ODM Purifying Seawater Into Drinking Water Manufacturers & Manufacturer Engineering

To generate an accurate hydraulic balance and membrane projection, we require: raw seawater Total Dissolved Solids (TDS), operating water temperature envelope (critical for viscosity calculations), silt density index (SDI), concentration of scale-forming ions (silica, barium, strontium, calcium), required permeate capacity (m³/day), and product water target standard (e.g., WHO drinking water guidelines, irrigation specs, or boiler-feed conductivity).

In standard SWRO, 55% to 60% of high-pressure energy remains stored in the reject brine exiting the membrane vessels at 65+ bar. Tongjie integrates isobaric rotary pressure exchangers that transfer this hydraulic pressure directly into incoming feed seawater with up to 98% efficiency. This drops required pump motor size and lowers net specific energy consumption to as low as 2.2 – 2.8 kWh per cubic meter of finished water.

Raw seawater contains approximately 4.5 to 5.0 mg/L of natural boron. At neutral pH, boron exists as uncharged boric acid, which passes through single-pass membranes, often yielding 1.2 to 1.8 mg/L (violating the WHO 0.5 mg/L threshold). We employ a two-pass architecture: the second pass is dosed with small amounts of NaOH to elevate pH to ~9.5, transforming boron into charged borate ions rejected at >98%. The permeate is subsequently remineralized through food-grade calcium carbonate beds to restore balanced drinking water pH and mineral content.

All wetted components operating on the high-pressure seawater side (after high-pressure boost pumps) are fabricated from genuine Super Duplex Stainless Steel (2507 / UNS S32750) or 254 SMO, boasting a Pitting Resistance Equivalent Number (PREN) > 42. Low-pressure manifolds utilize non-corrosive Schedule 80 PVC, UPVC, or Duplex 2205 to achieve multi-decade operational lifespans in aggressive marine atmospheres.

Yes. Our containerized plants are structurally integrated inside standard ISO sea shipping containers (20-foot or 40-foot High Cube), fully equipped with internal thermal insulation, heavy-duty HVAC climate control, automated chemical dosing skids, Clean-in-Place (CIP) systems, and pre-wired PLC control panels. On arrival at site, operators simply connect raw intake, product discharge, brine outfall, and main electrical power, permitting water production within days.