Publications
414 results found
Yu W, Graham NJD, 2015, Performance of an integrated granular media - Ultrafiltration membrane process for drinking water treatment, JOURNAL OF MEMBRANE SCIENCE, Vol: 492, Pages: 164-172, ISSN: 0376-7388
Yu W, Graham N, Yang Y, et al., 2015, Effect of sludge retention on UF membrane fouling: The significance of sludge crystallization and EPS increase, WATER RESEARCH, Vol: 83, Pages: 319-328, ISSN: 0043-1354
- Author Web Link
- Cite
- Citations: 48
Armand H, Stoianov I, Graham N, 2015, Investigating the Impact of Sectorized Networks on Discoloration, Computing and Control for the Water Industry (CCWI2015), Publisher: Elsevier, Pages: 407-415, ISSN: 1877-7058
Cost-effective management of leakage has driven the sectorization of water supply networks into discrete areas that are referred to as District Metered Areas (DMAs). The resulting change in network topology has a major impact on the hydrodynamic conditions and consequently changes in water quality. This paper investigates the impact of DMAs on the potential for discoloration by analysing the spatio-temporal distribution of historic discoloration-related customer contacts for a UK water company. The results demonstrate that the sectorization of networks could have a negative effect on discolouration. A management strategy to reduce the risk of discoloration in DMA-based systems is discussed.
Yu W, Xu L, Graham N, et al., 2015, Contribution of Fe3O4 nanoparticles to the fouling of ultrafiltration with coagulation pre-treatment, Scientific Reports, Vol: 5, ISSN: 2045-2322
A coagulation (FeCl3)-ultrafiltration process was used to treat two different raw waters with/without the presence of Fe3O4 nanoparticle contaminants. The existence of Fe3O4 nanoparticles in the raw water was found to increase both irreversible and reversible membrane fouling. The trans-membrane pressure (TMP) increase was similar in the early stages of the membrane runs for both raw waters, while it increased rapidly after about 15 days in the raw water with Fe3O4 nanoparticles, suggesting the involvement of biological effects. Enhanced microbial activity with the presence of Fe3O4 nanoparticles was evident from the measured concentrations of extracellular polymeric substances (EPS) and deoxyribonucleic acid (DNA), and fluorescence intensities. It is speculated that Fe3O4 nanoparticles accumulated in the cake layer and increased bacterial growth. Associated with the bacterial growth is the production of EPS which enhances the bonding with, and between, the coagulant flocs; EPS together with smaller sizes of the nano-scale primary particles of the Fe3O4-CUF cake layer, led to the formation of a lower porosity, more resilient cake layer and membrane pore blockage.
Xu LJ, Chu W, Graham N, 2015, Sonophotolytic degradation of phthalate acid esters in water and wastewater: Influence of compound properties and degradation mechanisms, JOURNAL OF HAZARDOUS MATERIALS, Vol: 288, Pages: 43-50, ISSN: 0304-3894
- Author Web Link
- Cite
- Citations: 26
Ritson JP, Graham NJD, Templeton MR, et al., 2015, From peat bog to drinking water: ecosystem services under a changing climate, British Society of Soil Science Early Careers Research Conference, York, UK
Ritson JP, Graham NJD, Templeton MR, et al., 2015, The sensitivity of peat soil and peatland vegetation to drought: release of dissolved organic carbon (DOC) on rewetting, European Geosciences Union (EGU) General Assembly, Vienna, Austria
Ritson JP, Clark JM, Graham NJD, et al., 2015, Dissolved organic carbon (DOC) release following drought: influence of DOC source and drought severity on drinking water treatment, 249th American Chemical Society (ACS) National Meeting and Exposition, Denver, Colorado, USA
Ren Z, Graham N, 2015, Treatment of Humic Acid in Drinking Water by Combining Potassium Manganate (Mn(VI)), Ferrous Sulfate, and Magnetic Ion Exchange, ENVIRONMENTAL ENGINEERING SCIENCE, Vol: 32, Pages: 175-178, ISSN: 1092-8758
- Author Web Link
- Open Access Link
- Cite
- Citations: 11
Yu W, Graham NJD, 2015, Application of Fe(II)/K<inf>2</inf>MnO<inf>4</inf> as a pre-treatment for controlling UF membrane fouling in drinking water treatment, Journal of Membrane Science, Vol: 473, Pages: 283-291, ISSN: 0376-7388
This paper describes some results of mini-pilot-scale tests concerning the performance of potassium manganate (K2MnO4) as a pre-treatment chemical prior to ultrafiltration. Manganate is an intermediate in the commercial preparation of permanganate and in aqueous reactions MnO42- can act as both an oxidant and a coagulant/adsorbent arising from the formation of insoluble MnO2. In addition, the combination of ferrous sulfate and manganate (Fe/Mn), offers a potentially cheaper and effective combination of pre-oxidant and coagulant compared to the chemicals used currently in water treatment (e.g. ozone, chlorine, ferric sulfate). In comparative tests with conventional ferric sulfate and using simulated raw water, the results showed that Fe/Mn pre-treatment substantially reduced membrane fouling in terms of the rate of trans-membrane pressure development (arising from both external and internal fouling). Fe/Mn pre-treatment was effective in reducing bacterial activity, changing the characteristics of organic matter and decreasing the production of extracellular polymeric substances (EPS) by bacteria. The external fouling in this process was determined by the EPS concentration, and the internal fouling mainly determined by the adsorption of lower MW organic matter to the membrane pores. Fe/Mn pre-treatment reduced the amounts of both types of fouling material within the cake layer and membrane pores in comparison to conventional pre-treatment with ferrous sulfate, most likely through the formation of solid-phase Fe(III) and MnO2 and by MnO42- oxidation, thereby leading to a substantial increase in membrane run time.
