| 1. |
- Bashitialshaaer, Raed, et al.
(author)
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Environmental Assessment of Brine Discharge and Wastewater in the Arabian Gulf
- 2011
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In: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3986 .- 1944-3994. ; 25, s. 276-285
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Journal article (peer-reviewed)abstract
- This study assesses the environmental effects of brine discharge into the Arabian/Persian Gulf and the option of mixing with wastewater to reduce the salt content in the discharge. The Arabian Gulf region occupies about 3.3% of the world area and has 1.0, 2.0 and 2.2% of the total world population in the years 1950, 2008 and 2050 (prognosis) respectively. The study area desalination capacities were obtained as 50, 40 and 45% of total world capacity at the end of 1996, 2008 and 2050 (prognosis) respectively. The trend towards increased recovery ratio in the desalination plants was considered as one important environmental factor. This will significantly increase the brine salt concentration from 1.5 to more than 2 times the seawater. The allocation of wastewater and brine is important for the Arabian Gulf. Straightforward water and salt mass balances were used to calculate residual flow, exchange flow and exchange time in the Arabian Gulf. For example, at zero wastewater discharge from 1996 to 2008, the net volume in the Arabian Gulf decreased by 7.4 million m3/day, the exchange volume increased by 69 million m3/day, and the mixing time decreased by 22.5 days. Discharging a mix of brine and wastewater in the Arabian Gulf reduces the water and salt exchange between the Gulf and the Indian Ocean. Nutrients in wastewater may cause problems such as eutrophication in the Gulf if the exchange of water is low or if wastewater is discharged to the Gulf with insufficient treatment.
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| 2. |
- Bashitialshaer, Raed, et al.
(author)
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Environmental Assessment of Brine Discharge Including Wastewater Collection in the Arabian Gulf
- 2009
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In: IDA-International Desalination Association.
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Conference paper (peer-reviewed)abstract
- The environmental effects of brine discharge in the Arabian/Persian Gulf have been assessed. The Arabic Gulf is a wide and shallow system having a horizontal shear dominance. The management choice of mixing brine with wastewater to reduce the salt content in the discharge has also been considered. Approximately 90% of the area around the Arabian Gulf has been compared with the world data for desalination and population growth rate. The Arabian Gulf region is occupying about 3.3% of the world area and 1.0, 2.0 and 2.2% of the total world population in the years 1950, 2008 and 2050 respectively. The annual population growth rate during the whole period is approximately 1.30 in the world and 2.07 in the area studied. The results for the study area were obtained from desalination capacities that are about 50, 40 and 45% of total world capacity for the end of 1996, 2008 and 2050 respectively.The increased recovery ratio in desalination plants over the years was considered as one important environmental factor. At the end of 1996 it was about 30 to 35% and 2008 about 40 to 45%. In some countries it can reach 50%. This development will significantly increase the brine salt concentration from 1.5 to more than 2 times seawater and negatively affect the receiving water. Water and salt mass balance were used to calculate residual flow, exchange flow and exchange time of the Arabian Gulf. For example at zero wastewater discharge and from 1996 to 2008, the net volume has decreased by the amount of 7.4 millions m3/day, exchange volume increased by 69 millions m3/day and the mixing time decreased with 22.5 days. For the next 42 years from 2008 until the year 2050 the calculation shows a decrease in the net volume by 48.7 millions m3/day, an exchange volume increase by 424 millions m3/day and a mixing time decrease of about 126 days. The more desalted water that is collected from the Gulf, the higher remaining salinity is found in the Gulf.With higher salinity in the Gulf, the exchange between the Gulf and the Indian Ocean will increase. Mixing brine with wastewater dampens the water and salt exchange between the Gulf and the Indian Ocean. This method will however also minimize the water that is coming from ocean to the Gulf. The content of nutrients in wastewater is positive for irrigation but with only secondary treatment problems like eutrophication in the Gulf may be increased if the exchange of water is low.
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| 3. |
- Flyborg, Lena, et al.
(author)
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A PLS model for predicting rejection of trace organic compounds by nanofiltration using treated wastewater as feed
- 2017
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In: Separation and Purification Technology. - : Elsevier. - 1383-5866 .- 1873-3794. ; 174, s. 212-221
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Journal article (peer-reviewed)abstract
- In this study a Partial Least Squares Projection of Latent Structures (PLS) model has been developed for predicting the rejection of pharmaceutical residuals by nanofiltration (NF) using treated municipal wastewater as feed. The objective was to provide a practical tool for wastewater reuse facilities for estimating the rejection of emerging organic contaminants based on their physiochemical characteristics. The model was developed by identifying the important physiochemical properties of pharmaceutical residuals for rejection by NF. The investigated pharmaceuticals were those present in the effluent from Henriksdal wastewater treatment plant (WWTP), Sweden. The rejection, at volume reduction factors (VRF) ranging from 2 to 20, was examined in a NF pilot plant at two occasions. The important variables for rejection by NF were, in descending order: polarizability, globularity, ratio hydrophobic to polar water accessible surface area and compound charge. Two studies were performed with a time interval of about a year with different wastewater matrices and age of membranes. For different VRFs, but in the same study, the model produced consistent predicted rejections. For the same VRF, but in the different studies, the regression lines were almost parallel, but with a deviation of about 7% for the predicted values. Most of the compounds were within the 95% prediction interval. The model also proved to be able to predict rejection using data from the literature. This confirms that the predictive PLS model can estimate the rejection albeit, with limitations. Generally the proposed predictive rejection model is most likely valid but the model coefficients need to be determined for each individual WWTP or wastewater reuse facility.
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| 4. |
- Flyborg, Lena, et al.
(author)
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Can treated municipal wastewater be reused after ozonation and nanofiltration? : Results from a pilot study of pharmaceutical remval in Henriksdal WWTP, Sweden
- 2010
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In: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 61:5, s. 1113-1120
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Journal article (peer-reviewed)abstract
- The objective of this study was to evaluate the potential of nanofiltration (NF) and ozonation for indirect potable reuse in terms of pharmaceutical residuals. To simultaneously obtain a reasonable retentate volume for further treatment, the tests were performed at a high volume reduction factor (VRF) of 60. The feed to the pilot plant was the effluent from a BNR plant with a final process step of chemical precipitation and rapid sand filtration. Two tests were performed 1) nanofiltration of treated wastewater followed by ozonation and 2) ozonated treated wastewater as feed to NF. Of the 95 pharmaceuticals analysed, three were not removed to the quantification limit, oxazepam in the first test and glibenclamide and ketoprofen in the second. The water quality after the two processes was similar, with an overall removal of pharmaceutical residuals of 99%. There are two advantages of ozonated water as feed to NF-a higher specific flux of 35% and a potential removal of ozonation by-products. The retention of some pharmaceuticals by NF was lower than anticipated, the major removal occurring in the ozonation. A tighter NF or RO is required in order to achieve higher pharmaceutical retention for further treatment of the retentate.
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