Design of Thermally Responsive Polymeric Hydrogels for Brackish Water Desalination: Effect of Architecture on Swelling, Deswelling, and Salt Rejection

Krisis air bersih khususnya di Kalimantan Selatan pada musim kemarau sering terjadi karena adanya intrusi air laut yang mengakibatkan air menjadi payau. Konsentrasi garam tinggi yang tidak sesuai baku mutu air bersih mengharuskan perlu adanya pengolahan. Oleh karena itu, proses desalinasi melalui pervaporasi menjadi pilihan untuk memisahkan kadar garam yang terlarut dalam air. Proses desalinasi dilakukan menggunakan membran silika yang dimodifikasi dengan menambahkan karbon dari pektin pisang untuk memperkuat struktur pori dan meningkatkan hidrostabilitas membran. Penelitian ini bertujuan untuk mengetahui kinerja membran silika-pektin pisang dengan metode pervaporasi (PV) menggunakan umpan air payau (NaCl 0,3 wt%) pada suhu ruang (~25°C). Bahan utama pada pembuatan membran ini adalah tetraethyl orthosilicate (TEOS). Membran silika-pektin pisang dengan konsentrasi 1% dikalsinasi pada suhu 300°C dan suhu 400°C melalui teknik RTP (Rapid Thermal Processing). Nilai fluks membran pada suhu kalsinasi 300°C sebesar 4,5 kg.m-2.jam-1 dengan nilai rejeksi garamnya sebesar 99,64 %. Sedangkan pada membran dengan suhu kalsinasi 400°C menghasilkan nilai fluks sebesar 13,2 kg.m-2.jam-1 dengan nilai rejeksi garam sebesar 99,78%. Kinerja kedua membran menunjukkan hasil yang sangat baik pada suhu kalsinasi 400°C dikarenakan adanya pengaruh penyisipan karbon dalam matriks silika sehingga pori yang terbentuk lebih kuat. Kata kunci: air payau, desalinasi air payau, membran silika-pektin, pektin pisang, pervaporasi. South Kalimantan during the dry season has been clean water scarcity, due to the sea water intrusion which formed brackish water. High salt concentration in brackish water is does not meet with clean water quality standards that necessary to processing before used. Therefore, the desalination process via pervaporation has chosen to separate the dissolved salt ions in water. The desalination process was carried out using a modified silica membrane by carbon templated from banana pectin to strengthen the pore structure and increase membrane hydro-stability. This work aims to determine the performance of banana silica-pectin membrane by pervaporation (PV) method, using brackish water (NaCl 0,3 wt%) at room temperature (~25°C). The main ingredient to make this membrane is tetraethyl orthosilicate (TEOS). Banana silica-pectin membrane with a concentration of 1% was calcined at 300 ° C and 400°C via RTP (Rapid Thermal Processing) technique. The water flux of membrane calcined at 300°C is 4,5 kg.m-2.h-1 with the salt rejection of 99,64%. Whereas the membrane in calcined temperature of 400°C produced a water flux of 13,2 kg.m-2.h-1 with a salt rejection of 99,78%. An excellent performance of both membranes showed at calcination temperature of 400°C due to the influence of carbon template in the silica matrices that makes the pores more robust. Keywords: banana pectin, brackish water, brackish water desalination, pervaporation, silica-pectin membrane.

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Potential of Nanofiltration for Brackish Water Desalination in Gaza Strip

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.233-235.2356 ◽

2011 ◽

Vol 233-235 ◽

pp. 2356-2358

Author(s):

A A. Abuhabib ◽

Abdul Wahab Mohammad ◽

Rakmi Abd-Rahman

Keyword(s):

