Contents
How to use this guide
This is a procurement-friendly, safety-first checklist for water treatment chemicals. Use it to align operations (targets and monitoring), EHS (safe handling and compliance), and procurement (specs, acceptance checks, and supply continuity).
Important: This is educational content. Always follow your site procedures and the supplier SDS/labels. Some families (especially biocides) may require additional regulatory controls depending on country and application.
Where it fits
- Process goal: define the KPI you are optimizing (scale, corrosion, biofouling, clarity, uptime, cost).
- Operating window: temperature, pH, flow, cycles/concentration factor, contact time, shear.
- Interfaces: what the chemistry touches (metals, elastomers, membranes, coatings, seals).
- Constraints: discharge limits, permit conditions, food-contact, site rules, storage limitations.
RFQ minimum dataset
A good RFQ prevents expensive rework. Include the data below so suppliers can propose compliant, supply-ready options.
| Category | What to include | Why it matters |
|---|---|---|
| Water analysis | Hardness, alkalinity, silica, chlorides, sulfate, iron/manganese, TOC/COD (if available), turbidity, microbiology baseline | Drives scale risk, corrosion risk, and chemical selection (especially antiscalants/RO) |
| Unit operation | Cooling tower, boiler, RO/UF, clarification, wastewater, closed loop | Different programs, dosing points, and acceptance checks |
| Operating conditions | Flow rate, temperature, pH range, cycles of concentration, blowdown rate, residence/contact time | Determines dose strategy and expected performance |
| Materials of construction | Metals and elastomers in contact; membrane type/model (if any) | Compatibility and corrosion control |
| Targets & KPIs | Scale/corrosion/biofouling limits; heat transfer targets; effluent limits; product water quality targets | Defines acceptance criteria and how success is measured |
| Compliance & documentation | SDS language needs, COA requirements, permits, restricted substances, labeling, transport constraints | Prevents non-compliant deliveries |
| Commercial | Monthly volume, packaging (drum/IBC/bulk), Incoterms, delivery location, lead-time expectations | Ensures supply continuity and correct packaging |
Key decision factors by chemical family
Use the table to shortlist candidates and define what you must specify and verify.
| Chemical family | Decision factors to define | Common pitfalls |
|---|---|---|
| Coagulants (aluminum/iron salts, PAC, etc.) | Raw water turbidity/organics, pH/alkalinity window, sludge handling, downstream filtration needs | Wrong basicity/strength; pH drift; underestimating alkalinity demand |
| Flocculants (anionic/cationic/nonionic polymers) | Charge type/density, molecular weight needs, shear sensitivity, make-down/mixing system | Over/under mixing; incorrect polymer charge; inconsistent viscosity affecting dosing |
| Antiscalants (cooling/RO) | Hardness, silica, alkalinity, temperature, concentration factor, membrane compatibility | Wrong product for silica scaling; incompatible with membranes; poor control of dosing accuracy |
| Corrosion inhibitors | Metallurgy, pH, cycles, oxidizing biocide compatibility, passivation needs | Mismatch to metallurgy; interference with oxidizers; insufficient monitoring |
| Biocides (oxidizing/non-oxidizing) | Biofouling severity, ORP targets (if used), contact time, discharge constraints, rotation strategy | Underdosing due to demand; forgetting neutralization/dechlorination where required; compliance gaps |
| pH control (acid/alkali) | Setpoint range, alkalinity/CO2 effects, dosing equipment/materials, safety controls | Incompatible materials; poor secondary containment; overfeeding due to bad instrumentation |
| Dechlorination (e.g., bisulfite) | Residual oxidant targets, ORP/DPD method, downstream sensitivity (membranes, biology) | Overfeed leading to low ORP; sulfite carryover; inconsistent assay |
Specification & acceptance checks (COA/SDS)
When comparing suppliers, ask for data you can verify on receipt and keep as part of traceability.
| Category | What to request | What to verify on receipt |
|---|---|---|
| Identity | Product name/grade, manufacturer, batch/lot traceability | Label matches PO; batch/lot recorded; tamper seals intact (if applicable) |
| COA (core) | Assay/active content, density, appearance; pH (if relevant); viscosity (polymers) | COA within agreed limits; no phase separation; viscosity consistent for dosing |
| Impurities / compliance | Any limits relevant to your process or permit (e.g., insolubles, metals, halogens—site dependent) | Meets site-specific thresholds; paperwork complete |
| SDS | Current SDS, local language as required, transport classification, PPE guidance | EHS approval; storage and handling SOP aligns with SDS |
| Packaging | Drum/IBC/bulk; liner and closure type; labeling requirements | Compatible with your pumps/hoses; secondary containment capacity |
| Logistics | Lead time, Incoterms, shelf life, storage conditions | FEFO practiced; shelf-life remaining is acceptable; storage conditions available on site |
Handling, storage & transfer basics
- Store in original, sealed packaging, away from incompatible materials (confirm by SDS).
- Use secondary containment and clear labeling in the operating area.
- For transfers: verify hose compatibility; use dedicated lines where practical; implement spill-control basics.
- Confirm ventilation, eyewash/shower availability, and PPE requirements for acids/alkalis and oxidizers.
Monitoring signals (quick KPIs)
Pick 2–4 signals you can measure consistently and trend them over time:
| Goal | High-value signals | Notes |
|---|---|---|
| Scale control | Heat exchanger approach temperature / ΔT, differential pressure, visual inspection during shutdown | Pair with conductivity/cycles tracking in cooling systems |
| Corrosion control | Corrosion coupons/probes, pH, conductivity, inhibitor residual (if applicable) | Trend by metallurgy and location |
| Biofouling control | ORP (where used), microbial counts, slime/film observation, ΔP increase trends | Use defined sampling points and timing |
| Clarification | Turbidity, settled water clarity, sludge volume/dewatering performance | Correlate with pH and coagulant dose |
Troubleshooting: symptom → first checks
| Symptom | First checks | Likely direction |
|---|---|---|
| Rising differential pressure | Confirm instrumentation; check filter condition; check turbidity/solids loading; review polymer make-down | Clarification/filtration program or polymer handling issue |
| Scale on heat transfer surfaces | Check cycles/conductivity trend; verify antiscalant dose pump calibration; review hardness/silica changes | Antiscalant mismatch or dosing/control drift |
| Microbial spikes / slime | Check biocide residual/ORP trend; review contact time; verify dosing point; check nutrient/organics changes | Biocide demand increased; need dose strategy or rotation adjustment |
| pH instability | Calibrate probes; check mixing and injection; verify chemical concentration; inspect valves/check valves | Instrumentation or dosing equipment issue; sometimes chemistry demand shift |
Need a compliant alternative?
Send your constraints and target performance. We’ll propose options with SDS/COA expectations and procurement-ready specs.
Educational content only. Always follow site EHS rules and the supplier SDS for safe use.