Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part 5: Combined Action of Phenols and Heavy metals

Problems are discussed of the combined action of phenols and metals on luminous bacteria. It is shown that the toxic effect of a mixture was not always equal to the expected additive action. An assumption is made that during a combined action phenols and metals act on the principle of competing inhibition.     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part I.: Use of Bacterial Luminescence Extinguishing for Biotesting of Phenols

Data are presented that confirm the employment of the bacterial luminescence for evaluating the toxicity of phenolic compounds. High sensitivity and speed properties of the method are shown. Phenolic compound concentrations are determined that produce toxic effects on luminous bacteria cells. It is shown that hydroquinone possesses the highest toxicity.     

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.     

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.     

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.     

Effect of Individual Phenolic Compounds and of Their Mixtures on Luminous Bacteria. Part 2: Interaction of p- and o-Diphenol Toxicity for Beneckea harveyi with Their Oxidation

Experimental material was obtained supporting a hypothesis on the interaction between p- and o-diphenol toxicity and their oxidation. It is shown that quinones – the products of pyrocatechol and hydroquinone oxidation – possess increased toxicity towards luminous bacteria cells.     

Effect of Individual Phenolic Compounds and of their Mixtures on Luminous Bacteria. Part 7: Change of Polyphenol Toxicity in the Presence of their Oxidases and Certain Practical Problems

Data are presented on the toxicity of hydroquinone and pyrocatechol in the presence of protein preparations possessing oxidase activity. Problems are discussed of their use as biologically active means.     

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.     

Cooxidation of Benzo(a)pyrene and Phenols on Activated Sludges

In the presence of the cancerogenic benzo(a)pyrene (4 × 10^?7 mole/1) the rate the of biochemical oxidation of phenols and a mixture of oil-shale alkylresorcinols (5 × 10^?5 mole/1) on activated sludges adapted to these phenols is reduced up to 30%. The oxidation of benzo(a)pyrene occurs at a high rate, the rate constant on both sludges being 6.8 × 10⁸ mole/1 · sec and exceeds the index of the processes of its selfpurification by two orders. The high efficiency of the biooxidation of benzo(a)pyrene is retained at a repeated use of the same biomass, thus no additional regeneration being needed. Some products of the, biooxidation of benzo(a)pyrene, such as 1,6- and 3,6-quinone, derivatives of chrysene and naphthalene, are identified.     

Coliform Bacteria in New Jersey Domestic Wells: Influence of Geology,Laboratory, and Method

Following passage of the New Jersey Private Well Testing Act, 50,800 domestic wells were tested between 2002 and 2007 for the presence of total coliform (TC) bacteria. Wells containing TC bacteria were further tested for either fecal coliform or Escherichia coli (FC/E. coli) bacteria. Analysis of the data, generated by 39 laboratories, revealed that the rate of coliform detections in groundwater (GW) was influenced by the laboratory and the method used, and also by geology. Based on one sample per well, TC and FC/E. coli were detected in wells located in bedrock 3 and 3.7 times more frequently, respectively, than in wells located in the unconsolidated strata of the Coastal Plain. In bedrock, detection rates were higher in sedimentary rock than in igneous or metamorphic rock. Ice‐age glaciers also influenced detection rates, most likely by removing material in some areas and depositing thick layers of unconsolidated material in other areas. In bedrock, coliform bacteria were detected more often in wells with a pH of 3 to 6 than in wells with a pH of 7 to 10 whereas the reverse was true in the Coastal Plain. TC and FC/E. coli bacteria were detected in 33 and 9.5%, respectively, of sedimentary rock wells with pH 3 to 6. Conversely, for Coastal Plain wells with pH 3 to 6, detection rates were 4.4% for TC and 0.6% for FC/E. coli.     

Reductive Degradation of Polychlorinated Phenols by Pd/C‐Formate: An Ecoefficient Remediation Method for Aqueous Chlorinated Phenols

A new catalytic dehydrohalogenation method for chlorinated phenols is described, which can be used to break down chlorinated pollutants in wastewater. It uses a system of Pd‐C as catalyst with sodium formate as reducing agent. This economic method is easy to perform with a complete degradation of the pollutant within 12 to 30 h at room temperature. The ecoefficieny of the procedure is compared with eleven alternative methods showing the special advantages of the method.     

Comparative Toxicity of Heavy Metals and Interaction of Metals on a Freshwater Pulmonate Snail Lymnaea acuminata (Lamarck)

In static bioassays the toxicity of heavy metal ions against Lymnaea acuminata over 24 … 96 h is tested. The values of the LC_50,96h for the metals tested are, in mg/l: Hg²⁺ ?0.023; Cu²⁺-0.034, Cd²⁺ ?0.872, Ni²⁺ ?2.78, Cr⁶⁺ ?5.97 and Zn²⁺ ?10.49. In the combined solutions of Cu²⁺, Ni²⁺ and Zn²⁺ at least an additive effect of toxicity occurs in the presence of two metals. The same holds for the presence of the three metals; in this case, the relative toxicity against the mixture of two metallic salt solutions appears to be slightly reduced. The acute manifestation of the toxic effect occurs within 48 h, subsequently the relative mortality decreases especially in the mixed solutions.     

