Recycling of textile wastewaters treated with various combinations of advanced oxidation processes (AOP)

Advanced oxidation processes (AOPs) are widely used for treatment of wastewaters containing recalcitrant\ud organic compounds from industrial and municipal wastewater; many advantages over other technologies\ud have been found and good treatment results have been obtained so far. Approaches which reduce fresh water\ud consumption are especially important for regions with shortage in fresh water resources and in high waterconsuming\ud industries. Within AOP4Water (a multinational project funded under the CORNET programme),\ud combinations of different AOP methods are being tested with the final aim to enable cost-efficient reuse of\ud AOP-treated effluents from textile industry. The key to wastewater reuse lies in increasing the efficiency of\ud AOP treatment that ensures the required water quality and decreasing operational costs. In the present study\ud a series of experiments was performed with real textile industry effluents using a single AOP method as well\ud as combinations. Following AOP treatments were applied: ozone (O3); O3+ UV irradiation (UV); O3 +\ud hydrogen peroxide (H2O2); and O3 + H2O2 + UV. The most effective combination for colour and COD\ud removal was O3 + H2O2 + UV with 75% - 86% of colour removal and 15% of COD removal

Effect of advanced oxidation processes (AOPs) on the biodegradability of municipal wastewater for its reuse in the textile industry

Reuse of treated municipal wastewater to supplement part of fresh water is becoming more and more\ud important. However, treated water can contain some pollutants that cannot be successfully removed with\ud classical biological wastewater treatment processes. Aim of the study presented was to assess whether\ud advanced oxidation processes (AOPs) and special enzymes enhance biodegradation of municipal wastewater\ud and if treated municipal wastewater can be reused in the production process of textile industry. To test\ud biodegradability we used a small-scale pilot wastewater treatment plant (PWWTP) consisting of six parallel\ud bioreactors with suspended activated sludge (CAS type). Bioreactors were supplied with untreated municipal\ud wastewater, AOP-treated municipal wastewater and AOP-treated municipal wastewater with addition of\ud special enzymes. The results showed that AOPs contributed to better biodegradation while enzymes did not.\ud Municipal wastewater treated by a combination of AOP and biological treatment was not suitable for reuse\ud in the dyeing process, but could potentially be reused in some other processes in the textile industry

Vpliv naprednih oksidacijskih procesov (AOPs) na biorazgradljivost komunalne odpadne\ud vode za njeno ponovno uporabo v tekstilni industriji

Reuse of treated municipal wastewater to supplement part of fresh water is becoming more and more\ud important. However, treated water can contain some pollutants that cannot be successfully removed with\ud classical biological wastewater treatment processes. Aim of the study presented was to assess whether\ud advanced oxidation processes (AOPs) and special enzymes enhance biodegradation of municipal wastewater\ud and if treated municipal wastewater can be reused in the production process of textile industry. To test\ud biodegradability we used a small-scale pilot wastewater treatment plant (PWWTP) consisting of six parallel\ud bioreactors with suspended activated sludge (CAS type). Bioreactors were supplied with untreated municipal\ud wastewater, AOP-treated municipal wastewater and AOP-treated municipal wastewater with addition of\ud special enzymes. The results showed that AOPs contributed to better biodegradation while enzymes did not.\ud Municipal wastewater treated by a combination of AOP and biological treatment was not suitable for reuse\ud in the dyeing process, but could potentially be reused in some other processes in the textile industry

Raziskava onesnaženosti odpadnih voda v slovenski tekstilni industriji in ekonomska upravičenost učinkovitega čiščenja

Wastewaters from textile industry are generally highly loaded. Their load can be determined by engineering standards, stand­ards of best available technologies and annual operational monitoring. Investigation presented covers all textile factories in Slovenia obligated by the Directive 96/61/ES on integrated pollution prevention and pollution control; two textile factories in Slovenia were studied in details. In the majority of discussed textile factories significantly higher pollution emissions that would be expected on the basis of engineering and Best Available Techniques (BAT) standards were found. The reason is outdated technological equipment which departs significantly from BAT standards. As the textile factories in Slovenia are mostly con­nected to public sewer networks which are terminated by central treatment facility, economic viability of installing treatment plants for efficient wastewater pre-treatment is questionable. It is mandatory to achieve the required criteria for discharge into public sewers. More efficient treatment is justified only when it is cost efficient. Economic viability is assessed in terms of costs, which consist of expenses for fresh water supply, environmental taxes, charges for wastewater collection and wastewater treatment and expenses of effective treatment within the factories.Odpadne vode iz tekstilne industrije so praviloma zelo obremenjene. Njihovo obremenitev lahko ugotavljamo preko inženirskih normativov, normativov najboljših razpoložljivih tehnologij ter z letnimi obratovalnimi monitoringi. Raziskava zajema vse zavezance na podlagi Direktive 96/61/ES o celovitem preprečevanju in nadzorovanju onesnaževanja okolja iz tekstilne industrije v Sloveniji, podrobneje pa smo raziskali dve tekstilni tovarni. Pri večini obravnavanih tekstilnih tovarn smo ugotovili bistveno večje emisije, kot bi jih pričakovali na podlagi inženirskih in Best Available Techniques (BAT) normativov. Razlog je zastarela tehnološka oprema, ki znatno odstopa od BAT normativov. Ker so v Sloveniji tekstilne tovarne večinoma priključene na javna kanalizacijska omrežja, ki se zaključijo s centralnimi čistilnimi napravami, se pojavlja vprašanje ekonomske upravičenosti postavitve učinkovitih čistilnih naprav za predhodno čiščenje odpadnih voda. Obvezno je doseganje pred­pisanih kriterijev za izpust v javno kanalizacijo. Bolj učinkovito čiščenje pa je upravičeno le, če je to ekonomsko upravičeno. Ekonomsko upravičenost presojamo iz vidika stroškov, ki so sestavljeni iz cene sveže vode, okoljske dajatve, cene za odva­janje in čiščenje odpadne vode ter stroškov za učinkovito lastno čiščenje

