Method for treating domestic wastewater with combined laminated vertical flow-horizontal subsurface flow wetland

Abstract

The invention relates to the technical field relevant to wastewater treatment, in particular to a method for treating domestic wastewater with a combined laminated vertical flow-horizontal subsurface flow wetland, which is composed of two parts, namely a laminated vertical flow wetland and a horizontal subsurface flow wetland. The laminated vertical flow wetland and the horizontal subsurface flow wetland are sequentially connected in series to form a compact combined wetland system. The laminated vertical flow wetland comprises a plurality of layers of filter bed modules filled with matrixes of different particle sizes. Wastewater is sprinkled down from the top of the laminated vertical flow wetland and stepwise enters each layer of filter bed module from top to bottom to be treated; and after the wastewater reaches the bottommost layer of the laminated vertical flow wetland, the wastewater passes through a perforated wall arranged at the bottom of the laminated vertical flow wetland and enters the later-level horizontal subsurface flow wetland to be further purified, and finally water flows out from the upper end of the horizontal subsurface flow wetland. According to the method, the ventilation re-oxygenation effect is strengthened, the pollutant treatment capacity of the combined wetland is increased, meanwhile the occupied area is reduced, and blocking is effectively prevented.

Description

technical field [0001] The invention relates to the related technical field of sewage treatment, in particular to a method for treating domestic sewage in a stacked vertical flow-horizontal subsurface flow combined wetland. Background technique [0002] Constructed wetland is a sewage treatment technology developed after the 1950s, and has been extensively studied all over the world since the 1970s. Compared with the traditional sewage treatment technology, due to its strong adaptability to pollution load changes, low engineering infrastructure and operating costs, effective treatment of pollutants, simple operation and maintenance management, and good landscape effects, artificial Wetland wastewater treatment technology is widely used around the world. Especially after the 1990s, in order to obtain better purification effects and higher standards for effluent nitrogen, various composite constructed wetland systems emerged. The common composite wetlands mainly include: vert...

AI Technical Summary

Problems solved by technology

[0005] ① Reoxygenation capacity is still limited

Constructed wetlands mainly rely on natural reoxygenation and the oxidation mechanism of wetland plant rhizosphere, and the oxidation capacity is limited

Vertical flow wetlands have a better reoxygenation effect than horizontal subsurface flow wetlands, and can achieve ideal purification effects when the pollution load is low, but when the pollution load is high, it is difficult for these oxygen to fully degrade organic matter and convert ammonia nitrogen It is easy to cause problems such as odor in the effluent, high concentration of organic matter and ammonia nitrogen

In addition, the lack of oxygen supply in vertical flow wetlands cannot produce a large amount of nitrate nitrogen as a substrate for denitrification, resulting in the unsmooth nitrification-denitrification pathway in the composite wetland system, which limits the removal of total nitrogen.

[0006] ②Easy to block

[0008] ④Larger floor area

Traditional vertical flow-horizontal subsurface flow composite wetlands can bear relatively low hydraulic and pollution loads, and the large footprint is the main limiting factor for the widespread application of this technology

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