Session 31 - Water treatment

[CEST2019_00936] Application of dissolved air flotation (DAF) and liquid ferrate on mitigation of algal organic matter (AOM) during algal blooms
by Abdullah H., Alshahri A., Fortunato L., Leiknes T.

In the Middle East, Harmful algal blooms (HABs) are considered a major contributor to membrane biofouling in Seawater Reverse Osmosis desalination plants. The presence of HABs in the raw feed water leads to the increase of membrane fouling rate, the increase of chemical consumption, leading to a temporary plant shutdown. Effective pretreatment can reduce the amount of organic foulants reaching the RO membrane and alleviate the problem of flux decline during RO operation and increasing the membrane lifetime. This research compared the effect of Liquid Ferrate and Ferric Chloride in combination with dissolved air flotation (DAF) for the treatment of the algal cells and algal organic matter (AOM) during algal blooms events. The experiments were performed using a bench-scale DAF unit; HABs conditions were simulated by harvesting AOM from cultivating Chaetoceros Affinis (CA) in raw seawater to a concentration of around 10 mg C/L of total organic carbon (TOC). The liquid ferrate was generated in-situ by wet oxidation of ferric chloride in an alkaline media. The best performances were registered with the combined use of liquid ferrate and DAF with removal of algal cells up to 100%, with ATP removal up to 99.99%, and AOM removal up to 70%.

Session: 31, Room: A, at Fri, 09/06/2019 - 16:30 to 16:45
Oral presentation in Water treatment
[CEST2019_00897] Application of TPMS architectures in water technology: Amazing potential for cost and energy savings and reduced environmental impacts
by Arafat H.

Additive manufacturing, also known as three-dimensional (3D) printing, is a state of the art technology that has been gaining momentum in several applications including aerospace, automotive industry and the medical field. Recently, 3D printing has also gained attention as a promising fabrication pathway for key components of membrane-based systems for desalination and water treatment as well. The unique benefit of 3D printing over conventional manufacturing processes lies in its ability to fabricate structures with complex morphologies that can be optimized for fluid flow, heat transfer, etc., based on the targeted application. One such class of complex geometries are triply periodic minimal surfaces (TPMS), which can be described mathematically such that they have no self-intersecting or enfolded surfaces. “Triply periodic” means that the structure can be patterned in the 3D space and “minimal surface” means that it locally minimizes surface area for a given boundary such that the mean curvature at each point on the surface is zero. These shapes have been shown to have been investigated for applications ranging from aerospace to biomedical tissue engineering. They have various properties with regards to enhanced, smooth fluid flow that make them ideal candidates for a number of applications in water research. Primary among these applications is the design of feed spacers, which was investigated by our research group over the last 3 years.

Session: 31, Room: A, at Fri, 09/06/2019 - 15:00 to 15:30
Oral presentation in Water treatment
[CEST2019_00504] New generation of patterned membranes for water treatment
by Asad A., Sameoto D., Sadrzadeh M.

Membrane technology is an energy-efficient separation process that is expected to dominate the water treatment industry. However, the high vulnerability of membranes to fouling has limited the expansion of sustainable and energy-efficient membrane processes. Surface patterning has been proven to be an effective method to improve the performance of membranes by increasing the permeate flux and lowering the attachment of fouling materials on membrane surfaces. In this study, a new generation of patterned membranes was prepared using a novel hydrogel facilitated phase separation (HFPS) method. Hydrogel contains a high water content which initiates phase separation as a nonsolvent upon contact with the polymer solution. Structuring a hydrogel mold provides the ability to control the location of the skin layer on the patterned side of the membrane. The performance of the patterned and the unpatterned membranes made with HFPS was examined in a cross-flow filtration system; a significant increase in the pure water flux (~100%) was observed for the patterned membrane. Moreover, a fouling experiment with bovine serum albumin (BSA) solution showed that the patterned membranes maintained 76% higher flux after 90 minutes of operation.

Session: 31, Room: A, at Fri, 09/06/2019 - 16:15 to 16:30
Oral presentation in Water treatment
[CEST2019_00171] Water quality control of Aposelemis Dam Reservoir
by Gyparakis S., Diamadopoulos E.

