## 3 Results
### Field Trials  
#### 3.2.1 Measured Dust Concentrations  
Figure 6 illustrates the concentrations of dust particle sizes (PM\({}_{2.5}\), PM\({}_{10}\), TSP) measured for soils treated with different biomaterial solutions. Each bar represents the calculated mean value from triplicate analyses. The data demonstrate that mine soils treated with any of the biomaterials showed a significant reduction of dust emissions after 3 days. With increasing exposure time, dust emissions increased steadily and peaked 21 days after the solutions were applied. By comparison, the data of water-treated and untreated mine soil show a different trend. The highest dust emissions were recorded on day 3 and continued to decline subsequently. In some cases, dust emissions of the control group (i.e., water-treated and untreated mine soil) achieved lower PM concentrations than treated soil samples. For example, untreated mine soil emitted less dust emissions from day 21 onwards than all test plots prepared with biomaterials.  
Figure 4: Wind-induced total weight loss (g) of treated mine soils wetted with four different rainfall intensities after four wet–dry cycles (mean values, n = 3). By comparison, untreated soil showed a total weight loss of 125.28 g after four measuring cycles.  
Figure 5: Effect of wet–dry cycles on wind-induced soil losses (g) from mine soils treated with different food processing by-products (mean values, n = 3): (**a**) chicory viruses, (**b**) corn steep liquor, (**c**) decantation syrup, and (**d**) palatinose molasses.  
The peak values of biomaterial-treated plots were significantly lower than those of the control group (i.e., water-treated and untreated soil). For untreated soil, PM\({}_{10}\) emissions amounted to 59.026 mg/m\({}^{3}\) (PM\({}_{2.5}\): 32.078 mg/m\({}^{3}\), TSP: 77.075 mg/m\({}^{3}\)). Soil treated with pure water achieved a PM\({}_{10}\) concentration of 27.649 mg/m\({}^{3}\) (PM\({}_{2.5}\): 20.981 mg/m\({}^{3}\), TSP: 39.176 mg/m\({}^{3}\)). By contrast, applications of palatinose molasses and corn steep liquor produced a decrease of PM\({}_{10}\) emissions to 5.003 mg/m\({}^{3}\) (PM\({}_{2.5}\): 3.152 mg/m\({}^{3}\), TSP: 8.482 mg/m\({}^{3}\)), and 3.184 mg/m\({}^{3}\) (PM\({}_{2.5}\): 2.351 mg/m\({}^{3}\), TSP: 5.169 mg/m\({}^{3}\)), respectively. In comparison, chicory vinasses and decantation syrup reduced PM\({}_{10}\) emissions to 2.148 mg/m\({}^{3}\) (PM\({}_{2.5}\): 1.863 mg/m\({}^{3}\), TSP: 2.697 mg/m\({}^{3}\)), and 1.756 mg/m\({}^{3}\) (PM\({}_{2.5}\): 0.900 mg/m\({}^{3}\), TSP: 2.896 mg/m\({}^{3}\)), respectively. Among the investigated biomaterials, decantation syrup demonstrated the highest effect on reducing PM\({}_{2.5}\) and PM\({}_{10}\) emissions after 21 days, while chicory vinasses was the most effective additive in suppressing TSP emissions. The lowest dust emissions were measured for all soil plots, including the control group (i.e., water-treated and untreated mine soil), 28 days after soil treatment.  
Figure 6: Wind-induced dust emissions from treated and untreated mine soils (mean values, n = 3): (**a**) PM\({}_{2.5}\), (**b**) PM\({}_{10}\), and (**c**) TSP. Dust emissions were measured 3, 7, 14, 21, and 28 days after application of dust suppressants. Abbreviations: CV = chicory vinasses, CSL = corn steep liquor, DS = decantation syrup, PAM = palatinose molasses, H\({}_{2}\)O = water-treated soil, US = untreated soil.  
A summary of the mean dust particle concentrations in air as detected during the field trial from variously treated mine soils is shown in Table A4, Appendix A.