Green solvents for cellulose dissolution is a key topic for green chemistry, especially natural cellulose with high molecular weight, and there are scarce solvents reported. Deep eutectic solvent (DES) is a typical kind of green solvent that has been attracted much attention recently. Here, high molecular weight natural cellulose (DP > 3000) was first isolated from wheat straw and then be directly dissolved in the choline/l-lysine (Ch/Lys) DES. The solution owns excellent stability, and the solubility reaches ∼5%. Rheological studies revealed that the natural cellulose can be well dispersed in the DES solution and showed gelation at high concentrations. The dissolved cellulose can be regenerated when the dilute acid aqueous solution was added into the solution. It provides an energy conversation and an environmentally friendly route to prepare a cellulose solution, which makes it possible to convert cellulose to valuable chemicals and materials in its homogeneous solution.

To remove salicylic acid from aqueous solutions, Biochars (BC300, BC400 and BC500) as a low-cost adsorbent derived from wheat straw was pyrolyzed under different temperatures, characterized by surface area determination, CHN elemental analysis, FUR spectroscopy, scanning electron microscopy and X-ray diffraction. Batch sorption studies were carried and the adsorption kinetics, isotherm and thermodynamic were investigated. The results showed that pseudo second-order kinetics were the best model (R-2>0.99) for describing the adsorption of salicylic acid onto biochars. Equilibrium data were well fitted to the Langmuir (R-2>0.9779) and Freundlich (R-2>0.9264) isotherm models. The maximum monolayer coverage capacity (Q(m)) was calculated according to the linear form of the Langmuir equation was 60.24 mg.g(-1) for BC300, 50.25 mg.g(-1) ;for BC400, 30.67 mg.g(-1) for BC500 and 21.83 mg.g(-1) for BC600. The values of Q(m) increased with operating temperatures among four adsorbents. Various thermodynamic parameters such as Gibbs free energy (Delta G(0)), enthalpy (Delta H-0), and entropy (Delta S-0) changes were computed, and the data showed that the sorption process of salicylic acid solution onto BC300, BC400 and BC500 were spontaneous and endothermic but that they were spontaneous and exothermic for BC600.

The start-up of completely autotrophic nitrogen removal over nitrite (CANON) process was investigated by seeding nitritation granular sludge in a continuous stirred tank reactor with typical geometry. Nitrogen loading rate (NLR) was increased from 1.5 to 3.3 kg N m(-3) d(-1), by shortening hydraulic retention time from 2.0 to 0.9 h under oxygen-limiting conditions. An extremely high nitrogen removal rate (NRR) of 2.83 kg N m(-3) d(-1) was achieved, due to the high specific NRR of huge biomass in the reactor. With the improvement of granular structure compactness, it was believed that the EPS accumulation could be beneficial to enhance nitrogen removal performance of granules. In addition, high-throughput pyrosequencing analysis revealed that a co-culture of aerobic and anaerobic ammonium oxidizing bacteria, affiliated to genera Nitrosomonas and Candidates Kuenenia respectively, had been established in mature CANON granules, while the growth of nitrite oxidizing bacteria (Nitrospira spp.) was effectively suppressed through substrate competitions between three groups of bacteria. Therefore, a single continuous reactor with granules is applicable to achieve high performance CANON process for treating ammonium-rich wastewater. (C) 2016 Elsevier B.V. All rights reserved.

Single biological aerated filter was adopted to treat corn silage effluent from dairy farm of Fengyang,China.Four main influencing factors(hydraulic loading,gas-water ratio,organic loading and filter bed height) on BAF system were studied in this experiment.The results show that the removal rates of COD and NH3-N both increase at first and then decrease when hydraulic loading is from 0.5 m3/(m2.h) to 3.0 m3/(m2.h),whose removal rates of COD and NH3-N reach the maximum with 83.5% and 74.9%,respectively at 1.5 m3/(m2.h);with the increase of the gas-water ratio,the removal rates of COD and NH3-N increase when the gas-water ratio is up to 3.5:1,the removal rates of COD and NH3-N reach the highest,87.5% and 75.2%,separately.COD and NH3-N are extremely difficult to treat under low organic loading,and when the organic loading is 2.4 kg/(m3.d),the removal rates of COD and NH3-N only reach 49.6% and 58.5%,but the removal rate of NH3-N is also rather low under too high organic loading,when the organic loading is 7.2 kg/(m3.d),the removal rate of NH3-N is just 61.7%.Influence of filter bed height upon treatment NH3-N is rather significant because of poor nitrification and the removal rate of NH3-N in the height range 0.6 m to 1.0 m is higher than others,therefore,the removal rate of NH3-N can be enhanced by properly increasing the filter bed height.It is feasible and effective to treat corn silage effluent by BAF system,which offers useful references for wastewater treatment and rural water environmental quality control.