Characterization of Fouling Potential for Pressure-Driven Membrane Processes: A New Simulated Flow Cell

1982 ◽  
Vol 14 (6-7) ◽  
pp. 499-522 ◽  
Author(s):  
R H Reed ◽  
G Belfort
Keyword(s):  
Water Quality ◽  
Flow Cell ◽  
Feed Water ◽  
Secondary Effluent ◽  
Membrane Systems ◽  
Membrane Processes ◽  
Wide Range ◽  
New Apparatus ◽  
Simulated Flow

Membrane systems are unit processes that are becoming widely accepted for the demineralization of saline and other waste waters. Dissolved and particulate material, specifically colloidal matter, present in the feed stream to membrane systems are considered the principal causes of membrane fouling and reduced efficiency. Conventional water analysis do not yield the information needed to determine the amount of fouling that will occur. Therefore, some rapid indication of the water quality and its potential to foul is needed. Presently there are five tests available to evaluate feed-water quality for membrane processes. However, in each of these tests the apparatuses used do not model tangential (shear) flow across the membrane surface. Therefore, a new apparatus was designed and constructed to predict how the feed water foulants would behave in a flow field. A new apparatus, named the Simulated Flow Cell (SFC), was developed and tested in the laboratory with feed waters containing polystyrene latex spheres (PSL) as foulants and in the field with well-water and precholorinated secondary effluent. The SFC reproduced essentially the same results as the standard non-flow cell when operated under the same conditions. However, the SFC was also able to model flow regimes to membrane systems. The Simulated Flow Cell was tested using irradiated polycarbonate membranes with pore diameters ranging from 0.1 µm to 1.0 µm. The feed water turbidity was varied during the testing by the addition of PSL spheres. Varying these parameters permitted data collection under a wide range of conditions. For laboratory feed water with the addition of PSL spheres, a theoretically expected threshold velocity was observed with the SFC using 0.1 µm pore diameter membranes. The threshold axial velocity was directly proportional to the square root of the initial flux through the 0.1 µm Nuclepore membranes, which is in agreement with data collected from actual hyperfiltration plant operations. The Simulated Flow Cell is a low cost apparatus for the rapid characterization of permeator feed waters. The Simulated Flow Cell promises to become an important tool in the ever widening use of membrane processes in water and wastewater applications.

scholarly journals Heat Transfer Analysis and Water Quality in Saline Water Desalination Using Solar Energy in Vacuum Condition

2018 ◽  
Vol 2 (1) ◽  
pp. 66
Author(s):  
Riana Ayu Kusumadewi ◽  
Suprihanto Notodarmodjo ◽  
Qomarudin Helmy
Keyword(s):  
Heat Transfer ◽  
Water Quality ◽  
Saline Water ◽  
Quality Standard ◽  
Water Desalination ◽  
Heat Transfer Analysis ◽  
Total Hardness ◽  
Feed Water ◽  
Distilled Water

The continues deficiency of consumable water is a significant issue in developing countries, and contaminated water can result in various diseases, which are often lethal. Solar desalination seems to be a promising method and alternative way for supplying fresh water. <strong>Aim:</strong> The aim of this research is to study heat transfer in desalination system and the quality of feed water, distilled water and brine compared to the quality standard. Feed water consists of salinity 12‰ and 38‰ salinity. <strong>Methodology and Result:</strong> At first, initial characterization of feed water was conducted, then temperature on fourteen points was measured using thermocouples and thermometer so heat transfer rate can be calculated. After that, the final characterization of water production was conducted. From the  observation, it was found that evaporative heat transfer for vacuum pressure of -0.05, -0.1, -0.15, -0.2, -0.25, and -0.3 bar respectively were 173.77, 180.07, 190.79, 481.66, 242.57, and 246.24 W/m2. The result of water quality test of distilled water produced from saline water desalination for some parameters respectively were pH 7.4; turbidity 2.73 NTU; TDS 27.45 mg/L; chloride 84.98 mg/L; Fe 2.13 mg/L; total hardness 0.1698 mg/L; and <em>Escherichia coli</em> 12 cell/mL . <strong>Conclusion, significance and impact study:</strong> It can be concluded that distilled water produced by desalination system was met drinking water quality standard according to Minister of Health Regulation No. 492 of 2010.

scholarly journals Removal Characteristics of N-Nitrosamines and Their Precursorsby Pilot-Scale Integrated Membrane Systems for Water Reuse

