scholarly journals Removal of Tetracycline Oxidation Products in the Nanofiltration Process

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 555
Author(s):  
Renata Żyłła ◽  
Stanisław Ledakowicz ◽  
Tomasz Boruta ◽  
Magdalena Olak-Kucharczyk ◽  
Magdalena Foszpańczyk ◽  
...  
Keyword(s):  
River Water ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Oxygen Demand ◽  
Oxidation Products ◽  
Amide Bond ◽  
Ozone Treatment ◽  
Xps Analysis ◽  
Filtration Process ◽  
H2o2 Oxidation

The possibility of removing tetracycline (TRC) from water in an integrated advanced oxidation and membrane filtration process was investigated. Ozonation and UV/H2O2 photooxidation were applied for the destruction of TRC. Six oxidation products (OPs) retaining the structural core of TRC have been identified. One new TRC oxidation product, not reported so far in the literature, was identified—ethyl 4-ethoxybenzoate. All identified OPs were effectively retained on the membrane in the nanofiltration process. However, chemical oxygen demand (COD) measurements of the filtrates showed that in the case of UV/H2O2 oxidation, the OPs passed through the membrane into the filtrate. Various water matrices were used in the research, including the river water untreated and after ozone treatment. It has been shown that organic matter present in surface water can improve pharmaceutical retention, although it contributes to significant membrane fouling. Pre-ozonation of the river water reduced the membrane fouling. The XPS analysis was used to show ozone and H2O2 influence on the top polymer layer of the membrane. It was shown that the oxidants can damage the amide bond of the polyamide.

Treatment of waste thermal waters by ozonation and nanofiltraton

2013 ◽  
Vol 67 (6) ◽  
pp. 1272-1279 ◽  
Author(s):  
Z. L. Kiss ◽  
A. Szép ◽  
S. Kertész ◽  
C. Hodúr ◽  
Z. László
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Oxygen Demand ◽  
Organic Content ◽  
Ozone Treatment ◽  
Thermal Waters ◽  
Toxic Compounds ◽  
Ozone Pretreatment ◽  
High Organic Content

After their use for heating, e.g. in greenhouses, waste thermal waters may cause environmental problems due to their high contents of ions, and in some cases organic matter (associated with an oxygen demand) or toxic compounds. The aims of this work were to decrease the high organic content of waste thermal water by a combination of ozone treatment and membrane separation, and to investigate the accompanying membrane fouling. The results demonstrated that the chemical oxygen demand and the total organic content can be effectively decreased by a combination of ozone pretreatment and membrane filtration. Ozone treatment is more effective for phenol elimination than nanofiltration alone: with a combination of the two processes, 100% elimination efficiency can be achieved. The fouling index b proved to correlate well with the fouling and polarization layer resistances.

scholarly journals Raw Water Storage as a Simple Means for Controlling Membrane Fouling Caused by Inorganic Foulants in River Water in a Tropical Region

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1592
Author(s):  
Hashimoto ◽  
Gunawan ◽  
Wattanachira ◽  
Wongrueng ◽  
Takizawa
Keyword(s):  
Organic Carbon ◽  
River Water ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Natural Waters ◽  
Water Storage ◽  
Storage Period ◽  
Tropical Region ◽  
Raw Water ◽  
Inorganic Substances

Natural waters in tropical countries are turbid and rich in inorganic substances such as iron and manganese. Hence, membrane fouling by these inorganic substances is the most serious problem in membrane filtration processes for potable water production. This study aimed to assess raw water storage as a simple but effective means for controlling membrane fouling in the filtration of river water in a tropical country. Raw water taken from the Ping River in Chiang Mai, Thailand, in different seasons, was either immediately filtered or stored in a tank for two days before filtration through a polyvinylidene difluoride (PVDF) membrane with a nominal pore size of 0.1 μm. The turbidity and particulate organic carbon (POC) in the raw water were reduced by storage, while dissolved manganese was oxidized during the storage period. Although the amounts of metallic substances retained on membranes were larger than those of silica and organic matter, their contribution to the fouling resistance was found to be less than silica and organic carbon. The fouling analysis using hydraulically irreversible fouling index (HIFI) was found to be not able to measure the effects of storage when the initial flux increased. Hence, the ratio of the hydraulically reversible fouling index (HRFI) to the total fouling index (TFI), i.e., HRFI/TFI, was proposed to elucidate the effects of raw water storage on membrane fouling, which was manifest during the early stage of membrane filtration operation.

scholarly journals A Simple Method to Identify the Dominant Fouling Mechanisms during Membrane Filtration Based on Piecewise Multiple Linear Regression

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 171 ◽  
Author(s):  
Hao Xu ◽  
Kang Xiao ◽  
Jinlan Yu ◽  
Bin Huang ◽  
Xiaomao Wang ◽  
...  
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Model Fitting ◽  
Multiple Linear Regression Model ◽  
Cake Filtration ◽  
Filtration Process ◽  
Simple Method

