Influence of Polyphenols and Quinones on Aquatic Plants and Their Blocking of SH-Groups

The influence of dioxybenzenes and their quinones on Dunaliella salina, Nitella sp. and Elodea canadensis was investigated. It was established that the higher the rate of polyphenol oxidation by the aqueous plants, the higher the toxicity of the compound being studied is and the larger the reduction of the SH-group content due to the incubation of plants in these polyphenol solutions is. Formation of o- and p-benzoquinones by the aquatic plants in the course of dioxybenzene oxidation was proved. Treatment of plants with quinone solutions led to a larger SH-group concentration drop than with phenols. Oxidation products of pyrocatechol, caffeic and chlorogenic acids caused the greatest decrease of the SH-group content directly at the moment of their preparation, i. e., when the o-quinone concentration was at its maximum. The conclusion is drawn that a higher degree of toxicity to the aquatic plants of pyrocatechol and hydroquinone, in comparison with other phenols, is due to their ability to oxidize phenols to quinones. It is suggested that one of the possible biochemical mechanisms for demonstrating the toxic action of the phenol oxidation products is the blocking of SH-groups.     

Effect of Individual Phenolic Compounds and of Their Mixtures on Luminous Bacteria. Part 3. Combined Action of Phenolic Compounds on Aquatic Organisms

Data on the action of mono- and polyatomic phenol mixtures on hydrobionts are discussed. Luminescent bacteria, Daphnia, algae zoospores, higher aquatic plants–Elodea and duckweed – were used as test objects. It is established that the toxicity of a paired mixture of mono- and polyatomic phenols is lower than the toxicity of their components.     

About the Role of Quinones in the Action of Some Polyphenols on the Streaming of Protoplasm in Nitella sp. Cells

The concentration of phenols and quinones which stopped the protoplasmic movement in the Nitella cells after 15 min was determined. The quinones (β-naphthoquinone, α-naphthoquinone, p-benzoquinone, o-toluquinone, o-bromanil) stopped the protoplasmic movement in the concentration of (1 3) 10^?4 M, phenols (m-cresol, p-cresol, hydroquinone, guaiacol, phenol, gallic acid, pyrogallic acid, resorcinol) in the concentration of (0.2 5) 10^?2 M, except catechol – 2 10^?3 M. Very high toxicity of catechol and in the prolonged experiments (3 hours) also of hydroquinone is connected with the action of quinonoid productions of its oxidation. This suggestion is confirmed by the experiments:

• – by adding the phenol solutions to Nitella shoots (catechol, hydroquinone, resorcinol) we observed the greatest increase of oxygen absorption in case of catechol (86%), less in case of hydroquinone (38%), and for resorcinol oxygen absorption practically remained on the control level;
• – the action of catechol, hydroquinone and p-benzoquinone did not take place in the presence of glutathione and cysteine (but not cystine and oxidated glutathione);
• – diethyldithiocarbamate as an inhibitor of o-diphenoloxidase reduced the ability of catechol solutions to stop the protoplasmic movement;
• – the low concentrations of benzoquinones were able to stop the protoplasmic movement;
• – for stopping the protoplasmic movement under the prolonged time of incubation from 15 min to 3 hours there was necessary a lower concentration of solutions of hydroquinone and catechol in comparison with resorcinol.

     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part 6: On Possibilities of Using o- and p-Diphenols as Pesticides

A brief discussion is suggested of a possibility of employing in the practice of the analyses results on the combined action of phenols described in the preceeding parts of the work and of the interaction of the increased toxicity of phenolic compounds with the processes of their oxidation.     

Treatment of a Trifluraline Effluent by Means of Oxidation‐Coagulation with Fe(VI) and Combined Fenton Processes

