Funding:

Project coordination:    DVGW research centre TUHH

Project partner:  

• Politecnico di Milano (IT)
• Kompetenzzentrum Wasser Berlin (DE)
• BioDetection Systems (NL)
• Eurecat - Centre Tecnologic de Catalunya (ES)
• Umweltbundesamt (DE)
• Helmholtz-Zentrum für Umweltforschung (DE)
• Consorci d’Aigües de Tarragona (ES)
• Tutech Innovation GmbH (DE)
• Metropolitana Milanese SPA (IT)
• Multisensor systems (UK)

Project management / project work:

Dr. Anissa Grieb / Jon Wullenweber

Situation:

One focus of SafeCREW will be the investigation of previously unknown disinfection by-products and the further characterisation of already known ones and their formation. With the results, the participating companies intend to develop commercially available methods of quantifying and reducing these by-products so that negative effects on human health can be prevented.

The SafeCREW consortium will use three case studies in northern Germany, Italy and Spain to drive the further characterisation of water quality, and develop new water treatment methods and better management of water distribution networks to maintain high drinking water quality. This will include all processes from source via treatment and up to distribution.

Besides the project coordination, the focus of our research institute within the project is on the chemical-free removal of natural organic matter to prevent formation of disinfection by-products. For this purpose, Ultrafiltration with electro-conductive membranes will be further developed. We are also involved in the development of a passive sampler for pathogen monitoring in water distribution networks and in characterization of natural organic matter.

https://safecrew.org/

https://cordis.europa.eu/project/id/101081980

Follow us: @Safecrew_org or https://www.linkedin.com/showcase/safecrew-org/

Funding:

Project management / project work:

Prof. Mathias Ernst / Natalie Lüdemann

Situation:

Elevated nitrate levels in water bodies, especially in groundwater, are a global problem for drinking water supplies (World Health Organization 2011; Mohseni-Bandpi et al. 2013). Due to its carcinogenic properties and the risk of causing methemoglobinaemia, the recommendations of the World Health Organization (WHO) and the European Economic Community (EEC) are based on a drinking water limit of 50 mg NO3-/l, which is also included in the German Drinking Water Ordinance (TrinkwV; World Health Organization 2011). Various treatment techniques can be used to remove nitrate from drinking water, such as reverse osmosis, ion exchange, electrodialysis and biological denitrification. Biological treatment is increasingly coming into focus, as it offers a high level of water recovery at moderate costs through the complete and selective reduction of nitrate to nitrogen compared to physico-chemical processes (Rezvani et al. 2019).

Biological denitrification can be divided into auto- and heterotrophic denitrification. Heterotrophic denitrification is generally applied in wastewater treatment. Here, readily biodegradable organic carbon sources are needed, which, however, can pose a hygienic risk in drinking water treatment due to accelerated rapid growth of microorganisms. The autotrophic denitrification uses inorganic carbon such as CO2 only, this method is preferable for drinking water treatment, especially for groundwater (Rezvani et al. 2019). In recent years, bioelectrochemical systems (BES) are increasingly discussed with regard to biological denitrification (Cecconet et al. 2018; Rezvani et al. 2019).

The goal of this project is the development of an autotrophic denitrifying bioelectrochemical system for drinking water treatment. The focus is on the search for suitable cathode materials and their shapes, which are able to act as electron donors and suitable habitats for microorganisms. The process will be investigated with respect to its stability, relevant boundary conditions and challenges for implementation.

Initially simple batch tests were designed in order to identify main influencing parameters and optimize the fundamental processes in an innovative reactor setup. Subsequently, this experimental setup is carried out with different electrode materials and varying material properties and shapes. On basis of batch results, a continuous bioelectrical reactor systems shall be constructed.

Funding:

Project management / project work:

Prof. Dr. Mathias Ernst, Muhammad Ismahil

Situation:

Due to climate change, population growth and the increasing pollution of our environment, water scarcity has become a worldwide problem. As an alternative to conventional water treatment plants, membrane-based processes are currently the most effective solution for drinking water filtration, wastewater treatment and industrial energy applications (Abdelrasoul et al., 2020). The versatile membrane separation processes can be used for the removal of organic pollutants, particles, paint, microbes and viruses, as well as for the desalination of seawater (Ang et al. 2015). However, the challenges in membrane technology in terms of fouling behaviour, scaling and energy consumption require research and development to obtain more sustainable membrane applications.

Membrane modelling makes it possible to obtain important information about membrane performance and selectivity. Although the mechanisms of permeation and rejection are complex, a mathematical model allows minimising the number of laboratory experiments required for development, leading to reduced costs and time savings (Ang et al., 2015).

