Case Report
Reverse Osmosis (RO) Plant Performance Improvement Using Online Calibration and Monitoring: An Industrial Case Study
Shafqat Abbas*
,
Muhammad Faizan
Issue:
Volume 14, Issue 3, June 2026
Pages:
54-59
Received:
23 January 2026
Accepted:
6 February 2026
Published:
10 June 2026
Abstract: Reverse Osmosis (RO) systems are extensively employed in industrial water purification due to their ability to produce high-quality permeate for critical processes. However, long-term operation often suffers from performance deterioration caused by membrane fouling, sensor drift, and unstable operating conditions. These issues can lead to reduced permeate quality, increased differential pressure, and higher specific energy consumption, ultimately increasing operating costs and reducing system reliability. This study investigates the impact of online sensor calibration combined with continuous real-time monitoring on the operational performance of a 10 m3/h industrial RO plant over a one-month evaluation period. Key operational parameters—including permeate flow rate, differential pressure (ΔP), specific energy consumption (SEC), permeate total dissolved solids (TDS), salt rejection, and system recovery—were systematically monitored and analyzed before and after the implementation of a calibrated online monitoring system. The calibration process ensured improved accuracy and reliability of critical sensors, enabling more precise control of operating conditions and early identification of performance deviations. The results indicate a measurable improvement in both hydraulic and energy efficiency following the implementation of online calibration and real-time monitoring. Average permeate flow increased from 9.46 m3/h to 9.66 m3/h, while differential pressure across the membranes decreased from 1.69 bar to 1.50 bar, suggesting reduced fouling resistance and improved membrane performance. Furthermore, specific energy consumption decreased from 2.97 kWh/m3 to 2.80 kWh/m3, demonstrating enhanced energy efficiency without compromising system recovery, which remained stable throughout the study period. In terms of water quality, permeate TDS levels showed a significant reduction from a range of 28.6–22.7 ppm to 20.5–12.3 ppm. Correspondingly, average salt rejection improved from 97.5% to 98.4%, reflecting better separation efficiency and process control. These improvements collectively confirm that accurate online calibration and continuous real-time monitoring play a crucial role in mitigating membrane fouling, stabilizing system operation, and optimizing energy consumption. Overall, the findings highlight the importance of advanced monitoring and calibration strategies as effective operational tools for enhancing performance, ensuring consistent permeate quality, and improving the sustainability of industrial RO systems.
Abstract: Reverse Osmosis (RO) systems are extensively employed in industrial water purification due to their ability to produce high-quality permeate for critical processes. However, long-term operation often suffers from performance deterioration caused by membrane fouling, sensor drift, and unstable operating conditions. These issues can lead to reduced p...
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Research Article
Kinetic and Thermodynamic Modelling of Zinc Adsorption Onto Acid-activated Oyster and Periwinkle Shells
Issue:
Volume 14, Issue 3, June 2026
Pages:
60-75
Received:
29 June 2026
Accepted:
8 July 2026
Published:
24 July 2026
DOI:
10.11648/j.ajche.20261403.12
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Abstract: This study investigated the adsorptive removal of zinc ions (Zn2+) from aqueous solution using low-cost biosorbents derived from periwinkle shell char (PSC, Tympanotonus fuscatus) and oyster shell char (OSC, Crassostrea gigas), activated with 1.0 M HCl following calcination at 600°C. Characterization by XRF and FTIR confirmed that both adsorbents are predominantly composed of calcite (CaCO3), with calcium contents of 87.43% (PSC) and 91.26% (OSC), and exhibited surface hydroxyl and carbonate functional groups responsible for Zn2+ binding. Physicochemical analysis revealed specific surface areas of 186.4 m2/g (PSC) and 214.7 m2/g (OSC). Batch adsorption experiments were conducted to evaluate the effects of contact time, adsorbent dosage, temperature, initial Zn2+ concentration, and solution pH. Maximum Zn2+ removal of 82.6% (PSC) and 85.3% (OSC) was achieved at optimum conditions of pH 6.0, contact time of 60 min, adsorbent dosage of 1.0 g/100 mL, and temperature of 60°C. Adsorption kinetics were best described by the pseudo-first order model (R2 = 0.927 for PSC; R2 = 0.951 for OSC), with intraparticle diffusion identified as a contributing mechanism. Both Langmuir and Freundlich isotherm models satisfactorily correlated the equilibrium data; the Langmuir model yielded maximum monolayer adsorption capacities (qm) of 32.26 mg/g and 37.88 mg/g for PSC and OSC, respectively. Thermodynamic analysis revealed negative ΔG°, positive ΔH°, and positive ΔS° values, confirming that the adsorption process is spontaneous, endothermic, and associated with increased surface randomness. OSC consistently outperformed PSC across all parameters, attributable to its higher surface area, calcium content, and pore volume. These results demonstrate that both periwinkle and oyster shell chars are effective, sustainable, and low-cost adsorbents for zinc ion removal from wastewater.
Abstract: This study investigated the adsorptive removal of zinc ions (Zn2+) from aqueous solution using low-cost biosorbents derived from periwinkle shell char (PSC, Tympanotonus fuscatus) and oyster shell char (OSC, Crassostrea gigas), activated with 1.0 M HCl following calcination at 600°C. Characterization by XRF and FTIR confirmed that both adsorbents a...
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