Tetramethylammonium hydroxide wastewater treatment system

Abstract

The utility model relates to a tetramethylammonium hydroxide wastewater treatment system. The technical problems of large agent dosage, high energy consumption, easy membrane scaling and the like in the traditional treatment technology are mainly solved. The treatment system comprises a pretreatment unit, a forward osmosis unit and a drawn liquid regeneration unit, the pretreatment unit comprises a coarse filter, a forward osmosis raw material tank, a precision filter and a forward osmosis feeding pump which are sequentially connected through pipelines, and the forward osmosis raw material tank is provided with an acid adding pH adjusting pipeline; the draw solution regeneration unit comprises a light draw solution tank, a light draw solution feeding pump, a reverse osmosis membrane, a draw solution tank and a draw solution feeding pump which are sequentially connected through pipelines, the forward osmosis feeding pump is connected with an upper end inlet of the forward osmosis unit through a pipeline, and an upper end outlet of the forward osmosis unit is connected with the light draw solution tank through a pipeline; the light drawn liquid feeding pump is connected with a reflux inlet in the bottom end of the forward osmosis unit through a pipeline, a discharge outlet in the bottom end of the forward osmosis unit discharges forward osmosis concentrated liquid, and a discharge pipeline is arranged at the bottom end of the reverse osmosis membrane.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor industrial wastewater treatment, specifically to a tetramethylammonium hydroxide wastewater treatment system. Background Technology

[0002] TMAH wastewater is tetramethylammonium hydroxide waste liquid, mainly originating from the photolithography and developing processes in the semiconductor, LCD panel, and other electronic manufacturing industries. This wastewater is characterized by high salinity, high organic matter complexity, strong alkalinity, and toxicity. Traditional treatment technologies such as reverse osmosis and evaporation concentration consume large amounts of energy. In reverse osmosis, the membrane is easily affected by high salinity and organic matter, leading to scaling and fouling. Chemical precipitation and ion exchange methods require large amounts of chemical reagents, increasing operating costs. Traditional technologies struggle to achieve efficient treatment of TMAH wastewater with its high salinity, strong alkalinity, and high organic matter complexity. Utility Model Content

[0003] The purpose of this invention is to provide a tetramethylammonium hydroxide wastewater treatment system, which mainly solves the technical problems of traditional treatment technologies, such as large reagent consumption, high energy consumption, and easy membrane scaling. This invention can significantly reduce energy consumption; reduce the use of chemical reagents; and achieve efficient desalination and pollutant retention.

[0004] The technical solution of this utility model is as follows: A tetramethylammonium hydroxide wastewater treatment system, comprising a pretreatment unit, a forward osmosis unit, and a draw solution regeneration unit. The pretreatment unit includes a coarse filter, a forward osmosis feed tank, a precision filter, and a forward osmosis feed pump connected in sequence via pipelines. The forward osmosis feed tank is equipped with an acid addition pipeline for pH adjustment. The forward osmosis unit is a hollow fiber forward osmosis membrane module. The draw solution regeneration unit includes a dilute draw solution tank, a dilute draw solution feed pump, a reverse osmosis membrane, a draw solution tank, and a draw solution feed pump connected in sequence via pipelines. The forward osmosis feed pump is connected to the upper inlet of the forward osmosis unit via a pipeline. The upper outlet of the forward osmosis unit is connected to the dilute draw solution tank via a pipeline. The dilute draw solution feed pump is connected to the bottom reflux port of the forward osmosis unit via a pipeline. The bottom outlet of the forward osmosis unit discharges the forward osmosis concentrate. The bottom of the reverse osmosis membrane is equipped with a discharge pipeline.

[0005] The beneficial effects of this invention are as follows: Low energy consumption: operating pressure ≤0.5 bar, energy consumption is reduced by 50% compared to reverse osmosis. Low reagent dosage: no large amount of chemical reagents are required, reducing operating costs. Long membrane life: the water channel protein membrane is not prone to scaling, extending its life to 18 months. High treatment efficiency: single-pass TMAH removal rate ≥99.5%, concentrate concentration can reach 18.35%. Attached Figure Description

[0006] Figure 1 This is a block diagram of the system structure of this utility model.

