How to optimise chemical dosing in wastewater
Implementing a chemical dosing system for wastewater treatment is a very effective method to control H2S and odours. But, once a system is installed, how do you know whether it is operating efficiently? Are you wasting chemicals? Is your chemical treatment contributing to corrosion issues in the wastewater network?
OdourPro can help you to review and optimise your chemical dosing for wastewater.
How should you review your chemical dosing performance?
Before making any changes to your chemical dosing system, it is vital to evaluate the performance of the system in its current state. Failure to do this leads to a trial and error approach, which could never achieve the highest level of optimisation.
The first step in a review process is to sample and test the wastewater stream itself. This should be coupled with odour measurements around the network in order to benchmark current performance.
Secondly, a review of the network drawings should be conducted. The aim of this review is to re-evaluate dosing points and to check potential for turbulent flow. It is also critical that up to date information on wastewater flow volumes is available for this analysis.
Thirdly, check the odour complaint history of the chemical dosing system. Try to identify patterns in terms of time of day, seasons of the year, peak flow rate etc.
Finally, investigate the maintenance history of the chemical treatment system and the piping network. Are there periods where the dosing system has been offline? What were the reasons for this? Is there a regular pattern of plugged injection points? Check the piping network for signs of corrosion? What is the frequency of corrosion related failures on equipment or piping.
Once the review of the chemical dosing system performance is complete, action can be taken to optimise it.
What can you do to optimise your chemical dosing performance?
The chemical analysis of the wastewater stream along with odour analysis gives an indication of how much room there is to reduce chemical treatment. Changes should be made in a controlled way. Each change in chemical treatment rate should be accompanied by samples and analysis to confirm when the optimum rate is achieved.
Flow paced dosing is the ideal chemical treatment method. Using this approach ensures that the dosing rate is always optimum for the specific wastewater flow at the time. If your current system does not use flow paced dosing, OdourPro can assist you to implement this method immediately.
Move your dosing locations to the optimum points as identified in the review process. In cases where there was a high inefficiency of the existing system, it may even be possible to reduce the number of dosing points through this process.
Once the chemical dosing system is optimised, it is important to continue to monitor its performance and to maintain it regularly.
The importance of monitoring and maintenance
OdourPro uses a sophisticated automation technology for flow paced dosing control. This technology facilitates remote monitoring via telemetry so that supervisors can be constantly informed of wastewater and odour results. Having a system continuously monitored enables supervisors to identify problems before they cause environmental incidents and complaints. Reporting systems generate reports on a scheduled frequency. These reports show chemical usage and system performance to ensure the chemical treatment remains optimum.
Routine servicing and maintenance of chemical dosing systems keeps them online longer and prevents environmental incidents. OdourPro provides monthly services to inspect and adjust the dosing system as required. Our service technicians can typically repair a faulty system on the same day, provided the parts are immediately available.
Central Coast Council recently conducted a network wide review of their chemical dosing system. They were able to relocate dosing points, optimise dosing rates and improve the design standards of dosing facilities through this exercise.
Sydney Water also recently conducted a review of their dosing system performance as documented in this paper. An evaluation of historical and current analysis results enabled the team to make key adjustments to their system. In the end, some chemical dosing units were reduced by up to 50 per cent in terms of dosing rate, while one unit was decommissioned altogether. Sydney Water also invested significantly in online monitoring systems for H2S to achieve and maintain this high level of optimisation.
Contact OdourPro for more information about chemical dosing systems for wastewater
OdourPro has more than 25 years experience in providing solutions for municipal wastewater. We supply magnesium hydroxide, ferrous chloride and calcium nitrate chemical dosing systems for liquid phase treatment. We also supply online monitoring and maintenance services to help keep your system running at optimal conditions.
OdourPro on 21 November 2016
Do your access covers meet Australian Standards? Discover the common signs of non-compliant access covers here ...Read more