What is BS EN 14701‑4 about?
BS EN 14701 is the fourth part of an international multi-series standard that discusses the characterization of sludges for filtration properties.
BS EN 14701‑4 specifies a method for the determination of drainability of flocculated sludge. It provides a method that is also applicable to sludge suspensions from:
- Stormwater handling
- Urban wastewater collecting systems
- Urban wastewater treatment plants
- Plants treating industrial wastewater similar to urban wastewater
- Water supply treatment plants
Note: BS EN 14701‑4 gives a method that is also applicable to sludge suspensions from other origins.
Who is BS EN 14701‑4 for?
BS EN 14701‑4 on drainability of flocculated sludge is useful for entities dealing with:
- Authorities handling stormwater
- Entities dealing with urban wastewater collecting system
- Wastewater treatment plants
- Industrial wastewater treatment plants
- Water supply treatment plants
Why should you use BS EN 14701‑4?
The determination of drainability of flocculated sludge is an important parameter for evaluating their ability to be thickened using a draining process.
BS EN 14701‑4 gives you indications for the choice of flocculant or their dosage for drainability, in the view of thickening of the sludge through a filtering medium. It provides you with easy and quick tests, that are the best means to narrow the number of products to be tested in full-scale experiments and to adapt the pre-treatment to the sludge variability.
BS EN 14701‑4 sets an approach for the measurement results obtained that are the mass of filtrate collected in a standard time or the time required to recover a given volume of filtrate (commonly 50 % of the water content of the sludge). It also provides you with an outlook for the maximum volume of filtrate, the corresponding wet and dry mass of the sludge, the undissolved solids remaining in the filtrate as well as about the best flocculant, and its optimum dose in the case of comparative tests.
What’s changed since the last update?
BS EN 14701‑4:2018 supersedes EN 14701-4:2010, which is withdrawn. The main changes compared to the previous version are as follows:
- Calculation of the drainability index was added
- Annex D ‘use of drainability index’ added
- Editorially revised