[0007] In the diagram: 100 - Pretreatment unit, 101 - Coarse filter, 102 - Forward osmosis feed tank, 103 - Precision filter, 104 - Forward osmosis feed pump; 200 - Forward osmosis unit, 300 - Dried liquid regeneration unit, 301 - Diluted drawn liquid tank, 302 - Diluted drawn liquid feed pump, 303 - Reverse osmosis membrane, 304 - Dried liquid tank, 305 - Dried liquid feed pump. Detailed Implementation

[0008] Reference Figure 1 A semiconductor factory is treating TMAH wastewater. The influent water quality is as follows: TMAH concentration 3.2%, pH 10.4, COD 1450 mg / L. This invention, a tetramethylammonium hydroxide wastewater treatment system, is used. The system comprises three parts: a pretreatment unit 100, a forward osmosis unit 200, and a draw solution regeneration unit 300. The pretreatment unit 100 includes a coarse filter 101, a forward osmosis feed tank 102, a precision filter 103, and a forward osmosis feed pump 104, all connected sequentially by pipelines. The forward osmosis feed tank 102 is equipped with an acid addition pipeline for pH adjustment. The forward osmosis unit 200 uses a hollow fiber forward osmosis membrane module, employing an aquaporin forward osmosis membrane (model: HFFO02) manufactured by AQP AG of Denmark. The membrane module has a hollow fiber membrane structure, an operating pressure ≤0.5 bar, and a temperature of 25±2℃. The wastewater side (TMAH wastewater) and the draw solution side (sodium chloride solution) are separated by a membrane. Water molecules permeate to the draw solution side through the AQP channel, trapping TMAH and contaminants. The draw solution regeneration unit includes a dilute draw solution tank, a dilute draw solution feed pump, a reverse osmosis membrane, a draw solution tank, and a draw solution feed pump connected sequentially by pipelines. The forward osmosis feed pump is connected to the upper inlet of the forward osmosis unit via pipeline, and the upper outlet of the forward osmosis unit is connected to the dilute draw solution tank via pipeline. The dilute draw solution feed pump is connected to the bottom reflux port of the forward osmosis unit via pipeline, and the forward osmosis concentrate is discharged from the bottom outlet of the forward osmosis unit. A discharge pipeline is provided at the bottom of the reverse osmosis membrane. All components not specified in this invention are commercially available parts.

[0009] After system treatment, the concentrate concentration is 18.35%, the effluent TMAH concentration is <0.05%, COD is <50 mg / L; the water recovery rate is 75%, and the energy consumption is 0.6 kWh / m³.

Claims

1. A tetramethylammonium hydroxide wastewater treatment system, characterized in that: The system comprises three parts: a pretreatment unit, a forward osmosis unit, and a draw solution regeneration unit. The pretreatment unit includes a coarse filter, a forward osmosis feed tank, a precision filter, and a forward osmosis feed pump, all connected in sequence via pipelines. The forward osmosis feed tank is equipped with an acid addition pipeline for pH adjustment. The draw solution regeneration unit includes a dilute draw solution tank, a dilute draw solution feed pump, a reverse osmosis membrane, a draw solution tank, and a draw solution feed pump, all connected in sequence via pipelines. The forward osmosis feed pump is connected to the upper inlet of the forward osmosis unit via a pipeline, and the upper outlet of the forward osmosis unit is connected to the dilute draw solution tank via a pipeline. The dilute draw solution feed pump is connected to the bottom reflux port of the forward osmosis unit via a pipeline. The forward osmosis concentrate is discharged from the bottom outlet of the forward osmosis unit, and a discharge pipeline is provided at the bottom of the reverse osmosis membrane.

2. The tetramethylammonium hydroxide wastewater treatment system according to claim 1, characterized in that: The forward osmosis unit is a hollow fiber forward osmosis membrane module.

Images