scholarly journals Tertiary Treatment for Safely Treated Wastewater Reuse

2021 ◽  
Author(s):  
Nebil Belaid
Keyword(s):  
Membrane Fouling ◽  
Large Scale ◽  
Wastewater Reuse ◽  
Experimental Studies ◽  
Cross Flow ◽  
Treated Wastewater ◽  
Transmembrane Pressure ◽  
Tertiary Treatment ◽  
Quality Of Water ◽  
Total Process

The tertiary treatment of resulting water from a conventional biological treatment process is envisaged in the aim to obtain a high quality of water that can be reused for different purposes. This treatment is based on the integration of the membrane-based technologies in the total process of wastewater treatment. The experimental studies are carried out on a small pilot, equipped with different mineral membranes of micro and ultrafiltration. These membranes are used for the different tested processes (MF, MF-UF and cogulation-MF). The results obtained make it possible to attend a complete elimination of the total flora and an additional reduction of the other parameters such as turbidity, suspended matter, COD and BOD. Tests on a large scale are then carried out on a semi-industrial pilot, equipped with the same type of membranes. The optimization of the operating conditions made allow the obtaining under the conditions of transmembrane pressure 0.85 bar, a cross flow velocity of 2.25m/s and with ambient temperature a filtrate flux of about 200 L/hm 2. The coupling of a stage of coagulation in the membrane process allows the reduction of the effect of the membrane fouling and an improvement of 36% of the filtrate flux.

Gas sparged cross-flow microfiltration of biologically treated wastewater

2000 ◽  
Vol 41 (10-11) ◽  
pp. 173-180 ◽  
Author(s):  
L. Vera ◽  
S. Delgado ◽  
S. Elmaleh
Keyword(s):  
Shear Stress ◽  
Membrane Fouling ◽  
Cross Flow ◽  
Solid Content ◽  
Treated Wastewater ◽  
Inorganic Membrane ◽  
Form Complex ◽  
Cross Flow Filtration ◽  
Mass Transport Process ◽  
Flow Filtration

A novel technique was tested for reducing tubular mineral membrane fouling by injecting gas into a cross-flow stream. The injected gas is thought to form complex hydrodynamic conditions inside the microfiltration module, which increase the wall shear stress, preventing the membrane fouling and enhancing the microfiltration mass transfer. The experimental study was carried out with biologically treated wastewater filtered through a tubular inorganic membrane (Carbosep M14). The flux, monotonously increasing with gas velocity, was more than tripled. New dimensionless quantities of shear stress number and resistance number were developed by generalisation of the dimensional analysis already carried out for the steady state flux of classical unsparged cross-flow filtration. A unique formalism allowed then interpreting the experimental results of both classical diphasic filtration and sparged filtration. The main limiting mass transport process was due to the solid content.

scholarly journals Country-level and gridded estimates of wastewater production, collection, treatment and reuse

2021 ◽  
Vol 13 (2) ◽  
pp. 237-254
Author(s):  
Edward R. Jones ◽  
Michelle T. H. van Vliet ◽  
Manzoor Qadir ◽  
Marc F. P. Bierkens
Keyword(s):  
Large Scale ◽  
Western Europe ◽  
Wastewater Reuse ◽  
Treated Wastewater ◽  
Wastewater Management ◽  
Online Data ◽  
Untreated Wastewater ◽  
Country Level ◽  
Treated Wastewater Reuse ◽  
Global Population

Abstract. Continually improving and affordable wastewater management provides opportunities for both pollution reduction and clean water supply augmentation, while simultaneously promoting sustainable development and supporting the transition to a circular economy. This study aims to provide the first comprehensive and consistent global outlook on the state of domestic and manufacturing wastewater production, collection, treatment and reuse. We use a data-driven approach, collating, cross-examining and standardising country-level wastewater data from online data resources. Where unavailable, data are estimated using multiple linear regression. Country-level wastewater data are subsequently downscaled and validated at 5 arcmin (∼10 km) resolution. This study estimates global wastewater production at 359.4×109 m3 yr−1, of which 63 % (225.6×109 m3 yr−1) is collected and 52 % (188.1×109 m3 yr−1) is treated. By extension, we estimate that 48 % of global wastewater production is released to the environment untreated, which is substantially lower than previous estimates of ∼80 %. An estimated 40.7×109 m3 yr−1 of treated wastewater is intentionally reused. Substantial differences in per capita wastewater production, collection and treatment are observed across different geographic regions and by level of economic development. For example, just over 16 % of the global population in high-income countries produces 41 % of global wastewater. Treated-wastewater reuse is particularly substantial in the Middle East and North Africa (15 %) and western Europe (16 %), while comprising just 5.8 % and 5.7 % of the global population, respectively. Our database serves as a reference for understanding the global wastewater status and for identifying hotspots where untreated wastewater is released to the environment, which are found particularly in South and Southeast Asia. Importantly, our results also serve as a baseline for evaluating progress towards many policy goals that are both directly and indirectly connected to wastewater management. Our spatially explicit results available at 5 arcmin resolution are well suited for supporting more detailed hydrological analyses such as water quality modelling and large-scale water resource assessments and can be accessed at https://doi.org/10.1594/PANGAEA.918731 (Jones et al., 2020).

scholarly journals Effect of Photooxidation on Nanofiltration Membrane Fouling During Wastewater Treatment from the Confectionery Industry

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 793
Author(s):  
Anna Marszałek ◽  
Ewa Puszczało
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Cross Flow ◽  
Oxygen Demand ◽  
Industrial Applications ◽  
Treated Wastewater ◽  
Toc Removal ◽  
Before And After ◽  
Wastewater Quality ◽  
Uv Lamp

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.