Membrane fouling is a complicated issue in microfiltration and ultrafiltration. Clearly identifying the dominant fouling mechanisms during the filtration process is of great significance for the phased and targeted control of fouling. To this end, we propose a semi-empirical multiple linear regression model to describe flux decline, incorporating the five fouling mechanisms (the first and second kinds of standard blocking, complete blocking, intermediate blocking, and cake filtration) based on the additivity of the permeate volume contributed by different coexisting mechanisms. A piecewise fitting protocol was established to distinguish the fouling stages and find the significant mechanisms in each stage. This approach was applied to a case study of a microfiltration membrane filtering a model foulant solution composed of polysaccharide, protein, and humic substances, and the model fitting unequivocally revealed that the dominant fouling mechanism evolved in the sequence of initial adaptation, fast adsorption followed by slow adsorption inside the membrane pores, and the gradual growth of a cake/gel layer on the membrane surface. The results were in good agreement with the permeate properties (total organic carbon, ultraviolet absorbance, and fluorescence) during the filtration process. This modeling approach proves to be simple and reliable for identifying the main fouling mechanisms during membrane filtration with statistical confidence.

scholarly journals Fabrication of a High Water Flux Conductive MWCNTs/PVC Composite Membrane with Effective Electrically Enhanced Antifouling Behavior

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1548
Author(s):  
Xi Chen ◽  
Jiabin Gao ◽  
Yunchang Song ◽  
Yaping Gong ◽  
Meng Qi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Composite Membrane ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Water Flux ◽  
Pvc Membrane ◽  
Filtration Process ◽  
Electrically Conductive ◽  
Electrically Assisted ◽  
Conductive Membrane

Membrane fouling is a major issue that deteriorates the performance of membrane filtration systems. The electrically assisted membrane filtration process is proven to be effective for alleviating membrane fouling. In this study, we synthesized an electrically conductive membrane by incorporating multiwalled carbon nanotubes (MWCNTs) into polyvinyl chloride (PVC). The synthesized membranes have larger porosity than the PVC membrane (incorporating polyethylene glycol (PEG)), and thus possess much higher water flux under the same testing conditions. The initial and stable water fluxes are 2033 L/(m2·h) and 750 L/(m2·h), respectively, which are much higher than that of the pure PVC membrane. More importantly, the membrane has higher surface charge density and excellent electrical conductivity, but the surface hydrophilicity and toughness decreased with the addition of the MWCNTs. The 25 wt % MWCNTs/PVC composite membrane possesses suitable electrical conductivity of 0.128 S/m. The same membrane shows electro-enhanced antifouling performance during the antifouling test with yeast as a model foulant because the external electric field (−2 V) impulses a strong repulsion force while producing some micro bubbles to repel the foulant; thus, the membrane fouling is suppressed. In the current study, we develop a simple method to fabricate the electrically conductive membrane for application in the electrically assisted membrane filtration process.

scholarly journals Assessment of vibration amplitude and transmembrane pressure on vibratory shear enhanced membrane filtration for treating dairy wastewater

2021 ◽  
Vol 50 (1) ◽  
pp. 42-53
Author(s):  
Sz. Gy. Szerencsés ◽  
S. Beszédes ◽  
Zs. László ◽  
G. Veréb ◽  
D. Szalay ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Vibration Amplitude ◽  
Membrane Filtration ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Transmembrane Pressure ◽  
Operational Parameters ◽  
Limit Values ◽  
Energy And Environment

AbstractIn this study, statistical analysis was performed to investigate the influence of operational parameters based on experimental results. The research aimed to know whether a long-term discontinuous module vibration operation is possible without adversely affecting filtration efficiency. Polymer membranes were compared by surface characteristics with contact angle measurements and selected for further membrane filtration experiments for dairy wastewater treatment. The effect of the main operational parameters, membrane module vibration amplitude (Avibr.) and transmembrane pressure (TMP), was investigated using a vibratory shear enhanced processing (VSEP) module with ultrafiltration (UF) and nanofiltration (NF) membranes. Components of the permeates, including chemical oxygen demand (COD), were measured, and membrane rejections were calculated to compare with threshold limit values. The results suggest that proper combination of Avibr. and TMP could mitigate membrane fouling. However, discontinuous module vibration resulted in more clogged membrane with lower fluxes, but slightly higher rejections. We conclude that investigating the significance of operational parameters is necessary for a wider, more energy and environment-friendly application in wastewater treatment.

scholarly journals Modeling of submerged membrane filtration processes using recurrent artificial neural networks

2020 ◽  
Vol 9 (1) ◽  
pp. 155
Author(s):  
Zakariah Yusof ◽  
Norhaliza Abdul Wahab ◽  
Syahira Ibrahim ◽  
Shafishuhaza Sahlan ◽  
Mashitah Che Razali
Keyword(s):  
Neural Network ◽  
Dynamic Behavior ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Dynamic Models ◽  
Transmembrane Pressure ◽  
Permeate Flux ◽  
Filtration Process ◽  
Absolute Deviation ◽  
Auto Regressive

