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The heating of drinking water in households contributes significantly to the emission of greenhouse gases. As a water utility aiming to operate at a climate neutral level by 2020, Waternet needs to reduce its CO2 emission by 53 kton yr-1. To contribute to this ambition, a pilot project was carried out in Uilenstede, Amstelveen, the Netherlands, to recover the shower heat energy with a shower heat exchanger from Dutch Solar Systems. An experimental setup was built in the Waternet laboratory to evaluate the claimed efficiencies. The energy recovery efficiency observed in the lab was 61-64% under winter conditions and 57-62% under summer conditions, while the energy recovery efficiency observed in Uilenstede was 57% in December 2014. Based on the observations, 4% of the total energy consumption of households in Amsterdam (electricity and gas) can be recovered with a shower heat exchanger installed in all households in Amsterdam, which also means a 54 kton year-1 CO2 emission reduction can be achieved. [ABSTRACT FROM AUTHOR]

The heating of drinking water in households contributes for a significant amount to the emission of greenhouse gases. As a water utility aiming to operate climate neutral by 2020, Waternet needs to reduce its CO2 emission by 53 kton yr-1. To contribute to this ambition, a pilot project was carried out in Uilenstede, Amstelveen, the Netherlands, to recover the shower heat energy with a shower heat exchanger from Dutch Solar Systems. An experimental set up was built in the Waternet laboratory to compare field conditions and lab conditions. The energy recovery efficiency observed in the lab was 61-64% under winter conditions and 58-62% under summer conditions, while the energy recovery efficiency observed in Uilenstede was 57% in December 2014. Based on the observations, 4% of the total energy consumption of households in Amsterdam (electricity and gas) can be recovered with a shower heat exchanger installed in all households in Amsterdam, which also means a 54 kton yr-1 CO2 emission reduction. [ABSTRACT FROM AUTHOR]

Calcium carbonate pellets are produced as a by-product in the pellet softening process. In the Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high-potential market segments such as paper and glass. Substitution of the sand grain with a calcite grain (100% calcium carbonate) is in principle possible, and could significantly improve the pellet quality. In this study, the grinding and sieving of pellets, and the subsequent reuse as seeding material in pellet softening were tested with two pilot reactors in parallel. In one reactor, garnet sand was used as seeding material, in the other ground calcite. Garnet sand and ground calcite performed equally well. An economic comparison and a life-cycle assessment were made as well. The results show that the reuse of ground calcite as seeding material in pellet softening is technologically possible, reduces the operational costs by €38,000 (1%) and reduces the environmental impact by 5%. Therefore, at the drinking water facility, Weesperkarspel of Waternet, the transition from garnet sand to ground calcite will be made at full scale, based on this pilot plant research. [ABSTRACT FROM AUTHOR]

Eureau is the European Federation of National Associations of Water and Wastewater Services. At the request of Eureau Commission 1, dealing with drinking water, a survey was produced focusing on raw drinkingwater sources and drinkingwater treatment technologies applied in Europe. Rawwater sources concerned groundwater, surface water, surface water with artificial recharge and river bank filtration. Treatment schemes concerned no treatment, conventional treatment, advanced treatment and conventional plus advanced treatment. The response covered 73% of the population to which drinking water is supplied by the utilities joint in Eureau. Groundwater and surfacewater are themajor rawwater sources (>90%). In total, 59% of the drinking water supply concerns not-treated drinking water or drinking water treated with only conventional technologies, while 12% of the drinking water is not disinfected. Challenges for the European drinking water sector are the contamination of raw water sources with emerging substances, absence of disinfection and the potential formation of disinfection by-products. These challenges entail research needs such as the development of quantitative structure activity relationships (QSARs) to better understand and predict the removal rates of treatment technologies for emerging contaminants, the introduction of Water Safety Plans to safeguard the hygienic quality of drinking water, and the optimization of disinfection processes and strategies. [ABSTRACT FROM AUTHOR]

The city of Amsterdam is going to build a new housing estate: IJburg. About 18,000 houses will be built and finally 45,000 people will live in IJburg. An important objective is to realize a sustainable housing estate: the design is focused on water and energy saving, and theuse of sustainable building materials. An alternative water supply system, in which household water is used besides drinking water, may be an important contribution to this ambition. Household water can be used for toilet flushing, for washing clothes or for both. Amsterdam Water Supply developed five scenarios for such an alternative water supply system. Water saving and supply of two types of water are key elements in these scenarios. Based on a comprehensive selection in which public health aspects, technical feasibility, legislation, acceptance by the public, costs and environmental impact were used as criteria, the optimum scenario was chosen: a dual water system, supplying drinking water from the existing drinking water production plants, andsupplying household water for toilet flushing and washing, produced from a local surface water, the IJ-lake. [ABSTRACT FROM AUTHOR]

