Chang'an Electroplating Industrial Base B Area Electroplating Wastewater Treatment Project Case

Project Overview

Zone B of the Chang'an Town Electroplating Base in Dongguan City is located in Xinmin Community in the southeast of Chang'an Town, in the middle of the eastern development axis of the Pearl River Delta. It is adjacent to the Dongbao River (also known as Maozhou River) in the east and faces Nanshan District of Shenzhen across the river, and is adjacent to the Pearl River estuary in the south. Sanrenxing Environment planned and designed the production of industrial wastewater of 8,000 m3/d for Zone B of the Chang'an Electroplating Base, as well as the second phase 4,000 m3/d electroplating wastewater treatment project and reuse project construction and equipment installation.

Source of wastewater characteristics

1. Water quality of raw water:

Cyanide-containing wastewater: PH: 6-12, CODCr ≤ 300, total copper ≤ 300, hexavalent chromium ≤ 0.3, total nickel ≤ 1.5, total cyanide ≤ 250, ammonia nitrogen ≤ 30, conductivity ≤ 3000us/cm.

Chromium-containing wastewater: PH: 2-6, COD Cr ≤ 200, total copper ≤ 35, total nickel ≤ 1.5, hexavalent chromium ≤ 200, total nitrogen ≤ 120, total cyanide ≤ 0.6, conductivity ≤ 3000us/cm.

Nickel-containing wastewater: PH: 2-9, CODCr ≤ 200, total copper ≤ 35, total nickel ≤ 250, hexavalent chromium ≤ 0.3, total cyanide ≤ 0.6, total zinc ≤ 1, total nitrogen ≤ 12, total phosphorus ≤ 20, Conductivity ≤4000us/cm.

Comprehensive wastewater: PH:2～11, COD Cr ≤ 250, total copper ≤ 300, total nickel ≤1.5, total zinc ≤120, ammonia nitrogen ≤35, total phosphorus ≤30, conductivity ≤5000us/cm.

Mixed wastewater: PH:2～11, CODCr≤ 450, total copper ≤400, total nickel ≤50, hexavalent chromium ≤50, total cyanide ≤50, total zinc ≤60, total nitrogen ≤60, total phosphorus ≤40, conductivity ≤5000us/cm.

Pre-treatment wastewater: PH:2～11, CODCr ≤850, total copper ≤50, total nickel ≤1.5, hexavalent chromium ≤0.3, total cyanide ≤0.6, total zinc ≤5 0, total nitrogen ≤30, total phosphorus ≤400, Conductivity ≤4000us/cm.

Designed inlet and outlet water quality

2. Designed outlet water quality:

The workshop outlets of chromium-containing wastewater and nickel-containing wastewater meet the emission standards of the first seven types of pollutants in "Table 3" of the "Electroplating Pollutant Emission Standard" (GB21900-2008); the drainage water quality of the total outlet meets the "Table 3" standard of the "Electroplating Pollutant Emission Standard" (GB21900-2008). According to environmental protection policies, some standards are fine-tuned. The electroplating wastewater treatment in Area B of Changan Electroplating Base is divided into six categories: pre-treatment wastewater, nickel-containing wastewater, cyanide-containing wastewater, chromium-containing wastewater, comprehensive wastewater, and mixed wastewater. The pollutants contained in the wastewater are mainly copper, nickel, zinc, chromium, cyanide and other pollutants.

Wastewater process flow

Design process advantages

1) Wastewater is collected and classified into six categories: chromium-containing wastewater, nickel-containing wastewater, cyanide-containing wastewater, mixed wastewater, comprehensive wastewater and pre-treatment wastewater. Chromium-containing and nickel-containing wastewater meet the standards at the workshop discharge outlet, and other wastewater total discharge outlets meet the standards. The discharge outlets are clearly marked and the pipeline direction is clear.

2) The design has a high reuse rate of recycled water, and the quality of recycled water is close to the requirements of "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB/T 19923-2005).

3) The design of the recycled water reuse project adopts the "sand filtration + bag filtration + reverse osmosis" process to produce recycled water, moderately desalinate, and ensure the water quality requirements, while ensuring the service life of the membrane and reducing operating costs.

4) Concentrated water + pre-treatment water are mixed and treated with the "advanced oxidation + physical and chemical + precipitation + biochemical + secondary sedimentation" process to meet the standard discharge of the relevant emission limits of the "Emission Standards for Electroplating Pollutants" (GB21900-2008). 

5) The entire expansion project is built into a building. The underground floor is equipped with six types of wastewater collection tanks, three types of sludge concentration tanks, emergency tanks and recycled water storage tanks. The ground floor is equipped with a recycled water reuse system, equipment room, electric control room, sludge storage room and chemical warehouse. The ground floor is equipped with six types of wastewater treatment systems. The entire system flows from top to bottom, effectively achieving energy conservation and consumption reduction.

Project pictures

Dongguan Environmental Protection Company Dongguan Sanrenxing Environmental Technology Co., Ltd. is an environmental protection management enterprise integrating design, construction and operation. It has a mature wastewater treatment R&D team, wastewater analysis and laboratory testing team, wastewater treatment operation team, and engineering implementation and maintenance team to ensure that customers are provided with fast and accurate services. The main service directions are: industrial wastewater treatment, sewage station operation, evaporation and concentration equipment customization, etc. It is good at anodizing wastewater treatment and is familiar with a variety of wastewater treatment R&D and production processes. It controls the emission of pollution sources from the source and reduces the amount of sludge, which is more conducive to meeting emission standards and saving operating costs.