Yu W, Gregory J, Campos LC, et al., 2015, Dependence of floc properties on coagulant type, dosing mode and nature of particles, WATER RESEARCH, Vol: 68, Pages: 119-126, ISSN: 0043-1354
- Author Web Link
- Cite
- Citations: 54
Yu W, Campos L, Shi T, et al., 2015, Enhanced removal of manganese in organic-rich surface water by combined sodium hypochlorite and potassium permanganate during drinking water treatment, RSC ADVANCES, Vol: 5, Pages: 27970-27977
- Author Web Link
- Cite
- Citations: 15
Ritson JP, Bell M, Graham NJD, et al., 2014, Simulated climate change impact on summer dissolved organic carbon release from peat and surface vegetation: implications for drinking water treatment, Water Research, Vol: 67, Pages: 66-76, ISSN: 0043-1354
Uncertainty regarding changes in dissolved organic carbon (DOC) quantity and quality has created interest in managing peatlands for their ecosystem services such as drinking water provision. The evidence base for such interventions is, however, sometimes contradictory. We performed a laboratory climate manipulation using a factorial design on two dominant peatland vegetation types (Calluna vulgaris and Sphagnum Spp.) and a peat soil collected from a drinking water catchment in Exmoor National Park, UK. Temperature and rainfall were set to represent baseline and future conditions under the UKCP09 2080s high emissions scenario for July and August. DOC leachate then underwent standard water treatment of coagulation/flocculation before chlorination. C. vulgaris leached more DOC than Sphagnum Spp. (7.17 versus 3.00 mg g−1) with higher specific ultraviolet (SUVA) values and a greater sensitivity to climate, leaching more DOC under simulated future conditions. The peat soil leached less DOC (0.37 mg g−1) than the vegetation and was less sensitive to climate. Differences in coagulation removal efficiency between the DOC sources appears to be driven by relative solubilisation of protein-like DOC, observed through the fluorescence peak C/T. Post-coagulation only differences between vegetation types were detected for the regulated disinfection by-products (DBPs), suggesting climate change influence at this scale can be removed via coagulation. Our results suggest current biodiversity restoration programmes to encourage Sphagnum Spp. will result in lower DOC concentrations and SUVA values, particularly with warmer and drier summers.