For capacity extension of one of the drinking water production plants of Amsterdam Water Supply, four treatment schemes applying ultrafiltration (UF) are considered. The main purposes of the UF process are phosphate removal, removal of suspended solids and colloidal matter; and hygienic water quality improvement. In the pilot plant investigation, water from the Bethunepolder has been treated with UF. The feed water shows very large and rapid water quality variations, making it a difficult source to treat with UF. Hydraulic performance as well aseffluent water quality were studied. The results have shown that stable operation of the membranes is feasible and an excellent water quality can be produced. Phosphate was removed from average 60 mu g/l P to 20 mu g/l P in the ultrafiltrate. Iron and turbidity were almost completely removed, whereas a log-removal of at least 2.5 to 3.5 was reached for indicator organisms. It was concluded that UF is a powerful treatment process for extension of drinking water production at A WS and offers new opportunities for relatively small-scale, on-site production of household or industrial water. [ABSTRACT FROM AUTHOR]

Ammonium removal occurs in both the surface water reservoir and rapid sand filters of Amsterdam Water Supply. Nitrification in the reservoir is best modelled as a first order reaction with a temperature dependent breakdown coefficient. In moderate winters, the increase of ammonium concentration in the filter influent is compensated but stagnation of nitrification in the Winter of '95--'96 led to a two and halfmonth excess of the ammonium maximum admissible concentration. Only after the start of phosphate dosing, full restoration of nitrification was achieved. A model to alert for ammonium breakthrough was developed based on growth characteristics of Nitrosomonas. [ABSTRACT FROM AUTHOR]

The efficiency of activated carbon for pesticide removal is negatively influenced by the presence of natural organic matter (NOM) in water. NOM molecules compete with pesticides for adsorption sites and NOMmolecules block pores thus preventing pesticides entering the micropores. To improve the efficiency of GAC-filtration several possibilities are available. By using nanofiltration as a pretreatment for granular activated carbon (GAC) filtration. GAC lifetime for pesticide removal can be increased by a factor of 100. In situations where, besides pesticides removal, hardness removal and/or colour removal is required the combination of nanofiltration and GAC filtration is an interesting option. Ozonation prior to GAC-filtration also results in an increase in GAC lifetime for pesticide removal: NOM molecules become more polar (less adsorbable), smaller and more biodegradable, which results in less competition and pore blocking and so in an increased adsorption capacity of the GAC for pesticides. In laboratory experimentsan increase in GAC lifetime for pesticide removal of about 30--70% was determined by using an ozone dose of about 1.4 mg/l (in the presence of 2 mg/l DOC). Recently, Kiwa has investigated the possibilities of activated carbon fibres (ACF) as an alternative for granular activated carbon. This product is less influenced by the presence of NOM as a result of the pore structure which contains mainly micropores. With relatively short empty bed contact times of 20--60 sec ACF showed pesticide breakthrough a factor of 3 to more than 8 later than GAC-filtration (EBCT 20 min). [ABSTRACT FROM AUTHOR]

Amsterdam Water Supply intends to increase its production capacity by 13 x 106 m3/year. In one option for this extension, pretreated River Rhine water (coagulation-sedimentation-rapid sand filtration) will be treated by either ozonation-biological activated carbon filtration-slow sand filtration-reverse osmosis (scheme I), or by slow sand filtration-reverse osmosis (scheme II). Pilot plants were operated to study both process schemes. Special attention wasgiven to fouling and scaling of the RO units. Scheme I succeeded in producing a RO feed water quality with a very low fouling potential. Scaling concerned BaSO4 precipitation in the RO units. By injection of an anti-scalant in the RO feed water, BaSO4-scale formation could be avoided. However, the anti-scalant contributed to a severe biofouling of the RO elements. The operation of the RO systems appeared to be very successful without anti-scalant addition,and with HCl addition to avoid CaCO3-scale formation, A recovery of 88% was possible. In combination with the extended pretreatment scheme (scheme I). both fouling and scaling were prevented and the cleaning frequency could be reduced to less than once every 6 months. [ABSTRACT FROM AUTHOR]

Three integrated membrane systems (IMSs) are evaluated for surface water treatment, being: an IMS with soil passage and nanofiltration; an IMS with ultrafiltration and reverse osmosis; and an IMS with physical/chemical treatment and reverse osmosis. An IMS with bank filtration and nanofiltration shows an initial MTC decrease followed by a stabilisation for at least 40 days. Precursor parameters are decreased for more than 95%. An IMS with ultrafiltration and reverse osmosis is a very promising process. Ultrafiltration proves to be a superior pretreatment. After the initial MTC decrease no further productivity decline takes place for more than 6000 h. Biofouling causes a significant increase of the feed-concentrate pressure drop. Both membrane stepsare solid disinfection barriers although reverse osmosis membranes show some deficiencies. An IMS with slow sand filtration and reverse osmosis shows a significant biofouling caused by the anti-scalant dosage. Without an antiscalant dosage long running times without chemicalcleaning can be reached. Summarising, it can be concluded that all IMSs studied are very promising options for an integrated surface water treatment. [ABSTRACT FROM AUTHOR]