Brine Discharge Research Articles

Application of forward osmosis membrane technology for oil sands process-affected water desalination.

The extraction process used to obtain bitumen from the oil sands produces large volumes of oil sands process-affected water (OSPW). As a newly emerging desalination technology, forward osmosis (FO) has shown great promise in saving electrical power requirements, increasing water recovery, and minimizing brine discharge. With the support of this funding, a FO system was constructed using a cellulose triacetate FO membrane to test the feasibility of OSPW desalination and contaminant removal. The FO systems were optimized using different types and concentrations of draw solution. The FO system using 4 M NH4HCO3 as a draw solution achieved 85% water recovery from OSPW, and 80 to 100% contaminant rejection for most metals and ions. A water backwash cleaning method was applied to clean the fouled membrane, and the cleaned membrane achieved 77% water recovery, a performance comparable to that of new FO membranes. This suggests that the membrane fouling was reversible. The FO system developed in this project provides a novel and energy efficient strategy to remediate the tailings waters generated by oil sands bitumen extraction and processing.

Bioindicators as metrics for environmental monitoring of desalination plant discharges

Development of desalination projects requires simple methodologies and tools for cost-effective and environmentally-sensitive management. Sentinel taxa and biotic indices are easily interpreted in the perspective of environment management. Echinoderms are potential sentinel taxon to gauge the impact produced by brine discharge and the BOPA index is considered an effective tool for monitoring different types of impact. Salinity increase due to desalination brine discharge was evaluated in terms of these two indicators. They reflected the environmental impact and recovery after implementation of a mitigation measure. Echinoderms disappeared at the station closest to the discharge during the years with highest salinity and then recovered their abundance after installation of a diffuser reduced the salinity increase. In the same period, BOPA responded due to the decrease in sensitive amphipods and the increase in tolerant polychaete families when salinities rose. Although salinity changes explained most of the observed variability in both indicators, other abiotic parameters were also significant in explaining this variability.

Environmental implications of Tajoura reverse osmosis desalination plant

Water resources in North Africa are limited and do not meet the future water demand. The water shortage is very severe in Libya which is located in a semi-desert region. The available water resources in Libya are mainly the groundwater which is not enough to meet its people needs due to many reasons, among them is seawater intrusion. Desalination of seawater is one of the main alternatives for the substitution of water shortage in Libya and other North African countries. Despite the fact that desalination technology is an important option for providing potable/industrial water, it has some negative impacts on environment. High concentrated brine discharges from desalination plant is the main cause of negative impacts. Noise, visual impact, air pollution, impact on the aquifer, and disturbance of recreation areas are other environmental impacts on a more local scale. The aim of this study was to highlight the environmental impacts of Tajoura reverse osmosis desalination plant on the local environment. The findings of this study reveal that the most concerning issues identified from the existing Tajoura RO desalination plant are brine concentrate, noise pollution, and chemical hazards.

Environmental implications of salt facies in the Dead Sea

Thick sequences of salt (halite) have been recovered in a 456-m-long core drilled at the deepest floor of the Dead Sea by the Dead Sea Deep Drilling Project and extending ∼200 k.y. back in time. The salt sequences were precipitated in the ancient lake that occupied the Dead Sea Basin during the last three interglacials during intervals of extreme aridity in the lake’s watershed. The salt layers alternate with “mud” layers that indicate wetter periods in the watershed, when floods transported fine detritus matter to the lake. The salt sources include brine discharge and freshwater runoff that dissolved halite units. Dissolved salts accumulated in the lake during glacials and relatively wet periods when the lake expanded, and precipitated during interglacials when the lake levels dropped. This study establishes for the first time the evaporite facies and sedimentological features of the deep Dead Sea brine during interglacial periods, by using the modern precipitation of halite in the Dead Sea as an analogue for past halite depositional periods as recorded in the drill core. The halite intervals provide a record of facies characterizing a deep-water evaporitic environment. The halite layers consist mainly of two types of crystals: small cumulate crystals containing halite rafts, which indicate precipitation from the surface brine of the lake (epilimnion), and bottom-growth (usually large) halite crystals that precipitated on the lake floor (hypolimnion). The layers of small halite crystals formed during drier periods as compared to the bottom-growth crystals. The bottom-growth halite crystals contain variable quantities of detritus and show mild dissolution structures at the contact between the mud and the halite crystals. These two main types of halite, in combination with “muds” and gypsum, comprise seven categories of salt facies that reflect the hydrological conditions (dry-to-wet), and that display a cyclic (decadal to millennial) pattern along the sampled core intervals. Frequent alternation of these two salt crystal types suggests seasonal changes, whereby the small cumulate crystals were formed during the summer, and the bottom-growth crystals were formed during the winter, when the surface temperatures of the lake were low, and the surface water was less saline and less likely to be saturated with respect to halite. Comparison of the last interglacial halite with the modern halite facies, together with the absence of significant dissolution features within the halite and the cyclic nature of the facies, indicates that the lake was continuously deep (>100 m) during the last 200 k.y.