The amination water (AW) effluent stream from the industrial production of the trifluraline herbicide was submitted to an oxidation‐coagulation treatment with potassium ferrate, combined with advanced oxidation processes. The experimental results obtained by analysis of variance (ANOVA) for the oxidation‐coagulation‐Fenton process, evaluating the variables pH (A), Fe(VI) concentration (B), and H₂O₂ concentration (C), demonstrated that the regression equation resulting from the Response Surface Methodology (RSM) experimental design, for the quadratic model, was η_Abs (%) = 36.9– 21.58A + 8.37A² + 1.36B + 0.92B² + 1.08C + 1.52C² + 1.27AB – 1.34AC + 1.33BC. The maximum absorptiometric color reduction occurred at pH 3, with corresponding maximum amounts of iron and hydrogen peroxide. The absorptiometric color and COD reduction were 96% and 57%, respectively. For the oxidation‐coagulation‐photo‐Fenton process, the analyzed variables were pH (A), Fe(VI) concentration (B), H₂O₂ concentration (C), and temperature (D). The regression equation resulting from the quadratic model was η_Abs (%) = 38.3 – 20.2A + 8.12A² – 0.27B + 3.73B² + 0.3C + 3.6C² + 1.67D + 3.1D² + 1.72AB + 0.51AC – 1.82AD + 0.74BC – 1.11BD + 0.03CD. The ANOVA response showed that the highest absorptiometric color reduction occurred at pH 3, with respective maximum amounts of iron and hydrogen peroxide at 60°C. The maximum efficiencies achieved by the proposed treatment process for the trifluraline effluent stream were 95% and 85%, for absorptiometric color and COD reduction, respectively.     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part 4: Causes of the Weakening of p- and o-Dphenol Toxicity by Other Phenols

Experimental data are presented favouring a hypothesis of the elimination of quinones formed in the presence of hydroquinone oxidation in a mixture with other phenols. Results obtained on decreases of the quinone quantities in the mixture correlate with the data on a decrease of their toxicity for luminous bacteria.     

Bildungsbedingungen von Zinkferriten im Hinblick auf die Entfernung von Schwermetallen aus Abwässern durch Magnetseparation

Conditions of the Formation of Zinc-bearing Ferrites in Regard of Heavy Metal Removal from Wastewater by Magnetic Separation Magnetic separation techniques can be applied for heavy metal removal from wastewater if it is reached to link together the heavy metals with a substance which is sufficiently influenced by a magnetic field. Such a substance is the ferrimagnetic magnetite which can be prepared under special conditions – by oxidation of ferrous hydroxide – in wastewater. In this paper, zinc was chosen as an example for technically relevant, diamagnetic heavy metals. The investigations deal with the influence of zinc onto the structure and the magnetic properties of the reaction products produced by oxidation of zink-bearing ferrous hydroxide in aqueous solutions at room temperature. The oxidation was caused by synthetic air passing through the suspension. During the reaction, the parameters pH value, redox potential, and concentration of dissolved oxygen were observed continuously. The plots of these parameters versus time yield typical courses which can be used as measurement for the progress of the reaction. The results show that magnet ite can only be prepared if the molar ferrous concentration at the beginning is four times higher than the concentration of the dissolved oxygen. Furthermore, the oxidation rate must be slow, a condition which could be achieved by mass transfer controlled kinetics. The products of the oxidation of zinc-bearing ferrous hydroxide show a colour between black and brown. They consist of magnetite, zinc-bearing ferrite and amorphous iron hydroxide. It can be observed that with increasing initial zinc concentrations, increasing amounts of zinc-bearing ferrite but also of amorphous iron hydroxide are produced. Therefore, it seems that the impact of zinc on the reaction is in such a way that more amorphous compounds instead of the thermodynamically stabile ferrite are formed; The magnetic properties show also a dependence on the initial zinc concentration: The saturation magnetization decreases with an increase of the zinc concentration. The reaction product which results from the experiment with an initial mole ratio of Zn:Fe = 1:1 points out only paramagnetic behaviour.     

Where fast weathering creates thin regolith and slow weathering creates thick regolith

Weathering disaggregates rock into regolith – the fractured or granular earth material that sustains life on the continental land surface. Here, we investigate what controls the depth of regolith formed on ridges of two rock compositions with similar initial porosities in Virginia (USA). A priori, we predicted that the regolith on diabase would be thicker than on granite because the dominant mineral (feldspar) in the diabase weathers faster than its granitic counterpart. However, weathering advanced 20× deeper into the granite than the diabase. The 20 × ‐thicker regolith is attributed mainly to connected micron‐sized pores, microfractures formed around oxidizing biotite at 20 m depth, and the lower iron (Fe) content in the felsic rock. Such porosity allows pervasive advection and deep oxidation in the granite. These observations may explain why regolith worldwide is thicker on felsic compared to mafic rock under similar conditions. To understand regolith formation will require better understanding of such deep oxidation reactions and how they impact fluid flow during weathering. Copyright © 2012 John Wiley & Sons, Ltd.     

