Session 49 - Water and wastewater reuse

Text Mine water usually supposes one of the most important environmental problems of the extractive industry, where water quality is dependent of a great number of factors relatives to the ore deposit characteristics and to the exploitation method typology. But if water quality by nature or after convenient treatments stays inside the acceptable limits, according to the legislative quality standards, mine waters could be used for different uses. Then, new studies on the framework of the circular economy paradigm have led to found new possibilities for mine water, which in some cases can be considered as a potential water resource, generating new economic activities in the mining regions.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:57 to 17:00
Flash presentation in Water and wastewater reuse

Grey water and rain water are two options as alternative sources to alleviate water stress/scarcity across the world. This paper aims to investigate possible use of reclaimed grey water and harvested rain water from on-site premises as sources of flush water and irrigational water in and around households in the popular settlement district Atakoy of the water-stressed Turkish megacity Istanbul. Calculations using demographic and meteorological data along with an analysis of current municipal plans reveal that the rain water potential is 544 434 and grey water potential 2 070 662 (total)/880 032 (light grey water) m3/year in Atakoy. This indicates that 78% of 3 347 669 m3/year demand for flushes and irrigation of the entire green areas of privately-owned housing complexes may be covered by rain water and grey water in the area. While the entire flush water demand may be covered by light grey water only, 79% of flush water may be supplied if rain water is used. 98% of irrigational demand may be provided using both light grey water and rain water. The results show that considerable water savings may be achieved through the use of grey water/rain water which will aid sustainability.

Session: 49, Room: A, at Sat, 09/07/2019 - 15:30 to 15:45
Oral presentation in Water and wastewater reuse

Within the framework of the Horizon 2020, a European project called NextGen evaluates and champions transformational circular economy solutions and systems around resource use in the water sector. The Athens demo site is located in the Athens Urban Tree Nursery which is part of the Goudi Park, an area in the process of redevelopment and regeneration to become the key metropolitan park of the capital. The innovations that are being implemented within the project are the installation of a sewer mining modular unit for urban green irrigation at the point of demand with a capacity of 25m3/d. Additionally, compost-based eco-engineered growing media products will be reused as an onsite fertilizer, as part of a portfolio of autonomous, decentralized water, energy and materials circular solutions for cities in water scarce area. This paper involves information about the way the sewer mining will be implemented and also information about the wastewater treatment, the compost that will be produced and the energy balance of the whole system.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:54 to 16:57
Flash presentation in Water and wastewater reuse

Recirculating aquaculture systems (RAS) are a promising technology of fish production to reduce aquaculture environmental impact. Water recirculation relies on the stability of physical, chemical and biological processes to increase biosecurity. Although, disruptions in RAS systems can cause fish disease outbreaks by opportunistic pathogenic bacteria with an economic impact. The aim of this study was to characterize the water microbiota across the different sectors of a flatfish (Solea senegalensis) RAS unit, and understand its relation with the water quality parameters. Analysis was focused on the beneficial microbial community for a better environmental sustainability, but also on the opportunistic agents that threaten the fish welfare. Water samples were collected from four sectors at different filtration stages. For microbial diversity, DNA was extracted from the water samples, sequenced by Illumina MiSeq® and sequences output analyzed by SilvaNGS. Results show that Proteobacteria and Bacteroidetes were the most abundant phyla, and potential pathogenic bacteria were detected. They also indicate that salinity shifts can affect the structure of the bacterial community.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:00 to 16:15
Oral presentation in Water and wastewater reuse

Wastewater reclamation and reuse (WRR) is an emerging water generation tool for combating water stress. The objective of this paper is to develop a conceptual approach which will pave the way to WRR sustainable integration in a multi-resources regional or local system. For that purpose, a holistic Water Cycle Concept has been developed. The water cycle is divided into two partly overlapping circles: (a) Potable production circle, consisting of natural surface and ground water, desalinated water and rainwater, and (b) Recycled water circle, mainly for irrigation, industrial uses and streams rehabilitation. Greywater and direct potable use are developing options. The resulting water quality encounters are being analyzed, e.g. excess boron and magnesium deficiency in effluents originated from domestic desalinated water use are both detrimental to crops, lack of magnesium also endangers soil stability and food nutrition value. Innovative technologies for complementing the holistic approach have been developed, e.g. minerals recovery from seawater and brine, electrochemical and natural processes hybridization for nutrients and hormones removal and biofilms prevention by nanoparticles injection. In conclusion, holistic water cycle approach enables management of water quality challenges and directs innovative solutions that protect food resources and eliminate long term threats to public health.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:15 to 16:30
Oral presentation in Water and wastewater reuse
[CEST2019_00436] Advanced approaches to treat contaminants of emerging concern for water reuse
by Dionysiou D.

Contaminants of emerging concern (CECs) are frequently detected in treated wastewater effluent, because the traditional treatment train is not designed to eliminate them. The removal of CECs by conventional activated sludge is highly variable for different compounds depending on their biodegradability. To remove the CECs from wastewater more effectively for water reuse purpose, various advanced treatment technologies are adopted, including membrane separation (i.e., microfiltration, ultrafiltration, nanofiltration, reverse osmosis, multifunctional membranes, and membrane bioreactors), adsorption (granular, powdered, and biological activated carbon), ozonation, as well as advanced oxidation processes (Fenton-like, UV-based photochemical oxidation, and photocatalytic processes). Normally, these advanced approaches are applied as part of the overall process train in wastewater treatment to significantly reduce the level of CECs and improve the quality of the effluent. In this presentation, Prof. Dionysiou will elucidate several combinations of these technologies for water reuse application. Special attention will be given to the advantages and challenges those strategies are facing.