“Salty” conversation

Thiel replies: When thinking about potential toxicity, which Neal Reid mentions, it’s key to remember that almost all the material in the brine originated in the ocean. Nevertheless, ensuring environmentally friendly disposal continues to be an active area of research, and modern outfalls are very effective at dispersing the brine flow so as to minimize local increases in the concentration of salts and other dissolved compounds. A study for the Carlsbad desalination project in California concluded that properly designed outfalls have “impacts that extend only a few tens of meters from the discharge.”11. S. Jenkins et al., Management of Brine Discharges to Coastal Waters: Recommendations of a Science Advisory Panel, tech. rep. 694, Southern California Coastal Water Research Project (March 2012), p. ii. The Carlsbad plant also mixes the reverse-osmosis brine with seawater used for cooling a colocated power plant prior to discharge, which reduces its salinity before it hits the ocean. And as for the comparison to nuclear waste, let’s not forget that the diffusion time for the salt in the disposed brine is orders of magnitude less than the half-life of radioactive waste!To answer Jonathan Allen’s concern, the kWhe values given for the evaporative systems are exergetic values of the heat input. That approach uses the Carnot efficiency between the desalination system’s top temperature, which often reaches 70 °C, and an ambient temperature of 25 °C to convert between heat and work. The cost of the thermal energy input itself may be less than for electricity, but the costs associated with constructing, for example, a solar-thermal collector or a heat exchanger required to use waste heat can be significant. Lower energy consumption may not imply lower cost, but reverse osmosis is far and away the dominant choice of recent installed desalination capacity.Desalination powered by renewable energy is a topic of great interest to many in the desalination community—myself included!REFERENCESSection:ChooseTop of pageREFERENCES <<CITING ARTICLES1. S. Jenkins et al., Management of Brine Discharges to Coastal Waters: Recommendations of a Science Advisory Panel, tech. rep. 694, Southern California Coastal Water Research Project (March 2012), p. ii. Google Scholar© 2015 American Institute of Physics.

Minimizing brine discharge in a combined biophysical system for nitrate removal from inland groundwater

Abstract Health concerns regarding microbial contamination on the one hand and brine disposal regulations on the other limits the application of both biological and physico-chemical techniques for nitrate removal from polluted inland groundwater. In the current work, a combined system consisting of ion exchange (IX) and advanced biophysical treatment of the recirculated regenerant was investigated to achieve a safe and reliable process for nitrate removal from groundwater with minimal brine discharge and chloride addition to the product water. Using a feed water composing 26 mg NO 3 − –N/L, Cl − 243 mg/L and 16 mg SO 4 − 2 –S/L, optimal IX operation was found to be at a service cycle length of 380 bed volumes with ‘full treatment’ of the water source rather than a ‘split treatment’ option with shorter service cycle and final product water blending. ‘Full treatment’ resulted in nitrate concentrations meeting regulations while minimizing both Cl − addition to the treated water (1.11 meq Cl − added per meq NO 3 − –N removed) and waste brine production (0.25% of the water volume treated). In the product water, the DOC was 0.5 mg/L lower than the feed (tap) water and before disinfection the bacterial count was 10–700 cfu/mL. Spent regenerant was first treated in a sequential batch denitrification bioreactor followed by ozonation for polishing. The SBR unit achieved complete nitrate removal in 8 h with nitrate removal rates of 2.6 ± 0.4 g N/L reactor /d and a low average ethanol to nitrate mass ratio of 1.68 ± 0.18. An ozone dose of 3–5 mg/L brine allowed for efficient recycling of the denitrified regenerant by removing suspended solids by foam fractionation. In spite of the low brine blow-down, DOC in the recycled regenerant brine after more than a year of continuous operation was maintained at relatively low levels of 61.0 ± 11.6 mg/L.