2018 ◽  
Author(s):  
Haruka Takeuchi ◽  
Naoyuki Yamashita ◽  
Norihide Nakada ◽  
Hiroaki Tanaka
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Pilot Scale ◽  
Feed Water ◽  
Size Distributions ◽  
Membrane Systems ◽  
Chemical Cleaning ◽  
Membrane Processes ◽  
Ro Membrane ◽  
Feed Water Temperature

This study investigated the removal characteristics of N-nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF) / nanofiltration (NF) / RO; (2) sand filtration/three-step RO; and (3) ultrafiltration (UF) / NF and UF / RO. Variable removal of N-nitrosodimethylamine (NDMA) by the RO membrane processes could be attributable to membrane fouling and feed water temperature. The effect of membrane fouling on N-nitrosamines removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO membrane element. Membrane fouling enhanced N-nitrosamines removal by the pilot-scale RO membrane process. This finding contributes to better understanding of variable removal of NDMA by RO membrane processes. This study also investigated the removal characteristics of N-nitrosamines precursors. The NF and RO membrane processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO membrane processes for reducing FPs of NDMA, N-nitrosopyrrolidine (NPYR) and N-nitrosodiethylamine (NDEA) were different, suggesting different size distributions of their precursors.

A study about the use of chemicals in conventional tertiary treatment. Performances comparison of three municipal wastewater treatment plants and pilot plant experiences

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
A. Iborra-Clar ◽  
J.A. Mendoza-Roca ◽  
A. Bes-Pií ◽  
J.J. Morenilla-Martínez ◽  
I. Bernácer-Bonora ◽  
...  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Wastewater Reclamation ◽  
Valencian Region ◽  
Municipal Wastewater Treatment Plants

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.

Polymer Chemistry

2004 ◽  
Keyword(s):  
Conducting Polymers ◽  
Liquid Crystalline ◽  
Polymer Chemistry ◽  
Chain Growth ◽  
Crystalline Polymers ◽  
Wide Range ◽  
Cyclic Oligomers ◽  
Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

scholarly journals Organelle Genetics in Plants

2021 ◽  
Vol 22 (4) ◽  
pp. 2104
Author(s):  
Pedro Robles ◽  
Víctor Quesada
Keyword(s):  
Rna Editing ◽  
Posttranscriptional Regulation ◽  
Genome Engineering ◽  
Plant Mitochondria ◽  
Plastid Dna ◽  
Chloroplast Genomes ◽  
Wide Range ◽  
Organelle Genetics ◽  
Selection Of

Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled “Organelle Genetics in Plants.” This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.

scholarly journals Advances and Applications of Water Phytoremediation: A Potential Biotechnological Approach for the Treatment of Heavy Metals from Contaminated Water

2021 ◽  
Vol 18 (10) ◽  
pp. 5215
Author(s):  
Cristián Raziel Delgado-González ◽  
Alfredo Madariaga-Navarrete ◽  
José Miguel Fernández-Cortés ◽  
Margarita Islas-Pelcastre ◽  
Goldie Oza ◽  
...  
Keyword(s):  
Water Quality ◽  
Plant Species ◽  
Treatment Strategies ◽  
Pollution Sources ◽  
Water Contaminants ◽  
Biotechnological Approach ◽  
Wide Range ◽  
Great Relevance ◽  
Multidisciplinary Perspective ◽  
Viable Method

Potable and good-quality drinking water availability is a serious global concern, since several pollution sources significantly contribute to low water quality. Amongst these pollution sources, several are releasing an array of hazardous agents into various environmental and water matrices. Unfortunately, there are not very many ecologically friendly systems available to treat the contaminated environment exclusively. Consequently, heavy metal water contamination leads to many diseases in humans, such as cardiopulmonary diseases and cytotoxicity, among others. To solve this problem, there are a plethora of emerging technologies that play an important role in defining treatment strategies. Phytoremediation, the usage of plants to remove contaminants, is a technology that has been widely used to remediate pollution in soils, with particular reference to toxic elements. Thus, hydroponic systems coupled with bioremediation for the removal of water contaminants have shown great relevance. In this review, we addressed several studies that support the development of phytoremediation systems in water. We cover the importance of applied science and environmental engineering to generate sustainable strategies to improve water quality. In this context, the phytoremediation capabilities of different plant species and possible obstacles that phytoremediation systems may encounter are discussed with suitable examples by comparing different mechanistic processes. According to the presented data, there are a wide range of plant species with water phytoremediation potential that need to be studied from a multidisciplinary perspective to make water phytoremediation a viable method.

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