电渗析深度处理二级出水实现零排放和资源回收

采用电渗析法对二级出水进行深度处理实现"零排放",同时实现氮磷等资源的回收,考察了流速、电压和浓缩室电导率对脱盐率和氮磷回收率的影响。实验采用三膜对结构,结果表明,淡化室脱盐效果明显,电导率均可降到1μS/cm,氯离子、硝酸根和磷酸根去除率均在98%以上。改变反应器流速,发现流速较大时离子迁移更快,氮磷去除速率和回收率更高。减小外加电压,实验运行时间较长,迁移离子较慢,磷回收率下降。改变浓缩室电导率,电流效率和能量消耗等均未发生明显变化。     

浓盐水零排放技术的研究进展

浓盐水中含有丰富的矿物质等资源,对其进行零排放处理,不仅可以消除浓盐水对海洋环境的污染,同时还可实现对浓盐水中矿物质等资源的有效利用。本文分析了浓盐水中盐分、温度、金属污染物和化学药剂等对海洋生态环境的影响,介绍了对浓盐水进行综合利用的技术,重点阐述了膜蒸馏、正渗透、冷冻法和喷雾脱水法等浓盐水再浓缩处理技术的基本原理、影响因素及其工程实例。最后指出了浓盐水再浓缩处理技术和浓盐水综合利用技术相结合是实现浓盐水零排放的有效途径。     

Experimental studies on dynamic process of energy recovery device for RO desalination plants

A two-chamber hydraulic energy recovery unit with a programmable controller and a data acquisition system was set up. Tap water was used as the working fluid instead of the actual seawater and concentrate in SWRO desalination plants. Experimental results were obtained on the fluctuations of the pressure and flow rate to and from the energy recovery unit. Characteristics of the pressure at the chamber ends were discussed at the conditions of the chambers set horizontally or vertically, with and without pistons.     

Pilot plant synthesis of n-propyl propionate via reactive distillation with decanter separator for reactant recovery. Experimental model validation and simulation studies

Successful process intensification (PI) stories applied broadly are the reactive distillation (RD) processes used in esterification syntheses. One application is developed here with the heterogeneously catalyzed synthesis of n  -propyl propionate (ProPro) from 1-propanol (ProOH) and propionic acid (ProAc). In this investigation, conventional RD of ProPro was further improved. With the objective to recover product and reactant, an experimental column set-up was equipped with a decanter on top enabling to separate the distillate product into two main streams. The aqueous phase was discharged and part of the organic phase was refluxed back to the column. Experimental results comprising temperature and composition column profiles were obtained in a pilot-scale column (DN-50), equipped with structured packings (Sulzer BX and Katapak-SP 11 with Amberlyst 46™ for the reactive part). For simulation studies a non-equilibrium stage model (NEQ model) was applied which shows satisfactory agreement with the performed experiments. Further theoretical investigations of relevant operating parameters (total feed, molar feed ratio, reflux ratio and heat duty) and their effect on the overall process performance were realized. Studies with the given column configuration showed that product purity in the bottom stream could be increased to wProPro,bottom=91.0%$w_{\text{ProPro,bottom}}=91.0\%$ and maximum ProAc conversions to X_ProAc = 94.5%.     

硫酸钾尾液冷冻回收高硫钾比矿物工艺研究

以硫酸钾尾液为原料,研究低温冷冻回收高硫钾比矿物合理的工艺技术路线,探寻适宜的贮存条件,为加工车间夏季高温生产硫酸钾提供优质高硫钾比原料.在低温下进行冷冻试验,根据冷冻结晶矿物产率及其干基组分确定适宜的冷冻温度为-15～5℃,冷冻制得的结晶矿物硫钾比均在3.0～5.1,符合夏季生产硫酸钾所需原料硫钾比>2.5的要求.高...     

好氧-缺氧高效分离生物流化复合反应器处理生活污水的中试研究

鉴于污水处理中对氮、磷去除率的要求和内循环二相生物流化床反应器存在的不足,开发了一种一体化好氧-缺氧高效分离生物流化复合反应器(HSBCR)。HSBCR好氧循环流化区采用了独特的分格结构,并且在同一个反应器中实现了好氧,缺氧分区运行。HSBCR中试反应器处理生活污水的结果表明,随着好氧区水力停留时间从10 h延长到25 h,反应器对NH3-N的去除效果上升,对总氮的去除效果表明该反应器具有较好的反硝化效果。     

New perspectives on maturity method and approach for high performance concrete applications

This paper presents a maturity concept and approach of applying the maturity method for predicting the development of mechanical properties of high-performance concrete over time. An examination of the activation energy and assumptions taken in the developmental process of the existing maturity method is first presented to better understand the capabilities and limitations of the maturity method, which is supported by new and existing experimental evidence. A practical approach is then proposed in which the activation energy is determined mathematically by minimizing the error between the predictions and experimental data. It is based on a new concept that the same maturity is defined only when different specimens of the same concrete have achieved the same level of a specified property under different curing temperatures. This concept makes the maturity approach more robust and more general for application to different concrete mix formulations and different types of property. The accuracy and feasibility of the proposed approach were successfully confirmed by experimental evidence.