Optimization Of Activated Carbon Adsorption For Dyeing Wastewater Treatment

Carbon was obtained from 0.5g at different carbonization temperatures in 100mL grinding cone bottle, and 100mL was added.

Oscillate 30min on the oscillator at 120r/min and 25 C, and measure its absorbance value by filtration.

The carbonization temperature rises from 400 to 800, and the decolorization rate increases gradually. The reason is that in the carbonization process, the cellulose and lignin in the peanut shell decompose, produce dehydration and deacidification, and form a combination of aromatic nuclei, then dehydrogenation, a large number of aromatic nuclei combine directly, form a two dimensional plane structure and form a three-dimensional structure, forming a developed pore, so that the carbon after carbonized peanut shell has adsorbability.

When the carbonization temperature continues to rise to 900 degrees, the decolorization rate decreases. The reason is that the high temperature makes the cellulose carbonized nodules in the peanut shells impede the formation of pores.

The carbonization temperature is selected at 800 C.

When the carbonization time was extended from 30min to 150min, the decolorization rate of printing and dyeing wastewater increased gradually. When 150min exceeded 150min, the decolorization rate decreased with the increase of carbonization time, and the decolorization rate reached the maximum. At this time, most of the non carbon components and carbon and water compounds in peanut shells had been removed, forming a certain number of pore structure.

Therefore, the carbonization time is 150min..

The decolorization rate of peanut shell carbon after carbonization can be seen that the decolorization rate of peanut shell carbon without any treatment is very low, because the peanut shell carbon has not formed a well-developed pore structure, and some pores are blocked.

In order to improve the adsorption capacity of peanut shell carbon, it must be activated.

The dilution ratio, activation temperature, activation time and solid-liquid ratio of activator (H2SO4) are the main factors that affect the carbon activation of peanut shells.

In this paper, orthogonal experiment L9 (34) is used to optimize the conditions.

The 4 factors affecting the adsorption capacity of peanut shell activated carbon were: activation dilution ratio > activation time > temperature > solid / liquid ratio.

It can be seen from the results that the best condition is: A3B2C1D2.

In 100mL printing and dyeing wastewater, activated carbon 0.2g was added, oscillating at 120r/min and 25 C, and the influence of pH on the decolorization rate of printing and dyeing wastewater was observed at 120r/min.

When pH value is 1~5, printing and dyeing wastewater

The change is not great. Considering the cost of treatment, it is more reasonable to select the pH of printing and dyeing wastewater. Therefore, choose pH value of 5. in 100mL printing and dyeing wastewater, add activated carbon 0.2g, adjust the pH value of 5, the temperature is 25 degrees, oscillate 30min at different rates on the oscillator, and the effect of the oscillation speed on the decolorization rate of printing and dyeing wastewater.

With the increase of the oscillation rate, the decolorization rate increases gradually, and reaches the maximum value at 160r/min and then decreases gradually. The reason is that the oscillating rate is too large and the colored matter will be resolved. Therefore, the selection rate of oscillation is 160r/min.

The amount of activated carbon.

Take 6 printing and dyeing wastewater, each 100mL, add different amount of peanut shell activated carbon, adjust the pH value is 5, the temperature is 25 degrees, in the oscillator 160r/min oscillate adsorption 120min, the amount of activated carbon on the decolorization rate of wastewater is shown in Figure 6.

The amount of activated carbon from peanut hull has great influence on the decolorization rate of printing and dyeing wastewater.

With the increase of the amount of activated carbon in the peanut hull, the decolorization rate also increased. However, the effect of the dosage of 1.5g on the decolorization rate was not obvious. When the dosage of peanut shell activated carbon was 1.5g, the adsorption basically reached the saturation state, that is, the amount of activated carbon in peanut shell was 15g/L (1.5g/100mL), and the decolorization rate of printing and dyeing wastewater was 96.7%..

The optimum technological conditions for the preparation of activated carbon from peanut shells by sulfuric acid activation method are: carbonization temperature is 800 C, carbonization time is 150min, the dilution ratio of activator sulfuric acid is 1: 1, solid-liquid ratio is 1: 2, activation time is 90min, activation temperature is 60 C.

The adsorption effect is better for printing and dyeing wastewater.

The optimum conditions for the treatment of printing and dyeing wastewater by peanut shell activated carbon are: the dosage of adsorbent is 15g/L, the adsorption time is 120min, the oscillation rate is 160r/min, the pH value of the wastewater is 5, the temperature is 25 degrees, the decolorization rate of the printing and dyeing wastewater is 96.7%., the activated carbon is made from solid waste peanut shell, the resource utilization of peanut shell is realized, and a new way for preparing the raw material source of activated carbon is achieved, so as to achieve the goal of "treating waste with waste and recycling economy".