Levels of heavy metals in sediments in the vicinity of Chabahar Bay desalination plant

Desalination plants are potentially capable of having impacts on coastal marine environments due to the production of wastewater with high concentrations of salts (brine discharge) and some heavy metals. The aim of this study was to examine the concentration of accumulated metals (Ni, Cu, Cd, Fe, Zn, Pb) in the sediments near the brine discharge point in the Chabahar Bay. Twenty one sediment samples were collected from seven stations in summer pre-monsoon and post-winter monsoon, in April and October 2011. The results showed that stations closer to brine discharge points had higher concentrations of metals in the sediment than other stations. Metal contamination in sediment samples was below a critical level with the exception of cadmium with higher values than MAFF, ANZECC and FDEP standards at a maximum of 5.76 mg/kg dry weight. There was a clear decreasing gradient in heavy metal concentrations from station 2 to station 7, especially for Cd, Pb, Fe and Zn. The probable reason for this is the water circulation in the Chabahar Bay.

Pilot-scale study on the treatment of basal aquifer water using ultrafiltration, reverse osmosis and evaporation/crystallization to achieve zero-liquid discharge

Basal aquifer water is deep groundwater found at the bottom of geological formations, underlying bitumen-saturated sands. Some of the concerns associated with basal aquifer water at the Athabasca oil sands are the high concentrations of hardness-causing compounds, alkalinity, and total dissolved solids. The objective of this pilot-scale study was to treat basal aquifer water to a quality suitable for its reuse in the production of synthetic oil. To achieve zero-liquid discharge (ZLD) conditions, the treatment train included chemical oxidation, polymeric ultrafiltration (UF), reverse osmosis (RO), and evaporation-crystallization technologies. The results indicated that the UF unit was effective in removing solids, with UF filtrate turbidity averaging 2.0 NTU and silt density index averaging 0.9. Membrane autopsies indicated that iron was the primary foulant on the UF and RO membranes. Laboratory and pilot-scale tests on RO reject were conducted to determine the feasibility of ZLD crystallization. Due to the high amounts of calcium, magnesium, and bicarbonate in the RO reject, softening of the feed was required to avoid scaling in the evaporator. Crystals produced throughout the testing were mainly sodium chloride. The results of this study indicated that the ZLD approach was effective in both producing freshwater and minimizing brine discharges.

Comparison of 2D and 3D Models of Salinity Numerical Simulation

Abstract For the study of the effect of 2D and 3D mathematical model in salinity simulation, with Liuheng island strong brine discharge of seawater desalination project as an example, using 2D and 3D salinity mathematical models of Liuheng island to simulate coastal hydrodynamic environment and salinity distribution before and after the concentrated brine discharge, and analyzed the results. Finally got the applicable scope of the two models, it has an important significance in the study of similar problems.

Dense Jet Discharges in Shallow Water

AbstractExtensive Experiments on inclined dense jets typical of brine discharges into shallow water are reported. The experiments were conducted with nozzles oriented at 30°, 45°, and 60° to the horizontal and the spatial variations of tracer concentrations were measured by three-dimensional laser-induced fluorescence (3DLIF). Three flow regimes were identified: deep water, surface contact, and shallow water. The regimes depend on the value of dF/H, where d is the nozzle diameter, F the jet densimetric Froude number, and H the water depth; criteria were presented for the transitions between them. Flow images revealed complex three-dimensional interactions with the free surface, especially for steep nozzle angles in shallow water. Dilutions at critical points and their locations were measured. For deep water, all results followed those previously reported for fully submerged jets. As the depth decreases (or dF/H increases) to the surface contact regime, dilutions begin to decrease. Tracer concentration pro...

