RO chemistry · Membrane pair

RO antiscalant supplier in Pakistan with the matching membrane biocide.

UN-307 phosphonic-blend antiscalant for CaCO₃, CaSO₄, BaSO₄, SrSO₄, silica, and iron scales, paired with UN-611 non-oxidizing biocide for polyamide-membrane biofouling control. Both held buffer-stocked in Karachi, sourced from Shaanxi Ande Technology under our sole-agent contract. A written dosing programme ships with every order, sized to your feedwater analysis.

Request quote & COA Capability statement (PDF)
Why this pair, why us

Five things a plant chemist should know before signing an RO chemistry contract.

Most Pakistani RO plants buy antiscalant from one vendor and biocide from another, with no coordination on dose rotation. The biocide kills the bacteria; the antiscalant holds the calcium. Both have to work together to protect a $50,000 membrane stack.

Matched pair
UN-307 antiscalant and UN-611 biocide are formulated to coexist on a polyamide membrane stack. No phosphonate-quat interaction, no foaming on biocide shock. Single vendor accountability when flux declines unexpectedly.
Broad-spectrum scale control
UN-307 holds CaCO₃, CaSO₄, BaSO₄, SrSO₄, silica, and iron scales up to LSI +2.8 on concentrate. Covers most brackish groundwater in Punjab and Sindh on a single 2 to 5 ppm dose, no co-formulation required.
Karachi stockholding
UN-307 and UN-611 buffer-stocked in Clifton. 5 MT antiscalant or 2 MT biocide ships within the same business week. PKR-invoiced from Karachi, so the procurement officer is not chasing FX rate on every reorder.
Dosing programme
Every order ships with a written dosing programme sized to your feedwater analysis (LSI, S&DSI, silica, iron, hardness). Commissioning visit and quarterly KPI review on flux decline and cleaning frequency for recurring accounts within 250 km of Karachi.
COA per batch
Shaanxi Ande factory COA with every shipment: active content, pH, density, residual phosphonate (UN-307) or quat concentration (UN-611). MSDS arrives pre-shipment for HSE clearance.
Specifications

UN-307 and UN-611 on a single membrane programme.

Two chemistries, one feed point on the high-pressure pump suction (UN-307 continuous) plus one CIP-cycle add-point on the membrane housings (UN-611 shock). Both run from the same dosing skid hardware.

Product % active Dose Feed point TDS
UN-307 antiscalant40-50%2 to 5 ppm on feedwater (continuous)HP-pump suction, post-dechlorinationUN-307
UN-611 biocide20%25 to 75 ppm shock, 30-60 min, 1-3× weeklyMembrane housings, CIP cycleUN-611
UN-611 (offline preservation)20%500 to 1,000 ppm soakMembrane housings, offline storageUN-611

Compatible with polyamide TFC, CPA, and ESPA membranes from Hydranautics, DuPont (FilmTec), Toray, LG Chem, and Vontron. Max feedwater LSI +2.8 on the concentrate side. Both products non-chlorine-tolerant: ensure dechlorination upstream.

RO plant scenarios

Three composite cases on the UN-307 + UN-611 pair.

Anonymised but real. Drawn from Pakistani RO accounts on the AAS catalogue. Names available under NDA.

An IPP in Punjab during a 90-day membrane replacement window.

The plant runs a 200 m³/hr brackish-water RO on canal feed with seasonal silica spikes to 80 ppm SiO₂. The incumbent antiscalant was Nalco PermaTreat on 8-week air-freight lead times, and the plant ran out twice during the silica-spike season. We switched to UN-307 at 3.5 ppm with 4 MT held on rolling Karachi stock, plus UN-611 weekly shock at 50 ppm. Through the 90-day membrane swap window, the chemistry held continuously and the procurement officer stopped getting middle-of-night escalation calls.

A Faisalabad textile mill switched RO chemistry on cost-in-use math.

The mill was running Buckman's antiscalant on a 120 m³/hr brackish RO at 4.2 ppm dose, cost-in-use roughly PKR 14 per m³ permeate. We re-jar-tested with UN-307 at 3.0 ppm against the same feedwater, holding the same CaCO₃ and CaSO₄ inhibition, with cost-in-use coming down to roughly PKR 9.50 per m³. The savings paid for the UN-611 biocide additions plus a quarterly applications-engineer visit. The mill normalized cleaning frequency from every 4 weeks to every 9.

A Karachi pharmaceutical plant added a biocide layer to existing antiscalant.

The plant runs municipal-feed RO for utility water with antiscalant from an existing local blender. Persistent biofouling was driving CIP frequency to once every 3 weeks, with cleaning chemistry costs running over the chemistry budget. We added UN-611 at 50 ppm shock weekly without changing the antiscalant. ATP-swab counts on membrane surfaces dropped from 800 RLU to under 50, CIP frequency stretched to 9-week intervals, total RO chemistry spend fell ~30%.

Procurement

MOQ, dispatch, terms.

Three engagement shapes. Pricing is custom by product, volume, and packaging; the quote returns within 2 business days with the COA sample.

