Study on Degradation of Foamed Plastic Meal Cartridges (3)

Soil burying experiment:
The first stage: 2004.8.9~2004.9.6
A white, non-degradable plastic lunch box No. 4 to No. 6 (SL-1B) was embedded in the dry, plant-free soil layer;
White non-degradable plastic lunch boxes 7~9 (SL-1B) are embedded in the fertile soil of the trees;
(Table 1) Quality: Grams (g)
Date Number 4(g) 5(g) 6(g) 7(g) 8(g) 9(g)
8.9 0.166 0.158 0.175 0.168 0.163 0.173
8.16 0.166 0.158 0.177 0.168 0.163 0.173
8.23 0.166 0.155 0.18 0.169 0.164 0.174
8.30 0.165 0.156 0.175 0.168 0.164 0.173
9.6 0.165 0.155 0.176 0.167 0.163 0.174
9.11 0.166 0.155 0.176 0.167 0.163 0.174
9.20 0.164 0.156 0.175 0.167 0.163 0.173
9.27 0.164 0.156 0.175 0.168 0.162 0.174
Calculate the average from the above table: (Result: 0.001)
Date Number Dry soil (g) Fertile soil (g)
8.9 0.166 0.168
8.16 0.167 0.168
8.23 0.17 0.17
8.30 0.165 0.168
9.6 0.165 0.168
9.11 0.17 0.17
9.20 0.165 0.168
9.27 0.165 0.168

From the above table, it can be known that the weight loss of white non-degradable lunch boxes has no obvious tendency with time, showing a disorderly distribution.

The second stage: 2004.10.25~2004.11.22
The meal boxes A~C are embedded in the dry soil layer;
A is a carton, B is a brown biodegradable plastic, C is a white non-degradable plastic tree buried in the fertile soil lunch boxes No. 1 ~ 3;
1 is carton, 2 is brown degradable plastic, 3 is white non-degradable plastic (Table 2) Quality: Grams (g)
Date No. A. Carton(g) B.SJF-9(g) C.SL-1B(g) 1. Carton(g) 2.SJF-9(g) 3.SL-1B(g)
10.25 1.005 0.254 0.208 0.771 0.158 0.187
11.1 0.956 0.246 0.209 0.74 0.16 0.186
11.8 0.925 0.239 0.207 0.715 0.154 0.186
11.11 0.902 0.234 0.208 0.701 0.15 0.185
11.22 0.888 0.231 0.208 0.695 0.143 0.186
11.29 0.844 0.223 0.208 0.667 0.14 0.185
12.6 0.803 0.217 0.207 0.648 0.137 0.185
12.19 0.75 0.211 0.208 0.628 0.133 0.186

From the above table, it can be seen that the carton and the brown meal box exhibit certain degradability.
Activated sludge landfill method: Activated sludge after aeration was placed in three opaque plastic barrels. Three polystyrene lunch boxes were respectively embedded in activated sludge, covered with a lid and allowed to stand.
The first stage: 2004.8.9~2004.9.6
White non-degradable plastic lunch box (SL-1B)
(Table 3) Quality: Grams (g)
Date Number SL-1B\1 (g) SL-2B\2 (g) SL-3B\3 (g) Average (0.001) (g)
8.9 0.631 0.601 0.64 0.624
8.16 0.625 0.595 0.634 0.618
8.23 0.622 0.59 0.631 0.614
8.3 0.622 0.591 0.632 0.615
9.6 0.621 0.59 0.628 0.613
9.11 0.622 0.589 0.629 0.613
9.20 0.621 0.588 0.629 0.612
9.27 0.621 0.588 0.628 0.612

The second stage: 2004.10.25~2004.11.22
White non-degradable plastic lunch box (SL-1B)
Brown biodegradable plastic lunch box (SJF-9)
(Table 4) Quality: g (g)
Date Number SJF-9\1(g) SJF-9\2(g) SJF-9\3(g) Average (0.001) (g) SL-1B\1(g) SL-1B\2(g) SL-1B\3(g) Average (0.001) (g)
10.25 0.613 0.625 0.624 0.621 0.616 0.611 0.615 0.614
11.1 0.6 0.613 0.612 0.608 0.613 0.608 0.613 0.611
11.8 0.598 0.611 0.608 0.606 0.614 0.609 0.612 0.612
11.11 0.592 0.607 0.606 0.602 0.612 0.607 0.612 0.61
11.22 0.585 0.6 0.594 0.593 0.613 0.606 0.611 0.61
11.29 0.578 0.594 0.587 0.586 0.613 0.607 0.612 0.611
12.6 0.572 0.589 0.58 0.58 0.312 0.606 0.611 0.61
12.19 0.565 0.583 0.573 0.575 0.61 0.605 0.611 0.61

From Table 3 and Table 4, it can be seen that the polystyrene lunch boxes have certain degradability under the action of concentrated microorganisms, and the degradation of the degradable lunch boxes in the sludge is much stronger than in the soil.