Large eddy simulations of 45° inclined dense jets

Submerged inclined dense jets (negatively buoyant jets) occur in many engineering applications such as brine discharges from seawater desalination plants and de-cooling water discharges from liquefied natural gas plants, and their mixing behavior needs to be examined in details for the environmental impact analysis. In the present study, a detailed numerical investigation was performed using the large eddy simulation (LES) approach with both the Smagorinsky and Dynamic Smagorinsky sub-grid scale (SGS) models to simulate the characteristics of the inclined dense jet with 45° inclination. The numerical predictions included the jet trajectory, geometrical characteristics, jet spread and eddy structures. Experimental measurements were also obtained for the validation of the LES predictions, and data from existing studies in the literature were included for comparison. Overall, the LES predictions were able to reproduce the geometric characteristics of the inclined dense jet in a satisfactory manner in most aspects. The dilution was however generally underestimated, which was attributed primarily to the inability of the SGS models to reproduce the convective mixing induced by the buoyancy-induced instability using the adopted grid spacing in the bottom half of the inclined dense jet.

Amphipoda assemblages in a disturbed area (Alicante, Spain, Western Mediterranean)

AbstractThe distribution and composition of Amphipoda assemblages were analysed off the coasts of Alicante (Spain, Western Mediterranean), a disturbed area affected by several co‐occurring anthropogenic impacts. Although differences among sampled stations were mainly related to natural parameters, anthropogenic activities were linked with changes in amphipod assemblages. Expansion of the Port of Alicante, a sewage outfall and a high salinity brine discharge could be causing the disappearance of amphipods at stations closer to these disturbances. However, the completion of port enlargement works and mitigatory dilution of the brine discharge has led to the recovery of the amphipod assemblage. Among the natural parameters, depth determines the distribution of some of the species. While Siphonoecetes sabatieri was abundant at shallow stations, Ampelisca spp., Photis longipes, Pseudolirius kroyeri, Apherusa chiereghinii and Phtisica marina were more abundant at deeper stations. Grain size and percentage of organic matter also influenced amphipod distribution, resulting in changes in species composition and in the relative percentages of different trophic groups. Species such as Ampelisca brevicornis, Perioculodes longimanus, Urothoe hesperiae and Urothoe elegans were more abundant at stations with a high content of fine sand. Carnivorous species, mainly of the Oedicerotidae family, were more abundant at those stations with a low organic matter content, while detritivorous species were more abundant at stations with a higher mud content. Among 62 identified species, three were reported for the first time from the Spanish Mediterranean coast, two species were recorded for the second time and a new species of Siphonoecetes was found, Siphonoecetes (Centraloecetes) bulborostrum. These results confirm the need for further data on amphipods from the Mediterranean Spanish coast.

Prospects of environmental governance in addressing sustainability challenges of seawater desalination industry in the Arabian Gulf

Abstract The hyper-arid climate of the Arabian Gulf makes it an excessively water-deficient region. Ironically, the Gulf States count among the few places with the highest per capita water consumption and low tariff. Since a few decades ago, seawater desalination has been the most reliable source of portable water in the Gulf. Recently, many critical scholars raise concerns about the rising levels of brine discharge, effects of water intake and outfall systems infrastructure, plants’ high energy consumption and fragmented regulatory and policy frameworks. In this study, we explore the potentials of environmental governance in addressing sustainability risks of seawater desalination projects. The DPSIR model and the Earth system governance framework guided and supported our analysis of several multidimensional issues that underlie the characteristics of this industry. Thus, we identified 29 cause and effect factors as well as nine environmental governance intervention strategies. The study suggests that the industry's network of stakeholders can develop good ideas for fostering sustainability by using innovative tools such as hackathon—an interdisciplinary, participatory, solution-oriented, and consensus building platform. Finally, this study enjoins policymakers, businesses, and scientists to embrace more transparent, practical and holistic ideas in designing, executing and assessing technological innovations and interventions in national and regional water security initiatives.

