Method for treating chromium-containing wastewater by using barite adsorbent

Abstract

The invention discloses a method for treating chromium-containing wastewater by using barite adsorbent. The method comprises the following steps of: fusing, crushing and screening a barite mineral material, reacting the barite mineral material by using ferric chloride solution to generate the barite adsorbent for removing chromium ions from sewage containing 50 to 150 mg / L of chromium compound, and shaking the barite adsorbent for 1 hour in a 20 DEG C water bath thermostatic oscillator when the pH is 3 to 4, wherein the removal rate of the chromium ions in the sewage is over 99 percent; and adding a proper amount of barium chloride powder into the barite adsorbent for treating the high chromium content sewage so as to improve the removal rate of the chromium ions. The method has the advantages that: the barite is a most common barium-rich sulfate mineral, the globe surface has rich resources and the cost is low, so the method is convenient for popularization and application; and the barite adsorbent has simple preparation process, convenient operation and high adsorption rate of the chromium ions in the wastewater, can be repeatedly regenerated and recycled, and meets the energy conservation and emission reduction requirements.

Description

technical field

[0001] The invention relates to a method for treating waste water, in particular to a method for treating chromium-containing waste water with a barite adsorbent. Background technique

[0002] With the rapid development of my country's industry, serious environmental pollution problems have come along. Relevant data show that the quality of surface water and groundwater in many rivers, lakes and cities is deteriorating day by day, and people's drinking water sources are threatened by serious pollution. Chromium-containing wastewater is one of the most serious environmental pollution industrial wastewater. Cr6+ is relatively common in the electroplating and leather industries, with a large amount of discharge, high difficulty in treatment, and high treatment costs. Cr6+ is very harmful to human health. Its compounds have a strong oxidation effect and are harmful to the human digestive tract, respiratory tract, skin and mucous membranes. What's more, chromium ...

Examples

preparation example Construction

[0025] Preparation of the adsorbent:

[0026] The preparation method of barite adsorbent is characterized in that it comprises the following steps:

[0027] 1. Put the barite mineral material in an electric blast drying oven and roast at 100-110°C for 3-4 hours, cool to room temperature, grind and sieve through 80-100 mesh to obtain barite powder;

[0028] 2. Mix the above-mentioned barite powder with 0.10-0.20mol / L ferric chloride solution according to the weight ratio of barite powder: ferric chloride solution = 2-3:100, oscillate at a constant temperature of 300 times / min for 20-24 hours and pump Filter, and wash the filter cake with distilled water 2 to 3 times;

[0029] 3. Dry the above-mentioned washed and filtered filter cake in a blast drying oven at a temperature of 140-150°C for 1-2 hours;

[0030] 4. Crush and grind the dried filter cake above, and sieve it with 80-100 meshes to get the barite adsorbent. figure 1 .

Embodiment 1

[0031] Embodiment 1: Screening of different adsorbents

[0032] Take 0.2g different adsorbents such as barite, natural zeolite, sepiolite, bentonite, kaolin, diatomaceous earth, vermiculite powder, and 100ml concentration of potassium chromate solution of 50mg / L (simulating chromium in electroplating wastewater ion concentration) mixed, shaken in a water bath constant temperature oscillator at 20°C for 1 hour, after the reaction, the solution was centrifuged, and the supernatant was put into a small test tube, and analyzed and detected by a Shimadzu AA-6200 atomic spectrophotometer.

[0033] Table 2 Screening of the best adsorbent

[0034] Adsorbent removal rate (%)

[0035] Barite 99.00

[0036] Natural zeolite 83.59

[0037] Meerschaum 85.93

[0038] Bentonite 81.45

[0039] Kaolin 76.06

[0040] Diatomaceous earth 65.91

[0041] Vermiculite powder 71.46

[0042] Experimental results: barite is used to adsorb and treat heavy metal chromium in wastewater, which is bet...

Embodiment 2

[0043] Embodiment 2 Different initial concentration is to the influence test of adsorption:

[0044] Take 0.5g of barite adsorbent and mix it with 100ml of potassium chromate solution (simulating the concentration of chromium ion in electroplating wastewater) with a concentration of 30, 50, 100, 150, 200, 250, 300, 500mg / L respectively, and mix them at 20°C at room temperature , PH value of 3 to 4 conditions in a water bath constant temperature oscillator for 1 hour, after the reaction, the solution is centrifuged, the supernatant is taken into a small test tube, and analyzed by Shimadzu AA-6200 atomic spectrophotometer to detect Cr6+ ions concentration.

