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Sewage Treatment Systems

Modern sewage treatment involves the use of a range of processes varying from relatively simple lagoon systems to more complicated activated sludge and nutrient removal processes. Depending on the end use of the final effluent, the required quality varies. Effluent discharged to inland waterways requires a very high level of nutrient reduction. Effluent destined for reuse requires a lesser level of treatment. All treatment requires the removal of the carbon load and at least some of the nitrogen load.

Removal of the carbon and nitrogen loads requires excellent control of aeration.  A D.O. sensor that reads low is likely to cause over aeration of the wastewater, resulting in increased power and maintenance costs, and high total nitrogen levels in the final treated effluent. A D.O. sensor that reads high gives a false sense of security in that it appears the D.O. set point has been reached when in fact it has not. Under these conditions both N and P removal are reduced, resulting in an effluent high in ammonia and phosphorous. The resultant low oxygen levels can lead to the growth of nuisance filamentous biomass and a poor settling sludge.

Removal of N and P requires alternating aerobic, anoxic and anaerobic phases. On-line nutrient analysers allow these phases to be better monitored and even controlled using the instruments. If your plant has stringent effluent quality standards, on line nutrient analysers can continually monitor the process and the effluent quality.

An area that is sometimes overlooked is the design of new treatment plants or the upgrade of existing plants. For a design to be successful, and there are many examples where they have been less successful than hoped, the influent needs to be fully characterised to give the full scope of daily, weekly and even seasonal variation. Time spent in gathering this data will be well rewarded when your plant achieves the required outcomes, with certainty.

The variation of COD is perhaps the single most important parameter for design engineers. On-line monitoring provides an excellent way to collect this data.

What We Offer 

DCM Process Control offers a complete range of instruments for continuous, instantaneous, on-line monitoring of influent and effluent quality and for improved control of STPs and nutrient removal. These include COD, BOD, TOC, NO3 , NH3 , Turbidity and D.O. At DCM we know how treatment processes work and are available to assist in the commissioning and optimisation of STPs.

We can help you with your treatment processes and highlight the possibilitites for advanced control for improved treatment.

Instruments are available for you to purchase or lease or you can take advantage of short or long-term data supply contracts. For data supply contracts, we own, install, maintain and monitor the equipment at your site. We deliver to you the raw data, with analysis, in a form that suits your needs.

Industrial Wastewater

The accurate and determination of waste strength from food manufacturing industries is important to help control the loss of valuable product, to provide accurate information for trade waste limits and charges and to allow cost effieient operation of treatment processes.

Traditionally COD and Suspended Solids are used as measures of the strength of a waste. Laboratory measurements of COD require incubation of a sample in the presence of a strong oxidant as high tempperatures. Suspended Solids measurement requires filtering of the sample followed by careful drying and weighing. Both measurements take a significant time to perform. Imagine having instantaneous results for COD and SS!

Excellent aeration control is essential for the efficient operation of a modern Waste Treatment Plant. A D.O. sensor that reads low is likely to cause ovr aeration of the wastewater, resulting in high total nitrogen levels in the final treated effluent and in excessive power and maintenance costs. A D.O. sensor that reads high causes the DO set point to be reached prematurely. In both situations the plant is likely to run inefficiently and to fail discharge requirements.

What We Offer

DCM Process Control offres a range of continuous, instantaneous, on-line equipment together with the know-how that can help you monitor the influent to your waste treatment processes or to monitor effluent streams prior to discharge to sewer.

Our scientists and engineers can help you with your treatment processes and highlight the possibilities for advanced control for improved treatment.

Instruments are available for  you to purchase or lease or you can take advantage of short- or long-term data-supply contracts. For data supply contracts, we own, install, maintain and monitor the equipment at your site. We deliver to you the raw data, with analysis, in a form that suits your needs.