The Effects of Pore Volume and Compressive Strength on the Nano-Sized Recycling Material Mixtures.

In this study, the effect on pore volume and compressive strength was investigated using nano-sized blast furnace slag (BFS), fly ash (FA), and desulfurized gypsum (DG). In the chemical compositions of BFS and FA, the sum of the four ingredients, CaO, SiO2, A12O3, and MgO were shown to account for 97% and 87%, respectively. Particles smaller than 50 nm were shown to be distributed in the range of 47.9% to 50.7%, particles larger than 50 nm but smaller than 100 nm were distributed in the range of 19.0% to 29.1%, and particles sized 100 nm or larger were shown to be distributed in the range of 21.3% to 23.2%. As a result of analysis carried out using an scanning electron microscope (SEM), it was found that BFS, FA, and DS are mixtures of smooth spherical particles and unevenly shaped materials. As to the dependence of pore volume, which depends on pore size and compressive strength, the volume of pores of sizes between 3 and 10 nm showed a proportional trend where volume increases and, as a result, compressive strength also increases as the material age increases. Moreover, the volume of pores sized between 10 and 100 nm showed an inversely proportional trend where volume decreases and, as a result, compressive strength also decreases as the material age increases.

Removal of residual COD in biologically treated paper-mill effluent and degradation of lignin using nonthermal plasma unit.

This manuscript focused on the degradation behavior of lignin and the reduction of residual COD in the biologically treated paper-mill effluent by means of ionized gas from nonthermal plasma unit. The removal efficiencies of COD, lignin, and color after treated with ionized gas were over 95, 93, and 97%, respectively. It has been found that the degradation of aromatic ring has been proved by FTIR, 1H NMR and UV spectra. The degradation of lignin through ionized gas was accompanied with the increase of SO4(2-) and the decrease in pH. The results show that the residual COD in the biologically treated paper-mill effluent contains NBD matter with aromatic ring compounds. Also NBD organic matter such as aromatic ring in effluent treated with ionized gas was degraded. The residual COD declined by 60% at the ionized gas flow rate 5 L/min and HRT 30 min.