Membrane Filtration of Wastewater Split Flows originating from Paper Industry and Biological Wastewater Treatment of the generated Membrane Concentrates
© DIV Deutscher Industrieverlag GmbH (9/2011)
Wastewater effluents from deinking- and TMP processes were taken and were concentrated in 2 stages consisting of ultra- and nanofi ltration. Futher more, the concentrates were biologically treated with a single aerobic and a hybrid anaerobic-aerobic process. With a continuous anaerobic reactor and an aerobic SBR reactor experiments were conducted to study the variations in hydraulic retention time (HRT), food to biomass ratio (F/M) and wastewater concentrate. For the deinking wastewater concentrate, an overall average COD elimination of 51 % and 57 % was achieved for aerobic and anaerobic-aerobic treatment, respectively. Single stage aerobic treatment of TMP wastewater concentrate had an mean COD elimination effi ciency of 61 % and the hybrid anaerobic-aerobic treatment yielded 73 %. The temperature in the aerobic biological SBR reactor was kept stable at 30 °C with an F/M ratio between 0.01 and 0.5 gBOD5/(gSS · d).

Challenge of High Water Hardness and Elevated Temperature: MBR Pilot Trials in the Paper Industry under Mesophilic and Thermophilic Conditions
© DIV Deutscher Industrieverlag GmbH (9/2011)
The results of two MBR pilot trials conducted in paper mills are discussed. In the fi rst trial it was possible to operate a MBR pilot plant under the challenges of extremely high water hardness and a mean calcium concentration of 770 mg/L that caused massive scaling problems. An upstream lime softening pilot plant was designed and constructed. As a result, the fl ux increased again and the cleaning intervals could be extended signifi cantly. With the help of lime softening, 50–80 % of the calcium was removed upstream of the MBR pilot plant. The second part of the paper describes trials using a thermophilic aerobic MBR (TMBR) at 50 °C. A new and innovative use of submerged fl at-sheet MBR-modules to treat paper industry circuit wastewater was studied. The elimination rates of the TMBR regarding COD and BOD5 were 83 % and 99 %, respectively. A pilot trial was conducted at a fl ux of 4.5 to 8.5 L/m2/h. Lab experiments with a smaller membrane module had shown a higher fl ux of 8 to 13 L/m2/h.

Sulphate Removal from Ground Water – a Case Study
© DIV Deutscher Industrieverlag GmbH (9/2011)
With ratification of the new German drinking water directive, the maximum allowable sulphate concentration is raised from 240 to 250 mg/L. However, exceedances due to geogenic conditions up to 500 mg/L sulphate are no longer permitted. Water supply utilities affected by this change now have to consider suitable treatment technologies for the given conditions. In a case study, a semi industrial pilot plant was operated with different low pressure reverse osmosis and nanofi ltration membranes to identify conditions for a stable operation and the required antiscalant dosage to achieve this. Long term operation was possible with both membrane types at a yield of 80 % with 1.2 g/m³ of polycarboxylic acid continuously dosed as antiscalant. In order to elucidate the possibilities for concentrate discharge several treatment processes have been investigated.

Comparison of the Pretreatment Efficiency Between UF and Sand Filtration of a Desalination Process Using a Reverse Osmosis Membrane
© DIV Deutscher Industrieverlag GmbH (9/2011)
The pretreatment process is known to be the dominant infl uence factor in the RO process. Therefore, this study was done to evaluate effi ciency by comparing membrane fi ltration (UF) with two-stage sand fi ltrations for pretreatment of the RO process. SDI and particle size distribution of feed sea water and pretreatment permeate water were measured to analyse the infl uence of the fouling factor of the RO membrane. The SDI removal effi - ciency of the UF membrane fi ltration process was better than that for the sand fi ltration. The particle fraction under 20 μm of feed sea water and sand fi ltration permeate water was more than 93 % and 97 %, respectively. As for results of operation, micro particles were not removed by the sand fi ltration. Furthermore, although the UF membrane process had a higher recovery than the sand fi ltration process, the UF membrane process represented low RO resistance.

Design and Operation of an Ultrafiltration Plant for the Production of Drinking Water out of the River Scheldt
© DIV Deutscher Industrieverlag GmbH (9/2011)
In April 2009, the production capacity of the conventional drinking water treatment plant “de Gavers” in Harelbeke, Belgium, was extended from 25,000 to 32,000 m³/day by the construction of an ultrafi ltration unit. In this paper, the design of the ultrafi ltration unit is elaborated and the fi rst operational results with respect to membrane fouling, membrane integrity and effl uent quality are presented. With respect to membrane fouling, in-line coagulation applying a small dose of fl occulant was found to be necessary to keep membrane fouling under control. Membrane integrity testing demonstrated a log 4 removal for micro-organisms larger than 3 μm. Compared to the conventional coagulation-fi ltration plant the ultrafi ltration unit produces an effl uent with lower bacteria counts. Moreover, the turbidity of its effl uent is also substantially lower. However, the hydraulic yield of ultrafi ltration is considerably lower than that of the conventional treatment and it results in a higher waste water production.

Comparison of IMS-Free and IMS Real-Time PCR Detection of Giardia lamblia from Surface Water
© PSP - Parlar Scientific Publications (12/2010)
Giardia lamblia is one of the most important waterborne pathogenic protozoa. Its occurrence in source and drinking water threatens human health seriously. In this study, four quantitative real-time PCR protocols involving Envirochek filtration, flat membrane filtration, immunomagnetic separation (IMS) and IMS-free separation to detect G. lamblia from surface water were compared.

Closing down Pääsküla landfill. Post-closedown environmental monitoring and maintenance of the landfill
© NMC Ltd. (10/2010)
Pääsküla landfill is the largest municipal waste landfill in Estonia which was established 1972 and closed 2003. The landfill was closed down during 2003-2006 within ISPA (The Instrument for Structural Policies for Pre-accession) project. At the moment of closing down its volume was 4,5 million cubic metres, relative height 29 metres and its area nearly 30 hectares. The total cost of the project was 11 225 009 EUR (175 633 228 EEK) including V.A.T 18 per cent. Objectives of the projects were to minimize the environmental impacts in a long perspective against main hazards as contamination of groundwater and surface water, landfill gas leakage, health hazards to neighbourhood dwellings and nuisance like smell, fly trash, gulls and other birds and rodents.

Biofilms on aged Materials in Household Installation Systems
© DIV Deutscher Industrieverlag GmbH (8/2010)
The causes of contamination originate in the water itself and on materials in contact with water. Drinking water is not sterile and does not have to be. Water treatment plants’ strategy consists in removing the nutrients that bacteria feed on to produce “biostable” drinking water. This allows in many cases chlorination to be avoided. But it is known that even biologically stable drinking water with very low nutrient content still contains micro-organisms. These micro-organisms can multiply themselves if they encounter nutrients.

Sanitary Engineering Structure and Prerequisite in Minas Gerais, Brazil
© DIV Deutscher Industrieverlag GmbH (8/2010)
Introducing a Decentralised Water Treatment Plant

CPF Cast Surfaces Prove their Worth in Drinking Water Reservoirs
© DIV Deutscher Industrieverlag GmbH (9/2009)
According to EN 1508 [1], “Service reservoirs shall be designed, constructed and operated to prevent contamination or other chemical, physical and biological changes that are detrimental to the water quality”. Only approved materials shall be used in the surfaces in contact with the stored water. “ In order to facilitate subsequent cleaning and avoid bacterial growth, internal surfaces shall be as smooth and pore-free as possible.

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