Studies of Hydrochemical and Kinetic Characteristics of Small Water Bodies in the Context of Their Eutrophication

Comparison study data on the hydrochemical parameters, bacterio- and phytoplankton, and reduction–oxidation characteristics of two ponds in Krasnoyarsk are presented. These water bodies are of interest due to the fact that the ecosystems of these natural model objects respond to eutrophication in different ways. It is assumed that the reason for this difference is in the hydrophysical characteristics depending on the morphology of the basins of the water bodies rather than in the hydrochemical characteristics.     

Treatment of Integrated Steel Plant Wastewater Using Conventional and Advanced Techniques

The integrated steel industry is considered as one of the important industrial sectors, and its outputs are inputs for other sectors including construction, engineering, medical and scientific equipment, and defence. Massive production, consumption, and export of steel signify a country's economic index. This review outlines the World's steel production quantities, the processes involved, and wastewater generation from the industry and its treatment. Wastewater generated from steel plants is highly complex and requires intensive treatment before discharge into natural water bodies. Technologies adopted for treating wastewater generated from steel industries are deliberated, focusing on coking wastewater treatment. Microbial mediated processes provide an effective means of degrading the contaminants, but the toxicity of certain compounds during higher pollutant load inhibits its further treatment. However, these processes can be integrated with either electrochemical technologies or advanced oxidation processes (AOPs), which can reduce the toxicity level. Hence, when a highly concentrated and complex mixture of contaminants is considered, an integrated approach is a resourceful option in terms of cost-effectiveness and treatment efficiency.     

Some Methods of Phenol Elimination from Sewage Waters. Part 2: Sorption of Phenols and Their Quionid Oxidation Products

According to the results from investigations with different anion exchangers and synthetically obtained thiopolymers as thiopolystyrene and thiopolyvinylether, phenols and their oxidation products can be removed with different efficiencies. The individual methods of treatment and analysis are described. The results of the purification efficiency as well as the profile of the adsorption isotherms are presented in a large number of tables and figures.     

Electrokinetic treatment of polluted soil at pilot level coupled to an advanced oxidation process of its wastewater

Soil contaminated with hydrocarbons is a current problem of great importance. These contaminants may be toxic, can retain water and block gas exchange with the atmosphere, which produces a poor-quality soil unsuitable for ecological health. Electroremediation is among the treatments for the removal of such contaminants. In this research, a pilot-level electroremediation test was applied using a circular arrangement of electrodes with a Ti cathode at the middle of the cell surrounded by six IrO₂–Ta₂O₅ | Ti anodes. The presence of an NaOH electrolyte helps to develop the electromigration and electro-osmosis of gasoline molecules (at 1126 mg kg⁻¹) surrounded by Na⁺ ions. The hydrocarbons are directed towards the cathode and subsequently removed in an aqueous Na⁺ – hydrocarbon solution, and the –OH migrates to the anode. During electrokinetic treatment, the physicochemical characteristics of the soil close to either the cathode or anode and at the half-cell were evaluated during the three weeks of treatment. During that time, more than 80% of hydrocarbons were removed. Hydrocarbons removed by the electrokinetic treatment of gasoline-polluted soil were collected in a central wastewater compartment and subsequently treated with a Fenton-type advanced oxidation process. This achieved more than 70% mineralization of the hydrocarbons to CO₂ and H₂O within 1.5 h; its low toxicity status was verified using the Deltatox^® kit test. With this approach, the residual water complied with the permissible limits of COD, pH, and electrical conductivity for being discharged into water bodies, according to Mexican norm NOM-001-SEMARNAT-1996.     

