For many companies wastewater is an annoying by-product of their process and needs to be dealt with in order to comply with local discharge requirements to prevent heavy fines and damage to the environment. In a lot of cases there has been a system in place that has existed from day one but unfortunately more often than not it is not fit for purpose. Ultimately the system may require complete replacement. And with that comes a series of tough considerations.
How do you select the right wastewater treatment system?
The answer to this question can depend on a variety of things so let’s try and break this down.
When looking at the design of a Wastewater Treatment Plant (WWTP) the most important things to consider are as follows:
1. Purpose and Goal
Generally the main goal in the design of a WWTP process is to minimise the volume and toxicity and the final treatment residue, since final disposal can incur significant cost and liability. If you understand the purpose and goal of the project before selecting the preferred wastewater treatment technology and provider, it will make your life a lot easier in the long run.
2. Consider a Treatability Study
Treatability studies are an important part of the remedy selection process both in upgrades and new plants. They are small scale, cost-effective tests, typically performed in a laboratory that can give valuable insight into how proposed solutions will perform in the field. They take into account site-specific conditions by using wastewater from the field and can be used to compare potential technologies and determine the most appropriate solution.
3. Candidate Technologies
Selecting the right technology can be difficult especially when this is not your field of expertise or you are totally reliant on the Original Equipment Manufacturer (OEM). If you have conducted a treatability study your life will be a lot easier but if you haven’t, all is not lost, as the OEMs should have sufficient expertise to offer a suitable solution for your application. When selecting candidate technologies you should consider the following as a minimum.
The main criteria in more than 90% of all cases is the technology that will give the lowest Capex and still fulfils the demanded effluent criteria. However it’s worth remembering when you pay too much, you might lose a little money. When you pay too little, you might lose everything, because the thing you bought was incapable of doing the thing it was bought to do.
How often have you heard the line “I never would have bought the plant if I knew I would be spending this much money on chemicals and having to employ an operator full time to run it”. The above statement highlights how important it is to understand the Opex and maintenance costs from the beginning as a lot of the time it helps to spend a bit more money up front to reduce the ongoing costs.
If you were buying a car and you had to choose between a Toyota and an unknown brand that was 30% cheaper what would you buy? Could we assume in saying that most people would go for the Toyota? WWTP’s suppliers are no different, so be sure to ask for reference sites of the candidate technology being offered as this will give you peace of mind that the company you are dealing with has the quality to produce a plant that meets your expectations.
Potential Use of the Treated Water
Recycling water has many benefits but the most obvious one is that it saves potable water which means that you have the potential to save on costs both procuring potable water and disposing of the treated water. In selecting a new WWTP it would be wise to consider this as an option.
Local Service and Support
Who fixes it when it breaks, and where are they located? This is important: When it breaks it is going to need to be fixed. Local service for key equipment is a must.
As you can see it takes a lot of time and effort to properly select a WWTP. If you focus on the key aspects listed above, it will enable you to ask the right questions of your OEM’s, which will ultimately give you the best chance of selecting the best WWTP for your application.
At MAK Water, we are dedicated to helping industrial operations with their water, wastewater and sewage requirements, via the provision of high performing water treatment plants and systems. We have developed a reputation for delivering superior service and solutions, and for enabling our clients to reduce operating costs and extend equipment operating life.
Brendan Doherty, MAK Water Operations Manager WA