Yu W, Xu L, Graham N, et al., 2014, Pre-treatment for ultrafiltration: effect of pre-chlorination on membrane fouling, SCIENTIFIC REPORTS, Vol: 4, ISSN: 2045-2322
- Author Web Link
- Cite
- Citations: 52
Xu LJ, Chu W, Graham N, 2014, Atrazine degradation using chemical-free process of USUV: Analysis of the micro-heterogeneous environments and the degradation mechanisms, JOURNAL OF HAZARDOUS MATERIALS, Vol: 275, Pages: 166-174, ISSN: 0304-3894
- Author Web Link
- Cite
- Citations: 38
Yu W, Xu L, Qu J, et al., 2014, Investigation of pre-coagulation and powder activate carbon adsorption on ultrafiltration membrane fouling, JOURNAL OF MEMBRANE SCIENCE, Vol: 459, Pages: 157-168, ISSN: 0376-7388
- Author Web Link
- Cite
- Citations: 65
Ren Z, Nigel G, 2014, Effect and mechanism of manganate preoxidation for organics removal, SCIENCE CHINA-TECHNOLOGICAL SCIENCES, Vol: 57, Pages: 1160-1164, ISSN: 1674-7321
Xu LJ, Chu W, Graham N, 2014, Degradation of di-<i>n</i>-butyl phthalate by a homogeneous sono-photo-Fenton process with in situ generated hydrogen peroxide, CHEMICAL ENGINEERING JOURNAL, Vol: 240, Pages: 541-547, ISSN: 1385-8947
- Author Web Link
- Cite
- Citations: 38
Bond T, Templeton MR, Rifai O, et al., 2014, Chlorinated and nitrogenous disinfection by-product formation from ozonation and post-chlorination of natural organic matter surrogates, Chemosphere, Vol: 111, Pages: 218-224
Ritson JP, Graham NJD, Templeton MR, et al., 2014, The impact of climate change on the treatability of dissolved organic matter (DOM) in upland water supplies: a UK perspective, Science of the Total Environment, Vol: 473-474, Pages: 714-730
Bond T, Huang J, Graham NJD, et al., 2014, Examining the interrelationship between DOC, bromide and chlorine dose on DBP formation in drinking water - a case study, Science of the Total Environment, Vol: 470–471, Pages: 469-479
Graham NJD, Collins MR, 2014, Slow sand filtration: recent research and application perspectives, 5th International Slow Sand and Alternative Biological Filtration Conference, Publisher: IWA PUBLISHING, Pages: 3-16
- Author Web Link
- Cite
- Citations: 3
Yu W-Z, Graham N, Liu H-J, et al., 2013, Comparison of FeCl<sub>3</sub> and alum pre-treatment on UF membrane fouling, CHEMICAL ENGINEERING JOURNAL, Vol: 234, Pages: 158-165, ISSN: 1385-8947
- Author Web Link
- Cite
- Citations: 49
Aisopou A, Stoianov I, Graham N, et al., 2013, Analytical and experimental investigation of chlorine decay in water supply systems under unsteady hydraulic conditions, Journal of Hydroinformatics
This paper investigates the impact of the dynamic hydraulic conditions on the kinetics of chlorine decay in water supply systems. A simulation framework has been developed for the scale-adaptive hydraulic and chlorine decay modelling under steady and unsteady state flows. An unsteady decay coefficient is defined which depends upon the absolute value of shear stress and the rate of change of shear stress for quasi-unsteady and unsteady-state flows. By coupling novel instrumentation technologies for continuous hydraulic monitoring and water quality sensors for in-pipe water quality sensing a pioneering experimental and analytical investigation was carried out in a water transmission main. The results were used to model monochloramine decay and these demonstrate that the dynamic hydraulic conditions have a significant impact on water quality deterioration. The spatial and temporal resolution of experimental data provides new insights for the near real-time modelling and management of water quality as well as highlighting the uncertainty and challenges of accurately modelling the loss of disinfectant in water supply networks.
Yu W-Z, Liu H-J, Xu L, et al., 2013, The pre-treatment of submerged ultrafiltration membrane by coagulation-Effect of polyacrylamide as a coagulant aid, JOURNAL OF MEMBRANE SCIENCE, Vol: 446, Pages: 50-58, ISSN: 0376-7388
- Author Web Link
- Cite
- Citations: 51
Mechelhoff M, Kelsall GH, Graham NJD, 2013, Super-faradaic charge yields for aluminium dissolution in neutral aqueous solutions, CHEMICAL ENGINEERING SCIENCE, Vol: 95, Pages: 353-359, ISSN: 0009-2509
- Author Web Link
- Cite
- Citations: 28
Mechelhoff M, Kelsall GH, Graham NJD, 2013, Electrochemical behaviour of aluminium in electrocoagulation processes, CHEMICAL ENGINEERING SCIENCE, Vol: 95, Pages: 301-312, ISSN: 0009-2509
- Author Web Link
- Open Access Link
- Cite
- Citations: 76
Xu LJ, Chu W, Graham N, 2013, A systematic study of the degradation of dimethyl phthalate using a high-frequency ultrasonic process, ULTRASONICS SONOCHEMISTRY, Vol: 20, Pages: 892-899, ISSN: 1350-4177
- Author Web Link
- Cite
- Citations: 58
Xu LJ, Chu W, Graham N, 2013, Sonophotolytic degradation of dimethyl phthalate without catalyst: Analysis of the synergistic effect and modeling, WATER RESEARCH, Vol: 47, Pages: 1996-2004, ISSN: 0043-1354
- Author Web Link
- Cite
- Citations: 43
Yu W-Z, Graham N, Liu H-J, et al., 2013, Membrane fouling by Fe-Humic cake layers in nano-scale: Effect of <i>in-situ</i> formed Fe in-situ formed Fe(III) coagulant, JOURNAL OF MEMBRANE SCIENCE, Vol: 431, Pages: 47-54, ISSN: 0376-7388
- Author Web Link
- Cite
- Citations: 18
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.