V: Data Analysis and Discussion (1);
From Table 2 above, it can be seen that the weight loss rate of brown biodegradable lunch boxes and cartons increased substantially with the increase of soil burial time, but the weight loss of brown biodegradable lunch boxes was very slow. After 49 days of soil burial, The weight loss is only around 0.020, but there are fluctuations. I speculate that it may be certain conditions in the soil, such as soil moisture, temperature, or the population, amount, and activity of microorganisms, that cannot meet the degradation requirements of biodegradable plastics (10). The lower temperature in November has a greater impact on the microorganisms in the soil, which may be the main reason for the slow weight loss of brown degradable lunch boxes.

The weightlessness of the white non-biodegradable lunchboxes did not change significantly with time, showing an unordered distribution.

In the first soil-buried experiment, the weightlessness rate of the white non-biodegradable lunch box No. 5 was very strange, showing a very high value in the third week, and in terms of its average value, it was the highest in the white lunch box samples. Presumably, this may be due to the loss of mass due to volatilization of certain volatile components in the lunch box.
It can be concluded that under the experimental conditions of the soil burial experiment, the brown meal boxes showed some degradability, but relative to the white lunch boxes, under certain natural environmental conditions (such as in arid soil). ) There is no obvious difference.

From the values ​​in Table 3 above, it can be concluded that the white meal box has a certain degree of biodegradability, and the 49-day mass has changed by about 0.020 (g), which is a certain difference from the soil-buried experiment. When observing the surface of the lunch box, it was found that there were obvious holes on the surface. The longer the time was, the more the holes were, and the more sludge was embedded in the sludge. At the final removal, the green material was faintly visible. In the first two weeks, the lunch box had a large weight loss. It can be seen that the polystyrene lunch boxes have certain degradability under the action of concentrated microorganisms.
From the average value of Table 4, it can be considered that there is a certain difference in the biodegradability between the brown meal box and the white lunch box. The weight loss of the white lunch box in the activated sludge is not obvious, but the brown meal box loses weight quickly. It is more degradable in sludge than it is in soil.

Because the activity of microorganisms is related to temperature, humidity, and pH (11), the first experiment in summer, the average temperature is higher and it is a favorable time for the growth of microorganisms, so the weight loss of the white lunch box is very fast; the second experiment is at 10 From November to November, the temperature is relatively low, which has a great influence on the activity of microorganisms. The weight loss of white lunch boxes is very slow. Because the material of this experiment is the same, the pH and humidity of the solution are not considered.

Therefore, it can be concluded that both white and brown food boxes have a certain degree of biodegradability at a high concentration of sludge, but the size of the degradation is related to the activity of the microorganisms. This is evident in the white lunch box.

Through the above experiments, I reached the following conclusions:

1. Chemically dissolving polystyrene lunch boxes, although fast, it is impossible to determine the product. The gases produced when dissolved can also be harmful to the environment. The organic solvent required is itself a contaminant. Although edible raspberry ketone and vanillin were used as solvents in this experiment, the resulting solution was also somewhat polluted with water. Moreover, the use of microbiological edible dispersions is not effective, so the use of chemically dissolved polystyrene lunch boxes is not worth promoting.

2. The result of the soil burial experiment was credible. The fragment of the lunch box after the experiment was observed by the naked eye. The two white non-degradable samples showed no sign of damage, while the surface of the brown degradable lunch box fragment had obvious holes. This is consistent with the weight loss data of the lunch box. Brown biodegradable lunch boxes have certain biodegradability under soil-buried conditions.

3. Through this experiment of activated sludge landfill, it was found that brown biodegradable lunch boxes have high biodegradability under the conditions of active microorganisms, and it is worth advocating that activated sludge degradation can degrade the lunch boxes.

4. The active sludge landfilling experiment has certain progress. From the data in Table 3 and Table 4 and the naked eye observation, the white non-degradable lunch box has certain degradability in the high-concentration, high-activity microorganisms. Future experiments indicate the direction. The next experiment was to prepare the most suitable conditions for microbial activity by controlling different temperatures and different pH values, thereby degrading the white non-degradable plastic lunch box.

six. to sum up;

This experiment only made preliminary research on the biodegradability of the lunch box. According to my own thinking, the focus of the future research is on the exploration of experimental methods. This experiment only chose a more intuitive and simple method. In later experiments, anaerobic water phase and landfill experiments can be added. In specific experiments, in addition to exploring the basic conditions of the sample, the amount of microorganisms, and other experimental conditions, the impact of the particle size of the lunch box fragment on the degradation performance, as well as the oil, starch and other substances on the lunch box Co-metabolism was studied. In addition, the screening of specialized strains of degradable lunch boxes for industrial degradation can also serve as a research direction.