What is the typical water capacity of activated carbon?

What is the typical water capacity of activated carbon?

The water capacity of activated carbon is a critical indicator of its water absorption performance, typically expressed as the percentage of water adsorbed per unit mass (%). According to relevant standards and application scenarios, the general range is as follows:

‌General Standards‌

Wood-based activated carbon usually has a water capacity of no less than 60% (referencing GB/T 12496-2019).

Other types (e.g., coal-based, coconut shell carbon) may vary slightly due to raw materials and processing techniques, generally ranging between 50% and 70%.

‌Testing Method‌

Based on the GB/T 7702.4-2013 standard, the water capacity is determined by fully immersing the activated carbon sample in distilled water until saturation, then calculating the percentage of adsorbed water relative to the sample mass.

‌Influencing Factors‌

‌Pore Structure‌: The development of micropores (<2 nm) and mesopores (2–50 nm) directly affects water capacity.

‌Raw Materials and Processing‌: Coconut shell carbon, with its uniform pores, typically exhibits higher water capacity than coal-based carbon.

‌Storage Conditions‌: High temperature and humidity may lead to premature saturation, reducing effective water capacity.

‌Application Recommendations‌

In water treatment, evaluate activated carbon performance holistically by combining indicators like iodine value and specific surface area.

Regularly replace or regenerate activated carbon to avoid saturation (e.g., replace after treating 50 liters of water).

‌Note‌: Specific water capacity depends on the type of activated carbon, testing standards, and actual water quality conditions. Refer to product technical specifications or third-party test reports for precise data.

ST-62 activated carbon water capacity tester is suitable for measuring the water capacity of coal based granular activated carbon. It is designed and manufactured in accordance with the standard GB/T7702.5 "Test methods for coal based granular activated carbon - Determination of water capacity". The instrument consists of a vacuum pump, pressure gauge, gas regulating device, filtration device, etc., and is widely used in activated carbon laboratories.

The measuring device adopts a pressure gauge and a set of gas regulating devices for each gas path, ensuring that the vacuum degree of each filtration system can maintain the national standard requirements. Can be tested on two samples or simultaneously.