Background and Objective: Forest roads, which are predominantly unpaved, are highly susceptible to dust emission during vehicle traffic. This dust can lead to various complications, including health hazards for workers, mechanical damage to equipment, and environmental concerns. Dust control technologies are therefore crucial for mitigating these issues in forestry operations. Road dust suppression encompasses various methods aimed at minimizing the generation and suspension of airborne particles, particularly on unpaved roads. These methods can be broadly classified into reducing dust production, preventing its suspension, or capturing and removing it. This study aims to investigate the efficacy of biopolymers in controlling dust on the Arab-Dagh forest roads in Golestan Province.
Material and Methods: For this purpose, a wind tunnel with a contact surface area of 38 × 60 cm was utilized. Undisturbed surface samples from the region's forest roads were randomly selected. Three biopolymers—xanthan, guar, and beta-glucan—were applied separately at weight percentages of 0%, 0.5%, 1%, 2%, 3%, or 5% over the contact area of the wind tunnel. Subsequently, the treated road surfaces were exposed to wind speeds of 8 and 10 m/s using the wind tunnel apparatus. The duration of wind exposure was kept constant at two minutes for all samples. The accumulated wind-blown sediments were then collected in plastic cyclones and weighed with a precision of 0.1 mg. The experiments were conducted using a factorial design within a randomized complete block (RCB) framework. The primary treatments included the type of biopolymer (three levels), the application rate (four levels), and wind speed as the blocking factor (two levels). Three replicates were considered for each speed, resulting in a total of 24 treatments and 72 sediment samples. Statistical analyses were performed using SPSS software; data normality was verified via the Kolmogorov-Smirnov test, mean comparisons were conducted using the LSD test, and correlation analysis was carried out using the Pearson test.
Results: The results of the mean comparison tests indicated that all three biopolymer treatments significantly reduced dust emissions from the wind tunnel plots compared to the control group. Specifically, dust production for plots treated with beta-glucan, guar, and xanthan was 8.27, 7.23, and 7.78 g/m², respectively, whereas the control group yielded 11.58 g/m². Furthermore, increasing the biopolymer concentration led to a significant decrease in dust levels, with the most pronounced reduction observed at the 5% concentration. As wind speed increased from 8 m/s to 10 m/s, dust production significantly rose from 7.85 g/m² to 9 g/m². The analysis further revealed that the greatest dust reduction occurred with the 5% guar treatment, which achieved a decrease of 76.5% and 66.3% at wind speeds of 8 m/s and 10 m/s, respectively. Across all biopolymer treatments, the highest dust emissions were recorded at the lowest concentration (0.5%).
Conclusion: Based on the findings of this study, applying high concentrations of biopolymers via tractor-mounted field sprayers enables the effective large-scale use of dust suppressants. The experimental results provide evidence that biopolymer spray applications can effectively mitigate dust emissions on forest roads and even in mining operations in the short term. Consequently, the tested biopolymers represent a promising, bio-based, and environmentally friendly alternative for dust control.