At the Institute of Water Resources and Water Supply, several experimental research projects are being conducted on membrane filtration processes at laboratory and pilot scale. For example, PAN-UF membranes modified with amine groups are being investigated for the removal of oxygen anions from drinking water sources (Glass et al., 2021). Other innovative projects are investigating the electrosorption and desorption behaviour of natural organic substances on conductive membrane surfaces (Mantel et. al., 2021) or examining the treatment of spent filter backwash water using membrane filtration for water recycling in drinking water supplies. One of the challenges in the latter process is the fouling potential that arises on the membrane surface (Kast et. al., 2022).

The goal of this project is to develop a mathematical model that describes the relevant mechanisms in a porous membrane filtration process. Later, the model will be extended to include adsorption behaviour as well as electrostatic sorption and desorption effects. The experimental data collected from ongoing research projects will be used to validate the model.

Funding:

• Behörde für Umwelt, Energie, Klima und Agrarwirtschaft
• DVGW Research Centre TUHH
• EnergieConsult

Project management / project work:

Dr. Anissa Grieb

Situation:

A healthy urban climate requires an adequate amount of greenery on public and private areas, which need
sufficient water supply. In addition to the effects of climate change, population growth is leading to an increased
demand for drinking water - clearly noticeable in the Hamburg metropolitan area. The availability of sustainable
freshwater groundwater is already endangered by conflicts of use and geogenic influences (saline aquifers).
Various adaptation strategies are needed to ensure the long-term supply of drinking water. One starting point is
the increased use of alternative water sources, in particular rainwater, for purposes without requirement for
drinking water quality. At the Bergedorf cemetery, the existing rainwater drainage system is converted into a
management system as part of the RISA (RainInfraStructureAdaption) project, a joint project of BUKEA, Hamburg
Wasser and other partners.

For the conversion of the rainwater drainage system into a rainwater management system, the surface drainage of the paved areas of approximately 2 ha on the 53 ha property is collected in a rainwater storage tank in the future. The storage tank will be installed below the existing rainwater retention basin and filtered rainwater will be fed into the existing water distribution system. The distribution system for water supply at the gravesites will be completely separated from the drinking water network. In case of critical water levels in the tank, an automated replenishment with drinking water will be carried out via a free inlet, so that a permanent supply at the tapping points is guaranteed.

DVGW-TUHH will survey the project with scientific monitoring. For this purpose, the plant will be equipped with measuring technology so that the water inflow, drinking water replenishment and withdrawal are continuously recorded and linked with the climate and weather data. In addition to the system monitoring and electronic measurement data acquisition, regular sampling of the water quality and sedimented solids from the sand trap located in the inlet of the rainwater storage tank will be carried out to compare the collected data with the design approaches.

Funding:

Project management / project work:

Situation:

The use of antiscalants (AS) in the treatment of drinking water by means of  reverse osmosis (RO) or nanofiltration (NF) is common practice in Germany. Various technical products are used in the approx. 90 plants, generally based on phosphonic acid, but also phosphorus-free AS based on polyacrylic acids. The authorised antiscalants are specified in the § 20 list of the Drinking Water Ordinance.

The predecessor project KonTriSol (BMBF/DVGW funding, project end 2023) identified acute problems with the use of AS in membrane filtration. Residual concentrations of antiscalants were found in permeates and drinking water from corresponding systems.

Additionally, problematic substances might be formed in downstream processes such as disinfection or activated carbon filtration from the substances that enter the permeate.. In the case of P-free products, there are indications that the active ingredient content with a small molecular mass is ineffective or can cause biofouling.

Solutions are being sought with regard to the respective product contamination of the AS, human toxicity and operational behaviour.

With the direct involvement of the UBA as a project partner, safe operational, regulatory and legal conditions for Germany are to be derived.

The specific objectives are as follows:

• Further development of analytics for the various types of antiscalants, among other things to clarify the extent of AS transfer into the permeate of the RO/NF
• Simplification of the analysis of AS by developing an "analytical test battery" so that simplified, cost-effective and rapid characterisations can be implemented
• Identification of safe and effective AS formulations (with regard to secondary constituents, membrane permeability, fouling potential in RO/NF, contamination potential in drinking water distribution)
• Investigation of so-called "green" antiscalants (not yet authorised in Germany) with regard to effectiveness and possible side effects
• Proposals for a legally compliant application via the technical regulations of the DVGW (W236) and the § 20 list of the TrinkwV

Funding:

Coordination:    Inflotec GmbH

Partner:

• DVGW-Forschungsstelle TUHH
• Bundeswehr, Wehrwissenschaftliches Institut für Schutztechnologien
• Umweltbundesamt
• Surflay Nanotec GmbH

Project management / project work:

Dr.-Ing. Barbara Wendler, Julia Bennert

Situation:

The goal of the KeraRes project is to develop a new membrane process for resource-efficient water treatment. A ceramic nanofiltration membrane (NF) is produced by post-modification with polyelectrolytes, which is intended to enable the safe treatment of even difficult-to-treat water resources (e.g. river water, wastewater, rainwater) in a single treatment step. Particles (e.g. microplastics), bacteria and viruses as well as dissolved water constituents (organic matter, salts) are to be retained.

