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Groundwater exploration and contaminant migration testing in a confined karst aquifer of the Swabian Jura (Germany)
Published in A. Kranjc, Tracer Hydrology 97, 2020
H. Behrens, W. Drost, M. Wolf, J.P. Orth, G. Merkl
As a representative for a soluble chemical contaminant the herbicide isoproturon [N-(4-isopropylphenyl)-N′,N′-dimethylurea] was chosen. The substance was obtained in form of a 500 g suspension in a volume of 1 ℓ (traded product: “®Arelon flüssig”, made by HOECHST) which was diluted to 100 ℓ in water for the injection. The active substance has a solubility in water of 170 mg/l at 25 °C (Perkow 1988); after injection, its concentration fell soon below this value by further hydrodynamic dilution. For the detection water samples of 1 ℓ were taken in glass bottles. The tracer was separated from the water by solid phase extraction with ready-for-use extractors (BAKERBOND C-18), re-extracted with methanol, and quantitatively determined by HPLC. With this procedure the detection limit for isoproturon in the sampled water was about 0,005 ppb.
Crop Protection in Open Ponds
Published in Stephen P. Slocombe, John R. Benemann, Microalgal Production, 2017
Robert C. McBride, Val H. Smith, Laura T. Carney, Todd W. Lane
Additions of hypochlorite also have been used to control contaminants in open ponds, especially in Nannochloropsis cultures to control protozoa (Richmond 2013). Quinine has been shown to effectively kill ciliates while not killing Dunaliella strains (Moreno-Garrido and Canavate 2001). Glyphosate has been added to Nannochloropsis cultures resistant to glyphosate to maintain selectivity (Vick 2010). Disinfectant and ozone shock have been used in Nannochloropsis culture to clear contaminants (Weissman et al. 2010; Weissman and Radaelli 2010). Metronidazole has been successfully used in disinfecting Scenedesmus sp. cultures invaded by the zooflagellate Amphelidium sp. (Heussler et al. 1978). Pesticides such as trichlorphon, decamethrin, tralocythrin, and buprofezin have also been used to eradicate zoo-plankton in microalgal suspensions (Wang et al. 2013). Fungicides such as Triton-N and Funginex have been used as control measures for some fungal contaminants of Scenedesmus, such as P. scenedesmi (Benderliev et al. 1993; Ravikumar 2014), and chytrid-like organisms have also been successfully controlled in the field using the pesticide Headline (McBride et al. 2014). The fungicide benomyl has been used to treat pathogenic fungi in cultures of Euglena gracilis (Mokrosnop and Zolotareva 2013). DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) has been proposed as an effective herbicide to manage contaminant algae growth in cultures of Nannochloropsis (Gonen-Zurgil et al. 1996). Formaldehyde has been used to control some ciliates in algae cultures (Moreno-Garrido and Canavate 2001).
Measurement Techniques for Refractive Index and Second-Order Optical Nonlinearities
Published in Hari Singh Nalwa, Seizo Miyata, Nonlinear Optics of Organic Molecules and Polymers, 2020
Toshiyuki Watanabe, Hari Singh Nalwa, Seizo Miyata
Ledoux and Zyss126 studied " values of urea, monomethyl urea, dimethylurea, and tetramethylurea in different solvents. The " values were found to be solvent dependent. The " values of urea in water, DMF, and dimethyl sulfoxide (DMSO) were 0.45 X 10"". 0.3 X ICT30, and 0.29 X 10 3" esu, respectively. The " values of monomethylurea in water, DMF, and DMSO were 0.45 X 10 3. 0.65 X 10"30, and 0.43 X 10 '" esu, respectively. The dimethylurea showed " values of 0.6 X I0 31", 0.28 X 10 30, and 0.18 X 10"3 esu in water, DMF, and DMSO, respectively. The " values of tetramethylurea was 0.41 X 103" esu.
Eco-friendly synthesis of a novel adsorbent from sugarcane and high-pressure boiler water
Published in Environmental Technology, 2023
Alexandre Amado de Moura, Henrique Straioto, Wardleison Moreira Martins, Thiago Peixoto de Araújo, Alexandre Diório, Guilherme Andreoli Gil, Murilo Pereira Moisés, Maria Angélica Simões Dornellas Barros
The herbicide Diuron (DIU, 1-(3,4-dichlorophenyl)-3,3-dimethylurea) was provided by Nortox (Brazil) and the Methylene Blue (MB) was purchased from Anidrol (Brazil). The DIU and MB physical properties are displayed in Table 1. The stock solutions of DIU and MB were used to prepare the working solutions used in adsorption experiments. The stock solutions of DIU and MB were prepared by dissolving the contaminants in deionized water to a volume of up to 1000 mL. The working solutions were prepared by diluting the respective stock solutions with deionized water until the required concentration of the adsorption experiments. The sugarcane bagasse (SB) and the liquid discharge from the cogeneration boiler of a Brazilian alcohol mill were used in the hydrothermal carbonization process. As soon as the water boiler was collected, it was stored in a freezer at −2°C until its use in the adsorbent synthesis. The boiler water physical-chemical properties were: pH = 9.95, apparent colour = 0; turbidity of 0.54 NTU; Biochemical Oxygen Demand (BOD) of 180 mg L−1; Chemical Oxygen Demand (COD) of 271 mg L−1.
Mathematical modelling applied to the rate-limiting mass transfer step determination of a herbicide biosorption onto fixed-bed columns
Published in Environmental Technology, 2020
Gessica Wernke, Márcia Regina Fagundes-Klen, Marcelo Fernandes Vieira, Pedro Yahico Ramos Suzaki, Héllen Karoline Spricigo de Souza, Quelen Letícia Shimabuku, Rosângela Bergamasco
The increase in agricultural and industrial activities has contributed decisively to the water bodies’ contamination. Substances present in the soil, as herbicides, are among the major water pollutants. Among these agricultural products, the presence of Diuron was identified as one of the main causes of water bodies’ degradation [1]. This herbicide is associated with several environmental problems such as surface and groundwater contamination mainly through agricultural runoff [2]. Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] is a chemical herbicide of the fenilurea family, used in sugar-cane and pre- or post-emergence crops [3]. The main product generated is the 3,4-dichloroaniline (3,4 DCA), of cumulative effect on the environment [4] and non-biodegradable [5]. According to Chen and Young [6], the herbicide Diuron is one of the most used in California (EUA) and has often been detected in the water supply.
Kinetics of diuron under aerobic condition and residue analysis in sugarcane under subtropical field conditions
Published in Environmental Technology, 2019
Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] is an important soil-active herbicide used in sugarcane production. It belongs to the substituted phenylurea herbicide family, and is used to control a wide range of perennial and annual grassy weeds and broadleaf such as Cyperus iria, Portulaca racea, Echinochloa crusgalli, Cynotis sp., Amaranthus sp., Convonvulus sp. and Digitaria sp. as well as mosses. It is recommended for use in non-cropped and many horticultural and agricultural crops such as sugarcane, fruits, coffee, cotton, corn, sorghum, mint, alfalfa and wheat [6]. It is available in liquid suspension, granular, pelleted/tableted, flowable, wettable powder, soluble concentrate and premixes formulations. Diuron primarily inhibits the Hill reaction in photosynthesis, thereby affecting plant growth and development [7].