Non-point pollution reduction facilities

Introduction of non-point pollution reduction facilities

Instructions and drawings that contain the reduction principle, structure, and specifications of non-point pollution reduction facilities

A. Definition of the non-point pollution source

Non-point pollution source refers to an emission source that discharges unspecified sewage pollutants from unspecified places such as urban area, roads, farmland, mountainous areas, and construction sites. <Article 2(2) of Environmental Law>

B. Types of pollutants

Soil, nutrients, bacteria and viruses, oil and grease, metals (lead, zinc, cadmium, copper, nickel, etc.), organic matter, herbicides, pesticides and fungicides and other impurities

C. Explanation for the reduction principle of non-point pollutant

1) The principle that non-point pollution reduction facilities reduce non-point pollutants, schematic diagram and flow chart of facilities

2) Differentiated technical features from other non-point pollution reduction facilities

Our system provides an excellent efficiency by using high density (HDPE) granulous filter media.

Our filter is a high-density (HDPE) filter media to provide excellent SS adsorption efficiency. Most of facilities use “Geotex non-woven processed fiber” or “fiber ball”, which are excellent fiber materials for removing suspended solids (SS), but fibrous filter media has more disadvantages than advantages.
Fibrous filter media is excellent for temporary removal of suspended solids, but long-term frequent floating debris makes backwashing difficult. There are many problems for maintenance with frequent replacing the filter media due to deformation of the filter media since the floating material residues cause blockage of the filter media by mold, insects, etc, in the underground manhole.
High-density (HDPE) granular filter media, instead of fibrous media, has excellent backwashing and treatment efficiency by using highly efficient media. (SS treatment efficiency over 90% – see Attachment 1)

Good backwashing effect

Our high-density (HDPE) granulous filter media is shaped like a small cylinder with a specific gravity of 0.88, which is lighter than water. As the sludge is adsorbed to the granulous filter media, it becomes heavier than water and sinks to the lower part of the filter layer. It provides good backwashing effect because high-pressure air is intensively injected into the lower part where the contaminated filter media are gathered.

Our facilities are economical

Because high-density (HDPE) backwashable granulous filter media is used, the filter can be used semi-permanently only by backwashing. There is no filter abrasion, and the backwashing efficiency is excellent.

No need to replace the filter media unless otherwise special deformation material enters the rainwater.

D. Structure and characteristics of non-point pollution reduction facilities

1) The principle that the non-point pollution reduction facility reduce pollution including the overall structure of the facility and the characteristics of the detailed structure inside the facility

Pre-treatment tank

Sediment with a large specific gravity settles due to gravity, and the rising rainwater is transferred to the bottom of the filtration tank along the inlet pipe.

• Pre-treatment tank drainage pump: Drains stagnant water in the pre-treatment tank after the end of rain

Filtration tank

The bottom and high-density (HDPE) granulous filter media are separated by a perforated net to remove contaminants of the influent.

Drainage pump of filtration tank: Drains contaminated backwash water
High-density PE granulous filter media layer: Filled with high-density PE granulous filter media (h=1000mm) by 70%

Treated water tank

Stores the treated water for backwash water feed

• Backwash water feed pump: Transfers the backwash water to the filtration tank

Backwashing facilities

High pressure AIR inlet and AIR piping in the PE granulous filter media layer
Ring blower: located on the ground and generates and supplies high-pressure air.

Control panel

Supplies electricity to each facility and controls operation

E. Economy

The filter provides a high-density (HDPE) granulous filter media with good efficiency and can be used semi-permanently (10 years)
Has longer service life and superior backwashing compared to fiber filters
There is no deformation unless otherwise heat is applied, and no need to change the filter media.

F. Convenience of maintenance

ECOVISION21 (ECO-TYPE) filter material is designed for easy maintenance due to high-density (HDPE) and fluid formed in a round shape
The filter is connected to the air line and can be backwashed, so it can be used semi-permanently after washing for about 5 minutes.
Settling tank and filtration tank are easy to dredge sediment through vacuum suction (the operator does not need to enter the tank)
The facility is designed to transfer the stagnant water to a sewage pipe or wastewater storage tank through a pump.

Filter applied

Item	Unit	Material property
Material
Effective particle size	mm	1.151
Uniformity coefficient		3.3
Specific gravity	kg/㎥	881
Special coefficient	m/sec	0.02
Tensile strength	kgf/㎠	20 ~ 25
Elongation	%	400
Melting mass flow index	g/10min	0.7 ~ 1.0
Service life		Semi-permanent, no need to replace
Crishing resistance	N/㎟	1.7
Voids	%	34.3
Replacement cycle	The filter can be used semi-permanently because it can be washed and reused unless otherwise there is deformation by external pressure such as chemicals or heat.
Characteristics	The filter made of HDPE material processed in a pellet shape is filled in the media chamber. When the influent passes through the media chamber, it moves fluidly according to the level of the influent by the principles of gravity and buoyancy and reduces non-point pollution sources by precipitating and adsorbing fine solids and adsorbing oil components. The filter is hardly deformed, so it is reused after washing. In order to guarantee the activity of the granulous filter media during backwashing, the filling rate of the filter in the chamber is set to 70%.