Inland Treatment of the Brine Generated from Reverse Osmosis Advanced Membrane Wastewater Treatment Plant Using Epuvalisation System

The reverse osmosis (RO) brine generated from the Al-Quds University wastewater treatment plant was treated using an epuvalisation system. The advanced integrated wastewater treatment plant included an activated sludge unit, two consecutive ultrafiltration (UF) membrane filters (20 kD and 100 kD cutoffs) followed by an activated carbon filter and a reverse osmosis membrane. The epuvalisation system consisted of salt tolerant plants grown in hydroponic channels under continuous water flowing in a closed loop system, and placed in a greenhouse at Al-Quds University. Sweet basil (Ocimum basilicum) plants were selected, and underwent two consecutive hydroponic flowing stages using different brine-concentrations: an adaptation stage, in which a 1:1 mixture of brine and fresh water was used; followed by a functioning stage, with 100% brine. A control treatment using fresh water was included as well. The experiment started in April and ended in June (2012). At the end of the experiment, analysis of the effluent brine showed a remarkable decrease of electroconductivity (EC), PO₄³⁻, chemical oxygen demand (COD) and K⁺ with a reduction of 60%, 74%, 70%, and 60%, respectively, as compared to the influent. The effluent of the control treatment showed 50%, 63%, 46%, and 90% reduction for the same parameters as compared to the influent. Plant growth parameters (plant height, fresh and dry weight) showed no significant difference between fresh water and brine treatments. Obtained results suggest that the epuvalisation system is a promising technique for inland brine treatment with added benefits. The increasing of channel number or closed loop time is estimated for enhancing the treatment process and increasing the nutrient uptake. Nevertheless, the epuvalisation technique is considered to be simple, efficient and low cost for inland RO brine treatment.     

Reverse osmosis performance of organosilica membranes and comparison with the pervaporation and gas permeation properties

Hybrid organosilica membranes were successfully prepared using bis(triethoxysilyl)ethane (BTESE) and applied to reverse osmosis (RO) desalination. The organosilica membrane calcined at 300^°C almost completely rejected salts and neutral solutes with low‐molecular‐weight. Increasing the operating pressure led to an increase in water flux and salt rejection, while the flux and rejection decreased as salt concentration increased. The water permeation mechanism differed from the viscous flow mechanism. Observed activation energies for permeation were larger for membranes with a smaller pore size, and were considerably larger than the activation energy for water viscosity. The organosilica membranes exhibited exceptional hydrothermal stability in temperature cycles up to 90^°C. The applicability of the generalized solution‐diffusion (SD) model to RO and pervaporation (PV) desalination processes were examined, and the quantitative differences in water permeance were accurately predicted by the application of generalized transport equations. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1298–1307, 2013     

制药纯化水电导率及其制备

按照国内外药典对纯化水电导率的规定,建议制药用纯化水的电导率可小于5μS／cm,最低小于2μS／cm。对制药纯化水两级反渗透工艺与一级反渗透-混合床工艺的设备投资及运行成本比较,认为两级反渗透工艺,非常适用于制药行业。提出反渗透制水,可用陶瓷棒过滤器代替石英砂过滤器。介绍了表面带正电荷的膜在两级反渗透第二级应用的可行性。     

K2CO3生产中NH4Cl废水的回收技术

分析了反渗透的基本原理，详细介绍了采用反渗透膜分离技术回收利用K2CO3生产过程中产生的含NH4Cl废水的工艺过程。处理低浓度含NH4Cl废水100m^3／h和高浓度含NH4Cl废水40m^3／h工业化装置建成投产后，处理前低浓度废水含NH4Cl1000mg／L，高浓度废水含NH4Cl10000mg／L，pH=8～10；处理后，产品淡水含NH4Cl≤10mg／L、pH=7～8，产品浓水含NH4Cl≥60000mg／L、pH=8～lO。该装置的投运，取得了明显的经济效益和社会效益。     

反渗透膜的清洗

系统地介绍了膜污染的原因、污染物种类及清洗、防治方法。     

工业污水深度处理回用技术研究

通过对石化企业工业污水进行曝气生物滤池、连续微滤、反渗透等深度处理,使出水满足工业化用水的水质要求,从而得以回用。     

Targeting optimum resource allocation using reverse problem formulations and property clustering techniques

