优化混凝-SBR法处理皮革加工废水

对皮革加工废水采用优化混凝-SBR法处理进行了研究,利用均匀设计法优化混凝除Cr3 条件,考察了曝气时间、污泥浓度、沉降时间对SBR反应器降解效果的影响.确定的混凝条件:聚铝投加质量浓度400mg/L、pH=10;SBR后续工艺最佳曝气时间为12 h、沉淀时间为2.0 h、污泥质量浓度为5 g/L.对皮革加工废水采用优化混凝SBR处理的试验结果表明,出水总Cr去除率＞98%,CODcr去除率＞93%,各项主要指标达到国家所规定的一级排放要求.     

无泡曝气膜生物反应器在废水处理中的研究及应用

概述了新型生物膜反应器一无泡曝气膜生物反应器（MABR）的工作原理、技术特点，探讨了膜材料和气液操作条件等因素对MABR运行的影响，并着重介绍了其在有机废水和含氮废水处理中的应用和研究进展。最后指出当前该技术存在的问题，并展望了其广阔的发展前景。     

A segment probability method for calculating the molecular weight distributions of linear polycondensates in a continuous reactor

The molecular weight distribution (MWD) of polymers is a target of the optimization and control of industrial polymerization processes, as it dictates the processability and properties of polymers. A method, named as segment probability method, is developed to calculate the MWD of polycondensates produced by monomers of types A₂ and B₂ in a continuous reactor. It considers a growing chain as being composed of A and B segments in the middle of the chain and two terminal segments at the chain ends. It calculates the propagation probabilities of these different types of segments upon taking into account both the polycondensation and side reaction kinetics as well as the residence time distribution of the continuous reactor. The method is validated by poly(butylene terephthalate) (PBT) obtained from an industrial polymerization process composed of a continuous esterification reactor. The MWDs of the PBT calculated by this method are in agreement with those measured by size exclusion chromatography with mean square errors less than 10%.     

Enhanced hydrate formation under mild conditions using a novel spiral-agitated reactor

Hydrate-based solidified natural gas (SNG) technology provides a promising approach to store and transport natural gas, but demanding formation conditions and low methane storage capacity limit its application. Here, we presented a novel spiral-agitated reactor, and hydrate formation in pure water and amino acid systems was evaluated. It is worth to highlight that spiral agitation significantly enhances initial hydrate grow kinetics, and satisfied methane uptake of 134.9 V/V was obtained under a mild condition (4.3 MPa, 275.15 K, and 30 rpm). Impressively, when amino acids were introduced, late hydrate growth was greatly improved because of secondary uptake, and a large methane uptake (145.97 V/V) was obtained under a milder condition (3.8 MPa, 275.15 K, and 60 rpm), which increases by 82.97% comparing to that in pure water systems. These findings provide a new insight (synergistic effect of spiral agitation and amino acids) on enhanced hydrate production under extremely mild conditions.     

Wet air oxidation in a catalytic membrane reactor: Model and industrial wastewaters in single tubes and multichannel contactors

Recent results on catalytic wet air oxidation applied to a membrane contactor are presented that give new insight following a series of previous publications. Model and industrial effluents are treated in both single tube and multichannel catalytic systems. Characterisation of the catalytic material (solid analyses, electron microscopy, EDS and EPMA) is carried out, in order to determine the catalyst distribution. Catalytic results show performances heavily dependent on the nature of the effluent and the operating conditions, and to a lesser extent on the catalytic membrane characteristics. At 80 °C, an industrial effluent is oxidised at a membrane surface related rate of 3.8 mmol/s/m². This result is achieved using a membrane containing about 0.1 wt.% Pt. This allows a revised and improved technico-economical evaluation of the Watercatox process.     

Oxidative dehydrogenation of propane over V2O5-MgO/TiO2 catalyst: Effect of reactants contact mode

The performance of the active catalyst 5%V₂O₅-1.9%MgO/TiO₂ in propane oxidative dehydrogenation is investigated under various reactant contact modes: co-feed and redox decoupling using fixed bed and co-feed using fluid bed. Using fixed bed reactor under co-feed conditions, propane is activated easily on the catalyst surface with selectivities ranging from 30 to 75% depending on the degree of conversion. Under varying oxygen partial pressures, especially for higher than the stoichiometric ratio O₂/C₃H₈ = 1/2, nor the propane conversion or the selectivities to propene and COx are affected. The performance of the catalyst in the absence of gas phase oxygen was tested at 400 °C. It was confirmed that the catalyst surface oxygen participates to the activation of propane forming propene and oxidation products with similar selectivities as those obtained under co-feed conditions. The ability of the catalyst to fully restore its activity by oxygen treatment was checked in repetitive reduction–oxidation cycles. Fluid bed reactor using premixed propane–oxygen mixtures was also employed in the study. The catalyst was proved to be very active in the temperature range 300–450 °C attaining selectivities comparable to those of fixed bed.     

HCR工艺处理高浓度氨氮有机废水

研究了高效好氧生物反应器(HCR)系统处理高浓度氨氮有机废水的可行性,对影响系统处理效果的因素进行了分析和探讨.结果表明:当进水中氨氮为2 000～2 200 mg/L、COD 500～9000 mg/L、pH 9.5～10.0,系统反应的水力停留时间7.0～7.5 h时,氨氮去除率最高达到72%以上,氨氮容积负荷最高达到4.8 kg/(m3·d)以上,COD容积负荷最高达到21.6 kg/(m3·d).说明HCR系统预处理高浓度氨氮有机废水可行.     

超声波内环流气升式反应器处理印染废水

采用超声波内环流气升式反应器对某印染厂印染废水进行处理研究。考察了反应时间、臭氧流量、超声声强对印染废水的脱色率及COD去除率的影响。结果表明,随着反应时间的增加,脱色率和COD去除率均增大,最佳反应时间为30 min;脱色率及COD去除率随着臭氧流量的增加而增大,最佳流量为200L/h;超声声强最佳值为0.5 W/cm2,此时脱色率及COD去除率分别为74.8%、35.6%。实验证明,对印染废水的脱色率及COD去除率,超声波内环流气升式反应器处理效果大于超声与臭氧单独作用简单之和,脱色率和COD去除率分别提高了23.0%和6.5%。超声波内环流气升式反应器结合了超声波的声化学作用及内环流气升式反应器供气效率高的特点,发挥了超声波与内环流气升式反应器的协同效应。     

Use of Water as a Solvent in Directing Hydrogenation Reactions of Aromatic Acids over Pd/carbon Nanofibre Catalysts

By conducting the catalytic hydrogenation over water miscible Pd/carbon nanofibre catalysts, selective ring hydrogenation of aromatic acids can be performed in aqueous solution without the need to provide protection for the external acid function.     

磺化技术及产品开发趋势

综述了磺化工艺技术及产品开发的国内外现状与发展趋势,认为磺化工艺及工程技术将出现严重的两极分化,一方面,传统型磺化产品(如LAS、AES、AS、AOS)的生产规模将进一步大型化、集约化、专业化,相应地要求SO3气体膜式磺化反应器的单台生产能力进一步增大,整套生产装置的自控水平进一步提高;另一方面,小批量、功能型磺化产品需求的旺盛促进了多种形式的磺化反应器及多种磺化工艺技术的开发。