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Excess sludge a resource-rich organic waste, can be solubilized by thermophilic enzymes to extract proteins and anaerobic digestion of methane production to reduce sludge and use resources. At the same time, it can improve new ideas to relieve the pressure of the energy industry. To solve the problems of low enzyme-producing activity of wild strains and low hydrolysis rate of ES, this study utilized UV-DES compound mutagenesis to screen dominant mutant strains under optimized conditions, which were added to ES hydrolysis reaction system. The results showed that UV-DES mutagenesis could effectively improve the ability of S-TE and promote the hydrolysis of ES. The protease activity of the mutant strain KT16 obtained by screening was 46.7% higher than that of the original strain DC8. KT16 effectively degraded insoluble organic matter, reduced the average particle size of ES, and increased the concentrations of extracellular proteins, polypeptides, and amino acids to 1731.8, 521.3, and 510 mg·L-1, respectively. This study will provide a reference for the resource utilized.

In order to improve the utilization rate of the surplus sludge, this experiment investigated the efficient hydrolysis of the residual sludge, explored the effect of sludge nitrogen source, analyzed the influence on the content of protein, amino acid, polypeptide and particle size of the sludge hydrolysis index, and the extraction conditions were optimized by response surface analysis. The maximum protein extraction rate of the residual sludge at the reaction pH of 60°C and =7. Here, the particle size of S sludge was gradually reduced, reduced by 1.1% by 500 m-100 um, 7.5% by 30-50 μ m, 5.4% by 10 μ m-30 μ m, and 0-10 μ As m decreases 13% and sludge increased 13% Nt particles become thinner, larger than surface area and more developed pore structure.

In order to explore the enhancement effect of biochar on anaerobic digestion, oxytetracycline residue was used as the substrate for anaerobic digestion, and biochar was added to solve the problems of low efficiency and weak stability of traditional anaerobic digestion. The strengthening effects of biochar and zero-valent iron modified biochar were illustrated by the changes of gas production, stability and microbial community. The results show that adding biochar alone and nano-scale zero-valent iron modified biochar can reduce the concentration of ammonia nitrogen in the system, reduce the influence of ammonia inhibition on anaerobic digestion, promote the transformation and consumption of VFAs, and improve the stability of the system. The gas production efficiency increased by 20.74% and 15.49% respectively, reaching above 115.20 mL/g. In addition, biochar can also strengthen the removal of residual oxytetracycline, and its removal efficiency is increased by 2.37% and 4.82% respectively compared with the control group, and the content of residual oxytetracycline in the final system can be reduced to below 10 mg/L. After adding zero-valent iron to biochar, the abundance of acid-producing bacteria and methano-genic archaea increased in different degrees, thus strengthening the process of anaerobic digestion and methanogenesis. [ABSTRACT FROM AUTHOR]

The efficiency and kinetics of catalytic ozonation of Acid Red B over Cu-Mn/γ-Al2O3catalysts were investigated. Cu-Mn/γ-Al2O3catalysts were prepared by impregnation and characterized by X-ray diffraction and X-ray fluorescence. The removal efficiencies of Acid Red B and total organic carbon were up to 99.35% and 54.38%, respectively. The Cu-Mn/γ-Al2O3catalysts were stable and easy to be reused. The interim products were analyzed by means of Vis-UV absorption spectrum. Cu-Mn/γ-Al2O3catalytic ozonation of Acid Red B conformed to the pseudo–first-order kinetics reaction model. [ABSTRACT FROM PUBLISHER]

Abstract: In this work, the effects of corn straw pretreatments using Fungus Pleurotus florida and chemicals such as NaOH, ammonia, and urea on the biogasification performance by anaerobic digestion were compared. A laboratory-scale, single-phase and continuous anaerobic biogas digester was used for the evaluation. It was found that after different treatments, the compositional contents of corn straw such as lignin, cellulose, and hemicellulose would be degraded significantly, and that the physical structure of the lignocellulose matrix would also be changed. Our anaerobic digestion experiments showed that the biogas productivity was increased by all the pretreatments; and that the biogas production after NaOH treatment would be 207.07% and 16.58% higher than the raw corn straw and biologically pretreated ones, respectively. [ABSTRACT FROM AUTHOR]

The CeO 2 @ZSM-5 was prepared by the dipping method. We used ZSM-5 and CeO 2 as the carrier and load components, respectively. The aim was to reduce the low concentration of Cr(VI) in simulated wastewater (the concentration of Cr(VI) ranged from 0.2 to 1 mg/L). The characteristics of ZSM-5 and CeO 2 @ZSM-5 samples were determined by X-ray powder diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). Characterization results showed that the particle size, BET surface area and pore volume for CeO 2 @ZSM-5 was around 0.783 nm, 421.307 m 2 /g and 0.313 m 3 /g, respectively. In addition, the optimum conditions were obtained by the orthogonal test, and the details were as follows: optimal pH, adsorbent dose, initial concentration of Cr(VI) and equilibrium time were 3, 5 g/L, 0.6 mg/L and 70 min respectively. The removal of Cr(VI) was 99.56% in these conditions. The pseudo-second-order model best described the adsorption kinetics of Cr(VI) onto CeO 2 @ZSM-5. Isotherm data were treated according to Langmuir, Freundlich and Temkin isotherm models. The results showed that the Freundlich adsorption isotherm model fitted best in the temperature range studied. Adsorption capacity increased with temperature, showing the endothermic nature of Cr(VI) adsorption. The desorption results showed the best recovery of Cr(VI) using 0.1 M HCl.