Decoupling the constitutive equations from the balance and constraint equations allows for reformulating a conventional forward problem into two reverse problems. The first reverse problem is the reverse of a simulation problem, where the process model is solved in terms of the constitutive (synthesis/design) variables instead of the process variables, thus providing the synthesis/design targets. The second reverse problem (reverse property prediction) solves the constitutive equations to identify unit operations, operating conditions and/or products by matching the synthesis/design targets. Visualization of the problem is achieved by employing recently developed property clustering techniques, which allows a high-dimensional problem to be visualized in two or three dimensions. The clusters by definition satisfy intra-stream and inter-stream conservation through linear “mixing” rules, which allows for the development of consistent additive rules along with their ternary representation.     

Removal of fluoride from electronic industrial effluentby RO membrane separation

The electronics industry generates large amounts of fluoride-containing effluents. The objective of this studyis to study the feasibility of applying reverse osmosis (RO) membrane separation to reduce fluoride load to less than 1 kg/d. The effect of transmembrane pressure on the removal of fluoride ion has been investigated in detail, and the design parameters of a small RO separation unit were estimated. The present study indicated that the rejection of fluoride ion is typically higher than 98%, considering that the RO membrane was fully regenerated after each set of experiments. The effect of upstream concentration on the required mechanical pressure was determined by estimating the theoretical osmotic pressure of the feed solution. For industrial effluents, the process developed in this work allows us to reduce the treated volume from 6 m³/d to 0.36 m³/d without any pretreatment or adding additional compounds. The cost of the designed RO separation plant (€76,000) is much less than that of the conventional treatment (€533/m³) that deals mainly with volumes rather than specific     

RO membrane solute rejection behavior at the initial stage ofcolloidal fouling

This study investigated the rejection of salt and inert organic compounds by reverse osmosis membranes during the initial stage of colloidal fouling. Results of laboratory-scale experiments showed that colloidal fouling caused a marked decrease in flux, salt rejection and rejection of organics with molecular weight (MW) smaller than about 100 g/mol. Removal of neutrally charged organics was mainly by size or steric exclusion. Rejection of xylose, which has MW >100 g/mol, was not affected much by colloidal fouling. The decrease in salt and low MW organic rejections during the initial stage of colloidal fouling was attributed to cake-enhanced concentration polarization, whereby the colloidal cake layer hindered back diffusion of solutes from the membrane surface to the bulk solution, resulting in higher solute concentration gradient across the membrane. At higher channel wall shear rate, the rates of colloidal deposition, flux decline, decrease in salt rejection, and decrease in low MW organic rejection were lower.     

Evaluation of wastewater reclamation processes in a high-tech industrial park

The objectives of this research were to evaluate two different processes using for wastewater reclamation in a hightech industrial park area in Taiwan. The major units of the first AC-RO-IE system included sand filter, an activated carbon (AC) bed, microfiltration module, a reverse osmosis (RO) membrane and ionic-exchange (IE) columns. The second DAF-AC-RO system was comprised of coagulation/flocculation, dissolved air flotation (DAF), an activated carbon bed, microfiltration module and reverse osmosis membrane units. This study was carried out at a pilot-scale plant in situ that operated for approximately 1 year. According to the long-term experimental results, both the AC-RO-IE and the DAF-AC-RO processes illustrated excellent performances on inorganic and organic contaminant removal. Comparing the removal efficiency of the filtration-AC units in the AC-RO-IE system with the coagulation-DAF-AC units in the DAF-AC-RO system, the removal efficiency of TDS, SiO₂ and COD increased by 19.8%, 70.1% and 44.4% in the latter system, respectively. In addition, the combination of PAC-coagulation and DAF units could improve hardness removal, modify the form of dissolved silica, and reduce the SDI and MFI values. It showed good potential as a pretreatment unit in wastewater reclamation processes. Therefore, based on the reclaimed wastewater quality and process operational stability, the DAF-AC-RO system was suggested as a potential process for further application.