Formation of Dibenzodioxins and Dibenzofurans in the Photochemical Transformation of Polychlorinated Phenols

It is shown that in the direct photolysis of polychlorinated phenols (2,4,5-TCP, PCP) in aqueous solution, under the action of solar light or UV-radiation from artificial sources, polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF) are found among the products of transformation. A mechanism is suggested of formation of these toxic compounds via the intermediate formation of free radicals. In the oxidation of chlorophenols by singlet oxygen, free radicals are not formed. Addition of fulvic acids prevents formation of PCDD and PCDF in solar light, possibly as a result of trapping of intermediate radicals.     

Effects of Salinity and Mangrove Detritus on Desorption of Metals from Brackish Water Desorption of Metals from Brackish Water and Shrimp

Desorption and bioaccumulation of Cd, Zn, and Pb were studied using naturally contaminated sediment from a brackish water pond in the Sunderban Biosphere Reserve in India. Pattern of desorption of the metals from the sediment and bioaccumulation in fingerlings of the teleost Oreochromis mossambicusand postlarvae of the shrimp Penaeus monodon were studied as a function of salinity and loading of detritus of a mangrove plant. Effects of both salinity and loading of detritus on bioaccumulation of the metals were studied under two conditions: either the animals were allowed free access to the sediment or access was denied. Ninety‐six hour experiments showed that desorption of Cd and Pb from sediment into water increased with salinity of the medium while desorption of Zn decreased. Salinity of the medium also had a significant effect on the bioaccumulation of metals by fish; Cd and Pb accumulation decreased in saline medium while the accumulation of Zn increased. Conditions of access to sediment had no effect on the bioaccumulation of metals by fish; effect of interaction between salinity and access condition was also insignificant. The access conditions, however, significantly influenced accumulation of metal by the shrimp postlarvae. The effect of interaction between salinity and access condition was insignificant in influencing the bioaccumulation of all metals except Zn. The accumulation of Zn increased as a function of the salinity of the medium when shrimp postlarvae were allowed access to the sediment. Desorption of metals from sediment to water were below detection limits when detritus of a mangrove plant was added to the medium. Both the level of detritus and the conditions of access influenced accumulation of metals by fish, but the effect of interaction between the two factors were found to be insignificant. Shrimp postlarvae showed net accumulation only of Pb in the presence of detritus and the accumulation of Pb increased when the larvae were separated from the sediment. The results are important in understanding the mobility of metals between solid and aqueous phases in brackish water environments that experience periodic fluctuations in salinity and fluxes of organic load in the form of mangrove detritus.     

Porosity and Permeability in Ternary Sediment Mixtures

Permeability, k, and porosity, φ, were measured in mixtures of fine, medium, and coarse sand, where the volume fraction of each of the three components was systematically varied. The k was modeled well by the Kozeny‐Carman equation for three‐component mixtures by using a representative grain size parameter, d, computed by averaging the grain diameters of components recursively, with averaging methods based on whether finer components exist in sufficient volume to fill the pores within coarser components. The φ was modeled well by using linear interpolation with piecewise‐planar models. We explored the use of differing numbers of piecewise‐planar elements in the model, and illustrate the trade‐off between the increased accuracy and the increased data requirements that both come from adding more elements. The k model is a function of both d and φ, but more sensitive to d. The k model gave results consistent with measured values when computed using either measured φ values, or values from any of the φ models.     

Effect of Phototrophic Bacteria on Water Blooming

The eutrophication-induced blooming of sea or fresh water is found to be due to an anomalous burst of plankton development, which, in addition to diatom and euglena algae involves the predominance of blue-green and dinophytes (especially dinoflagellates). Characteristic representatives of plankton and toxin-generating algae are recognized. Data on the irrigation systems and drainage basins, subject to eutrophication as a result of a wide use of chemicals at paddy rice plantation in Oogata-Mura, Akita prefecture, Japan, are used to demonstrate the effect of phototrophic bacteria on organic matter decomposition in bottom sediment, which reduces water blooming and improves water quality.     

Effects of Wastewater-borne Heavy Metals on Mangrove Plants and Soil Microbial Activities

Effects of wastewater-borne heavy metals on growth of young plants (9-month-old Bruguiera gymnorrhiza) and soil microbial activities in mangrove microcosms were evaluated. During the 26-week loading period, each mangrove microcosm received 31.2 litres synthetic wastewater of three strengths: normal, medium (5 times of normal strength) and strong (10 times of normal strength). Normal strength wastewater had Cu, Zn, Cd, Cr and Ni concentrations of 3, 5, 0.2, 2 and 3 mg l⁻¹, respectively. Plant growth and total plant biomass in wastewater-treated microcosms were lower than that in the control, and the maximum reduction was found in microcosms receiving strong wastewater. Alkaline phosphatase activity and ATP contents of the mangrove soils receiving wastewater were also reduced. More than 95% reduction in these two parameters was found in soils loaded with strong wastewater. Microtox test demonstrated that soil elutriates obtained from microcosms receiving strong wastewater were of the greatest toxicity (EC₅₀ was 23%). These results show that high concentrations of heavy metals present in strong wastewater were toxic and posed negative effects to both mangrove plants and soil microbial activities. Microbial activities were generally more sensitive to the toxicity of heavy metals than plants.