Patent ID: 12221366

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to facilitate the understanding of the present disclosure, the present disclosure is described in detail below in conjunction with preferred examples, but the protection scope of the present disclosure is not limited to the following specific examples.

Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are merely for the purpose of describing specific examples, and are not intended to limit the protection scope of the present disclosure.

Unless otherwise specified, various reagents and raw materials used in the present disclosure all are commodities that can be purchased from the market or products that can be prepared by a well-known method.

The FeS-based pH-responsive material used in the examples and comparative examples was prepared through the following steps:

1) 8 parts by volume of deionized water and 15 parts by volume of absolute ethanol were taken and thoroughly mixed, and a pH was adjusted to 5.5 to obtain a mixed solution.

Mercaptopropionic acid and nanoscale silica (a molar ratio of the mercaptopropionic acid to the nanoscale silica was 1.2:1, and a molar ratio of the nanoscale silica to a ferrous salt was 1:2) were mixed in the above mixed solution and stirred to allow a full crosslinking reaction to produce sulfhydrylated and carboxylated silica.

2) According to the schematic diagram of the preparation process of the material inFIG.1: The sulfhydrylated and carboxylated silica as a crosslinking agent and CMC as a stabilizing and dispersing agent were added to a three-necked flask filled with a ferrous sulfate solution (0.6 mol/L, a molar ratio of the stabilizing and dispersing agent to ferrous sulfate was 2.0×10−3:1), and stirring was conducted at 35° C. in an oxygen-free environment to allow thorough mixing.

Then, the three-necked flask was equipped with a constant-pressure drop funnel in which a sodium sulfide solution of an equal volume to the ferrous sulfate solution (a molar ratio of Fe2+to S2−was 1.1:1) was placed and a three-way glass piston on which an N2balloon was arranged.

After an experiment began, the sodium sulfide solution was added dropwise to the three-necked flask by unscrewing a switch of the constant-pressure drop funnel, and a full reaction was allowed for 60 min at 30° C. under magnetic stirring in an oxygen-free environment to produce the FeS-based pH-responsive material.

The wastewater treated in the following examples and comparative examples was high-concentration copper-containing wastewater produced in a production process of a printed circuit board of a specified electronics Co., Ltd. in Jiangsu, namely, copper-containing wastewater from micro-etching. A concentration of each metal element in the wastewater was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and specific components were shown in Table 1. A content of the metal element after wastewater treatment was shown in Table 1.

TABLE 1Composition of a stock solution of the copper-containing wastewater from micro-etching of thespecified electronics Co., Ltd. in JiangsuElementCuZnPbFeNiCrContent6276.6514.483.580.320.220.14(mg/L)

Example 1

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 4.20±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

A precipitate produced after the copper-containing wastewater from micro-etching was treated by the FeS-based pH-responsive material in this example was subjected to energy dispersive spectroscopy (EDS). Results showed that there were C, O, Fe, Cu, and S elements in the precipitate, with weight proportions of 12.48%, 2.34%, 0.85%, 57.46%, and 26.87%, respectively.

Example 2

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 5.00±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

Example 3

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 5.80±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

Example 4

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 5.00±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1:1, and a reaction was allowed for 20 min.

Comparative Example 1

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 1.00±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

Comparative Example 2

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 2.00±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

Comparative Example 3

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 3.00±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

Comparative Example 4

An appropriate amount of the copper-containing wastewater from micro-etching was taken and added to a reaction vessel, a pH was adjusted to 7.00±0.05 using a sulfuric acid solution with a volume concentration of 10% and a sodium hydroxide solution with a mass concentration of 20%, the FeS-based pH-responsive material prepared above was added with a molar ratio of S2−in the material to Cu2+in the copper-containing wastewater from micro-etching controlled at 1.2:1, and a reaction was allowed for 20 min.

A solution produced after the treatment in each of Examples 1 to 4 and Comparative Examples 1 to 4 was filtered to obtain a filtrate and a precipitate with CuS as a main component. A concentration of residual Cu2+in the filtrate was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), as shown in Table 2.

TABLE 2Metal element content after the copper-containingwastewater from micro-etching is treated[S2−]:Cu2+(mg/Cu2+recoveryExamplespH[Cu2+]L)rate (%)Example 14.20 ± 0.051.2:1.01.1599.82Example 25.00 ± 0.051.2:1.00.4599.93Example 35.80 ± 0.051.2:1.00.9699.85Example 45.00 ± 0.051.0:1.043.5299.31Comparative1.00 ± 0.051.2:1.0280.2456.21Example 1Comparative2.00 ± 0.051.2:1.0220.0565.62Example 2Comparative3.00 ± 0.051.2:1.093.3685.41Example 3Comparative7.00 ± 0.051.2:1.0157.3675.41Example 4

According to the comparison of data of the examples and comparative examples in Table 2: When the copper-containing wastewater from micro-etching is treated with the FeS-based pH-responsive material of the present disclosure at a pH value of 3.95 to 6.05, a content of copper ions in the treated copper-containing wastewater from micro-etching is low, and a recovery rate of copper ions is 99.8% or more. When a pH of a solution system is too low or too high, a recovery effect of the FeS-based pH-responsive material for copper ions is greatly reduced.