Brine Management: Substituting Chlorine with On-Site Produced Sodium Hypochlorite for Environmentally Improved Desalination Processes

Abstract

The main environmental problem related to the desalination of seawater is the brine discharge coming from the processes of desalination of seawater. For coastal desalination plants, the most practical and least expensive brine disposal method is to discharge it into the sea at the plant's outfall. However, there are several harmful environmental effects caused by this direct discharge. This discharged brine (concentrate wastewater) has many properties, which badly affects the environment. It consists of highly concentrated salts and any un-reacted pre-treatment chemicals. It also brings with it heavy metals resulting from the corrosion of tube and flash chamber wall material. Therefore, the largest impact of desalination on the environment occurs at the outfall of the desalination plant. This work addresses the problem of brine or wastewater generated from desalination production process. The work was conducted with the objective of shedding light on the business opportunities associated with brine wastes by using the brine for on-site generation of sodium hypochlorite. Sodium hypochlorite is a useful and valuable chemical product. It is the most widely used active chlorine compound in disinfection. In general, the suggested experimental process was aimed at the dual benefit of on-site generation of sodium hypochlorite and reducing the concentration of the brine. Therefore, the process will not only generate the sodium hypochlorite, but also will protect the environment.

A Novel Application in Green Chemical Processing Using Reject Brines and Carbon Dioxide as Raw Materials

“…As stated earlier, reject brines and carbon dioxide are two forms of environmental pollutants that we are facing in the course of obtaining fresh water from sea water [13][14][15]. Solving this problem is pursued by the strategy illustrated in Figure 1.…”

Reject Brines from Desalination as Possible Sources for Environmental Technologies

“…The brine flow rates are large and generally vary with the type of technology; they are up to 40% for RO and up to 90% for MSF of the intake flow rate (Mickley, 2010). The reject water is a concentrate stream having a salinity higher than source feed water, up to 65,000-85,000 mg L -1 (Abdul-Wahab & Al-Weshahi, 2009), double or close to double that of natural seawater. The disposal of such a huge amount of high salinity water is one of the main environmental concerns.…”

“…The challenge is to change the concept from saline waste to saline resource opening several opportunities to provide a reduction of brine disposal costs and volumes involved. The beneficial uses reported in the literature include aquaculture, oil and gas well field injection to maintain pressures, feedstock for hypochlorite production, dust control and de-icing, soil remediation, zero liquid discharge, wetlands treatment, salt recovery, and solar ponds (e.g., Abdul-Wahab & Al-Weshahi, 2009;GHD, 2003;Mickley, 2010). An innovative and non-traditional use of the brine is its involvement in several industrial processes with the dual beneficial objective to reduce its volume to be discharged and mitigate the negative effects of some contaminants such as CO 2 and animal waste.…”

Artificial neural networks and genetic algorithms: An efficient modelling and optimization methodology for active chlorine production using the electrolysis process

“…This would lead to a reduction in chemical costs for the process of chlorine production. [39,40] The ANN-GA approach for modelling and optimization of electrochemical processes has been applied before. Picos and Peralta-Hernández [41] utilized ANN models to predict the behaviour of an electro-oxidation pilot presstype reactor, which treats synthetic wastewater prepared with a synthetic Violet 54-B dye.…”