Water and Wastewater Treatment Plant Maintenance
It is of the utmost importance that WTPs and WWTPs are operated efficiently to guarantee the quality of the treated water/effluent according to the specifications determined in the project, complying with current environmental legislation or the required quality standards where they will be used.
Besides an efficient operation, with the processes well controlled and monitored, the condition of the equipment and facilities must be in ideal conditions in terms of their state of preservation and operation.
For this to happen, it is necessary to implement a maintenance management that can guarantee periodic and planned maintenance at the treatment plants, ensuring that all the equipment and installations work satisfactorily and continuously.
Drawing up a maintenance plan é the beginning of the whole management process.
A maintenance plan is understood to be a set of documents in which all the critical preventive maintenance activities are recorded, their frequency of execution, the location of the equipment, the specification of parts to be used, as well as the tools employed and who the professionals are who are trained to carry out the activities..
A good maintenance plan brings countless benefits, among them we can highlight:
- The assurance of operational continuity;
- The reduction of unscheduled downtime;
- The reduction of costs with purchases of urgent materials;
- The reduction in the cost of emergency overtime;
- A greater durability of the equipment and installations;
- The contribution to workforce safety.
Drawing up a Maintenance Plan
It’s not an easy or quick task, as it requires dedication and technical knowledge of maintenance processes.
To be a good preventive maintenance planit is essential that it contains the following information:
- The identification of the equipment (brand, model, manufacturer and other relevant information);
- The location of the equipment;
- The services that will be performed;
- The periodicity of execution;
- The professionals who will perform the activities;
- The resources required (tools, parts, consumables, support materials, among others);
- The time allotted for execution;
- Information about safety: PPEs and EPCs required; NRs applied to the activities, among other specific procedures that may be necessary;
- Environmental information such as the correct disposal of waste generated during maintenance.
For the elaboration of maintenance plans, various software and applications available on the market can be applied. The choice of which tool to use in the elaboration of maintenance plans will depend on the resources available, as well as on the degree of investment the company wishes to make.
Putting the Maintenance Plan into practice
It is not enough just to elaborate a good maintenance plan, it is necessary that it is put into practice in an organized, systemic and controlled way.
A flow chart of the maintenance planning process is shown below:
When it comes to preventive maintenance at water and wastewater treatment plants, some points should be given special attention:
- Flocculators: preserving the physical structure of these tanks is very important to avoid corrosion, cracks and fissures. Special attention should be paid to the agitation blades and propellers, and to the gear systems, which should always be well lubricated.
- Agitators: Its correct functioning is fundamental to the process. Pay attention to the lubrication of the gears, blades, and propellers, and always keep them well aligned, avoiding shaft warping.
- Decanters: They are usually made up of bottom and surface scrapers and can be operated manually or automatically (solenoid valves, automatic valves). Such equipment can suffer greatly from corrosion, and the use of corrosion prevention procedures and products should be widely employed.
- Filters: In a WTP/ETE we can have sand filters, charcoal filters, walnut shell filters, among others. This equipment requires special attention and periodic inspections to ensure proper operation and reliability in the process. The controls and moving parts must be lubricated regularly.
- Dosing pumps: This equipment is essential and very important throughout the treatment process. Its operation must be reliable. Regular maintenance and daily monitoring through a checklist are essential activities.
- Feed/transfer pumps and motors: In the same way that metering pumps need to be guaranteed to work reliably, the other pumps and motors in the unit should be periodically inspected and checked, following the maintenance plan. A daily visual inspection, either by the operator or the maintenance professional, makes a difference and often prevents unexpected downtime of this equipment.
- Sludge drainage equipment: Such as centrifuges, filter presses and dewatering presses. All this equipment requires a lot of attention to lubrication and periodic inspections of its components, in accordance with the information provided in the manufacturer’s manual. Pay attention to noises and noises that are considered abnormal. An intervention as soon as possible can avoid high costs.
- Line analyzers: Among the most commonly used are pH, turbidity, alkalinity, conductivity and ORP. They must be cleaned and calibrated frequently. It requires special attention to the electrical contacts. The manufacturer’s manual should be used to develop the preventive maintenance plan.
Generally speaking, the implementation of maintenance management in water and effluent treatment plants can be the difference and bring numerous benefits, in particular, process stability, cost reduction and an increase in the useful life of the installations.
Seeking to meet the needs of the market, the EP Groupthrough EP Engineeringhas the 360with extremely qualified, dedicated and experienced professionals, offering design and construction services for treatment plants, as well as operation, maintenance and analytical monitoring, ensuring that your treatment plant can provide the best results in terms of efficiency and operating costs.
Article by Odair José Krause
