Genotoxické účinky odpadních vod

Import 29/03/2011Prezenční546 - Institut environmentálního inženýrstvíNeuveden

Chlorpyrifos v potenciálně rizikových útvarech povrchových vod

262

Nanostructured TiO2 and ZnO prepared by using pressurized hot water and their eco-toxicological evaluation

The eco-toxicological effects of unconventionally prepared nanostructured TiO2 and ZnO were evaluated in this study, since both oxides are keenly investigated semiconductor photocatalysts in the last three decades. Unconventional processing by pressurized hot water was applied in order to crystallize oxide materials as an alternative to standard calcination. Acute biological toxicity of the synthesized oxides was evaluated using germination of Sinapis alba seed (ISO 11269-1) and growth of Lemna minor fronds (ISO 20079) and was compared to commercially available TiO2 Degussa P25. Toxicity results revealed that synthesized ZnO as well as TiO2 is toxic contrary to commercial TiO2 Degussa P25 which showled stimulation effect to L. minor and no toxicity to S. alba. ZnO was significantly more toxic than TiO2. The effect of crystallite size was considered, and it was revealed that small crystallite size and large surface area are not the toxicity-determining factors. Factors such as the rate of nanosized crystallites aggregation and concentration, shape and surface properties of TiO2 nanoparticles affect TiO2 toxicity to both plant species. Seriously, the dissolution of Ti4+ ions from TiO2 was also observed which may contribute to its toxicity. In case of ZnO, the dissolution of Zn2+ ions stays the main cause of its toxicity.Web of Science196art. no. 19

Toxicity and mutagenicity of low-metallic automotive brake pad materials

Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro.Web of Science131443

Antibacterial, antifungal and ecotoxic effects of ammonium and imidazolium ionic liquids synthesized in microwaves

Ionic liquids are increasingly used for their superior properties. Four water-immiscible ionic liquids (butyltriethylammonium bis(trifluoromethylsulfonyl)imide, octyltriethylammonium bis(trifluoromethylsulfonyl)imide, dodecyltriethylammonium bis(trifluoromethylsulfonyl)imide, butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) and their water miscible precursors (bromides) were synthesized in a microwave reactor and by conventional heating. The best conditions for microwave-assisted synthesis concerning the yield and the purity of the product are proposed. The heating in the microwave reactor significantly shortened the reaction time. Biocide and ecotoxic effects of synthesized ionic liquids and their precursors were investigated. All tested compounds had at least a little effect on the growth or living of microorganisms (bacteria or mold). The precursor dodecyltriethylammonium bromide was found to be the strongest biocide, but posed a risk to the aquatic environment due to its relatively high EC50 value in the test with Vibrio fischeri. We assumed that apart from the alkyl chain length, the solubility in water, duration of action, or type of anion can influence the final biocide and ecotoxic effect.Web of Science2521art. no. 518

Improvement of sewage sludge hazardous characteristics using physical, physicochemical and biodegradation methods

New developments in the area of wastewater treatment together with increasing numbers of households connected to wastewater treatment plants have resulted in a considerable increase of sewage sludge production. Physical and physicochemical processes applicable within the primary treatment to sewage sludge conditioning are able to reduce its dangerous characteristics. These processes can be used individually or in combination with biodegradation. The aim of our study was to evaluate the use of UV radiation, the electrostatic field, the action of high-heat plasma and combination of these methods for reduction of contamination of sewage sludge with PCBs, PAHs and heavy metals. Another approach included a biodegradation treatment with bacteria. The effects of physical, physicochemical and biodegradation treatments on sewage sludge characteristics were measured both by chemical analysis and with the Vibrio fischeri acute toxicity test. All samples of sewage sludge were toxic before degradation. Combination of physical, physicochemical and biodegradation processes was identified as the most effective method for reducing toxicity of sewage sludge. Combination of physical, physicochemical and biodegradation processes is an innovative approach in biodegradation treatment. It also improves the utilization of sewage sludge after reducing its toxicity.Web of Science22suppl. 1S7

Ecotoxicity of TiO2, cerium and zirconium doped TiO2 photocatalysts prepared by different preparation methods and using different titanium precursors

Ecotoxicological effects of manufactured TiO2, cerium doped TiO2 and zirconium doped TiO2 prepared by different chemical methods and using different chemical precursors were evaluated, since these nanomaterials are keenly investigated semiconductor photocatalysts for waste and drinking water and waste gas purification in last three decades. Acute biological toxicity of manufactured photocatalysts was evaluated based on Sinapis alba seeds germination and Lemna minor fronds growth tests, and was compared to commercial photocatalyst TiO2 Degussa P25. Toxicity tests exhibited good sensitivity for monitoring of the toxicity of investigated nanomaterials. TiO2 toxicity results demonstrate that TiO2 prepared using titanyl sulphate as a Ti precursor are toxic to both plant species contrary to TiO2 prepared using titanium (IV) isopropoxide. Cerium doped TiO2 with Ce amount <5.5 wt.% proved to be non-toxic to both plant species and zirconium doped TiO2 even stimulates both plant species growth. Small crystallite-size and high surface area are not the toxicity-determining factors. In case of TiO2 prepared by using titanyl sulphate (TiO2-TH-C, TiO2-TH-PW), the chemical issues, i.e. the huge release of Ti4+ ions to nutrient aqueous solutions from TiO2 photocatalysts and the presence of SO42− onto TiO2 photocatalyst surfaces were identified. The presence of SO42− was identified as the chemical cause of TiO2 toxicity to both Lemna minor fronds and Sinapis alba seeds. High toxicity of Ce0.05Ti0.95On photocatalyst to Sinapis alba seeds was attributed to high content of cerium (∼9 wt.%) in TiO2 which led to formation of CeO2 of nuclei-size.Web of Science38art. no. 10276

Identifikace antropogenních tlaků v české části mezinárodního povodí řeky Odry

Identifikace antropogenních tlaků na stav půd, kvalitu vodních zdrojů a na změnu habitatu vodních ekosystémů s možností predikce či průkazu konkrétních dopadů na biologické komponenty dotčeného vodního ekosystému. Zpráva je rozdělena do pěti oblastí: 1. Bilance znečištění povrchových vod v povodí řeky Odry, 2. Průkaz a predikce antropogenních tlaků na biologické komponenty vodních ekosystémů, 3. Vliv intenzifikace chovu ryb na jakost vod, 4. Publikace výsledků řešení projektu, 5. Souhrnné hodnocení antropogenních tlaků v povodí řeky Odry. Zpráva shrnuje zásady pro zlepšování a ochranu jakosti vodního prostředí v povodí řeky Odry. Patří mezi ně snižování znečištění toků z nebodových zdrojů, které musí směřovat především do oblasti zemědělské výroby. Z bodových zdrojů je třeba věnovat maximální pozornost podniku Mittal Steel Ostrava-Kunčice a důlním vodám. Dalším opatřením je nezbytnost zkvalitnění monitoringu včetně zlepšení systému včasného varování. Zvýšenou pozornost je třeba věnovat používání pesticidů v okolí a vodám vypouštěných komunálními ČOV. Mezi důležité aspekty pro ochranu vod patří odpovídající hospodaření rybářů a péče o rybníky

Výzkum v oblasti odpadů jako náhrady primárních surovinových zdrojů

Zpráva obsahuje stručné informace o projektu a jeho řešení v roce 2007