The possibility of removal of endocrine disrupters from paper mill waste waters using anaerobic and aerobic biological treatment, membrane bioreactor, ultra-filtration, reverse osmosis and advanced oxidation processes

Producción CientíficaAn endocrine disrupter is an exogenous agent that interferes with the synthesis, binding, secretion, transport, action or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis, reproduction, development, and behaviour. Some of them are suspected of causing abnormalities in sperm and increasing hormone-related cancers in humans. Studies have also been published on the estrogen-like responses of endocrine disrupters in wildlife, such as birds, amphibians, reptiles and fish. Endocrine disrupters include a wide variety of pollutants such as alkylphenols, bisphenol A, pesticides, polycyclic aromatic hydrocarbons (PAHs), phthalates, heavy metals, and natural or synthetic hormones. They may be released into the environment in different ways. One of the most important sources of endocrine disrupters are industrial waste waters. The conventional waste water treatment processes are not specifically designed to remove traces of dangerous organic contaminants (except for heavy metals) so the latter are consequently consumed by aquatic organisms and through them may also enter human food chain. In the presented research the following treatments for removing of organic endocrine disrupting compounds from paper mill waste waters were compared: anaerobic biological treatment, membrane bioreactor, and reverse osmosis (pilot plant A), and combined (anaerobic and aerobic) biological treatment, ultra-filtration and reverse osmosis (pilot plant B) at pilot scale and advanced oxidation processes (Fenton, photo-Fenton, photo-catalysis with TiO2 and ozonation) at laboratory scale. The results indicated that the concentrations of organic endocrine compounds from paper mill waste waters were efficiently reduced (100%) by both combinations of pilot plants, photo-Fenton oxidation (95%) while the ozonation, photo-catalysis with TiO2 reagent and Fenton reaction was less effective (70–80%).Comunidad Autónoma de Madrid - (Proyecto S-0505/AMB-0100)Ministerio de Ciencia e Innovación - (Proyecto CTM2008-06886-C02- 01)Unión Europea - (Project 211534

Potentially toxic planktic and benthic Cyanobacteria in Slovenian freshwater bodies: detection by quantitative PCR

Due to increased frequency of cyanobacterial blooms and emerging evidence of cyanotoxicity in biofilm, reliable methods for early cyanotoxin threat detection are of major importance for protection of human, animal and environmental health. To complement the current methods of risk assessment, this study aimed to evaluate selected qPCR assays for detection of potentially toxic cyanobacteria in environmental samples. In the course of one year, 25 plankton and 23 biofilm samples were collected from 15 water bodies in Slovenia. Three different analyses were performed and compared to each other; qPCR targeting mcyE, cyrJ and sxtA genes involved in cyanotoxin production, LC-MS/MS quantifying microcystin, cylindrospermopsin and saxitoxin concentration, and microscopic analyses identifying potentially toxic cyanobacterial taxa. qPCR analyses detected potentially toxic Microcystis in 10 lake plankton samples, and potentially toxic Planktothrix cells in 12 lake plankton and one lake biofilm sample. A positive correlation was observed between numbers of mcyE gene copies and microcystin concentrations. Potential cylindrospermopsin- and saxitoxin-producers were detected in three and seven lake biofilm samples, respectively. The study demonstrated a potential for cyanotoxin production that was left undetected by traditional methods in both plankton and biofilm samples. Thus, the qPCR method could be useful in regular monitoring of water bodies to improve risk assessment and enable timely measures

Biodiversity patterns of cyanobacterial oligotypes in lakes and rivers: results of a large-scale metabarcoding survey in the Alpine region

