Kutatási jelentés a magyarországi kommunális szennyvíztisztító telepek energiahatékonysági vizsgálatának módszertani megalapozásához

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Effect of coupling primary sedimentation tank (PST) and microscreen (MS) to remove particulate organic carbon (POC): a study to mitigate energy demand in municipal wastewater treatment plants

Abstract Particulate Chemical Oxygen Demand (COD) removal is one of the first and foremost steps in a wastewater treatment plant (WWTP). It is a highly essential step that supports subsequent biological steps to achieve discharge limits. However, the energy demand for subsequent biological steps is significant due to the requirement of physical processes such as aeration. As a part of the project: WWTP of the future, it was expected that by coupling primary sedimentation tank (PST) and microscreen (MS) as advanced primary treatment (APT), around 60 to 70% removal of total COD and more than 90% of total suspended solids could be achieved which can replace such energy-intensive steps. To achieve this, a pilot plant set up including two different types of rotatory drum sieves (8 and 20 μm) was coupled with a PST in the WWTP Büsnau, Stuttgart, Germany, and the efficiency of APT was undergone for deeper investigations. The results showed that applying APT processes is an innovative and robust approach for removing more solids in municipal WWTPs so that retrofitting treatment plants comes true with a marginal footprint. However, the long-term performance of the APT system demonstrated that the system’s ability to remove solids is highly limited by MS capacity and strength of produced flocs/filter-cakes inside the MS against shear forces, which makes it easier for flocs to be detained by MS. Therefore, additional auxiliary steps like flocculation are recommended to be synchronized with APT system to enhance its efficiency. Additionally, applying a middle mesh size sieve, for instance, a 15 μm, along with changing the backwashing regime, could be considered the next alternative

Batch studies of phosphonate and phosphate adsorption on granular ferric hydroxide (GFH) with membrane concentrate and its synthetic replicas

Phosphonates are widely used as antiscalants for softening processes in drinking water treatment. To prevent eutrophication and accumulation in the sediment, it is desirable to remove them from the membrane concentrate before they are discharged into receiving water bodies. This study describes batch experiments with synthetic solutions and real membrane concentrate, both in the presence of and absence of granular ferric hydroxide (GFH), to better understand the influence of ions on phosphonate and phosphate adsorption. To this end, experiments were conducted with six different phosphonates, using different molar Ca:phosphonate ratios. The calcium already contained in the GFH plays an essential role in the elimination process, as it can be re-dissolved, and, therefore, increase the molar Ca:phosphonate ratio. (Hydrogen-)carbonate ions had a competitive effect on the adsorption of phosphonates and phosphate, whereas the influence of sulfate and nitrate ions was negligible. Up to pH 8, the presence of CaII had a positive effect on adsorption, probably due to the formation of ternary complexes. At pH > 8, increased removal was observed, with either direct precipitation of Ca:phosphonate complexes or the presence of inorganic precipitates of calcium, magnesium, and phosphate serving as adsorbents for the phosphorus compounds. In addition, the presence of (hydrogen-)carbonate ions resulted in precipitation of CaCO3 and/or dolomite, which also acted as adsorbents for the phosphorus compounds

Chemikalienmanagement und Umweltschutz in der textilen Kette

Die Bekleidung als Grundbedürfnis des Menschen wird heute global in sehr komplexen Lieferketten hergestellt. Nach der Ernährung, dem privaten Transport und dem Wohnen hat die Textilproduktion den höchsten Umwelt-Fußabdruck. Dazu tragen vor allem die Baumwollproduktion, die Herstellung von Farbstoffen und optischen Aufhellern, die Textilveredlung (das Vorbehandeln, Färben, Drucken und Ausrüsten) sowie die Gebrauchsphase der Textilien mit ihren vielen Wasch- und Trocknungsvorgängen bei. Von besonderer Bedeutung ist der hohe Chemikalieneinsatz, der bis zu 1 kg chemischer Produkte je Kilogramm Textil betragen kann. Angesichts tausender vermarkteter chemischer Produkte ist es schwierig, einen Überblick zu erhalten über all die chemischen Stoffe, die vor allem mit dem Abwasser aus der Textilveredlung und -pflege emittiert werden. Nur auf Basis von Fakten und der medienübergreifenden integrierten Betrachtung der textilen Kette lassen sich Konzepte und konkrete Maßnahmen definieren, die zur nachhaltigen Verminderung des Umwelt-Fußabdruckes der Textilproduktion beitragen. Deshalb wird hier aus technisch-naturwissenschaftlicher Sicht das Chemikalien- und Umweltmanagement der gesamten textilen Kette beleuchtet. Dieses umfasst die Erstellung von Positivlisten für Chemikalien sowie die Berücksichtigung von REACh und neuen Erkenntnissen bezüglich Schadstoffen, schadstoffanalytische Aspekte, die umweltfreundlichere Herstellung von Farbstoffen, optischen Aufhellern und Textilhilfsmitteln, prozessintegrierte Maßnahmen bei der Textilveredlung, den Umgang und die Lagerung chemischer Stoffe sowie die Behandlung und das Recycling von Textilabwasser einschließlich eines neuen globalen Abwasserstandards

Minimisation of wastewater emissions from textile finishing industries

Wastewater is the most important emission from textile finishing. There are many options to prevent and minimise textile wastewater emissions. Measures and techniques with a focus on wastewater treatment including sludge disposal are presented. However, process- and production-integrated measures are outlined as well