasibility, advocates say the approach could shorten processing times and cut water losses, in contrast to traditional methods. KIOST officials indicate plans to push the technology toward higher volumes of sea sand to keep pace with demand. Supporters argue that properly desalinated sea sand can extend the life of concrete structures and improve overall safety, provided the processes remain tightly controlled to prevent reintroduction of salts during handling and curing. Critics, meanwhile, caution that any desalination technology should be evaluated for energy use and lifecycle emissions, especially when integrated with large-scale construction projects.

Direct Air Capture and desalination combine in a first-of-its-kind pilot in Korea

A separate development involves a startup focused on removing CO2 from the atmosphere by joining direct air capture (DAC) with seawater desalination. The firm has signed a memorandum of understanding with a state-owned water utility and a wastewater-treatment company to co-create what is described as the world’s first fully integrated facility for carbon removal and water management using seawater desalination. The plan, named Project Octopus, envisions a pilot that uses desalination brine to draw salt for a sorbent that captures CO2 in the air, producing a limestone-like mineral once the captured CO2 is locked away. Fresh water would be produced as a byproduct for heavy industries in the area. The pilot is intended to serve the Daesan Industrial Complex, a petrochemical hub that currently accounts for a large share of national output and emissions.

Energy intensity is a core consideration for this approach, as the pilot will be grid-connected and powered largely by fossil fuels. The project aims to capture up to 500 metric tons of CO2 per year from the atmosphere and filter another 500 metric tons per year from smokestacks, a total that remains a fraction of the Daesan Complex’s annual emissions of about 17 million metric tons. The pilot’s construction is planned for this year with a reported budget of around $2–3 million, while a fully commercial facility could require $100–200 million and potentially break ground no earlier than late 2026. Proponents describe the pilot as a potential path to lower environmental impact for petrochemical hubs, though critics warn that DAC projects can risk water security or perpetuate fossil-fuel use if not managed carefully.

Oman’s Barka 5 desalination plant: financing and long-term operation

In a separate sector, GS Inima, the water services subsidiary of GS E&C, will carry out the Barka 5 desalination project in Oman and operate the plant for two decades under a contract with the Oman Power & Water Procurement Company. When finished, Barka 5 will process about 100,000 cubic metres of water per day. Financing for the scheme amounts to roughly $130 million, with the majority (about 70%) provided by the Export-Import Bank of Korea and other Omani financiers. The remaining portion (around 30%) is to be funded by Hana Bank, a Seoul-based lender. The project is positioned to deliver significant revenue, with an anticipated $540 million in lifetime earnings for the operators. The plant is located roughly 60 kilometers west of Muscat and represents a notable example of cross-border collaboration in water infrastructure.

Taken together, these developments illustrate a timely shift toward advanced desalination technologies that can support both construction materials and industrial water needs while exploring carbon-management options. They also reflect ongoing debates about the trade-offs between accelerating climate goals and ensuring robust energy and water systems for heavy industry. In the construction space, the KIOST device offers a practical route to safer, more sustainable sea-sand use; in the energy and climate space, the DAC-desalination pilot frames a novel approach to CO2 management that remains contingent on energy sources and scale; and in the water sector, the Oman project demonstrates how large financing partnerships and long-term operation agreements enable critical supply infrastructure. As the industry weighs benefits against challenges, these efforts underscore a broader push to turn environmental constraints into opportunities for safer, more efficient construction and water management.

Frequently Asked Questions

What is the purpose of the KIOST ultrasonic sea-sand desalination device?

The device is designed to desalinate sea sand with high salt content using ultrasonic washing, reducing salt to a target level compatible with construction standards while conserving water compared with traditional sand washing methods.

What salt level is targeted for sea sand used in construction?

A maximum salt content of 0.04% is targeted for sea-sand aggregates used in construction.

How does the KIOST method differ from traditional sand washing?

It uses cavitation-driven ultrasonic washing with a 1:2 sand-to-water mix and short processing times, providing desalination with less water use and enabling operation in confined spaces.

What is Project Octopus and who is involved?

Project Octopus is a pilot that combines direct air capture with seawater desalination to remove CO2 from the atmosphere and manage water, developed through an MOU with K-water and a wastewater company to build the integrated facility near a large petrochemical hub.

What are the projected CO2 capture figures for the pilot?

The pilot aims to capture about 500 metric tons of atmospheric CO2 annually and filter an additional 500 metric tons from smokestacks, a scale that could grow if the project expands to commercial scale.

What are the financials and scope of Oman’s Barka 5 desalination plant?

Barka 5 is financed at roughly $130 million, with about 70% coming from Ex-Im Korea and Omani lenders and the remainder from Hana Bank; it will produce about 100,000 cubic metres of water daily and operate for 20 years.

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