## 2 Materials and Methods
### Methods of Performance Characterization  
(1) Moisture absorption and retention performance test. The moisture absorption performance of a dust suppressor is characterized by the moisture content. The moisture content rate of dust samples was calculated based on Equation (1). \[W_{i}=\frac{m_{i}-m_{a}}{m_{0}}\times 100\% \tag{1}\]  
where \(W_{i}\) is the moisture content rates of dust samples in hour \(i\) (\(\%\)), \(m_{i}\) is the mass of the Petri dish and dust sample in hour \(i\) (g), \(m_{a}\) is initial mass of dry Petri dish and dust sample (g), and \(m_{0}\) is the mass of the dry dust sample (g). The moisture retention performance of the dust suppressor is characterized by the water loss rate. The water loss rate was calculated according to Equation (2). \[W_{g}=\frac{G_{i}-G_{a}-G_{0}}{G_{0}}\times 100\% \tag{2}\]  
where \(W_{g}\) is the water loss rate of the dust sample (\(\%\)), \(G_{a}\) is the mass of the clean and dry Petri dish and the dust sample (g), \(G_{i}\) is the mass of the dust sample and Petri dish at hour \(i\)/day (g), and \(G_{0}\) is the mass of 11 nm of solution (g). (2) Survival rate of plant. The leaf number in each group was counted on the first and the last day to spray reagents. The growth rate and the growth speed inhibition percentage of each group \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Concentration Serial Number**} & \multicolumn{5}{c}{**Factors**} \\ \cline{2-5}  & **BS** & **XS** & **NB** & **BZ** \\ \hline
1 & 3\% & 3\% & 0.06\% & 0.06\% \\
2 & 4\% & 4\% & 0.08\% & 0.08\% \\
3 & 5\% & 5\% & 0.10\% & 0.10\% \\
4 & 6\% & 6\% & 0.12\% & 0.12\% \\ \hline \hline \end{tabular} Note: The i of BS, XS, NB, and BZ\({}_{i}\) below indicates the concentration serial number of each component corresponding to this table.  
\end{table} 
Table 1: Factor concentration level table. were calculated based on Equation (3). The growth rate and the growth speed inhibition percentage of each group were calculated based on Equation (3). The growth rate and the growth speed inhibition percentage of each group were calculated based on Equation (3). \[\left\{ \begin{array}{l}V=\frac{\ln(N/N_{0})}{\text{t}}\\ I=\frac{V_{0}-V_{0}}{V_{0}}\times 100\%\end{array} \right. \tag{3}\]  
where \(I\) is the leaf number of the plant at (t), \(N_{0}\) is the leaf number of the initial plant, t is the experiment duration (days), \(V\) is the plant growth rate, \(V_{0}\) is the growth rate of the control group, and \(V_{\text{n}}\) is the growth rate of the experimental group. Chlorophyll content. On the seventh day of plant culture, chlorophyll was extracted from leaves in each group as per the design of the plant toxicity experiment in Section 3.2.2. A UV-6100 spectrophotometer (The manufacturer's location is Nanbei Instrument Equipment Co. LTD in Zhengzhou, China. The test was conducted according to Chinese standard GB/T 26813-2011 Dual beam UV-VIS spectrophotometer.) was adopted to determine the absorbance of chlorophyll-extracting solution in each group for 665 nm and 649 nm light waves. The chlorophyll contents in each group were calculated based on Equation (4). \[\left\{ \begin{array}{l}C_{\text{a}}=13.95A_{665}-6.88A_{649}\\ C_{\text{b}}=24.96A_{649}-7.32A_{665}\\ w=\frac{(C_{\text{a}}+C_{\text{b}})\times V\times\text{n}}{100\times\text{m}} \end{array} \right. \tag{4}\]  
where \(A_{665}\) is absorbance at the wavelength of 665 nm, \(A_{649}\) is absorbance at the wavelength of 649 nm, \(C_{\text{a}}\) is the concentration of chlorophyll a (mg/L), \(C_{\text{b}}\) is the concentration of chlorophyll b (mg/L), w is the chlorophyll content (mg/g), \(V\) is the volume of the chlorophyll-extracting solution (mL), n is the dilution ratio of chlorophyll-extracting solution, which is 1 in this experiment, and m is the mass of crushed leaves (g). Wind erosion resistance. The dust suppressor solution was prepared according to the optimal dust suppressor formula.