Experimental study on ratio optimization and application of improved bonded dust suppressant based on wetting effect.

Traditional bonded dust suppressants have high viscosity, insufficient fluidity and poor permeability problems, which is adverse to the formation of a continuous and stable solidified layer of dust suppressant solution on the surface of a dust pile. Gemini surfactant has efficient wetting performance and environmental protection performance, it is introduced as a wetting component to improve the flow and penetration performance of bonded dust suppressant solution, polymer absorbent resin (SAP) and sodium carboxymethyl starch (CMS) were selected as the main components of dust suppressant. A proportioning optimization model was constructed based on response surface methodology (RSM), and the concentration of each dust suppression component was selected as the independent variable, water loss rate, moisture retention rate, wind erosion rate and solution viscosity were chosen as the dependent variables in this model. The optimal formulation of the improved bonded dust suppressant was obtained by analyzing the laboratory experiments and field tests data. The results show that the effective time (≥15d) of the newly developed dust suppressant is 45 times longer than that of pure water (≈1/3d), and 1.875 times longer than that of the comparative dust suppressant (8d), the comprehensive cost is 27.36% lower than that of the similar dust suppressant product for mining enterprises.Implications: This paper presents the research idea of optimizing the bonded dust suppressant based on the improvement of wetting performance. And the paper used response surface method to obtain a wetting and bonding composite dust suppressant formulation. The field test shows that the dust suppressant has good dust suppression performance and economic benefits. This study laid the foundation for the development of new and efficient dust suppressants, and had important theoretical and application values for reducing dust environmental hazards and preventing occupational diseases.

Prevalence and Molecular Characteristics of FAdV-4 from Indigenous Chicken Breeds in Yunnan Province, Southwestern China.

Fowl adenovirus-induced hepatitis-pericardial effusion syndrome outbreaks have been increasingly reported in China since 2015, resulting in substantial economic losses to the poultry industry. The genetic diversity of indigenous chicken results in different immune traits, affecting the evolution of these viruses. Although the molecular epidemiology of fowl adenovirus serotype 4 (FAdV-4) has been well studied in commercial broiler and layer chickens, the prevalence and genetic characteristics of FAdV-4 in indigenous chickens remain largely unknown. In this study, samples were collected from six indigenous chicken breeds in Yunnan province, China. FAdV-positive samples were identified in five of the six indigenous chicken populations via PCR and 10 isolates were obtained. All FAdVs belonged to serotype FAdV-4 and species FAdV-C. The hexon, fiber, and penton gene sequence comparison analysis demonstrated that the prevalence of FAdV-4 isolates in these chickens might have originated from other provinces that exported chicks and poultry products to Yunnan province. Moreover, several distinct amino acid mutations were firstly identified in the major structural proteins. Our findings highlighted the need to decrease inter-regional movements of live poultry to protect indigenous chicken genetic resources and that the immune traits of these indigenous chickens might result in new mutations of FAdV-4 strains.