<span lang="EN-US">The modeling of membrane filtration processes is a challenging task because it involves many interactions from both biological and physical operational behavior. Membrane fouling behaviour in filtration processes is complex and hard to understand, and to derive a robust model is almost not possible. Therefore, it is the aim of this paper to study the potential of time series neural network based dynamic model for a submerged membrane filtration process. The developed model that represent the dynamic behavior of filtration process is later used in control design of the membrane filtration processes. In order to obtain the dynamic behaviour of permeate flux and transmembrane pressure (TMP), a random step was applied to the suction pump. A recurrent neural network (RNN) structure was employed to perform as the dynamic models of a filtration process, based on nonlinear auto-regressive with exogenous input (NARX) model structure. These models are compared with the linear auto-regressive with exogenous input (ARX) model. The performance of the models were evaluated in terms of %<em>R<sup>2</sup></em>, mean square error (MSE,) and a mean absolute deviation (MAD). For filtration control performance, a proportional integral derivative (PID) controller was implemented. The results showed that the RNN-NARX structure able to model the dynamic behavior of the filtration process under normal conditions in short range of the filtration process. The developed model can also be a reliable assistant for two different control strategies development in filtration processes.</span>

scholarly journals Membrane Filtration as Post-Treatment of Rotating Biological Contactor for Wastewater Treatment

2021 ◽  
Vol 13 (13) ◽  
pp. 7287
Author(s):  
Sharjeel Waqas ◽  
Muhammad Roil Bilad ◽  
Nurul Huda ◽  
Noorfidza Yub Harun ◽  
Nik Abdul Hadi Md Nordin ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Post Treatment ◽  
Rotating Biological Contactor ◽  
Promising Alternative ◽  
Biological Performance ◽  
Development And Environment

A rotating biological contactor (RBC) offers a low energy footprint but suffers from performance instability, making it less popular for domestic wastewater treatment. This paper presents a study on an RBC integrated with membrane technology in which membrane filtration was used as a post-treatment step (RBC–ME) to achieve enhanced biological performance. The RBC and RBC–ME systems were operated under different hydraulic retention times (HRTs) of 12, 18, 24, and 48 h, and the effects of HRT on biological performance and effluent filterability were assessed. The results show that RBC–ME demonstrates superior biological performance than the standalone RBC. The RBC–ME bioreactor achieved 87.9 ± 3.2% of chemical oxygen demand (COD), 98.9 ± 1.1% ammonium, 45.2 ± 0.7% total nitrogen (TN), and 97.9 ± 0.1% turbidity removals. A comparison of the HRTs showed that COD and TN removal efficiency was the highest at 48 h, with 92.4 ± 2.4% and 48.6 ± 1.3% removal efficiencies, respectively. The longer HRTs also lead to better RBC effluent filterability. The steady-state permeability increased respectively by 2.4%, 9.5%, and 19.1% at HRTs of 18, 24, and 48 h, compared to 12 h. Our analysis of membrane fouling shows that fouling resistance decreased at higher HRTs. Overall, RBC–ME offered a promising alternative for traditional suspended growth processes with higher microbial activity and enhanced biological performance, which is in line with the requirements of sustainable development and environment-friendly treatment.

scholarly journals Polysulfone–Polyvinyl Pyrrolidone Blend Polymer Composite Membranes for Batik Industrial Wastewater Treatment

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 66
Author(s):  
Arifina Febriasari ◽  
Huriya ◽  
Annisa Hasna Ananto ◽  
Meri Suhartini ◽  
Sutrasno Kartohardjono
Keyword(s):  
Membrane Fouling ◽  
Industrial Wastewater ◽  
Membrane Filtration ◽  
Oxygen Demand ◽  
Composite Membranes ◽  
Mechanical Tests ◽  
Polyvinyl Pyrrolidone ◽  
Inversion Method ◽  
Water Contact ◽  
Polysulfone Membrane

Batik wastewater, in general, is colored and has high concentrations of BOD (biological oxygen demand), COD (chemical oxygen demand), and dissolved and suspended solids. Polysulfone (PSf)-based membranes with the addition of polyvinyl pyrrolidone (PVP) were prepared to treat batik industrial wastewater. PSf/PVP membranes were prepared using the phase inversion method with N-methyl-2 pyrrolidone (NMP) as the solvent. Based on the membrane characterization through FESEM, water contact angle, porosity, and mechanical tests showed a phenomenon where the addition of PVP provided thermodynamic and kinetic effects on membrane formation, thereby affecting porosity, thickness, and hydrophilicity of the membranes. The study aims to observe the effect of adding PVP on polysulfone membrane permeability and antifouling performance on a laboratory scale through the ultrafiltration (UF) process. With the addition of PVP, the operational pressure of the polysulfone membrane was reduced compared to that without PVP. Based on the membrane filtration results, the highest removal efficiencies of COD, TDS (total dissolved solid), and conductivity achieved in the study were 80.4, 84.6, and 83.6%, respectively, on the PSf/PVP 0.35 membrane operated at 4 bar. Moreover, the highest color removal efficiency was 85.73% on the PSf/PVP 0.25 operated at 5 bar. The antifouling performance was identified by calculating the value of total, reversible, and irreversible membrane fouling, wherein in this study, the membrane with the best antifouling performance was PSf/PVP 0.25.

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