[0045] Table 3 Adsorption experiments at different initial concentrations (adsorption of Cr6+)

[0046] Cr6+ initial concentration Cr6+ removal rate

[0047] (mg / L)

[0048] 30 100.00%

[0049] 50 99.02%

[0050] 100 99.02%

[0051] 150 98.29%

[0052] 200 98.25%

[0053] 250 98.13%

[0054] 300 97.63%

[0055] 500...

technical field

[0001] The invention relates to a method for treating waste water, in particular to a method for treating chromium-containing waste water with a barite adsorbent. Background technique

[0002] With the rapid development of my country's industry, serious environmental pollution problems have come along. Relevant data show that the quality of surface water and groundwater in many rivers, lakes and cities is deteriorating day by day, and people's drinking water sources are threatened by serious pollution. Chromium-containing wastewater is one of the most serious environmental pollution industrial wastewater. Cr6+ is relatively common in the electroplating and leather industries, with a large amount of discharge, high difficulty in treatment, and high treatment costs. Cr6+ is very harmful to human health. Its compounds have a strong oxidation effect and are harmful to the human digestive tract, respiratory tract, skin and mucous membranes. What's more, chromium ...

Examples

preparation example Construction

[0025] Preparation of the adsorbent:

[0026] The preparation method of barite adsorbent is characterized in that it comprises the following steps:

[0027] 1. Put the barite mineral material in an electric blast drying oven and roast at 100-110°C for 3-4 hours, cool to room temperature, grind and sieve through 80-100 mesh to obtain barite powder;

[0028] 2. Mix the above-mentioned barite powder with 0.10-0.20mol / L ferric chloride solution according to the weight ratio of barite powder: ferric chloride solution = 2-3:100, oscillate at a constant temperature of 300 times / min for 20-24 hours and pump Filter, and wash the filter cake with distilled water 2 to 3 times;

[0029] 3. Dry the above-mentioned washed and filtered filter cake in a blast drying oven at a temperature of 140-150°C for 1-2 hours;

[0030] 4. Crush and grind the dried filter cake above, and sieve it with 80-100 meshes to get the barite adsorbent. figure 1 .

Embodiment 1

[0031] Embodiment 1: Screening of different adsorbents

[0032] Take 0.2g different adsorbents such as barite, natural zeolite, sepiolite, bentonite, kaolin, diatomaceous earth, vermiculite powder, and 100ml concentration of potassium chromate solution of 50mg / L (simulating chromium in electroplating wastewater ion concentration) mixed, shaken in a water bath constant temperature oscillator at 20°C for 1 hour, after the reaction, the solution was centrifuged, and the supernatant was put into a small test tube, and analyzed and detected by a Shimadzu AA-6200 atomic spectrophotometer.

[0033] Table 2 Screening of the best adsorbent

[0034] Adsorbent removal rate (%)

[0035] Barite 99.00

[0036] Natural zeolite 83.59

[0037] Meerschaum 85.93

[0038] Bentonite 81.45

[0039] Kaolin 76.06

[0040] Diatomaceous earth 65.91

[0041] Vermiculite powder 71.46

[0042] Experimental results: barite is used to adsorb and treat heavy metal chromium in wastewater, which is bet...

Embodiment 2

[0043] Embodiment 2 Different initial concentration is to the influence test of adsorption:

[0044] Take 0.5g of barite adsorbent and mix it with 100ml of potassium chromate solution (simulating the concentration of chromium ion in electroplating wastewater) with a concentration of 30, 50, 100, 150, 200, 250, 300, 500mg / L respectively, and mix them at 20°C at room temperature , PH value of 3 to 4 conditions in a water bath constant temperature oscillator for 1 hour, after the reaction, the solution is centrifuged, the supernatant is taken into a small test tube, and analyzed by Shimadzu AA-6200 atomic spectrophotometer to detect Cr6+ ions concentration.

[0045] Table 3 Adsorption experiments at different initial concentrations (adsorption of Cr6+)

[0046] Cr6+ initial concentration Cr6+ removal rate

[0047] (mg / L)

[0048] 30 100.00%

[0049] 50 99.02%

[0050] 100 99.02%

[0051] 150 98.29%

[0052] 200 98.25%

[0053] 250 98.13%

[0054] 300 97.63%

[0055] 500...

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