Pilot tier (25 to 200 kg)
Trial drums of UN-307 and UN-611 with matching COA at no commercial commitment. 2 to 3 working days dispatch from Karachi. Suits side-stream pilot or CIP-cycle comparison against an incumbent.
Program tier (5 to 25 MT)
Same-week ex-Karachi on UN-307; 2 to 3 working days on UN-611. 30-day TT terms for repeat accounts. Drum or IBC packaging. Quarterly KPI review bundled in for recurring contracts within 250 km of Karachi.
Bulk tier (50 MT and up)
Factory-direct from Shaanxi Ande. 4 to 6 weeks production plus 21 to 35 days sea freight CIF Karachi. LC at sight or 30-day TT on established accounts. FOB Shanghai available where the buyer brings their own forwarder.
Consigned stock
For multi-year RO programmes (100+ MT/yr total chemistry), we run consigned stock at Port Qasim bonded under the buyer's name. Customs cleared on call-off, invoiced as drawn. PKR-equivalent rates available.

Pricing bands are not published. Each quote is sized to product, volume, INCO, and packaging. The cost-in-use comparator at /calculators/cost-in-use/ runs delivered cost against your incumbent on per-m³-permeate basis.

Program path

RO chemistry runs better on a programme than on SKU purchases.

Buying UN-307 and UN-611 ad-hoc when the drum runs out leaves the plant exposed to three risks: lead-time gaps on reorder, dose drift between chemists, and no accountability when membrane flux declines. A programme path collapses all three: continuous chemistry supply, quarterly KPI review, dosing programme refreshed when feedwater profile shifts, single vendor when the flux number moves.

The Refinery RO programme handles the same chemistry duty with engineering wrapped around it (commissioning, ops & maintenance, sludge audit). Read the program brief if your duty is large enough to justify the structure.

Read the Refinery Process Chemistry Programme →

Read the China-Pakistan corridor model →

Common questions

RO chemistry procurement, what to expect.

What RO antiscalant grades do you supply in Pakistan?

UN-307 is our flagship: phosphonic-blend broad-spectrum antiscalant for CaCO₃, CaSO₄, BaSO₄, SrSO₄, silica, and iron scales. 40 to 50% active content, dosed at 2 to 5 ppm on feedwater. Approved for potable RO pretreatment when paired with appropriate dechlorination upstream. Compatible with CPA, ESPA, TFC, and polyamide membranes from all major OEMs.

Do you supply RO membrane biocide alongside the antiscalant?

Yes. UN-611 is a non-oxidizing biocide formulated for polyamide composite membranes. 20% active content, shock-dosed at 25 to 75 ppm for 30-60 minutes, 1 to 3 times weekly. Unlike chlorine and other oxidants which destroy polyamide membrane active layers, UN-611 is fully compatible with TFC and CPA membranes. Most accounts buy UN-307 and UN-611 together as a complete RO chemistry pair.

What feedwater conditions does UN-307 handle?

UN-307 holds calcium carbonate scale to LSI +2.8 on the concentrate side, which covers most brackish groundwater in Punjab and Sindh. For seawater desalination duties, the typical dose moves to 4 to 5 ppm on the feedwater. For high-silica feedwater (60+ ppm SiO₂), we adjust dose upward and may pair with an antifoulant. Submit your feedwater analysis and we return a written dosing programme.

How does cost-in-use compare to Nalco PermaTreat and Genesys?

UN-307 typically lands 20 to 30% lower delivered-PKR vs Nalco PermaTreat or Genesys equivalents when normalised on active content and dose rate. The bigger advantage on Pakistani sites is operational: Karachi stockholding means a 5 MT order ships the same week vs months on the European-imported brands. The cost-in-use calculator at /calculators/cost-in-use/ runs the math against your incumbent.

What's the MOQ?

200 kg drum for stock-spec on both UN-307 and UN-611. Trial drums of 25 to 50 kg are available on request for new accounts running pilot tests on their RO train. Program-scale tiers run 5 MT same-week ex-Karachi through 50 MT factory-direct from Shaanxi Ande on 4-week production plus 21 to 35 days sea freight CIF Karachi.

Do you provide a dosing programme with the chemistry?

Yes. Every UN-307 order includes a written dosing programme based on your feedwater analysis (LSI, S&DSI, silica, iron, hardness profile). For ongoing supply contracts, our applications engineer visits the plant on commissioning and reviews flux decline and cleaning frequency quarterly. The dose gets retuned when feedwater profile shifts (seasonal canal water, well rotation, etc.).

Can I get samples before ordering?

Yes. We send a 1 to 2 kg sample of each, plus matching COAs and TDS, at no commercial commitment. Most plant chemists run a side-stream pilot or a CIP-cycle comparison before signing. Sample dispatch is 2 to 3 working days from Karachi.

Request RO chemistry quote

Send the feedwater analysis, get a dosing programme back.

Three minutes of intake (membrane type, flow rate, feedwater analysis if available). Rayhan's team replies with a written dosing programme, indicative quote, and the matching factory COA sample within 2 business days.

Austin Anderson Solutions · C-86, Block-2, Clifton, Karachi 75600

+92 (21) 35874214-5 · rayhan@austinandersonsolutions.com

WhatsApp 24/7: +92 300 823 9990