Water treatment professionals frequently face challenges when dealing with high total dissolved solids (TDS) streams, especially in predicting solid formation and changes in boiling points during processes like desalination or evaporation. For reverse osmosis (RO) concentrate containing high levels of nitrate, phosphate, boron and silica – alongside a TDS concentration around 9,000 mg/L- it is critical to understand how different water analysis reconciliation options affect the system chemistry.
OLI software is used to explore how varying reconciliation methods influence solid formation and boiling point behavior, offering valuable insights into optimizing water treatment processes.
Addressing high TDS water challenges in water treatment
Managing high TDS water streams brings challenges like scaling risks, inaccurate boiling point predictions, and data discrepancies. When ions are unbalanced, it can lead to significant issues with solid formation and suboptimal boiling outcomes.
OLI software offers robust tools – OLI Studio Stream Analyzer, OLI Studio ScaleChem, and Flowsheet: ESP on the desktop, as well as OLI Engine API, OLI ScaleChem API, and OLI Process API in the Cloud – for balancing ions, matching pH and alkalinity with lab data, and adjusting for CO2 and total inorganic carbon (TIC). These capabilities are especially critical in desalination and oil and gas applications, where maintaining accurate chemistry is paramount.
How OLI software resolves water chemistry imbalances
Water analysis reconciliation options in OLI software allow users to adjust cation and anion levels to ensure electro-neutrality in water streams. OLI enables adjustments using different options like prorating ions, selecting makeup ions (e.g., sodium or calcium) and reconciling pH and alkalinity through titration.
For example, balancing the RO concentrate with sodium as a makeup ion results in lower solid formation, whereas a more reactive element like calcium leads to a higher level of solids. In ScaleChem and Flowsheet: ESP, the user may also choose to reconcile based on the measured gas-phase CO2 can also be incorporated, which is especially important in applications like oil and gas where total inorganic carbon plays a significant role in chemistry.
Reconciliation methods and their Impact on solids formation
The selection of reconciliation methods has a direct impact on solids formation. In cases where reconciliation by electroneutrality alone is applied, higher levels of solids may be predicted. However, when pH and alkalinity are reconciled using hydrochloric acid, the solid formation can decrease significantly (down to 33 mg/L). This reduction occurs because hydrochloric acid lowers the pH, which suppresses the formation of calcium sulfate, a common scaling agent.
Additionally, different makeup ions change the predicted amount of solids. When calcium is chosen as the makeup ion, the predicted solids formation increases from 13,000 mg/L to 16,000 mg/L, due to its propensity to form precipitates like calcium sulfate. For industries concerned with scaling risks, calcium may offer a more conservative prediction of solid formation.
Best practices for water chemistry reconciliation
Accurate data entry is critical for successful reconciliation in OLI software. Entering complete lab data for metals, anions, neutral species, pH and alkalinity helps avoid interference in the analysis, such as that caused by phosphate, boron, or CO2.
Choosing appropriate makeup ions based on the chemistry of the water is also crucial. For instance, while selecting calcium might give a conservative estimate of scaling risk, it runs the risk of overpredicting the actual amount of solids if calcium isn’t dominant in the sample. Understanding these nuances can help create more accurate predictions.
Why OLI software is the ideal solution for water treatment
OLI software’s reconciliation tools offer a significant advantage for industries dealing with high-TDS water streams. OLI’s flexibility in balancing ions and adjusting for key factors like pH, alkalinity and CO2 makes it an invaluable solution for optimizing water treatment operations and mitigating risks like scaling.
For industries like oil and gas or desalination, where high TDS water is common, OLI’s ability to model real-world conditions with precision leads to more reliable outcomes, improving operational decision-making and reducing costly errors.
Ensuring the best possible outcomes for high TDS water
With OLI software, you can confidently address high TDS water treatment, knowing that the reconciliation options provide a detailed and accurate analysis of water chemistry. OLI’s ability to tailor these analyses to match real-world conditions ensures better management of solid formation, boiling point changes, and overall water treatment processes, reducing the risk of scaling and improving efficiency.
Watch the Full Spotlight Seminar
To explore these concepts further, sign up to watch the on-demand Spotlight Seminar where these reconciliation techniques are demonstrated in detail. For more information or to discuss your specific water chemistry challenges, get in touch with an OLI expert via our contact page.