Session: 49, Room: A, at Sat, 09/07/2019 - 15:00 to 15:30
Oral presentation in Water and wastewater reuse

In the last decades, the interest in biofuel production is sensibly growing as a good source of sustainable energy and a valid alternative to fossil ones. One of the most promising biofuel is butanol and might be produced by starting from different substrates, such as second generation ones, that have the advantage to be in the future more cost effective, as soon as the relevant production processes will be fully developed and optimized.
In this case, the entering lignocellulosic material undergoes biological digestion up to a mixture mainly of acetone, butanol and ethanol, respectively. The digestion product, called ABE, requires the separation of almost pure butanol from the other components, in order to qualify as a biofuel. A possibility to perform this separation is by fractioned distillation, which has the advantage to be operated with ease, but leads to very high operating costs.
In this work, the separation of n-butanol from ABE was performed by means of membrane technology in four subsequent steps: ultrafiltration (UF), pervaporation (PV), nanofiltration (NF) and a last step of demixing once the n-butanol concentration reaches values within the miscibility gap. The study focused on the productivity, selectivity and longevity of the adopted membranes; in particular, it was observed by experimental campaign that membrane fouling must be strongly inhibited to achieve technical and economic feasibility of the overall proposed process.

Session: 49, Room: A, at Sat, 09/07/2019 - 15:45 to 16:00
Oral presentation in Water and wastewater reuse

In this study, we describe a sustainable system for treatment and reuse of grey wastewater in urban areas through vertical green walls constructed on unused surfaces of buildings. The system integrates the benefits linked to the introduction of green spaces in urban areas with the advantages connected with the reuse of purified greywater (non-potable reuse) and the reduction of potable water use, allowing a sustainable use of water resources. We constructed a vertical green wall composed of modular panels with 12 vegetated pots per panel. The green wall was irrigated with synthetic greywater, and the removal efficiency was monitored weekly with regards to different parameters (e.g., BOD5, COD, nitrogen, phosphorus). The results showed good results in terms of treatment performances, indicating the suitability of the green wall for treatment of greywater.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:30 to 16:45
Oral presentation in Water and wastewater reuse

Mining wastewaters, containing heavy metals such as copper (Cu) and zinc (Zn), have a huge impact on the environment due to they are not biodegradable and tend to bioaccumulate in plants or living organisms. Therefore, in this work the performance of ion-exchange and solvent-impregnated resins were compared for the separation and recovery of valuable metals (Cu, Zn) from acidic mine waters (AMW). Lewatit 207 as an ion-exchange resin, and an impregnated resin containing Di-2-ethylhexylphosphate, named Lewatit 1026, were evaluated for extract both metal ions. Additionally, the metal extraction was determined as a function of pH (from 1 to 5) when an AMW was used to carry out the experiments. Batch experiments results showed that best extraction of Zn was obtained using Lewatit 1026 being around 96% (pH=2.5-3); whereas Lewatit 207 performance was optimum for Cu extraction (about 99%) at pH=3-4. Moreover, using a fixed-bed configuration column, it was possible to separate and concentrate Zn (10 times) and Cu (40 times) by using Lewatit 1026 and 207, respectively. Overall, the application of an ion-exchange process showed a great potential in the recovery of valuable metals from mine waters to promote a circular economy scheme in the metallurgical industries.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:48 to 16:51
Flash presentation in Water and wastewater reuse

Acidic mine waters (AMWs) contains moderate concentrations of sulphuric acid, relatively high concentrations of metals (Al, Fe, Cu and Zn) and minor amounts or rare earth elements (REE). The established management routes for AMW treatment include a neutralization-precipitation step, which implies a high cost due to the reagents consumption. Nanofiltration (NF) membranes are emerging as an alternative to conventional methods to treat AMW due to a good passage of mono-charged ions (e.g. hydrogen sulphate, proton) for further recovery of sulphuric acid and high rejection of multi-charged ions, such as transition metals and REE. The behavior of one typical NF membrane (NF270, poly(piperazinamide)) was tested in a cross-flow experimental set-up with model solutions at pH 1.0. Moreover, experimental results were modelled according to Solution-Electro-Diffusion Model coupled with reactive transport to characterize the transport of species across the membrane, by means of the membrane permeances. Finally, the performance of NF270 working at batch mode was predicted with the obtained membrane permeances.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:51 to 16:54
Flash presentation in Water and wastewater reuse

The objective of the study was to evaluate the effectiveness of cationic surfactant (Tequat LC90i, TEAQ) removal from aqueous solutions with the use of tubular ceramic ultrafiltration and microfiltration modules. Research included an assessment of the feed solution parameters (surfactant concentration, presence of electrolyte) and process conditions (transmembrane pressure and linear velocity) on the transport and separation properties of the membranes. It was found that pressure-driven membrane processes enable cationic surfactants solutions purification – TEAQ retention coefficients exceeded 80%.

Session: 49, Room: A, at Sat, 09/07/2019 - 16:45 to 16:48
Flash presentation in Water and wastewater reuse