Professional Water Turbidity Sensor

At a time when the world is paying more and more attention to environmental protection, the importance of water quality monitoring is self-evident. However, its development has encountered many bottlenecks. On the one hand, the uneven distribution of monitoring points and the insufficient number of monitoring points cannot fully and accurately reflect the water quality of the water area. Taking a large lake as an example, only a few monitoring points are set up sporadically around it, and the center of the lake and other areas have been in the monitoring blind spot for a long time. Once the water quality is abnormal, it is difficult to detect it in time. On the other hand, the aging of monitoring equipment and lagging technology have resulted in poor detection capabilities for trace pollutants and emerging pollutants. For example, some old sensors have extremely low detection sensitivity for some new pesticide residues, which cannot meet the increasingly stringent monitoring needs. At the same time, the massive monitoring data lacks unified standards and effective sharing mechanisms, forming "data islands" with low utilization rates. ​


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In response to these thorny issues, industry experts and relevant departments have taken active actions. In order to optimize the layout of monitoring points, multiple departments such as water conservancy and environmental protection have jointly conducted research and scientifically planned additional monitoring points based on factors such as water functions and water flow directions. In terms of technological innovation, we will increase capital investment and encourage enterprises to develop new monitoring equipment, such as high-sensitivity sensors made of nanomaterials, which have greatly improved detection accuracy compared to traditional equipment. In terms of data management, we will start to build a national water quality monitoring data sharing platform to break down data barriers between departments and regions, promote data circulation, provide strong support for water quality management decisions, and help the water quality monitoring industry reach new heights.

Drinking water safety is clearly a critical priority.Yet the number of threats to water safety continues to grow daily, and include animal and human waste, improper disposal of chemicals, pesticides, and deep earth injection of hazardous materials. Contamination is also a threat due to improper water treatment and disinfection procedures, as well as from poorly maintained water distribution systems.

The Safe Drinking Water Act, has established national health-based standards that address both man-made and naturally occurring contamination. Compliance requires consistent, accurate measurement of water parameters performed in the lab, field, and online. While many measurements can be made in the lab, key variables such as pH, conductivity, fluoride, and chlorine can also be measured online in real-time to warn immediately if limits are exceeded.

Usually there is four steps for drinking water process
First step is Pre-treatment for source water
Second step is Filtration
Third step is disinfection process
Fourth step is distribution ,we have to measure pH,turbidity,hardness,residual chlorine,conductivity(TDS),then we can know the potential risks or threaten to public heath on time.the residual chlorine value should be over 0.3mg/L when be piped out from drinking water plant, and over 0.05mg/L at end of pipe network.turbidity must less 1NTU,pH value is between 6.5~8,5,pipe will be corrosive if pH value is less 6.5pH and easy scale if pH is over 8.5pH.

At present online water quality monitoring system can monitor water quality 24 hours and real time.it also provide quickly and correct information to decision-makers based on water quality changes in real time,Thereby providing people with healthy and safe water quality.

This paper presents three representative field application cases to verify the actual performance, economic benefits and technical advantages of ACITEK LDO Model 1 in seawater aquaculture, municipal wastewater treatment plant and coastal river nutrient monitoring projects.


Case 1: Seawater Industrial Mariculture Base Real-Time DO Control


1.1 Project Background


A large-scale coastal marine ranch in Fujian operates recirculating seawater breeding tanks for grouper and abalone, covering 12,000 m² breeding area.



Original monitoring scheme: Traditional polarographic dissolved oxygen electrodes
Pain points encountered:


Seawater contains high Cl⁻, algae and barnacle attachment; electrode membrane fouled within 7–10 days, data drifted severely;
Weekly membrane replacement, monthly electrolyte refilling, daily manual cleaning; 2 full-time maintenance staff required for 32 breeding tanks;
H₂S produced by residual bait decomposition poisoned polarographic electrodes, leading to invalid readings and delayed oxygen supply adjustment;
Without stable real-time DO data, aerators ran at full load all day, resulting in huge electricity waste; low DO at night caused occasional fish hypoxia mortality (annual loss over 180,000 RMB).






1.2 Solution Deployment


The project replaced all old electrodes with ACITEK LDO Model 1 seawater version dissolved oxygen sensors:



Installation: 1 probe per recirculation tank, installed on pipeline thread interface (standard thread compatible with existing tank fixtures); 10m matched sensor cable connected to ACITEK G800 controller;
Configuration: Factory pre-calibration, plug-and-play without on-site calibration; built-in automatic temperature compensation, immune to seawater temperature fluctuation 12–32°C;
Linkage control: Set DO threshold 5.0–7.5 mg/L; when DO <5.0 mg/L, system auto-starts aerators; when DO >7.5 mg/L, aerators reduce frequency or shut down.



1.3 On-Site Operation Results



Ultra-low maintenance workload

No consumables (membrane/electrolyte) needed. Only quarterly simple surface wiping of sensor cap required. The maintenance team cut staffing from 2 to 1 part-time worker, saving labor cost around 65,000 RMB annually. The sensor cap maintains 12-month service life covered by official warranty.
Strong seawater anti-interference performance

Not affected by high-concentration chloride, sulfide, residual feed organic matter and marine biofouling. Continuous 12-month immersion test showed no measurement drift, data accuracy kept ±0.05 ppm below 5 ppm as original specification.
Energy saving & mortality reduction

Precise aeration frequency regulation cut aeration power consumption by 22%. Night hypoxia incidents were completely eliminated; fish survival rate increased from 82% to 97%, reducing aquaculture economic loss by over 160,000 RMB each year.
Customer Feedback

"The ACITEK LDO sensor solves our long-standing seawater measurement trouble. Stable readings without frequent replacement parts greatly lower our operating cost, and scientific oxygen control significantly improved breeding output." — Farm Technical Director



Case 2: Municipal Wastewater Plant Secondary Biochemical Treatment Tank Monitoring


2.1 Project Background


A medium-sized municipal sewage treatment plant in Jiangsu adopts AAO secondary treatment process, daily treatment capacity 40,000 tons. Dissolved oxygen in aerobic tank is the core parameter to balance nitrification efficiency and aeration energy consumption.



