Membrane contactor processes for wastewater reclamation in space Part I. Direct osmotic concentration as pretreatment for reverse osmosis
Membrane contactor processes for wastewater reclamation in space Part I. Direct osmotic concentration as pretreatment for reverse osmosis
复制标题
DOI：
10.1016/j.memsci.2004.08.039
复制
发表时间：
2005-07-15
影响因子：
9.5
通讯作者：
Childress, AE
中科院分区：
文献类型：
--
作者：
Cath, TY;Gormly, S;Childress, AE
评估了一种创新系统，该系统结合了三种不同的膜工艺，用于在未来的太空任务中回收和再利用废水。直接渗透浓缩（DOC）系统由五个反渗透（RO）元件阵列组成，是一种直接渗透（DO）预处理过程。以及直接渗透/渗透蒸馏（DO/OD）组合预处理工艺。确定了三个子系统的优化操作条件，包括反渗透压力、盐水回路中的盐负荷和流速。测量了预处理过程中的传质和传热。研究发现 DO 工艺中的水通量很大程度上取决于所用膜的类型；对于专门为此应用设计的三醋酸纤维素膜，其范围为 10 至 251/(m(2)h)；对于市售 RO 膜，其范围为 0.5 至 2。还发现通过双 DO/OD 过程的水通量高度依赖于膜上的温度梯度——随着温度梯度的增加而增加。确定了系统最低能耗的条件，并将其用于估算处理太空产生的废水的具体能源成本。还估计了连续运行的盐补给重量。与替代技术相比，DOC 系统以较低的能源成本（< 90 x 10(3) J/l (25 Wh/l)）提供较高的废水回收率（> 95%），并且补给量最少（< 20 kg/年）。 (c) 2005 Elsevier B.V. 保留所有权利。
An innovative system that combines three different membrane processes for reclamation and reuse of wastewater in future space missions was evaluated. The direct osmotic concentration (DOC) system consists of an array of five reverse osmosis (RO) elements, a direct osmosis (DO) pretreatment process. and a combined direct osmosis/osmotic distillation (DO/OD) pretreatment process. Optimized operating conditions, including RO pressures, salt load in the brine loop, and flow velocities were determined for the three subsystems. Mass and heat transfer in the pretreatment processes were measured. Water flux in the DO process was found to be strongly dependent on the type of membrane used; it ranged from 10 to 251/(m(2)h) for a cellulose triacetate membrane specifically designed for this application and from 0.5 to 2 for commercially available RO membrane. Water flux through the dual DO/OD process was also found to be highly dependent on temperature gradient across the membranes-increasing with increasing temperature gradient. The conditions for minimum energy consumption of the system were determined and used in estimating the specific energy cost of treating the wastewater generated in space. The weight of salt resupply for continuous operation was also estimated. When compared to alternative technologies, the DOC system provides high wastewater recovery (> 95%), at low energy cost (< 90 x 10(3) J/l (25 Wh/l)), with minimal resupply (< 20 kg/year). (c) 2005 Elsevier B.V. All rights reserved.