A pre-treatment concept for increasing the recovery ratio of coastline BWRO plants, while providing Mg2+ in the product water

Desalination ◽  
2021 ◽  
Vol 515 ◽  
pp. 115202
Author(s):  
Yonatan Gräber ◽  
Paz Nativ ◽  
Ori Lahav
2008 ◽  
Vol 58 (9) ◽  
pp. 1837-1840 ◽  
Author(s):  
L. Zou ◽  
P. Sanciolo ◽  
G. Leslie

The project investigated and demonstrated that using a selective nanofiltration (NF) membrane and a reverse osmosis (RO) membrane in sequence can produce recycled water with useful levels of nutrient ions, and lower the sodium absorption ratio (SAR) to minimise soil salinity. The recovery of nutrient and useful ions from the wastewater makes NF-RO treated recycled water an attractive option for agricultural irrigation. It was found that the addition of polyacrylic acid (PAA) significantly increased the rejection of divalent ions by SR2 NF element, and kept the sodium rejection largely unchanged. This effect enhanced the enrichment of divalent ions in the NF rejects, and allowed sodium ions to pass to the RO stage. The product water included NF reject and the RO permeate. Overall, the MF-NF-RO train with a PAA aided NF pre-treatment can produce a product water fit for agriculture irrigation purpose, and reduce the scaling on the RO membrane due to calcium ions which are removed by NF, leading to the higher RO recovery. This approach achieved overall higher water production with less waste for disposal.


2011 ◽  
Vol 6 (2) ◽  
Author(s):  
L. Hernández-Leal ◽  
G. Zeeman ◽  
H. Temmink ◽  
C. J. N. Buisman

A total treatment concept was developed for grey water from 32 houses in Sneek, The Netherlands. A thorough characterization of COD, nutrients, metals, micropollutants and anions was carried out. Four biological treatment systems were tested: aerobic, anaerobic, combined anaerobic + aerobic and a bioflocculation system. Micropollutants were measured in grey water and effluent from three biological treatment systems. The best performing biological treatment system, the aerobic one showed the highest COD and micropollutant removal at a low sludge yield. The bioflocculation system could concentrate 70% of the COD of grey water into a concentrated stream. Advanced treatment with ozone and activated carbon showed to be effective to remove all micropollutants below limits of quantification. A total treatment system is proposed based on the pre-treatment with a bio-flocculation system, aerobic post-treatment and ozonation as a disinfection and micropollutant removal step.


Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1348 ◽  
Author(s):  
Farshad Mohammadtabar ◽  
Behnam Khorshidi ◽  
Armin Hayatbakhsh ◽  
Mohtada Sadrzadeh

This study explores the feasibility of implementing five hybrid coagulation-membrane processes for the treatment of the boiler blow-down (BBD) water from an oil sands steam assisted gravity drainage (SAGD) operation. The processes involved (1) direct nanofiltration (NF) of the BBD water, (2) pre-treatment of the NF retentate using ion exchanger regeneration wastewater (IERW) as a chemical coagulant followed by NF, (3) pre-treatment of BBD water using IERW followed by NF, (4) dual pre-treatment of BBD water using IERW and soda ash (sodium carbonate, Na2CO3) followed by NF, and (5) forward osmosis (FO) treatment of the BBD water using IERW as a draw solution followed by NF treatment of diluted draw solution. These scenarios were compared based on total flux decline ratio (DRt), flux recovery ratio (FRR), and total dissolved solids (TDS) removal over the final NF treatment to suggest an efficient treatment technique to avoid an undesired increase in the capital and operating expenses. It was found that process-1 provided the highest selectivity toward dissolved solids (80%) with a flux decline and recovery ration of 89.6% and 97.4%, respectively. Considering the permeation flux, process-4 exhibited the lowest flux decline (86.1%) and highest recovery ratio (97.5%) compared to other processes, proving the successful role of soda ash softening, as a chemical pretreatment method, in improving the performance of membrane filtration. Process-2 presented a mediocre performance with DRt, FRR, and TDS rejection of 93.3%, 97.3%, and 74%, respectively. Finally, process-3 and process-5 showed the lowest performance among all the scenarios with low flux recovery and low permeability, respectively. In addition, process-3 was expected to be cost-efficient since it only uses an on-site generated waste as a coagulant for the chemical pretreatment of the membrane filtration unit. The optimum scenario was proposed to be the two-stage membrane process, with direct NF of BBD followed by the post-treatment of the retentate via a hybrid chemical conditioning using IERW and soda ash softening, followed by a second NF. Overall, this integrated process offered a highly efficient mean with a zero liquid discharge (ZLD) system for the treatment of high pH wastewaters into an uncontaminated stream for the boilers.