Evaluation of Treatment Schemes Appropriate for Wastewater Reuse in Greece

2013 ◽  
Vol 5 (2) ◽  
pp. 1-8
Keyword(s):  
Uv Radiation ◽  
Wastewater Treatment Plants ◽  
Wastewater Reuse ◽  
Quality Criteria ◽  
Stochastic Approach ◽  
Experimental Information ◽  
Treated Wastewater ◽  
Secondary Effluent ◽  
Wastewater Reclamation ◽  
Tertiary Treatment

The scope of this paper is the evaluation of wastewater reuse quality criteria and treatment specifications, appropriate to Greek conditions. The parameters that affect wastewater reuse criteria were taken into consideration, concerning among others reuse priorities, available treatment plants and effluent characteristics. The proposed wastewater reclamation criteria were verified by a series of lab-scale experiments, designed to study the feasibility and effectiveness of the following treatment schemes to produce treated wastewater suitable for reuse: a) disinfection of secondary effluent with UV radiation and chlorination and b) tertiary treatment and disinfection of wastewater with UV radiation and chlorination. The experimental data were analyzed using a stochastic statistical model that employs Monte Carlo simulation. The main scope of the stochastic approach was the regeneration of a greater set of data, based on the defined by the experimental information mathematical distribution of each parameter involved and the determination of relative probability distributions. Following this approach the standards proposed are realistic and feasible and in the case of restricted reuse can be readily achieved by the existing wastewater treatment plants in Greece. Even in the case of unrestricted reuse the additional treatment required can be achieved at a moderate cost, through upgrading of the existing plants with tertiary treatment.

Tertiary treatment of secondary effluent using ultrafiltration for wastewater reuse: correlating membrane fouling with rejection of effluent organic matter and hydrophobic pharmaceuticals

2019 ◽  
Vol 5 (4) ◽  
pp. 672-683 ◽  
Author(s):  
Fangshu Qu ◽  
Hao Wang ◽  
Junguo He ◽  
Gongduan Fan ◽  
Zhihui Pan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Membrane Fouling ◽  
Wastewater Reuse ◽  
Secondary Effluent ◽  
Water Reclamation ◽  
Tertiary Treatment ◽  
Effluent Organic Matter ◽  
Retention Efficiency

Permeability loss and the low retention efficiency of soluble organics significantly restrict the application of ultrafiltration (UF) for water reclamation.

Cross-flow ultrafiltration for surface water treatment in North Thailand

2000 ◽  
Vol 41 (10-11) ◽  
pp. 69-76
Author(s):  
S. Takizawa ◽  
S. Babel ◽  
N. Pradhan ◽  
T. Prathomrungsiyunkul ◽  
K. Suwannarit ◽  
...  
Keyword(s):  
Surface Water ◽  
Membrane Fouling ◽  
Experimental Studies ◽  
Cross Flow ◽  
Variable Cross ◽  
Chemical Cleaning ◽  
Filtration Resistance ◽  
Cake Layer ◽  
The Cross ◽  
North Thailand

Experimental studies on cross-flow ultrafiltration were carried out to evaluate the applicability to treat surface water in North Thailand. Hollow-fiber UF modules (polyacrylonitrile, MWCO 13,000 daltons, I.D. 0.8 mm, and module length 1126 mm) were used in the experiments. While the permeation flux was controlled at 1.0 m/d, the cross-flow velocity was either fixed at 0.1 m/s or varied as the membrane fouling proceeded. The comparative study on fixed and variable cross-flow velocities revealed that the variable velocity operation was superior to achieve a longer operational period before chemical cleaning. Intensive backwashing was performed when the filtration resistance rose over 1013 m–1, which revealed that more than 80% of the resistance was caused by cake-layer that can be removed by the intensive backwashing. However, the operational period was only 54% of the one for the new membranes, which suggested that the percentage reduction of the filtration resistance should not be used as an index of the efficiency of chemical or physical membrane cleaning. Despite shortened operational periods, the intensive backwashing was proposed to be an easy and rapid method to recover the permeability of fouled membranes without chemical use. The cross-flow UF system used in this study was found to be easy to operate even in small water systems in developing countries.

scholarly journals Forward osmosis membrane fouling and cleaning for wastewater reuse

