A Case Study of Decentralized Off-Grid Water Treatment Using Reverse Osmosis

Author(s):  
Reza Baghaei Lakeh ◽  
Daniel Andrade ◽  
Kyle J. Miller ◽  
Bowen Du ◽  
Joshua Pham ◽  
...  

Decentralized water treatment consists of a variety of water treatment techniques for dwellings, industrial facilities, homes, and businesses independent of the power grid. According to the United States Geological Survey, brackish groundwater is abundant in the southwestern states including California; hence it can potentially be considered a new source for California’s water portfolio. Most of membrane-based desalination technologies (e.g. reverse osmosis) have high energy demand and cost. Using renewable energy (mostly solar photovoltaics) in concert with membrane-based water desalination can be utilized to develop decentralized and off-grid brackish water desalination systems especially for remote and rural regions. In this paper, the results of a case study on decentralized off-grid brackish water system have been presented and discussed. The system utilizes a high pressure pump that can provide a feed flow rate of 2.2 gpm of at 140 psi. The system is run by solar photovoltaic panels through a battery bank. The results of the study show that the system is capable of treating brackish water at a salt rejection rate of more than 97.5% and a recovery rate up to 80%.

2015 ◽  
Vol 15 (5) ◽  
pp. 1027-1033 ◽  
Author(s):  
Manoj Chandra Garg ◽  
Himanshu Joshi

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.


Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 616
Author(s):  
Jeffrey L. Pearson ◽  
Peter R. Michael ◽  
Noreddine Ghaffour ◽  
Thomas M. Missimer

Brackish water desalination, using the reverse osmosis (BWRO) process, has become common in global regions, where vast reserves of brackish groundwater are found (e.g., the United States, North Africa). A literature survey and detailed analyses of several BWRO facilities in Florida have revealed some interesting and valuable information on the costs and energy use. Depending on the capacity, water quality, and additional scope items, the capital cost (CAPEX) ranges from USD 500 to USD 2947/m3 of the capacity (USD 690–USD 4067/m3 corrected for inflation to 2020). The highest number was associated with the City of Cape Coral North Plant, Florida, which had an expanded project scope. The general range of the operating cost (OPEX) is USD 0.39 to USD 0.66/m3 (cannot be corrected for inflation), for a range of capacities from 10,000 to 70,000 m3/d. The feed-water quality, in the range of 2000 to 6000 mg/L of the total dissolved solids, does not significantly impact the OPEX. There is a significant scaling trend, with OPEX cost reducing as plant capacity increases, but there is considerable scatter based on the pre- and post-treatment complexity. Many BWRO facilities operate with long-term increases in the salinity of the feedwater (groundwater), caused by pumping-induced vertical and horizontal migration of the higher salinity water. Any cost and energy increase that is caused by the higher feed water salinity, can be significantly mitigated by using energy recovery, which is not commonly used in BWRO operations. OPEX in BWRO systems is likely to remain relatively constant, based on the limitation on the plant capacity, caused by the brackish water availability at a given site. Seawater reverse osmosis facilities, with a very large capacity, have a lower OPEX compared to the upper range of BWRO, because of capacity scaling, special electrical energy deals, and process design certainty.


Desalination ◽  
1977 ◽  
Vol 24 (1-3) ◽  
pp. 341-364 ◽  
Author(s):  
G. Boari ◽  
C. Carrieri ◽  
P. Mappelli ◽  
M. Santori

2020 ◽  
Vol 135 ◽  
pp. 106729 ◽  
Author(s):  
Alanood A. Alsarayreh ◽  
M.A. Al-Obaidi ◽  
A.M. Al-Hroub ◽  
R. Patel ◽  
I.M. Mujtaba

2009 ◽  
Vol 3 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Jian-Jun Qin ◽  
Boris Liberman ◽  
Kiran A. Kekre ◽  
Ado Gossan

Reverse osmosis (RO) has been widely applied in various water and wastewater treatment processes as a promising membrane technology. However, RO membrane fouling is a global issue, which limits it operating flux, decreases water production, increases power consumption and requires periodical membranes Cleaning-in-Place (CIP) procedure. This may result in low effectiveness, high cost and adds environmental issues related to the CIP solutions disposal. Forward osmosis (FO) or direct osmosis (DO) is the transport of water across a semi-permeable membrane from higher water chemical potential side to lower water chemical potential side, which phenomenon was observed in 1748. The engineered applications of FO/DO in membrane separation processes have been developed in food processing, wastewater treatment and seawater/brackish water desalination. In recent years, DO has been increasingly attractive for RO fouling control as it is highly efficient and environmentally friendly technique which is a new backwash technique via interval DO by intermittent injection of the high salinity solution without stoppage of high pressure pump or interruption of the operational process and allows keeping RO membrane continuously clean even in heavy bio-fouling conditions and operating RO membranes at high flux. This paper provides the state-of-the-art of the physical principles and applications of DO for RO fouling control as well as its strengths and limitations.


2018 ◽  
Vol 565 ◽  
pp. 104-111 ◽  
Author(s):  
Junfeng Zheng ◽  
Yujian Yao ◽  
Meng Li ◽  
Lianjun Wang ◽  
Xuan Zhang

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