In this work, we characterised the cyanobacterial communities in the plankton and littoral biofilm of 38 lakes and in the biofilm of 21 rivers in the Alps and surrounding subalpine regions by 16S rRNA gene metabarcoding. We found little overlap in the distribution of amplicon sequence variants (ASVs) between the three habitats and between water bodies. The differences were caused by environmental filtering acting on the selection of the most abundant ASVs and a high contribution of rare oligotypes. The differentiation of community and genotype composition from specific water bodies was explained to a significant extent by environmental variables and morphometry. The taxonomic consistency of ASVs classified under the same genus name was assessed by phylogenetic analyses performed on three representative dominant genera, namely Cyanobium, Tychonema and Planktothrix. The analyses revealed eco-evolutionary adaptations in lakes and rivers, including some evidence for a polyphyletic nature. Monitoring individual genotypes in relation to environmental conditions will be useful to define the ecological amplitude of these taxa. However, the persistence or ephemeral nature of some of the rarest and most unusual ASVs has remained unknow

A participatory approach for adapting river basins to climate change

Climate change is expected to reduce water availability in the Mediterranean region and water management needs to adapt to future conditions. The aims of this study were (1) to develop a participatory approach for identifying and evaluating management options for river basin climate adaptation and (2) to apply and evaluate the approach in four case-study river basins across the Mediterranean. As part of the approach, a diverse group of stakeholders joined a series of workshops and consultations in four river basins located in Cyprus, Slovenia, Spain and Tunisia. In each river basin, stakeholders expressed their views on challenges in their river basins, as well as options to tackle these challenges. We used the information on challenges, as well as the factors contributing to these challenges to develop a fuzzy cognitive map for each basin. These maps were converted into mathematical models and were used to assess the impact of a total of 102 suggested management options for the four river basins. We linked the options and their estimated impacts with a multi-criteria analysis to identify the most preferred options. The approach was positively evaluated by the participating stakeholders and allowed the link of stakeholders' knowledge and perceptions about their river basin with their preferences for options to adapt the management of their river basins to future conditions

Vpliv ultrazvoka za zaviranje rasti alg na netarčne organizme – pregled literature

There is an increasing interest in using ultrasonication in controlling algal (cyanobacterial) blooms and biofouling, a physical method with presumably no adverse effects on non-target organisms, such as fish and zooplankton. At the beginning the use of ultrasound (US) to control algae and biofouling has focused on high-power US causing cavitation; however, due to the potential damage to non-target organisms including marine mammals and human divers, high-power US causing cavitation are not used anymore for algae control in natural environment. Current ultrasonic algae control devices use low-power and thus control algae and biofouling by utilising resonance frequencies and the sound pressure caused by a sound wave propagating through a water column. There are only few studies existing on the effect of US on non-target organisms with incomplete information on wavelengths and intensities of US devices. However, we can conclude that non-cavitation US devices used to control algae and reduce biofouling had no adverse health effects on studied fish species with no feeding and behaviour changes noticed. Caution should be taken when installingUS devices in marine locations since they may interfere with communication between sea mammals or may cause adverse effects on fish from subfamily Alosinae, the only known fish able to detect US. The studies dealing with non-cavitation US used to control algae and biofouling on non-target zooplankton have conflicting results from high mortality to no evident effects. Therefore, caution should be taken when using US for counteract algal growth in ponds or lakes, especially in terms of zooplankton and natural balance maintenance.V zadnjih letih narašča zanimanje za uporabo ultrazvoka (UZ) za nadzor prekomerne razrasti alg (cianobakterij) v vodnih telesih in tvorbe biofilma na plovilih, hladilnih napravah in drugih industrijskih objektih. UZ deluje po fizikalnih načelih in po trditvah proizvajalcev nima negativnih vplivov na netarčne organizme, kot so ribe in zooplankton. Prvi poskusi uporabe UZ za zaviranje rasti alg in tvorbe biofilma so potekali z uporabo visoko energijskih UZ, ki povzročajo kavitacijo, vendar se je uporaba le-teh kmalu opustila zaradi morebitnih negativnih vplivov na netarčne organizme, kamor sodijo tudi morski sesalci in potapljači. Danes se za zaviranje rasti alg uporabljajo nizko energijski UZ, ki za kontrolo rasti alg in biofilma uporabljajo resonančne frekvence in zvočni tlak, ki ga povzroča zvočni val s širjenjem skozi vodni stolpec. O vplivu UZ na netarčne organizme obstaja le malo raziskav in še to znepopolnimi informacijami o karakteristikah testiranih UZ. Kljub temu lahko povzamemo, da nizko energijski UZ, ki se uporabljajo za zatiranje alg in zmanjšanje tvorbe biofilma, nimajo škodljivih vplivov na preučevane vrste rib. Kljub temu priporočamo previdnost pri uporabi UZ v morskem okolju, saj lahko ultrazvočni valovi ovirajo komunikacijo med morskimi sesalci ali škodijo ribam iz poddružine Alosinae - edine znane ribe s sposobnostjo zaznavanja UZ. Raziskave o vplivu nizko energijskih UZ na netarčne zooplanktonske organizme kažejo nasprotujoče si rezultate, od akutnih letalnih učinkov do odsotnosti vpliva. Zato je potrebna previdnost pri uporabi UZ za zmanjševanje rasti alg v ribnikih ali jezerih, zlasti z vidika varovanja zooplanktona in s tem ohranjanja naravnega ravnovesja