Simultaneous Determination of 11 Sulfonamides by HPLC–UV and Application for Fast Screening of Their Aerobic Elimination and Biodegradation in a Simple Test

Sulfonamides (SAs) are one of the most frequently used antibiotics. SAs have been found in various environmental compartments. If SAs are not degraded in the environment, they can affect bacteria by their antibiotic properties and contribute to bacterial antibiotic resistance. Therefore, the biodegradability of 11 SAs (sulfanilamide, sulfaguanidine monohydrate, sulfadiazine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethoxypyridazine, sulfachloropyridazine, sulfamethazine, sulfamethoxazole, and sulfadimethoxine) was studied. For this purpose, the Closed Bottle Test (CBT, OECD 301D) was performed, which includes a toxicity control. In order to monitor the environmental fate of the parent compound and to check for transformation products, a simple, efficient, and reliable HPLC–UV method for the simultaneous determination of these SAs has been developed. Acetonitrile and water (with 0.1% formic acid) were used as mobile phase solvents for gradient elution. The method was validated in terms of precision, detection and quantitation limits, selectivity, and analytical solution stability. In the CBT, none of these SAs was readily biodegradable. The HPLC–UV analysis confirmed that no degradation of any SA took place. In the toxicity control, these SAs showed no toxic effect in the used concentration of environmental bacteria applied in the test.     

Impairments Induced by Sublethal Doses of Sevin and Thiodan on the Brain of a Freshwater Teleost Channa striatus BL. (Channidae)

Prolonged exposure to two pesticides Sevin and Thiodan for 30 days produced impairments in the brain of Channa striatus on the following ways:

• – Separation and damage to meninges of cerebral hemispheres
• – severe damage to all the five layers of the optic textum
• – severe damage to torus longitudinalis
• – partial damage to the molecular and grannular layers of the corpus cerebelli.
• – no effect on diencephalon and myelencephalon.

     

Toxicity studies of elemental sulfur in marine sediments

Elemental sulfur(ES) is a component essential for proper development of animals, but it can be toxic for aquatic organisms. The objectives of the study reported here included determination of ES concentrations in sediment collected in the area of the Gulf of Gdansk(Baltic Sea) and search for the possible correlations with the ecotoxicity results. Sediment samples were collected from four locations: the Vistula River mouth, in the Port Basin, in the area of discharge of the treated wastewater from the Wastewater Treatment Plant(WWTP) and in the area of the sunken World War Ⅱ s/s 'Stuttgart' shipwreck. The levels of elemental sulfur were determined using a gas chromatograph coupled with a mass spectrometer(GC-MS). Toxicity of marine sediment samples was estimated for three biotest organisms-bioluminescent bacteria Vibrio fischeri, crustacean Heterocypris incongruens, and Synapis alba plant. The highest toxicity of sediments for all indicator organisms was observed in samples taken at the place of the shipwreck(2-100%). The same samples had a high sulfur content(16.7-143.2 μg/g dry weight(d.w.))therefore, it was decided to investigate whether the presence of ES in the sediment in the studied area can have an impact on the results of the ecotoxicity determination in real samples. However, the removal of sulfur from the samples resulted in no significant changes in the level of toxicity of the samples. In this research it could not be confirmed that the presence of elemental sulfur is the only factor responsible for the observed sediment toxicity. It seems that other compounds or their mixtures present in the sediment may have a significant influence on the results obtained.     

Fate of Pesticides and Their Transformation Products: First Flush Effects in a Semi‐Arid Catchment

Although it is known for many years, that transformation products (TPs) of pesticides are often more persistent, mobile, and sometimes more toxic than the parent compound, former catchment scale studies of substance release and flushing effects focused only on the parent compound. In this study, four river points were sampled in the Hula Valley, Israel, and samples were analyzed in the lab for chlorpyrifos (CP) and endosulfan residues (including transformation products; TPs). Sampling results of the first rainfall in autumn 2009 identified a strong release of most substances to the rivers. First flush effects of these substances were assessed regarding the risk for drinking water supply and ecology, like fresh water invertebrates and fish. Although, these substances were found in Jordan River water during the first significant rainfall the observed levels are below international drinking water guideline values with no adverse effects on human health in the region. However, the observed CP and chlorpyrifos oxon (CPO) levels are above the acute toxicity for fresh water invertebrates and fish. The study shows that the Hula Valley was an important source of pesticides and TPs at the Upper Jordan River basin and that substance flushing is extremely important for pesticides‐monitoring campaigns.     

