scholarly journals Membrane Technologies in Wastewater Treatment: A Review

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 89 ◽  
Author(s):  
Elorm Obotey Ezugbe ◽  
Sudesh Rathilal

In the face of water shortages, the world seeks to explore all available options in reducing the over exploitation of limited freshwater resources. One of the surest available water resources is wastewater. As the population grows, industrial, agricultural, and domestic activities increase accordingly in order to cater for the voluminous needs of man. These activities produce large volumes of wastewater from which water can be reclaimed to serve many purposes. Over the years, conventional wastewater treatment processes have succeeded to some extent in treating effluents for discharge purposes. However, improvements in wastewater treatment processes are necessary in order to make treated wastewater re-usable for industrial, agricultural, and domestic purposes. Membrane technology has emerged as a favorite choice for reclaiming water from different wastewater streams for re-use. This review looks at the trending membrane technologies in wastewater treatment, their advantages and disadvantages. It also discusses membrane fouling, membrane cleaning, and membrane modules. Finally, recommendations for future research pertaining to the application of membrane technology in wastewater treatment are made.

2012 ◽  
Vol 65 (7) ◽  
pp. 1179-1189 ◽  
Author(s):  
S. Martin Ruel ◽  
J.-M. Choubert ◽  
H. Budzinski ◽  
C. Miège ◽  
M. Esperanza ◽  
...  

The next challenge of wastewater treatment is to reliably remove micropollutants at the microgram per litre range. During the present work more than 100 substances were analysed through on-site mass balances over 19 municipal wastewater treatment lines. The most relevant substances according to their occurrence in raw wastewater, in treated wastewater and in sludge were identified, and their fate in wastewater treatment processes was assessed. About half of priority substances of WFD were found at concentrations higher than 0.1 μg/L in wastewater. For 26 substances, potential non-compliance with Environmental Quality Standard of Water Framework Directive has been identified in treated wastewater, depending on river flow. Main concerns are for Cd, DEHP, diuron, alkylphenols, and chloroform. Emerging substances of particular concern are by-products, organic chemicals (e.g. triclosan, benzothiazole) and pharmaceuticals (e.g. ketoprofen, diclofenac, sulfamethoxazole, carbamazepine). About 80% of the load of micropollutants was removed by conventional activated sludge plants, but about two-thirds of removed substances were mainly transferred to sludge.


2021 ◽  
Author(s):  
Deniz Şahin

In recent times, membrane technology has proven to be a more favorable option in wastewater treatment processes. Membrane technologies are more advantageous than conventional technologies such as efficiency, space requirements, energy, quality of permeate, and technical skills requirements. The forward osmosis (FO) membrane process has been widely applied as one of the promising technologies in water and wastewater treatment. Forward osmosis uses the osmotic pressure difference induced by the solute concentration difference between the feed and draw solutions. The proces requires a semi-permeable membrane which has comparable rejection range in size of pollutants (1 nm and below). This chapter reviews the application of FO membrane process in wastewater treatment. It considers the advantages and the disadvantages of this process.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2343
Author(s):  
Maria Rosa di Cicco ◽  
Manuela Iovinella ◽  
Maria Palmieri ◽  
Carmine Lubritto ◽  
Claudia Ciniglia

Over the past decades, wastewater research has increasingly focused on the use of microalgae as a tool to remove contaminants, entrapping nutrients, and whose biomass could provide both material and energy resources. This review covers the advances in the emerging research on the use in wastewater sector of thermoacidophilic, low-lipid microalgae of the genus Galdieria, which exhibit high content of protein, reserve carbohydrates, and other potentially extractable high-value compounds. The natural tolerance of Galdieria for high toxic environments and hot climates recently made it a key player in a single-step process for municipal wastewater treatment, biomass cultivation and production of energetic compounds using hydrothermal liquefaction. In this system developed in New Mexico, Galdieria proved to be a highly performing organism, able to restore the composition of the effluent to the standards required by the current legislation for the discharge of treated wastewater. Future research efforts should focus on the implementation, in the context of wastewater treatment, of more energetically efficient cultivation systems, potentially capable of generating water with increasingly higher purity levels.


Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 793
Author(s):  
Anna Marszałek ◽  
Ewa Puszczało

The research in this article aimed to present the possibilities of wastewater treatment coming from the confectionery plant in the nanofiltration (NF) process and the use of photooxidation to mitigate membrane fouling. The process was carried out initially in a dead-end flow system, where the most favorable membrane was selected. Next, the purification efficiency and blocking intensity of this membrane in the system were compared with cross flow. The next research involved the use of a photolytic oxidation process to pretreat sugar wastewater. UV radiation was emitted by a medium pressure mercury UV lamp model TQ 150 V. The effectiveness of the process was also evaluated based on the degree of pollutant load removal. The evaluation of the efficiency of a treatment process was based on the change of wastewater quality indicators before and after the membrane process. The following parameters were controlled: color, COD (chemical oxygen demand), TOC (total organic carbon), absorbance of UV254, nitrate, phosphate, ammonium, conductivity, and pH. During the course of pressure filtration, the following properties of the membrane were determined: the dependence of the volumetric flux of the permeate on the process duration, the permeability of the membrane, as well as the contact angle of the membranes. It was found that the use of UV reduced the phenomenon of fouling of nanofiltration membranes. The value of the permeate volumetric flow after the hour of running the process increased by 17%. However, no impact of UV on the efficiency of wastewater treatment was found. However, the NF process provided the required quality of treated wastewater that can be reused in industrial applications. The NF process resulted in a total decrease in absorbance, 99% TOC removal, and 98% color removal.


