A number of harmful effects on the ecosystem, the life of humankind, and living species caused by dye-contaminated wastewater have urged the development for an efficient and cost-efficient treatment method for colored effluents. The cellulose-based adsorbents have been considered as a facile and efficient approach to remove hazardous pollutants because of the abundance of inexpensive agricultural wastes in Viet Nam. This study aims to investigate the elimination of methylene blue (MB) and crystal violet (VL) from wastewater using a fixed-bed column of pre-treated durian peel. Examined variables in the process are bed depths (2–6 cm), flow rate (5–20 mL/min), and influent dye concentrations (200–600 mg/L). The highest adsorption amount of pre-treated DP was 235.80 mg/g and 527.64 mg/g, respectively, on a 600 mg/L of methylene blue and crystal violet achieved within a bed height of 4 cm and a flow rate of 10 mL/min. Accordingly, the breakthrough curves were constructed and modeled using the relevant theoretical models under the effects of different experimental conditions. Pre-treated durian peel was found to exhibit high adsorption capacity for cationic dye in an initial concentration of 200–600 mg/L with complete removal being obtained.

Although conventional activated sludge has been demonstrated to be a feasible approach for extracting nitrogenous chemicals and organic pollutants from wastewater, it still has a number of drawbacks. In this research, a pilot-scale biocord-integrated fixed-film activated sludge (Biocord-IFAS) reactor fed with actual domestic wastewater was operated to examine the effect of varying hydraulic retention time (HRT) on the COD and nitrogen removal. The type of material employed in this study is fibrous polypropylene (biocord), which is a major difference. The contribution of the Biocord-IFAS to COD removal efficiency reached 94.2% at HRT of 8 h and gradually decreased to 82.9% when HRT was reduced to 4 h. During the investigation period, a slight decrease in nitrification was found at a shorter HRT. The NH4+-N removal efficiencies at HRTs of 10, 8, 6, and 4 h were 97.8%, 98.7%, 97.1%, and 96.3%, respectively. The average effluent nitrate concentration was 5.3 mg/L with HRTs from 10 to 6 h, but over 30 mg/L with an HRT of 4 h. The SEM analysis results show that microorganisms have formed on the biocord surface. The results of this research have demonstrated the potential application of IFAS reactors in bioremediation procedures employing biocord material with great processing efficiency.

The accelerator driven subcritical reactor (ADSR) is very interested in the recent years. One of the researches is about the fuel, fuel should be thorium or uranium; the coolant is liquid lead or molten salt. This paper presents the results of research on the radioactive spectrum of thorium in molten salt, uranium in molten salt, and liquid lead. These research results include energy spectrums of alpha, beta, gamma, neutrino particles; the energy spectrums of the daughter nucleus.