scholarly journals Membrane Distillation for Wastewater Treatment: A Mini Review

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3480
Author(s):  
Zhongsen Yan ◽  
Yuling Jiang ◽  
Lingshan Liu ◽  
Zhongsheng Li ◽  
Xiaolei Chen ◽  
...  

Water serves as an indispensable part of human life and production. On account of the overexploitation of traditional water sources, the demand for wastewater recycling is expanding rapidly. As a promising water treatment process, membrane distillation (MD) has been utilized in various wastewater treatments, such as desalination brine, textile wastewater, radioactive wastewater, and oily wastewater. This review summarized the investigation work applying MD in wastewater treatment, and the performance was comprehensively introduced. Moreover, the obstructions of industrialization, such as membrane fouling, membrane wetting, and high energy consumption, were discussed with the practical investigation. To cope with these problems, various strategies have been adopted to enhance MD performance, including coupling membrane processes and developing membranes with specific surface characteristics. In addition, the significance of nutrient recovery and waste heat utilization was indicated.

2019 ◽  
Vol 360 ◽  
pp. 1330-1340 ◽  
Author(s):  
Sebastian Leaper ◽  
Ahmed Abdel-Karim ◽  
Tarek A. Gad-Allah ◽  
Patricia Gorgojo

2020 ◽  
Vol 20 (7) ◽  
pp. 2858-2874
Author(s):  
Mostafa Abd El-Rady Abu-Zeid ◽  
Xiaolong Lu ◽  
Shaozhe Zhang

Abstract The low flux and high energy consumption problems of the conventional three-stage air-gap membrane distillation (AG-AG-AG)MD system caused by the low temperature difference between hot and cold feed at both sides of the membrane and high boundary layer thickness were solved successfully by replacing one of the three stages of air gaps by a water gap. The novel three-stage air-gap–water-gap membrane distillation (AG-AG-WG)MD system reduced energy consumption and increased flux due to efficient internal heat recycling by virtue of a water-gap module. Heat and mass transfer in novel and conventional three-stage systems were analyzed theoretically. Under a feed temperature of 45 °C, flow rate of 20 l/h, cooling temperature of 20 °C, and concentration of 340 ppm, the (AG-AG-WG)MD promoted flux by 17.59% and 211.69%, and gained output ratio (GOR) by 60.57% and 204.33% compared with two-stage (AG-WG)MD and one-stage AGMD, respectively. This work demonstrated the important role of a water gap in changing the heat and mass transfer where convection heat transfer across the water gap is faster by 24.17 times than conduction heat transfer through the air gap. The increase in flux and GOR economized the heating energy and decreased waste heat input into the system. Additionally, the number of MD stages could increase the achieving of a high flux with operation stability.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3515
Author(s):  
Yiqing Zhang ◽  
Kashif Shaad ◽  
Derek Vollmer ◽  
Chi Ma

Textile manufacturing is a multi-stage operation process that produces significant amounts of highly toxic wastewater. Given the size of the global textile market and its environmental impact, the development of effective, economical, and easy-to handle alternative treatment technologies for textile wastewater is of significant interest. Based on the analysis of peer-reviewed publications over the last two decades, this paper provides a comprehensive review of advanced oxidation processes (AOPs) on textile wastewater treatment, including their performances, mechanisms, advantages, disadvantages, influencing factors, and electrical energy per order (EEO) requirements. Fenton-based AOPs show the lowest median EEO value of 0.98 kWh m−3 order−1, followed by photochemical (3.20 kWh m−3 order−1), ozonation (3.34 kWh m−3 order−1), electrochemical (29.5 kWh m−3 order−1), photocatalysis (91 kWh m−3 order−1), and ultrasound (971.45 kWh m−3 order−1). The Fenton process can treat textile effluent at the lowest possible cost due to the minimal energy input and low reagent cost, while Ultrasound-based AOPs show the lowest electrical efficiency due to the high energy consumption. Further, to explore the applicability of these methods, available results from a full-scale implementation of the enhanced Fenton technology at a textile mill wastewater treatment plant (WWTP) are discussed. The WWTP operates at an estimated cost of CNY ¥1.62 m−3 (USD $0.23 m−3) with effluent meeting the China Grade I-A pollutant discharge standard for municipal WWTPs, indicating that the enhanced Fenton technology is efficient and cost-effective in industrial treatment for textile effluent.


2018 ◽  
Vol 26 (3(129)) ◽  
pp. 104-109 ◽  
Author(s):  
Maciej Thomas ◽  
Krzysztof Barbusiński ◽  
Simona Kliś ◽  
Ewa Szpyrka ◽  
Marek Chyc

The article attempts to assess the usefulness of the Taguchi method to optimise the purification process of synthetic textile wastewater (pH 6.7 - 7.2, Conductivity = 6.71 - 6.84 mS/cm, Salinity = 3581 - 3648 mg NaCl/l, Colour = 560 - 4710 mg Pt/l, COD = 2220 - 2290 mg O2/l, TOC = 394 - 551 mg/l) using K2FeO4. The research was conducted using 3 types of wastewater containing anionic detergent (sodium lauryl sulfate, 100 mg/l) and differing only in the concentration of azo dye Acid Green 16 (AG 16). Technical K2FeO4 was used as an oxidiser, which was subjected to physico-chemical analysis (purity, UV-VIS spectrum, surface characteristics and chemical composition using SEM and EDX methods). For planning and optimising the wastewater treatment process, the Taguchi method was used for four input parameters: pH (2, 7, 12), reaction time (10, 30, 50 min), AG 16 concentrations (20, 120, 220 mg/l) and K2FeO4 concentrations (25, 125, 225 mg/l), for which 9 experiments were performed in accordance with the plan adopted. Test result analysis allowed to indicate the optimal values for individual input parameters (pH 2, time = 50 min, AG 16 = 20 mg/l, K2FeO4 = 125 mg/l). Under these conditions, visual discoloration of wastewater was obtained (AG 16 = 0.4 mg/l, ↓98% ), colour removal (66 mg Pt/l, ↓88%) and DOC (249 mg/l, ↓37%).


2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Hilal Al Maawali ◽  
Dr. Jimoh Kayode Adewole ◽  
Asma Al Kharusi ◽  
Jihan Al-Qartoubi ◽  
Maryam Al Maamari ◽  
...  

The essence of water in our everyday activities cannot be overemphasized. The major source of water in the Middle East is seawater and the most widely used technique for water treatment is Reverse osmosis (RO). However, the major challenge in the use of RO is the high-energy consumption resulting from the need for pumping at very high pressure. In this research work, the capability of a low-pressure Membrane Distillation (MD) technique as a replacement for RO was evaluated. A comparative study of MD and RO was done using process intensification, cost estimation, and process economic approach. The study was performed using process intensification metrics including mass intensity; waste intensity; productivity/size ratio; productivity/weight ratio; flexibility and modularity. The cost estimation involving the capital and operating expenses for RO and MD desalination plants was also determined based on the productivity of the plants. Moreover, process economic factors including profits, cash flow, and cumulative cash flow were also evaluated. The preliminary results obtained showed that the MD and RO possess the same capability to be used in the desalination plant based on process intensification. In addition, MD can be preferred in a situation where waste heat can be harnessed from neighboring industries. MD can also be better than RO with respect to the resistance of MD membrane materials to fouling. On the other hand, MD is more expensive than RO based on cost estimation and process economic results obtained.


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