Title Page
Contents
Abstract 6
Chapter 1. Introduction 10
1.1. Risk of microplastics 12
1.2. Risk of carbaryl 13
Chapter 2. Materials and methods 15
2.1. Preparing materials 15
2.1.1. Microplastics powder 15
2.1.2. collection microplastics from freshwater sediment 15
2.2. Statistical analysis of adsorption experiments of microplastics 16
2.2.1. Adsorption experiments over time of microplastics on carbaryl 16
2.2.2. Adsorption experiments isotherm of microplastics on carbaryl 17
2.2.3. Adsorption model application formula 17
2.3. Synthetical analysis of adsorption experiment 18
2.3.1. The effect of pH ion on microplastics adsorption 18
2.3.2. microplastics characteristic analysis 18
2.4. Daphnia magna toxicity test 23
2.4.1. Daphnia magna an ecotoxicity experimental organism 23
2.4.2. Daphnia magna toxicity test preparation 24
2.4.3. Types of microplastics Daphnia magna 24
Chapter 3. Results and Discussions 26
3.1. electronical interaction 26
3.2. pH effect on adsorption 26
3.3. Effect of Microplastic Adsorption of Carbaryl over Time (Adsorption kinetic of microplastics on Carbaryl) 26
3.4. Isothermal adsorption experiment 32
3.4.1. Freundlich model 32
3.4.2. Langmuir Model 32
3.5. The results of daphnia magna toxicity test 41
Chapter 4. Conclusions 44
Reference 45
Table 1. Analysis surface area of standard microplastics and freshwater sediment microplastics 22
Table 2. Analysis zeta potential of microplastics 22
Table 3. Kinetic parameters for the adsorption of carbaryl on PP, PE, Mix 1 and Mix 2 at pH4 31
Table 4. Kinetic parameters for the adsorption of carbaryl on PP, PE, Mix 1, Mix 2 and FWS MPs at pH7 31
Table 5. Kinetic parameters for the adsorption of carbaryl on PP, PE, Mixed microplastics 1:1:1:1:1 and Mixed microplastics freshwater sediment ratio at pH8.5 31
Table 6. Isotherm parameters for the adsorption of carbaryl on PP, PE, Mix 1 and Mix 2 at pH 4 40
Table 7. Isotherm parameters for the adsorption of carbaryl on PP, PE, Mix 1, Mix 2 and FWS MPs at pH 7 40
Table 8. Isotherm parameters for the adsorption of carbaryl on PP, PE, Mix 1 and Mix 2 at pH 8.5 40
Table 9. Toxicity test Results of Standard microplastics 42
Table 10. Toxicity test Results of Standard microplastics 43
Fig.1. SEM image of standard microplastics (PP, PE, PET, PS, PVC). 19
Fig.2. FTIR result peak of Standard microplastics. 19
Fig 3. FTIR result peak of Freshwater sediment microplastics. 20
Fig.4. Freshwater sediment Microplastics type 20
Fig 5. Freshwater sediment size distribution 21
Fig 6. Microplastics floating on the surface in toxicity test using Daphnia magna 25
Fig 7. Microplastics sinking in toxicity test using Daphnia magna 25
Fig 8. kinetics model fit for the adsorption Carbaryl on PP, PE, Mix1 and Mix 2 at pH 4. 28
Fig 9. kinetics model fit for the adsorption Carbaryl on PP, PE, Mix 1, Mix 2 and FWS MPs at pH 7. 29
Fig 10. kinetics model fit for the adsorption Carbaryl on PP, PE, Mix 1, Mix 2 and FWS MPs at pH 8.5. 30
Fig 11. Langmuir Isotherm model fit for the adsorption Carbaryl on PP, PE, Mix 1, Mix2 at pH 4. 34
Fig 12. Langmuir Isotherm model fit for the adsorption Carbaryl on PP, PE, Mix 1, Mix2, FWS microplastics at pH 7. 35
Fig 13. Langmuir Isotherm model fit for the adsorption Carbaryl on PP, PE, Mix 1, Mix2, FWS microplastics at pH 8.5. 36
Fig 14. Freundlich Isotherm model fit for the adsorption Carbaryl on PP, PE, Mix 1 and Mix2 at pH 4. 37
Fig 15. Freundlich Isotherm model fit for the adsorption Carbaryl on PP, PE, Mix 1, Mix2, FWS microplastics at pH 7. 38
Fig 16. Freundlich Isotherm model fit for the adsorption Carbaryl on PP, PE, Mix 1 and Mix 2 at pH 8.5. 39