Comparative characteristics of the petrographic composition and quality of coal series С12 and С13 of the Prydniporovia Block

Taking into consideration the whole history of geological development of the Western Donbas, data on composition and grade of С12 series coal involved information about the geotectonic development of the Basin. To satisfy the objectives, a system of research methods, covering petrographic, computational, statistical, chronological, comparative and other methods, has been applied. In the process of identification of the petrographic composition and grade of series С12coal on the territory of the Prydniprovia Block, and determination of lateral regularities of their change as well as change in stratigraphic section of the Lower Carboniferous, data of petrographic as well as chemical and technological indices of the coal seam c1 were generalized along with data of all seams of С13 series. The activities helped define genetic features of series С12coal as well as stratigraphic and lateral regularities of changes in the coal composition. The differences in the petrographic composition as well as in the chemical and technological characteristics of series С12 and С13 are indicative of dissimilar conditions of formation of their peat depositions. It has been determined that compared with С13 series coal, the coal of С12 series contains more humidity and fewer mineral impurities. It is characterized by higher values of sulfur content, volatile-matter content, and combustion heat. The ultimate composition of coal seams of С12series is characterized by smaller values of carbon and oxygen contents as well as greater hydrogen content. The conclusions on common features and differences in the petrographic composition as well as chemical and technological features of coal seams of С12and С13 series, and regularities of their changes over the area of the seam occurrence was assessed.

Occurrence, Removal, and Mass Balance of Polycyclic Aromatic Hydrocarbons and Their Derivatives in Wastewater Treatment Plants in Northeast China

Polycyclic aromatic hydrocarbons (PAHs), 33 methylated PAHs (Me-PAHs), and 14 nitrated PAHs (NPAHs) were measured in wastewater treatment plants (WWTPs) to study the removal efficiency of these compounds through the WWTPs, as well as their source appointment and potential risk in the effluent. The concentrations of ∑PAHs, ∑Me-PAHs, and ∑NPAHs were 2.01–8.91, 23.0–102, and 6.21–171 µg/L in the influent, and 0.17–1.37, 0.06–0.41 and 0.01–2.41 µg/L in the effluent, respectively. Simple Treat 4.0 and meta-regression methods were applied to calculate the removal efficiencies (REs) for the 63 PAHs and their derivatives in 10 WWTPs and the results were compared with the monitoring data. Overall, the ranges of REs were 55.3–95.4% predicated by the Simple Treat and 47.5–97.7% by the meta-regression. The results by diagnostic ratios and principal component analysis PCA showed that “mixed source” biomass, coal composition, and petroleum could be recognized to either petrogenic or pyrogenic sources. The risk assessment of the effluent was also evaluated, indicating that seven carcinogenic PAHs, Benzo[a]pyrene, Dibenz[a,h]anthracene, and Benzo(a)anthracene were major contributors to the toxics equivalency concentrations (TEQs) in the effluent of WWTPs, to which attention should be paid.

Prediction of Effective Elasticity Coefficients of Composite Biofuel

It is suggested that fuel pellets made of composites based on solid plant waste should be considered as stochastic systems that are anisotropic in microvolumes but isotropic in the entire structure, i.e. quasi-isotropic in volume. Based on this hypothesis and the analysis of the known micromechanical models for forecasting physical and mechanical constants of composite materials, the expediency of using the Reuss-Voigt and Hashin-Strickman models to determine the effective elastic coefficients of composite biofuels is substantiated. The results of calculations made on these models for a number of two-component biofuel pellets are given. An experimental evaluation of effective Young's modulus and Poisson's ratio for two-component pellets with "straw + brown coal" composition was carried out. The obtained results of experimentally determined values of coefficients satisfactorily correspond to their calculated values: deviations are up to 26%. The Reuss-Voigt model was used in the calculations because the conditions required for the application of the Hashin-Strickman model are not met for composite pellets consisting of straw and brown coal. The results of the study will be useful in calculating or selecting press equipment for the production of quality fuel pellets from composites based on solid plant waste.