The aim of this study is to check the vertical water quality profile of Aposelemis Reservoir. The water quality was studied in nine (9) different water reservoir depth points: S9: 0 m, S8: 02 m, S7: 03 m, S6: 05 m, S5: 07 m, S4: 09 m, S3: 10 m, S2: 13 m and S1: 15 m. A sudden change in the temperature of the water was observed at the water depth of 7 m (thermocline phenomenon) and a change in pH (from pH> 8 to pH <7.5) at the depth of 3 m. A sharp increase in metal concentration was identified in greater water depth, as well as prevalent the soluble form of them (Mn, Fe, etc.). Relating to microbial load, it was much lower in water depth > 2m, compared to 0-2 m. As the water sampling depth was increasing, the Total Organic Carbon (TOC) was decreasing, in contrary with the nutrient concentration (N, P) which was increasing. Color and odor values appear elevated in water depth greater than 5 m.

Session: 31, Room: A, at Fri, 09/06/2019 - 15:30 to 15:45
Oral presentation in Water treatment
[CEST2019_00175] Monitoring of the main operational parameters of Aposelemis Water Treatment Plant (WTP)
by Gyparakis S., Diamadopoulos E.

The purpose of this study is to present the annual monitoring data of the main water quality operational parameters of Aposelemis Water Treatment Plant (WTP). The main quality parameters studied are: turbidity, pH, suspended solids, conductivity, manganese (Mn), coliform bacteria, Escherichia Coli and Clostridium Perfringens of the untreated and treated surface water of the Aposelemis reservoir. There is a seasonal variation in the turbidity and in the microbiological parameters of WTP incoming water. The Suspended Solids fluctuation follows the entry water turbidity fluctuation. There is no significant difference between the water entry and exit conductivity. The produced water by Aposelemis WTP is of high quality and fulfills all the legislation requirements for water intended for human consumption.

Session: 31, Room: A, at Fri, 09/06/2019 - 16:45 to 17:00
Oral presentation in Water treatment
[CEST2019_00162] Polyethersulfone/Polyamide11Cost Effective, Antifouling- Nanofiltration Blend Membrane
by Abdallah H., Shalaby M.S., Alanezi A.A., Shaban A.M.

Nanofiltration membranes (NF) are considered and used extensively in seawater softening, food, textile, and mining industries for the removal of di-and multi-valents to increase RO lifetime by decreasing fouling rates, and chemical cleaning intervals. In this work, blend membranes of polyethersulfone and polyamide11 were prepared by phase inversion process. The membranes were characterized by scanning electron microscopy (SEM),pore size distribution, mechanical properties and membranes performance. The results indicated that, the membrane (N2), which was prepared using PA11 (1 wt%) with a solution of sodium dodecyl sulphate (0.5wt%) and TiO2 (1 wt%) provides the best performance according to rejection percentage. Where, the rejection percentage of magnesium sulfate reached 99 %, 97% and 91% as a function of feed synthetic salt solution of concentration 1g/l, 2 g/l, and 5 g/l respectively. Permeate flux of (N2) was the lowest one due to having a dense top layer of this membrane and low mean pore size (7.7 nm) which was 66.7 L/m2.h, 64.2 L/m2.h and 53.5 L/m2.h as a function of feed synthetic salt solution of concentration 1g/l, 2 g/l and 5 g/l respectively. The fouling test was carried out using methylene blue dye, where the membrane (N2) exhibits good antifouling properties.

Session: 31, Room: A, at Fri, 09/06/2019 - 16:00 to 16:15
Oral presentation in Water treatment
[CEST2019_00062] Potential of Using Real-time OiW Monitoring for Control of Produced Water Treatment in Offshore Oil & Gas Production
by Zhenyu Y., Durdevic P., Jespersen S., Hansen D.S.

From the process control point of view, any reliable and online Oil-in-Water (OiW) measurement could provoke a brand new control paradigm for produced water treatment. However, the real-time OiW monitoring is still an open and ad-hoc situation in recent decades. The fundamental issue, i.e., the OiW measurement is methodology dependent, leads to numerous challenges, such as (i) how to verify the reliability and accuracy of a specific methodology/instrument; (ii) how to handle and interpret the measured data in a most objective manner; and (iii) how to keep a cost-effective on-site calibration and maintenance under the harsh offshore conditions etc. The paper reports our latest achievements and observations in usage of fluorescence- and microscopy-based OiW monitoring technologies for advanced Produced Water Treatment (PWT) control and evaluation, particularly by focusing on the de-oiling hydrocyclone installations.

Session: 31, Room: A, at Fri, 09/06/2019 - 15:45 to 16:00
Oral presentation in Water treatment