2004 ◽  
Vol 50 (12) ◽  
pp. 119-124 ◽  
Author(s):  
K.W. Chau

The fractal structure and particle size of flocs are generally recognized as the two most crucial physical properties having impact on the efficiency of operation of several unit processes in water and wastewater treatment. In this study, an experimental investigation is undertaken on the effect of aggregate structure in water and wastewater treatment in Hong Kong. The fractal dimension of the resulting aggregate is employed as a measure of the aggregate structure. Small angle light scattering technique is used here. Different amounts of polymers are mixed to bacterial suspensions and the resulting structures are examined. The addition of polymer may foster aggregate formation by neutralization of the bacterial surface charge and enhance inter-particle bridging. The aggregation behavior may affect the efficiency of certain water and wastewater treatment processes such as dewatering and coagulation. The impacts of aggregate structure on two representative processes, namely, ultra-filtration membrane fouling and pressure filter dewatering efficiency, are studied. It is found that the looser flocs yield a more porous cake and less tendency to foul whilst more porous filter cakes yield more ready biosolids dewatering.


2001 ◽  
Vol 44 (11-12) ◽  
pp. 427-433 ◽  
Author(s):  
R.L. Craggs

Algal turf scrubbing (ATS) is a novel wetland technology that has been designed and engineered to promote natural wastewater treatment processes. Algal turf scrubbing improves water quality by passing a shallow stream of wastewater over the surface of a gently sloped floway. The floway is colonised by a natural heterogeneous assemblage of periphyton consisting of cyanobacteria, filamentous algae and epiphytic diatoms together with aerobic bacteria and fungi. Algal photosynthesis provides oxygen for aerobic breakdown of wastewater by heterotrophic bacteria. Pollutants are extracted from the wastewater by several processes including assimilation, adsorption, filtration and precipitation. The algal turf is harvested periodically to remove the accumulated periphyton biomass and associated pollutants from the system. This paper will present results from a demonstration ATS facility in Patterson, California which was used to polish secondarily treated wastewater. The design and operational factors that influence the treatment performance of ATS systems is discussed. Results indicate the potential of the ATS for nutrient removal from secondarily treated wastewater and agricultural drainage waters.


2021 ◽  
Vol 18 ◽  
Author(s):  
Rahul Silori ◽  
Syed Mohammad Tauseef

: In recent years, pharmaceutical compounds have emerged as potential contaminants in the aquatic matrices of the environment. High production, consumption, and limited removal through conventional treatment processes/wastewater treatment plants (WWTPs) are the major causes for the occurrence of pharmaceutical compounds in wastewater and aquatic environments worldwide. A number of studies report adverse health effects and risks to aquatic life and the ecosystem because of the presence of pharmaceutical compounds in the aquatic environment. This paper provides a state-of-the-art review of the occurrence of pharmaceutical compounds in treated wastewater from various WWTPs, surface water and groundwater bodies. Additionally, this review provides comprehensive information and pointers for research in wastewater treatment and waterbodies management.


2019 ◽  
Vol 80 (3) ◽  
pp. 541-550 ◽  
Author(s):  
Kito Ohmura ◽  
Christian M. Thürlimann ◽  
Marco Kipf ◽  
Juan Pablo Carbajal ◽  
Kris Villez

Abstract Today, the development and testing of methods for fault detection and identification in wastewater treatment research relies on two important assumptions: (i) that sensor faults appear at distinct times in different sensors and (ii) that any given sensor will function near-perfectly for a significant amount of time following installation. In this work, we show that such assumptions are unrealistic, at least for sensors built around an ion-selective measurement principle. Indeed, long-term exposure of sensors to treated wastewater shows that sensors exhibit fault symptoms that appear simultaneously and with similar intensity. Consequently, this suggests that future research should be reoriented towards methods that do not rely on the assumptions mentioned above. This study also provides the first empirically validated sensor fault model for wastewater treatment simulation, which is useful for effective benchmarking of both fault detection and identification methods and advanced control strategies. Finally, we evaluate the value of redundancy for remote sensor validation in decentralized wastewater treatment systems.


2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Inna Kamenev ◽  
Andres Viiroja ◽  
Juha Kallas

AbstractThe aim of the present research was to find a combination of biological and chemical oxidation processes that improves the purification efficiency of recalcitrant wastewater treatment at reduced ozone consumption. The following wastewater treatment processes were experimentally studied: conventional aerobic biooxidation, post-ozonation of biologically treated wastewater, a combined process - aerobic bio-oxidation with ozonation in a re-circulation system - and aerobic bio-oxidation with direct introduction of ozone-containing water into a bioreactor. A synthetic landfill leachate corresponding in its composition to leachate of young landfills, thermo-mechanical pulping water, and phenolic effluent from the Estonian oil shale industry were used as wastewaters. It was established that compared with conventional aerobic bio-oxidation, the combined process enables an improvement in purification efficiency even at relatively low ozone doses (10 to 60 mgO


1996 ◽  
Vol 33 (3) ◽  
pp. 59-72 ◽  
Author(s):  
Marcos von Sperling

The paper presents a series of tables, figures and charts which can be used for the preliminary selection of wastewater treatment systems, specially in developing countries. The systems analysed are: stabilization ponds, activated sludge, trickling filters, anaerobic systems and land disposal. Within each system, the main process variants are covered. A main summary table for quantitative analysis is presented, including easily usable information based on per capita values (US$/cap, W/cap, m2 area/cap, m3 sludge/cap). Other tables for qualitative comparison among systems are also included, one based on a one-to-five-star scoring and the other on a balance between advantages and disadvantages of the main treatment processes. The sludge treatment and disposal is also covered, including a comparative analysis based on a scoring system.


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