Effect of Salinity on the Growth of Clam

The brine discharge from the seawater desalination plant will affect the receiving water to some extent in physics, chemistry, biology, and so on, especially harmful to the benthos and marine lives in the adjacent water area. In this paper, the experiment was conducted to investigate the effects of different salinities on the growth, survival rates in clam from low-salinity under controllable conditions in laboratory. The results show that individuals grew best at salinity 30 to 35. When the salinity exceeded 40, the survival rate and ILS50 of the individuals decreased significantly. Therefore, it is necessary to develop effective means of reducing the negative influence of brine discharged on the marine environment.

Modeling brine discharge dispersion from two adjacent desalination outfalls in coastal waters

A far field mathematical model for two brine outfall discharges that incorporates the effect of an oscillating tidal current is used to study the merging and interaction of two brine plumes in coastal waters. The maximum compounded shoreline concentration is formulated and used as a measure for assessing the long term salinity build-up of brine discharges into the sea. It is found that the modern engineering practice which installs a two-port diffuser at the end of the outfall pipe does produce less potential environmental impact.

Effects of High Salinity Wastewater Discharges on Unionid Mussels in the Allegheny River, Pennsylvania

AbstractWe examined the effect of high salinity wastewater (brine) from oil and natural gas drilling on freshwater mussels in the Allegheny River, Pennsylvania, during 2012. Mussel cages (N = 5 per site) were deployed at two sites upstream and four sites downstream of a brine treatment facility on the Allegheny River. Each cage contained 20 juvenile northern riffleshell mussels Epioblasma torulosa rangiana). Continuous specific conductance and temperature data were recorded by water quality probes deployed at each site. To measure the amount of mixing throughout the entire study area, specific conductance surveys were completed two times during low-flow conditions along transects from bank to bank that targeted upstream (reference) reaches, a municipal wastewater treatment plant discharge upstream of the brine-facility discharge, the brine facility, and downstream reaches. Specific conductance data indicated that high specific conductance water from the brine facility (4,000–12,000 µS/cm; mean 7,846) compared to the reference reach (103–188 µS/cm; mean 151) is carried along the left descending bank of the river and that dilution of the discharge via mixing does not occur until 0.5 mi (805 m) downstream. Juvenile northern riffleshell mussel survival was severely impaired within the high specific conductance zone (2 and 34% at and downstream of the brine facility, respectively) and at the municipal wastewater treatment plant (21%) compared to background (84%). We surveyed native mussels (family Unionidae) at 10 transects: 3 upstream, 3 within, and 4 downstream of the high specific conductance zone. Unionid mussel abundance and diversity were lower for all transects within and downstream of the high conductivity zone compared to upstream. The results of this study clearly demonstrate in situ toxicity to juvenile northern riffleshell mussels, a federally endangered species, and to the native unionid mussel assemblage located downstream of a brine discharge to the Allegheny River.

Chemical elements of brine discharge from operational Tajoura reverse osmosis desalination plant

Despite the fact that desalination is an important technology for providing desalted water, it has some disadvantages that have not been taken seriously into consideration. Such technology can have undesirable effect on the environment. Environmental related impact could occur from the early days of plant construction and, subsequently, when the plant is in operation. Tajoura reverse osmosis desalination plant is the largest desalination plant of its kind in Libya. It has been under operation for nearly three decades without serious consideration of its impact on the environment. This paper is the first attempt in that direction. The main objective of this study is to measure the chemical components of brine concentrate discharged from Tajoura plant, and to highlight their impact on the environment. This study was conducted in the Water Desalination Department in Tajoura Nuclear Research Center. Samples were collected from feed source (seawater), and from reject stream (brine discharge point). Samples were analyzed at water department’s facility using suitable instrument. The obtained results show differences in most of the measured chemical components between seawater and brine discharge which was highly expected. It was found that brine discharge contained traces of metals such as chromium and none of some other metals such as iron. Therefore, contamination with metals is below a critical level. This can be attributed to the fact that metal equipment is not used in Tajoura RO plant. The major concern of brine discharged from Tajoura plant is represented by its high salinity as its increase from feedwater exceeds by far 1 psu.