Conventional NF membrane systems are fundamentally subject to the problem of fouling (particles, organics, precipitates, biofilm), i.e. the membranes become clogged with increasing operating time due to the formation of a covering layer of organic and inorganic particles. Backwashing is not possible with conventional NF wound membrane modules and only part of the covering layer can be removed again by membrane cleaning (cleaning-in-place). The energy requirement therefore increases over the operating time up to the point at which the membrane modules have to be replaced. The KeraRes membrane process aims to solve this problem by regenerating the LbL coating: the old LbL layer is dissolved by increasing the pH and then reapplied.

The KeraRes project is focussing on the development of an innovative water treatment technology. To this end, functional polyelectrolyte layers are applied to ceramic membranes using the layer-by-layer (LbL) process. The coated membranes are intended to efficiently remove polyvalent ions such as hardness formers, as well as organic molecules, including persistent compounds such as PFAS.

The backwashability and regenerability of the NF separation layer enable a one-step process that makes pre-treatment of the water by microfiltration superfluous. Energy efficiency can be further increased through better control of fouling.

The sub-project of the DVGW Research Centre TUHH primarily involves the characterisation of the LbL-coated membranes. In order to record and optimise the properties of the coating, the coated membrane surface is examined for its structure and charge properties. The filtration behaviour (separation properties and permeate flux) is recorded in laboratory tests with various waters, including the fouling and backwashing behaviour and energy requirements. This characterisation enables conclusions to be drawn for further adjustments to the coating. The filtration tests with model waters and test waters provide comprehensive data for module development and the evaluation of the filtration process.

Funding:

Project management:

Dr. Muhammad Ali Inam

Situation:

The presence of high concentrations of ionic contaminants in groundwater reservoirs pose a serious threat to humans and environment. Amongst, selenium (Se) oxyanions have been recorded in groundwater because of mining, petroleum refining, fossil fuel combustion, and irrigation [2]. In accordance, high Se concentration i.e., 2103 μg/L, 800 μg/L, 2700 μg/L and 4475 μg/L have been found in Soan Sakesar Valley, Pakistan; Atacama Desert, Chile; Martin Creek Reservoir, Texas, USA; and Sirmaur district of Himachal Pradesh, India; respectively [3]. Nevertheless, Se is an essential mineral required by human body however it becomes noxious when found in greater concentrations in drinking water supplies. The oral intake of higher Se concentration (>400 μg/day) may cause serious health problems including reproductive anomalies and developmental abnormalities in foetus, hair loss, body pain, muscle damage, liver and kidney failure, cancer, and even death may occur. Therefore, German drinking water ordinance, World Health Organization (WHO) and U.S. Environmental Protection Agency has set Drinking Water Regulation Limit (DWRL) for Se as 10 μg/L, 40 μg/L and 50 μg/L, respectively [4,5]. To meet stringent Se guidelines and ensure public health safety, an efficient and technoeconomic feasible treatment approach is needed.

Amongst, adsorption technology utilizing commercial iron-based adsorbents has shown promising performance for removing contaminants including metal oxyanions from a wide range of water matrices. However, eliminating Se from drinking water is challenging owing to its toxicity, solubility and varying oxidation states. It is commonly found in environment as selenate (Se(VI): HSeO4‾, SeO42-), selenite (Se(IV): H2SeO3, HSeO3‾, SeO32-), selenium (Se(0)) and selenide (Se(-II): H2Se, HSe‾) depending on pH and redox conditions [2]. Previous research [6–8] has shown wide applicability of commercially available iron-based adsorbent i.e., granular ferric hydroxide (GFH) for removal of other oxyanions including arsenic, phosphate, vanadium etc. from water. Therefore, it may be hypothesized that GFH may contain potential in eliminating toxic Se oxyanions from drinking water supplies. In addition, release of iron from poorly crystalline GFH structure into the solution particularly at low redox potential, leading to its higher residual content, has been rarely investigated. Therefore, it will be critical to examine the stability of GFH at long term operations along with its effectiveness in remediating targeted contaminants. In accordance, little is known on how Se oxyanions will behave and react with GFH in aqueous environment. It will therefore be worth exploring the mechanistic insights into the fate, mobility, transformation, and removal behavior of Se species under environmentally relevant conditions. In addition to commercial adsorbents, prior research has focused on utilization of iron-based sorbents for Se remediation from drinking water, however, all these studies only discussed in-depth understanding of batch mode operation [9]. Moreover, there always remains a research gap in utilizing adsorbent material in GEH® adsorbent unit for continuous mode Se treatment from drinking water supplies. Therefore, the planned project aims to address these research gaps and provide practical and sustainable solution to drinking water industries when dealing with toxic Se oxyanions.