Methods of Analyzing Quinones in Water and Their Application in Studying the Effects of Hydrophytes on Phenols. Part 4: Accumulation of Exogenic Phenols,Localization of Endogenic Phenols and o-Diphenol Oxidase in Nitella Cells

By using Nitella, with the aid of a technique which is described in detail the uptake of resorcinol by the cytoplasm was demonstrated and quantitatively determined under different test conditions. In contrast to the phenol oxidation products of hydroquinone and pyrocatechol, the further “fate” of the resorcinol taken up by the cell substance is not yet fully clear. The rate of resorcinol absorption has been defined with a permeability constant.     

Diversity as a Measure of Water Pollution and an Aid for Biological Water Analysis

– Five aquatic ecosystems, Yamuna river, Krishna river Eastern Kalinadi, Kadrabad drain and Peacock lake have been studied with reference to diversity and physico-chemical characteristics and biological indices. – A list of species have been selected with reference to polluted, mildly polluted or unpolluted water conditions. Though it is difficult to call any species strictly indicator species, certain species of Bacillariophyceae, bottom biota and Entomostraca can be regarded as indicative species. – The quantitative distributions of the species of different groups have been analysed statistically. Margalef's Community Diversity Index (d), Shannon Weaver Function, coefficient of rank correlation and partial and multiple correlation coefficient were calculated as to find out the order of precedence in different taxonomical groups. – The linear regression against BOD and the whole biocenosis were calculated, which indicate the relation as diversity d=6.7854 –0.0080 BOD±0.9695 where r₂= B=0.7365. Similarly, multiple linear regressions were also calculated using diversity against BOD, pH and temperature for each aquatic ecosystem. – All these observations indicate that diversity of organisms can be used to measure the water pollution intensity.     

Sulfur metabolism by marine heterotrophic bacteria involved in sulfur cycling in the ocean

Sulfur cycling in the biosphere is tightly interwoven with the cycling of carbon and nitrogen, through various biological and geochemical processes. Marine microorganisms, due to their high abundance, diverse metabolic activities, and tremendous adaptation potential, play an essential role in the functioning of global biogeochemical cycles and linking sulfur transformation to the cycling of carbon and nitrogen. Currently many coastal regions are severely stressed by hypoxic or anoxic conditions, leading to the accumulation of toxic sulfide. A number of recent studies have demonstrated that dissimilatory sulfur oxidation by heterotrophic bacteria can protect marine ecosystems from sulfide toxicity. Sulfur-oxidizing bacteria have evolved diverse phylogenetic and metabolic characteristics to fill an array of ecological niches in various marine habitats. Here, we review the recent findings on the microbial communities that are involved in the oxidation of inorganic sulfur compounds and address how the two elements of sulfur and carbon are interlinked and influence the ecology and biogeochemistry in the ocean. Delineating the metabolic enzymes and pathways of sulfur-oxidizing bacteria not only provides an insight into the microbial sulfur metabolism, but also helps us understand the effects of changing environmental conditions on marine sulfur cycling and reinforces the close connection between sulfur and carbon cycling in the ocean.     

Use of Chrysotile Fibres in the Degradation of Cationic and Nonionic Surfactants in Aqueous Solutions

It was previously observed that sodium dodecylbenzenesulfonate (SDBS) is degraded in the presence of chrysotile fibres. A higher catalytic efficiency was obtained than the reported values for TiO₂ under the same conditions. Chrysotile, a clay mineral fibre of low cost and relatively abundant, probably acts as a catalyst through an Advanced Oxidative Process (AOP) involving free radical formation. In this work, experiments with non‐ionic – Triton X‐45 (octil‐phenoxy polyethoxy ethanol) – and cationic – Herquat 3500 (alkyl dimethyl benzyl ammonium chloride) – surfactants were carried out. Diluted aqueous solutions (50 ppm) of these surfactants were kept in contact with chrysotile (4.0 g) in the dark at room temperature. The aromatic ring disappearance was followed through the absorbance peaks at 224 nm (Triton X‐45) and 208 nm (Herquat 3500) in the UV spectra. After 4 h, reductions in the surfactant solution concentration of 65.0% and 35.0% were observed for the Triton X‐45 and the Herquat 3500 surfactants, respectively. In both cases, reactions carried out without aeration showed a lower reduction of the aromatic ring concentration (30.0% less) when compared to the values obtained for the systems with airflow. The system containing the non‐ionic surfactant seems to achieve equilibrium after 2 h, what is not observed for the cationic surfactant system.