Treatment of basal water using a hybrid electrodialysis reversal–reverse osmosis system combined with a low-temperature crystallizer for near-zero liquid discharge

Basal aquifer water is saline groundwater that often needs to be dewatered prior to mining. The oil sands industry is seeking cost-effective methods to treat basal aquifer water in order to allow its recycle to the bitumen extraction process. A hybrid desalination system consisting of advanced electrodialysis reversal (EDR)–reverse osmosis (RO) combined with a low-temperature evaporator/crystallizer was assessed as an opportunity to treat basal aquifer water for a near-zero liquid discharge (ZLD) approach. The pilot-scale plant had a capacity of 50m3/day influent. Pretreatment through sedimentation and ultrafiltration proved to be effective in removing both suspended solids and turbidity. The hybrid EDR–RO desalination system achieved about 77% recoveries, with brine concentrations up to 125,000mg/L. The results showed that the evaporator-crystallizer was able to concentrate the EDR–RO brine to a conductivity of just over 250mS/cm, while producing additional freshwater. This proof-of-concept study demonstrated that the hybrid EDR–RO system combined with a low-temperature evaporator/crystallizer was an effective near-zero ZLD approach to produce freshwater and minimize brine discharge when treating basal aquifer water.

Optimal Management of Brine from Seawater Desalination Plants in Gaza Strip: Deir AL Balah STLV Plant as Case Study

Brine salty water that is produced from Reverse Osmosis desalination plants usually has very large quantity and contains much higher salts ratio than that found in the sea. The disposal of such brine water has risks on environment. The objective of the research is to investigate the best brine disposal option in Gaza Strip. Five options for the disposal of brine were studied: 1) disposal of brine to the sea; 2) discharge of brine to wastewater plant; 3) deep well injection; 4) evaporation pond and 5) land irrigation. The new desalination plant Short-Term Low Volume (STLV) of a capacity of 6000 m3/d was used as a case study. Initially, the cost for each option was calculated separately, where it was found that the least cost is to pump the brine to the sea without affecting the seawater and marine life. To support this decision, two methods were used to reach the optimal option for the disposal of brine: Multi-Criteria Analysis (MCA) and Analytic Hierarchy Process (AHP). In MCA the measurement includes: economic, environmental, technical, political and social aspects, depending on a group of academics and experts in that field to fill in the questionnaire, which is a part of the analysis. As a result of that, the highest percentage among other options goes to pump the brine directly to the sea. On the other hand, the second method, which is Analytic Hierarchy Process (AHP), used the method of matrices among the different options and linked it with the standards that have been selected in the first method (MCDA). AHP method indicated also the best disposal of brine by pumping the brine to the sea.

Benthic community recovery from brine impact after the implementation of mitigation measures

In many regions, seawater desalination is a growing industry that has its impact on benthic communities. This study analyses the effect on benthic communities of a mitigation measure applied to a brine discharge, using polychaete assemblages as indicator. An eight-year study was conducted at San Pedro del Pinatar (SE Spain) establishing a grid of 12 sites at a depth range of 29–38 m during autumn. Brine discharge started in 2006 and produced a significant decrease in abundance, richness and diversity of polychaete families at the location closest to the discharge, where salinity reached 49. In 2010, a diffuser was deployed at the end of the pipeline in order to increase the mixing, to reduce the impact on benthic communities. After implementation of this mitigation measure, the salinity measured close to discharge was less than 38.5 and a significant recovery in polychaete richness and diversity was detected, to levels similar to those before the discharge. A less evident recovery in abundance was also observed, probably due to different recovery rates of polychaete families. Some families like Paraonidae and Magelonidae were more tolerant to this impact. Others like Syllidae and Capitellidae recovered quickly, although still affected by the discharge, while some families such as Sabellidae and Cirratulidae appeared to recover more slowly.