Previous problem: Polarographic DO probes easily blocked by activated sludge foam; data fluctuated widely, unable to support automatic variable-frequency blower control; operators relied on manual sampling calibration twice per week, aerators operated with excessive air supply, high power consumption.



2.2 Project Scheme



Deploy 8 sets of ACITEK LDO Model 1 probes evenly distributed in aerobic biochemical tank;
Probe specification: 155mm length, 28.25mm diameter, Noryl corrosion-resistant body, maximum 3.5 bar pressure resistance adapting to tank immersion depth;
Data transmission: Max 100m transmission distance to G800 control unit, realizing real-time DO curve display and blower linkage regulation.









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Sensor Installed in Aeration Tank









2.3 Application Benefits



Stable measurement without flow demand

ACITEK LDO technology does not consume oxygen during detection, requiring no minimum water flow. Even in static sludge deposition zones, T90 response time <40s, quickly capturing DO concentration changes.
Cut down maintenance frequency drastically

Factory pre-calibration eliminates monthly air calibration work; no anode/cathode cleaning, membrane and electrolyte replacement. Calibration cycle extended to 6 months, annual maintenance time reduced by 70%.
Aeration energy consumption reduction

Stable continuous DO signal supports intelligent blower variable frequency control, maintaining aerobic tank DO steady at 2–3 mg/L. Annual power saving for aeration system reaches about 130,000 kWh, equivalent to 100,000 RMB electricity cost reduction.
Effluent standard compliance improvement

Stable dissolved oxygen environment promotes microbial nitrification, effluent ammonia nitrogen concentration stably below national discharge standard, compliance rate raised from 92% to 99.8%.



Case 3: Coastal Estuary Water Nutrient & Discharge Compliance Monitoring


3.1 Project Profile


Local ecological environmental bureau launched coastal river real-time water quality monitoring stations to track nutrient salt and DO variation, supervise industrial wastewater outlet discharge up to standard. Water body is brackish mixing fresh water and seawater, with complex interference substances including heavy metal ions, residual chlorine (<4 ppm), sulfate and surfactant.


3.2 Equipment Selection Reason


Traditional electrochemical DO sensors suffer severe cross-interference from H₂S, metal ions and chloride in brackish water, causing measurement distortion. ACITEK LDO Model 1 has exclusive anti-interference performance, unaffected by H₂S, K⁺, Na⁺, heavy metal ions, Cl⁻ and low-concentration residual chlorine, fully matching estuary water monitoring demands.


3.3 Field Operation Effect



Long-term continuous immersion for 10 months without data distortion, accurately recording daily DO fluctuation for nutrient eutrophication analysis;
Support remote unattended monitoring, sensor cable up to 10m, immersion depth up to 34m to cover multi-layer water body sampling;
One-point air calibration simple operation for routine inspection, convenient for environmental law enforcement personnel on-site verification;
Data provides reliable basis for early warning of algal bloom and pollution source tracing, assisting environmental management department to complete regular water quality assessment reports.



Core Advantages Verified by All Three Field Cases


Combining seawater breeding, municipal sewage and coastal environmental monitoring practical application data, ACITEK LDO Model 1 shows irreplaceable strengths compared with conventional DO electrodes:



Zero pre-use calibration & no drift

3D factory calibration before delivery, out-of-box usable; no signal drift under long-term continuous operation, ensuring long-period data authenticity.
Ultra-low operation & maintenance cost

No consumables (membrane, electrolyte), only annual replacement of sensor cap; labor and material maintenance expenditure reduced by over 60% versus polarographic sensors.
Powerful anti-interference for complex water bodies

Optical luminescent principle avoids electrode poisoning; suitable for seawater, sludge wastewater, brackish estuary water with various ion contaminants.
Wide environmental adaptability

0–50°C operating temperature, 3.5 bar pressure resistance, compact small footprint for flexible pipeline/tank installation; compatible with ACITEK G800 controller for automatic linkage control.
Cost-effective seawater dedicated version

Stainless steel sensing head with corrosion resistance against saline water, one-year full machine warranty, support OEM/ODM customized cable length and thread interfaces for engineering integrators.



Conclusion


ACITEK LDO Model 1 (AC9020000-SW) luminescent dissolved oxygen sensor has achieved remarkable energy-saving, labor-saving and efficiency-improving results in marine aquaculture, municipal wastewater secondary treatment and coastal water environmental monitoring projects. Its low-maintenance, high-stability and strong anti-interference characteristics perfectly solve the long-standing pain points of traditional dissolved oxygen electrodes in complex water quality scenarios, especially seawater working conditions. For water treatment system integrators, aquaculture enterprises and environmental monitoring institutions pursuing long-term reliable online DO detection, ACITEK LDO Model 1 is a preferred cost-performance optical dissolved oxygen monitoring solution.