1. Quartz sand filtration: The “primary guardian” of water quality pretreatment
Quartz sand filtration is one of the most widely used pretreatment technologies in the field of water treatment. Its core function is to remove suspended impurities from water, laying a solid foundation for subsequent advanced treatment. The filtration principle is based on physical interception and contact flocculation: The quartz sand filter media is strictly graded to form a multi-layer filter bed structure – the upper layer uses quartz sand with larger particle sizes to intercept large suspended particles; the lower layer gradually decreases in particle size to capture fine impurities, forming an efficient filtration system with “coarse on top and fine on the bottom”. When water flows through the filter bed, suspended particles and colloidal substances are adsorbed on the surface of the sand particles or trapped in the pores of the filter layer. At the same time, the biofilm formed on the surface of the sand particles can also assist in decomposing some organic pollutants.
The core advantages of quartz sand filter media lie in its strong stability, low cost, and ease of maintenance. Natural quartz sand boasts high hardness (Mohs hardness level 7), stable chemical properties, and resistance to acid and alkali corrosion, with a service life of up to 3-5 years. The filter bed is easy to backwash; impurities trapped can be stripped away through reverse water flow flushing, restoring filtration capacity. This technology is widely used in waterworks pretreatment, industrial circulating water filtration, swimming pool water treatment, and other scenarios. It can effectively reduce the turbidity of raw water, remove visible impurities such as sediment, rust, and algae, and ensure the water quality meets the inlet requirements for subsequent treatment.
II. Activated carbon filtration: The “adsorption expert” for deep purification
Activated carbon filtration is a deep treatment technology based on adsorption, with the core function of removing trace organic pollutants, odors, color, and some heavy metals from water. It is a key link in enhancing the taste and safety of water quality. Activated carbon has an extremely developed porous structure, with a specific surface area of 1000-1500 square meters per gram, equivalent to the size of a football field. This structure endows it with strong physical and chemical adsorption capabilities: on the one hand, it adsorbs organic matter (such as pesticide residues, humic acid, industrial solvents) and odor molecules (such as chlorine and moldy smells) in water through van der Waals forces; on the other hand, it reacts chemically with heavy metal ions (such as lead, mercury, chromium) through surface functional groups, achieving ion exchange and fixation.
Based on the raw materials and preparation process, commonly used activated carbon filter materials are divided into granular activated carbon (GAC) and powdered activated carbon (PAC): GAC is suitable for filter packing, can be reused after regeneration, and is commonly used in advanced drinking water treatment and purification of wastewater treatment tailwater; PAC needs to be prepared and used immediately, has a fast adsorption rate, and is mostly used for emergency treatment of sudden water pollution incidents (such as algae outbreaks and organic matter leaks). The core advantage of activated carbon filtration lies in its strong adsorption capacity and comprehensive purification effect, which can effectively solve the problem of trace pollutants that quartz sand filtration cannot remove, enabling water quality to achieve “high quality” on the basis of “cleanliness”.
III. Synergistic application of the two: The “golden combination” for water purification
In practical water treatment projects, quartz sand filtration and activated carbon filtration are often used in series, forming a complete system of “pretreatment + advanced treatment” that exerts a purification effect where 1+1>2. The specific process is as follows: raw water first enters the quartz sand filter to remove more than 90% of suspended particles and colloids, reduce water turbidity, prevent subsequent activated carbon filter beds from being clogged, and extend the service life of activated carbon; the pretreated clean water then enters the activated carbon filter to remove residual organic matter, odor, residual chlorine, etc., ultimately producing water that meets drinking or industrial use standards.
The advantages of this combined mode are quite significant: quartz sand filtration “escorts” activated carbon filtration, reducing filter material loss and maintenance costs; activated carbon filtration, on the basis of quartz sand filtration, “strives for excellence”, enhancing water quality safety and taste. This combination is widely used in scenarios such as deep purification of tap water, bottled water production, industrial high-purity water preparation, and pool water circulation treatment, and is currently one of the most mature and reliable water treatment solutions.
IV. Core Difference Comparison: Selecting Adaptive Scenarios as Per Requirements
comparative dimension
quartz sand filtration
Activated carbon filtration
core principle
Physical retention + Contact flocculation
Physical adsorption + Chemical adsorption
Main removal object
Suspended particles, colloids, sediment, and rust
Organic matter, off-flavor, residual chlorine, heavy metals
Filter material characteristics
High hardness, strong stability, and capable of backwashing and regeneration
Highly porous, strong adsorption, requiring regular replacement/regeneration
core function
Pre-treatment to reduce turbidity
Advanced treatment to enhance water purity and taste
Applicable scenarios
Raw water pretreatment, circulating water filtration
Drinking water advanced purification, emergency water treatment, tail water purification
Post time: Jan-15-2026