2016 ◽  
Vol 7 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Youngbeom Yu ◽  
Seockheon Lee ◽  
Sung Kyu Maeng
Keyword(s):  
Activated Sludge ◽  
Flow Velocity ◽  
Membrane Fouling ◽  
Suspended Solids ◽  
Wastewater Reuse ◽  
Forward Osmosis ◽  
Cross Flow ◽  
Short Period ◽  
Cross Flow Velocity ◽  
Cleaning Methods

Membrane fouling properties and different physical cleaning methods for forward osmosis (FO) and reverse osmosis (RO) laboratory-scale filtration systems were investigated. The membrane fouling, with respect to flux reduction, was lower in FO than in RO when testing an activated sludge effluent. Cross-flow velocity, air-scouring, osmotic backwashing and effect of a spacer were compared to determine the most effective cleaning method for FO. After a long period of fouling with activated sludge, the flux was fully recovered in a short period of osmotic backwashing compared with cleaning by changing cross-flow velocity and air-scouring. In this study, the osmotic backwashing was found to be the most efficient way to clean the FO membrane. The amount of RNA recovered from FO membranes was about twice that for RO membranes; biofouling could be more significant in FO than in RO. However, the membrane fouling in FO was lower than that in RO. The spacer increased the flux in FO with activated sludge liquor suspended solids of 2,500 mg/L, and there were effects of spacer on performance of FO–MBR membrane fouling. However, further studies are required to determine how the spacer geometry influences on the performance of the FO membrane.

scholarly journals A Step Forward to the Characterization of Secondary Effluents to Predict Membrane Fouling in a Subsequent Ultrafiltration

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1975
Author(s):  
Anderson Alejandro Benites-Zelaya ◽  
José Luis Soler-Cabezas ◽  
Eva Ferrer-Polonio ◽  
José Antonio Mendoza-Roca ◽  
María Cinta Vincent-Vela
Keyword(s):  
Membrane Fouling ◽  
Wastewater Reuse ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Ann Model ◽  
Tertiary Treatment ◽  
Mediterranean Countries ◽  
Membrane Technique ◽  
Artificial Neural Network Ann ◽  
Main Components

Nowadays, wastewater reuse in Mediterranean countries is necessary to cover the water demand. This contributes to the protection of the environment and encourages the circular economy. Due to increasingly strict regulation, the secondary effluent of a wastewater treatment plant requires further (tertiary) treatment to reach enough quality for its reuse in agriculture. Ultrafiltration is a membrane technique suitable for tertiary treatment. However, the most important drawback of ultrafiltration is membrane fouling. The aim of this work is to predict membrane fouling and ultrafiltered wastewater permeate quality for a particular membrane, using the information given by an exhaustive secondary effluent characterization. For this, ultrafiltration of real and simulated wastewaters and of their components after fractionation has been performed. In order to better characterize the secondary effluent, resin fractionation and further membrane ultrafiltration of the generated fractions and wastewater were performed. The results indicated that hydrophobic substances were lower than hydrophilic ones in the secondary effluent. Supelite DAX-8, Amberlite XAD-4 and Amberlite IRA-958 resins were found not to be specific for humic acids, proteins and carbohydrates, which are the main components of the effluent organic matter. Two models have been performed using statistics (partial least squares, PLS) and an artificial neural network (ANN), respectively. The results showed that the ANN model predicted permeate quality and membrane fouling with higher accuracy than PLS.

Fouling and long-term durability of an integrated forward osmosis and membrane distillation system

2015 ◽  
Vol 72 (11) ◽  
pp. 2000-2005 ◽  
Author(s):  
T. Husnain ◽  
B. Mi ◽  
R. Riffat
Keyword(s):  
Membrane Fouling ◽  
Tap Water ◽  
Membrane Surface ◽  
Wastewater Reuse ◽  
Forward Osmosis ◽  
Cross Flow ◽  
Domestic Wastewater ◽  
Membrane Distillation ◽  
Hydrophobic Membrane

An integrated forward osmosis (FO) and membrane distillation (MD) system has great potential for sustainable wastewater reuse. However, the fouling and long-term durability of the system remains largely unknown. This study investigates the fouling behaviour and efficiency of cleaning procedures of FO and MD membranes used for treating domestic wastewater. Results showed that a significant decline in flux of both FO and MD membranes were observed during treatment of wastewater with organic foulants. However, shear force generated by the increased cross-flow physically removed the loosely attached foulants from the FO membrane surface and resulted in 86–88% recovery of flux by cleaning with tap water. For the MD membrane, almost no flux recovery was achieved due to adsorption of organic foulants on the hydrophobic membrane surface, thus indicating significant irreversible fouling/wetting, which may not be effectively cleaned even with chemical reagents. Long-term (10 d) tests showed consistent performance of the FO membrane by rejecting the contaminants. However, organic foulants reduced the hydrophobicity of the MD membrane, caused wetting problems and allowed contaminants to pass through. The results demonstrate that combination of the FO and MD processes can effectively reduce irreversible membrane fouling and solve the wetting problem of the MD membrane.

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