Brackish Water ◽

Gaza Strip ◽

Rejection Rate ◽

Water Desalination ◽

Nanofiltration Membranes ◽

Operational Conditions ◽

Salt Rejection ◽

Good Potential ◽

Water And Wastewater ◽

And Performance

Nanofiltration membranes have proven their applicability in desalination as well as many other fields in water and wastewater industries. Two commercial nanofiltration membranes denoted as NF and ASP30 were chosen to be investigated in terms of their characteristics and performance in order to determine their suitability and applicability for brackish water desalination in Gaza Strip. In this work, membranes flux and rejection of two additional salts (Na2SO4 and KCl) is reported. Both membranes showed higher rejection rate for Na2SO4 (99% for NF and 75% for ASP30) when compared to KCl (36% for NF and 32% for ASP30). ASP30 had higher flux for both salts solutions (110 L.mˉ².hˉ¹ for Na2SO4 and 121 L.mˉ².hˉ¹ for KCl) while NF membrane had lower flux for both of them (78.4 L.mˉ².hˉ¹ for Na2SO4 and 72.5 L.mˉ².hˉ¹ for KCl). In addition, the variation of salt rejection versus permeation provides a possibility of optimizing operational conditions of both membranes. The results indicated good potential in applying both membranes to desalinate brackish water of Gaza Strip which is characterized by up to 2000 mg/l TDS of which Chloride is up to 700 mg/l.

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Optimization and economic analysis for a small scale nanofiltration and reverse osmosis water desalination system

Water Science & Technology Water Supply ◽

10.2166/ws.2015.059 ◽

2015 ◽

Vol 15 (5) ◽

pp. 1027-1033 ◽

Cited By ~ 3

Author(s):

Manoj Chandra Garg ◽

Himanshu Joshi

Keyword(s):

Predictive Model ◽

Reverse Osmosis ◽

Brackish Water ◽

Energy Demand ◽

Specific Energy Consumption ◽

Water Desalination ◽

Small Scale ◽

Water Recovery ◽

Salt Rejection ◽

Validation Experiment

This paper presents the results of a techno-economic investigation of a nanofiltration (NF) and reverse osmosis (RO) process for treating brackish water. Optimization experiments of six commercially available small scale RO and NF membranes were carried out using formulated artificial groundwater. A predictive model was developed by using response surface methodology (RSM) for optimization of input process parameters of brackish water membrane processes to simultaneously maximize water recovery and salt rejection while minimizing energy demand. A predictive model using multiple response optimization revealed that CSM RO and NF250 membranes showed the optimal efficiency with 20.24% and 18.98% water recovery, 90.22% and 70.64% salt rejection and 17.87 kWh/m3 and 9.35 kWh/m3 of specific energy consumption (SEC), respectively. Furthermore, confirmation of RSM predictions was carried out by an artificial neural network (ANN) model trained by RSM experimental data. Predicted values by both RSM and ANN modeling methodologies were compared and found within the acceptable range. Finally, a membrane validation experiment was carried out successfully at proposed optimal conditions, which proved the accuracy of the employed RSM and ANN models. Detailed analyses of the economic assessment showed that the recovery rate can play a major role in reducing the cost of a membrane system.

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Low-Resistance Monovalent-Selective Cation Exchange Membranes for Energy-Efficient Ion Separations

10.26434/chemrxiv.12555230.v1 ◽

2020 ◽

Author(s):

Eyal Wormser ◽

Oded Nir ◽

Eran Edri

Keyword(s):

Cation Exchange ◽

Brackish Water ◽

Molecular Layer ◽

Water Desalination ◽

Molecular Layer Deposition ◽

Selective Layer ◽

Trade Off ◽

Membrane Selectivity ◽

Layer Deposition ◽

Water Energy Nexus

<div> <div> <div> <p>The desalination of brackish water provides water to tens of millions of people around the world, but current technologies deplete much needed nutrients from the water, which is detrimental to both public health and agriculture. A selective method for brackish water desalination, which retains the needed nutrients, is electrodialysis (ED) using monovalent-selective cation exchange membranes (MVS-CEMs). However, due to the trade-off between membrane selectivity and resistance, most MVS-CEMs demonstrate either high transport resistance or low selectivity, which increase energy consumption and hinder the use of such membranes for brackish water desalination by ED. Here, we used molecular layer deposition (MLD) to uniformly coat CEMs with ultrathin layers of alucone. The positive surface charge of the alucone instills monovalent selectivity in the CEM. Using MLD enabled us to precisely control and minimize the selective layer thickness, while the flexibility and nanoporosity of the alucone prevent cracking and delamination. Under conditions simulating brackish water desalination, this compound provides monovalent selectivity with negligible added resistance—the smallest reported resistance for a monovalent-selective layer, to date—thereby alleviating the selectivity–resistance trade-off. Addressing the water–energy nexus, we show that using these membranes in ED will cut at least half of the energy required for selective brackish water desalination with current MVS-CEMs. </p> </div> </div> </div>

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