Search results for " osmosis"

Consensus-Based Distributed State Estimation of Biofilm in Reverse Osmosis Membranes by WSNs

2017

The appearance of biofilm has become a serious problem in many reverse osmosis based systems such as the ones found in water treatment and desalination plants. In these systems, the use of traditional techniques such as pretreatment or dozing biocides are not effective when the biofilm reaches an irreversible attachment phase. In this work, we present a framework for the use of a WSN as an estimator of the biofilm evolution in a reverse osmosis membrane so that effective solutions can be applied before the irreversible phase is attained. This design is addressed in a complete distributed and decentralized fashion, and subject to realistic constraints where cooperation between nodes is perfo…

Cast multibilayer films from polymerizable lipids

1987

Reverse osmosis and nanofiltration membranes for highly efficient PFASs removal: overview, challenges and future perspectives

2021

Today, it is extremely urgent to face the increasing shortage of clean and safe water resources, determined by the exponential growth of both world population and its consumerism, climate change and pollution. Water remediation from traditional chemicals and contaminants of emerging concerns (CECs) is supposed to be among the major methods to solve water scarcity issues. Reverse osmosis (RO) and nanofiltration (NF) membrane separation technologies have proven to be feasible, sustainable and highly effective methods for the removal of contaminants, comprising the extremely persistent and recalcitrant perfluoroalkyl substances (PFASs), which failed to be treated through the traditional water …

Surface water RO permeate remineralization through minerals recovery from brines

2022

Assisted-Reverse Electrodialysis (A-RED) technology was applied following reverse osmosis (RO) of a surface water resource in order to recover minerals from its brine and directly remineralize the RO unit's permeate. Four different sets of cation/anion exchange membranes were benchmarked using single- and mixed-salts synthetic solutions as well as real brine and permeate streams produced from three-stage reverse osmosis applied to Seine River water. The process, operating under equal permeate and brine channel flows (2 cm/s velocities) and applied voltage varying from 0 to 10 V, showed viable remineralization results. Optimal recovery at 10 V applied allowed increasing permeate mineral cont…

Modelling the Reverse ElectroDialysis process with seawater and concentrated brines

2012

Technologies for the exploitation of renewable energies have been dramatically increasing in number, complexity and type of source adopted. Among the others, the use of saline gradient power is one of the latest emerging possibilities, related to the use of the osmotic/chemical potential energy of concentrated saline solutions. Nowadays, the fate of this renewable energy source is intrinsically linked to the development of the pressure retarded osmosis and reverse electrodialysis technologies. In the latter, the different concentrations of two saline solutions is used as a driving force for the direct production of electricity within a stack very similar to the conventional electrodialysis …

Seawater desalination : state of the art on conventional technologies

2009

Optimization of Osmotic Desalination Plants for Water Supply Networks

2016

Water scarcity and the poor quality of water resources are leading to a wider diffusion of desalination plants using the Reverse Osmosis (RO) process. Unfortunately, the cost of a cubic meter of fresh water produced by an RO plants is still high and many efforts are in progress to increase the efficiency of the membranes used in osmotic plants and to limit the energy required by the process. A further reduction of the energy cost could be obtained by an optimal operation of the desalination plant so reducing the hourly energy cost, or by coupling the RO plant with an energy production plant based on direct osmosis (Pressure Retarded Osmosis PRO). The economic viability of the desalination p…

Consensus based distributed estimation of biomass concentration in reverse osmosis membranes

2015

The correct estimation of biofilm formation in industrial environments, such as reverse osmosis plants, has become a topic of great interest. The occurrence of this natural process is the cause of huge economic losses due to a decrease of performance and maintenance costs in these plants. Current solutions based on water pretreatment or the dozing of biocides are not effective due to the lack of information about the state of the biofilm in the water system. In this work, we propose the use of a wireless sensor network that, based on the measurement of the biofilm thickness growth at the substratum of each sensor, estimates the biomass concentration within the biofilm, and, eventually, the …

Performance evaluation of CHCP hybrid seawater desalination plants

2007

There are many ways to improve efficiency and reduce fresh water cost in desalination plants, like the integration of two or more desalination systems into a hybrid mechanical/thermal lay-out. Most common results that could be achieved by hybrid systems are savings in pretreatments, overall cost reduction and significant primary energy savings, especially when cogeneration unit are concerned. In this paper a small size (2000 m 3 /day) thermal desalination system (MEE) is coupled with a single-stage seawater reverse osmosis (SWRO) system; the system is fed by a natural gas (NG) reciprocate engine, where heat is recovered both from exhaust gases and from the cooling jacket water circuit. Tech…

A critical assessment of desalination operations in Sicily

2005

In this paper a brief history of desalination plants in Sicily is presented together with an in-depth description of processes and operating data, relevant to the plants actually operating on the island. 5 multi stage flash (MSF) units and one reverse osmosis (RO) plant are operating in Gela (total nominal production of about 80,000 m 3 /d), thus providing drinking water for more than 300,000 people living in the southern coast of the island. A thermal vapour compression multiple effect distillation (TVC-MED) plant (36,000 m 3 /d) is operating in Trapani and a small mechanical vapour compression (MVC) unit (5000 m 3 /d) is located in Porto Empedocle. In the oldest MSF units in Gela, several…