The phrase "a tertiary step" is correct and usable in written English.
It can be used when discussing a sequence of actions or stages, particularly in processes or methodologies where steps are categorized by their order or importance.
Example: "After completing the primary and secondary steps, we will move on to a tertiary step that involves data analysis."
Alternatives: "a third step" or "a subsequent step".
When treatment standards require the removal of plant nutrients from the sewage, it is often done as a tertiary step.
The children referred to our pediatric neurology clinic, which is a tertiary step medical center in our country, with chronic or recurrent headaches (n = 310) were prospectively evaluated between February 2001 and February 2004.
When a tertiary step was necessary, the plates were washed and incubated for 1 h at 37°C with HRP-conjugated component (antibody or streptavidin).
Further research is needed to investigate the feasibility of adding a tertiary treatment step to increase the nutrients and microorganisms removal from grey water.
Whereas, for example, the Swiss Federal Government started projects introducing a tertiary treatment step at many of its WWTPs, the discussion whether additional wastewater treatment technologies are ecologically worthwhile is still ongoing [9].
This study examines the use of a moving bed biofilm reactor (MBBR) as a tertiary treatment step for ammonia removal in high temperature 35-45°C 35-45°Ceffluents quandifies different phenotypes of ammonia and nitrite oxidizing bacteria responsible for nitrification at elevated temperatures.
These secondary and tertiary steps were performed at room temperature for 30 minutes.
To determine the irritation threshold, n-butanol (Sigma-Aldrich) was diluted into PEG 200 and placed into glass bottles in an 18 tertiary-step dilution.
MIT is also located in the heart of the city, making it extremely convenient to access, and has provided a fantastic experience on my first steps into getting a Tertiary education.
Wetlands can be used as a secondary or tertiary treatment step, following chemical and/or biological treatments, and rely upon natural processes in shallow water or temporarily flooded land that is able to support aquatic life [18].
In Sweden, hospitalization for type 2 diabetes may be a secondary or tertiary referral step; type 2 diabetes is diagnosed in primary care centers, which refer the patients to hospital outpatient clinics or directly to inpatient clinics.
