Unlock instant, AI-driven research and patent intelligence for your innovation.

Application of Photocatalytic Removal of Heavy Metal Chromium in High Salt Wastewater in Open Wetland

A high-salt wastewater and photocatalytic technology, applied in the field of water treatment, can solve the problems of low removal rate of heavy metal ions, high operating costs and construction costs, secondary pollution of recycled wastewater, etc. effect of dosage

Active Publication Date: 2020-03-17
SHANGHAI INST OF TECH
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Sewage treatment plants can remove salt and heavy metals in sewage to meet discharge standards, but this treatment method has high operating and construction costs and is likely to cause secondary pollution of recycled wastewater, which does not meet the requirements of modern social ecological concepts; Wetland treatment, the amount of heavy metal ions removed is limited, the removal rate of heavy metal ions is not high, and the removal time is long, generally takes a quarter or more, and the overall efficiency is low

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Application of Photocatalytic Removal of Heavy Metal Chromium in High Salt Wastewater in Open Wetland

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] (1) Construction of treatment pool 1: Excavate a treatment pool 1 near the polluted water source, with a depth of 0.5m, a length of 12m, and a width of 6m. Considering the terrain, the slope of the bottom surface is 0. The surface area of ​​treatment pool 1 is 436.8m2. Estimated calculation formula for surface area: As=(Q×(lnCo-lnCe)) / (Kt×d×n) (m 2 ), the Q inflow flow rate is 126 (m 3 / d), Co is the influent BOD of 200 (mg / l), Ce is the effluent BOD of 20 (mg / l), Kt is the rate constant related to temperature, Kt=1.014×(1.06) （T-20） , T is 26. d is 60cm for the depth of the matrix bed, n is 10% for the porosity of the matrix, and a water outlet hole with an aperture of 30cm is set at the bottom of the treatment pool 1 end;

[0028] (2) Layout of the water inlet and outlet system: the water inlet pipe 2 should be 0.3m higher than the treatment tank 1, and the water inlet pipe 2 generally adopts a porous water inlet pipe; the water outlet system is generally based on ...

Embodiment 2

[0035] (1) Construction of treatment pool 1: Excavate a treatment pool 1 near the polluted water source, with a depth of 0.8m, a length of 8m, and a width of 4m. Considering the terrain, the bottom slope will drop by 0.5%. The surface area of ​​treatment pool 1 is 228.8m 2 . The estimated calculation formula of surface area: As=(Q×(lnCo-lnCe)) / (Kt×d×n)(m 2 ), the Q influent flow rate is 56.1 (m 3 / d), Co influent BOD is 250 (mg / l), Ce effluent BOD is 25 (mg / l), Kt is the rate constant related to temperature, Kt=1.014×(1.06) （T-20） , T is 25. d is the depth of the matrix bed, which is 120cm in this example, and n is the porosity of the matrix, which is set from 25% in this example. Set a water outlet hole with a diameter of 50cm at the bottom of the treatment tank;

[0036] (2) Layout of the water inlet and outlet system: the water inlet pipe 2 should be 0.4m higher than the treatment tank 1, and the water inlet pipe 2 generally adopts a porous water inlet pipe; The botto...

Embodiment 3

[0043] (1) Construction of treatment pool 1: Excavate a treatment pool close to the polluted water source, with a depth of 1m, a length of 10m, and a width of 5m. Considering the terrain, the bottom slope will drop by 1%. The surface area of ​​treatment pool 1 is 328.4m2. The estimated calculation formula of surface area: As=(Q×(lnCo-lnCe)) / (Kt×d×n)(m 2 ), the Q influent flow rate is 87.7 (m 3 / d), Co influent BOD is 300 (mg / l), Ce effluent BOD is 20 (mg / l), Kt is the rate constant related to temperature, Kt=1.014×(1.06) （T-20） , T is 27. d is the depth of the matrix bed, which is 200cm in this example, and n is the porosity of the matrix, which is set from 40% in this example. Set a water outlet hole with a diameter of 50cm at the bottom of the treatment tank;

[0044] (2) Layout of the water inlet and outlet system: the water inlet pipe 2 should be 0.5m higher than the treatment tank 1, and the water inlet pipe 2 generally adopts a multi-hole water inlet pipe; The botto...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
pore sizeaaaaaaaaaa
particle diameteraaaaaaaaaa
heightaaaaaaaaaa
Login to View More

Abstract

The invention discloses a technology and application for removing heavy metal chromium from high salinity wastewater in an outdoor wetland by a photocatalysis method. The technology comprises the following steps: (1) building a treatment pond of which the depth is 0.5-1 m, a proportion of length to width is equal to 2:1, and a gradient is 0%-1%, and installing a water outlet hole at the bottom ofthe tail end of the treatment pond; (2) installing a water inlet pipe on a place which is 0.3-0.5 m higher than the treatment pond, and installing a water outlet pipe, which is communicated with the water outlet hole, at the bottom of the tail end of a water outlet area; (3) forming a treatment pond substrate by two layers, wherein the bottom layer is filled with building gravels, and the upper layer is filled with carbonate stones; (4) grinding iron-ore slags to be powder-like by using a grinding machine and uniformly scattering above the treatment pond substrate layer, and adding the iron-ore slags according to a weight ratio of Cr(VI) to iron-ore slags in inlet water quality which is equal to 1:1-2; (5) adding hydrogen peroxide according to a weight ratio of iron-ore slags to hydrogen peroxide which is equal to 1:1.5-3; and (6) after finishing the above steps, injecting 2-5 mg / l of chromium-contained sewage from the water inlet pipe, to obtain a water inlet flow rate according to Q=F / K, to obtain hydraulic retention time according to Q=Fqt / 0.365, and HRT=V / Q(h), and purifying the Cr(VI) after the sewage is flowed out from the water outlet hole.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to an application of a photocatalytic method for removing heavy metal chromium in high-salt wastewater in open-air wetlands. Background technique [0002] High-salt chromium-containing wastewater mainly comes from industrial wastewater, such as printing and dyeing wastewater, electroplating wastewater, iron and steel metallurgical wastewater, tannery wastewater, and a large amount of wastewater generated in chemical production. This type of wastewater has the characteristics of large water volume, large fluctuations in water quality and water volume, high pollution load, high alkalinity, high chroma, high content of suspended solids, and good biodegradability. Moreover, hexavalent chromium in sewage is highly toxic and carcinogenic, and is easy to migrate in the environment. Reducing hexavalent chromium to low-toxic trivalent chromium is a key step in the treatme...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C02F1/72C02F1/30B01J23/745B01J35/00B01J37/00C02F101/22
CPCB01J23/745B01J35/004B01J37/0036C02F1/30C02F1/722C02F1/725C02F2101/22
Inventor 李丹丹韩建秋
Owner SHANGHAI INST OF TECH