Author(s):  
E Y. Wang ◽  
J. T. Cherian ◽  
A. Madsen ◽  
R. M. Fisher

Many steel parts are electro-plated with chromium to protect them against corrosion and to improve their wear-resistance. Good adhesion of the chrome plate to the steel surface, which is essential for long term durability of the part, is extremely dependent on surface preparation prior to plating. Recently, McDonnell Douglas developed a new pre-treatment method for chrome plating in which the steel is anodically etched in a sulfuric acid and hydrofluoric acid solution. On carbon steel surfaces, this anodic pre-treatment produces a dark, loosely adhering material that is commonly called the “smut” layer. On stainless steels and nickel alloys, the surface is only darkened by the anodic pre-treatment and little residue is produced. Anodic pre-treatment prior to hard chrome plating results in much better adherence to both carbon and alloy steels.We have characterized the anodic pre-treated steel surface and the resulting “smut” layer using various techniques including electron spectroscopy for chemical analysis (ESCA) on bulk samples and transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS) on stripped films.


2021 ◽  
Vol 160 (1) ◽  
pp. 234-243
Author(s):  
Diana Samoil ◽  
Nazek Abdelmutti ◽  
Lisa Ould Gallagher ◽  
Nazlin Jivraj ◽  
Naa Kwarley Quartey ◽  
...  

2004 ◽  
Vol 74 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Liu ◽  
Russell ◽  
Smith ◽  
Bronson ◽  
Milbury ◽  
...  

Because reactive oxygen species have been implicated as mediators of inflammatory bowel disease (IBD), we evaluated the potential preventive and therapeutic effects of two dietary antioxidants, glutathione (GSH) and coenzyme Q10 (CoQ10) on dextran sulfate sodium (DSS)-induced colitis in mice. Fifty female 8-wk old Swiss-Webster mice were randomly assigned to 4 groups for a pre-treatment 'prevention' study: (1) GSH (1% of diet); (2) CoQ10 (200 mg/kg/d); (3) DSS only (3% of drinking water); (4) control (no treatment). The mice in groups 1 and 2 were fed with GSH or CoQ10 for 21 wks, and the mice in groups 1, 2 and 3 were provided DSS from wk 7 for 4 cycles (1 cycle = 1 wk DSS followed by 2-wk water). Another 50 mice were randomly assigned to 4 groups for a 21-wk 'treatment' study where the mice in groups 1, 2, and 3 were administered DSS for 6 cycles (18 wks) to induce colitis. GSH and CoQ10 were added from wk 7 until the completion of the protocol. Loose stools and hemocult positivity were modestly but significantly reduced with GSH or CoQ10 at several periods during the intervention in both the prevention and treatment studies. In contrast, histological evaluation revealed increases in colonic dysplasia and ulceration with GSH or CoQ10. Thus, in this mouse model, GSH and CoQ10 appear to have a beneficial effect on acute signs of IBD, but may have an adverse impact on the chronic pathophysiology of the disease. Further studies using additional animal models are required to determine whether GSH or CoQ10 provide a favorable or unfavorable benefit:risk ratio in the prevention or treatment of IBD.


2014 ◽  
Vol 84 (3-4) ◽  
pp. 0140-0151 ◽  
Author(s):  
Thilaga Rati Selvaraju ◽  
Huzwah Khaza’ai ◽  
Sharmili Vidyadaran ◽  
Mohd Sokhini Abd Mutalib ◽  
Vasudevan Ramachandran ◽  
...  

Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100 - 300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76 % and 79 % in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2 %, 95.0 %, and 95.6 %, respectively (p < 0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.


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