Plant type biochar adsorbing heavy metal Cd in water body and preparation method and application of biochar

Abstract

The invention discloses a plant type biochar adsorbing heavy metal Cd in a water body and a preparation method and application of the biochar, and belongs to the field of plant type biochar preparation. The method comprises the steps that weed plant-radix phytolaccae serves as a raw material, fresh plants are subjected to crushing, drying, soil burying and compacting, high-temperature carbonizing,cooling and drying, impurity removing, grinding and sieving, and the plant type biochar is obtained. The biochar carbonization rate is high and can reach 36.70%. It has good adsorption effect on heavy metal Cd, and the adsorption rate can reach 90.16%. In addition, solid-liquid separation is conducted with waste water obtained after treatment. Raw materials are low in price and easy to obtain, and the weed plants without economic value are recycled, and an efficient, clean and inexpensive method is provided for removing heavy metal Cd-contaminated water body.

Description

technical field

[0001] The invention relates to a plant-type biochar capable of efficiently adsorbing heavy metal Cd in water bodies, a preparation method and application thereof, and belongs to the field of plant-type biochar preparation. Background technique

[0002] Throughout the ages, there are many types of biochar, which can be mainly divided into two categories, namely plant charcoal and animal charcoal. Vegetable charcoal such as charcoal, straw carbon, shell charcoal; animal charcoal such as animal bone charcoal, animal manure charcoal. Elements such as carbon, hydrogen, and oxygen constitute the main part of biochar, among which carbon element accounts for 70-80%. Heavy metals in water can be removed by physical and chemical methods. However, chemical methods often add some unnecessary chemical elements to the water body. Physical adsorption can adsorb impurities with small particle sizes in water, and the method is simpler and more environmentally friendly. T...

Examples

Embodiment 1

[0025] This embodiment provides a pokeweed plant type biochar

[0026] (1) preparation method comprises the steps:

[0027] 1. Taking materials: Take 20 fresh pokeweed stems (fresh weight 576.43g), 20 pokeweed roots (fresh weight 79.34g), 20 pokeweed stems (fresh weight 286.83g) and 20 pokeweed stems with leaves removed. Whole pokeweed (that is, only the leaves of pokeweed are removed, and three parts of the stem and root are kept) (fresh weight 1061.21g).

[0028] 2. Crush: Cut these plants into pieces about 3 cm long, and put them into different crucibles.

[0029] 3. Drying: Place in an oven at 70°C for 15 hours.

[0030] 4. Soil burial and compaction: Dry the soil at 70°C for 20 hours, pass through an 80-mesh sieve, and set aside. The purpose of the soil is only to insulate the air, so it is not limited to the source of the soil. The pots containing the dried pokeweed stems, stalks, roots, and whole pokeweed with leaves removed were filled with soil, and the plants wer...

Embodiment 2

[0038] Example 2 Application of plant-type biochar in the adsorption of heavy metal Cd in water

[0039] Method: Take 28 centrifuge tubes with a capacity of 50mL and divide them into seven groups. Each group takes 0.3 g of pokeweed stalk biochar, pokeweed root biochar, pokeweed stem biochar and leaf-removed whole pokeweed biochar prepared in Example 1 and adds them into different centrifuge tubes respectively, and then adds 20 mL of pokeweed at a concentration of 10.27mg / L of CdCl 2 solution, put it on the shaker (250r / min, 25°C), and start timing. Take out a group from the shaker at 5min, 20min, 60min, 90min, 120min, 180min, and 240min, respectively, and put the centrifuge tube in a centrifuge (5000r / min) for 10min to make the biochar precipitate at the bottom of the centrifuge tube . Filter the supernatant through a filter paper with a pore size of 0.45 μm, filter it into a labeled volumetric flask to measure the absorbance, convert the concentration according to the stan...

Embodiment 3

[0043] Influence of dosage of plant-type biochar and solution pH on adsorption effect

[0044] (1) Effect of the amount of plant-based biochar on the adsorption effect

technical field

[0001] The invention relates to a plant-type biochar capable of efficiently adsorbing heavy metal Cd in water bodies, a preparation method and application thereof, and belongs to the field of plant-type biochar preparation. Background technique

[0002] Throughout the ages, there are many types of biochar, which can be mainly divided into two categories, namely plant charcoal and animal charcoal. Vegetable charcoal such as charcoal, straw carbon, shell charcoal; animal charcoal such as animal bone charcoal, animal manure charcoal. Elements such as carbon, hydrogen, and oxygen constitute the main part of biochar, among which carbon element accounts for 70-80%. Heavy metals in water can be removed by physical and chemical methods. However, chemical methods often add some unnecessary chemical elements to the water body. Physical adsorption can adsorb impurities with small particle sizes in water, and the method is simpler and more environmentally friendly. T...

Examples

Embodiment 1

[0025] This embodiment provides a pokeweed plant type biochar

[0026] (1) preparation method comprises the steps:

[0027] 1. Taking materials: Take 20 fresh pokeweed stems (fresh weight 576.43g), 20 pokeweed roots (fresh weight 79.34g), 20 pokeweed stems (fresh weight 286.83g) and 20 pokeweed stems with leaves removed. Whole pokeweed (that is, only the leaves of pokeweed are removed, and three parts of the stem and root are kept) (fresh weight 1061.21g).

[0028] 2. Crush: Cut these plants into pieces about 3 cm long, and put them into different crucibles.

[0029] 3. Drying: Place in an oven at 70°C for 15 hours.

[0030] 4. Soil burial and compaction: Dry the soil at 70°C for 20 hours, pass through an 80-mesh sieve, and set aside. The purpose of the soil is only to insulate the air, so it is not limited to the source of the soil. The pots containing the dried pokeweed stems, stalks, roots, and whole pokeweed with leaves removed were filled with soil, and the plants wer...

Embodiment 2

[0038] Example 2 Application of plant-type biochar in the adsorption of heavy metal Cd in water

[0039] Method: Take 28 centrifuge tubes with a capacity of 50mL and divide them into seven groups. Each group takes 0.3 g of pokeweed stalk biochar, pokeweed root biochar, pokeweed stem biochar and leaf-removed whole pokeweed biochar prepared in Example 1 and adds them into different centrifuge tubes respectively, and then adds 20 mL of pokeweed at a concentration of 10.27mg / L of CdCl 2 solution, put it on the shaker (250r / min, 25°C), and start timing. Take out a group from the shaker at 5min, 20min, 60min, 90min, 120min, 180min, and 240min, respectively, and put the centrifuge tube in a centrifuge (5000r / min) for 10min to make the biochar precipitate at the bottom of the centrifuge tube . Filter the supernatant through a filter paper with a pore size of 0.45 μm, filter it into a labeled volumetric flask to measure the absorbance, convert the concentration according to the stan...

Embodiment 3

[0043] Influence of dosage of plant-type biochar and solution pH on adsorption effect

[0044] (1) Effect of the amount of plant-based biochar on the adsorption effect

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