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Immobilization of Cu2+ using stabilized nano zero valent iron particles in contaminated aqueous solutions

Ayob A., Ismail N., Teng T. T., Abdullah A. Z.

Environment Protection Engineering

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2012

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Vol. 38, nr 3

119--131

EN

Batch kinetic experiments were conducted to investigate the feasibility of using carboxylmethyl cellulose (CMC)-stabilized nano zero valent iron (nZVI) particles for immobilization of Cu2+ in water. The effects of nZVI concentration, pH, and initial concentration of CuCu2+ have been studied. Cu2+ immobilization increased from 59.10% to 98.10% as the nZVI concentration increased from 0.2 to 2.0 g/1. The adsorption kinetics of Cu2+ ions was fitted to a pseudo-second order model and both Langmuir and Freundlich isotherms fit experimental data. SEM-EDX indicates that slightly porous and fragile particles were formed due to the corrosion on the nZVI surface.

2

The effect of a support material on the nitrification rate in biofilm reactors

Kowalski E., Mazierski J., Suschka J.

Environment Protection Engineering

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2010

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Vol. 36, nr 2

45-61

EN

The nitrification process in a Packed Bed Biofilm Reactor (PBBR) was investigated. The inert and carbonaceous materials were tested as the support materials. The results proved the feasibility of nitrification at pH value below 5.0. On the inert support material the bicarbonates and ammonia concentrations decreased simultaneously, but when the bicarbonates present in the bulk liquid were exhausted, the nitrification ceased. For the alkaline support media, the alkalinity in bulk liquid decreased to almost zero, but the carbonaceous support materials (marble, dolomite and Dofiltr™) react with the protons and buffer the system inside biofilm. If the marble or other carbonaceous support materials are used, the packed bed material due to dissolution controls the pH inside the fixed biofilm. In reactors, the mean residence time and the Peclet number were measured. On the basis of two models (dispersion model and reactors in series model) the nitrification constant rates in reactors were estimated.

3

Effect of the type of aluminium coagulant and water pH on the destabilization of colloids

Świderska-Bróż M., Rak M.

Environment Protection Engineering

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2009

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Vol. 35, nr 4

63-72

EN

The study was conducted on a laboratory scale with the aim to examine how the type and dose of the aluminium coagulant as well as water pH influence the extent of colloid destabilization. The samples used for the purpose of the study contained water from the River Odra, with a natural or an adjusted pH, and were treated with aluminium sulphate (alum) or prehydrolyzed polyaluminium chlorides. The results obtained have revealed that polyaluminium chlorides are more efficient neutralizers of the negative electrokinetic potential of the colloids than alum. As a consequence, the substitution of alum by polyaluminium chlorides reduced the required concentration (g Al/m3) of watersoluble aluminium hydrolysis products which provided a comparable decrease in the absolute value of the ? potential. The efficiency of polyaluminium chlorides was found to increase with their basicity and with the polymerization of the products of aluminium prehydrolysis. A major factor contributing to the value of the negative ? potential of the colloids and to the extent of their destabilization was the concentration of H+ ions. The decrease in the pH value was concomitant with the decrease in the absolute value of the ? potential of the colloids that were present in the river water and with the increase in the extent of their destabilization by the coagulants examined. The effect of H+ ion concentration (in the water being treated) on the destabilization of colloids was the strongest with the alum coagulant and decreased with the increasing basicity of the polyaluminium chlorides tested.

4

Effect of acidification of feeding in gruppy fish (Lebistes reticulatus vel Poecilia reticulata)

Urban-Jezierska E.

Polish Journal of Ecology

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2002

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Vol. 50, nr 1

25-43

EN

The response of four categories of the fish Lebistes reticulatus (young fishes, females with embryos and without embryos, and males) to 24-h exposure in stream waters that differed in pH: water I, pH = 6.01-6.25, water II, pH = 4.36-4.55, and water III, pH = 4.11-4.39 was examined. Tap water - water 0 (pH = 7.54-8.26) was considered as control. In strongly acidified water, the metabolosm of L. reticulatus was modified. Mainly proteins were digested, and lipids were cumulated in faeces, increasing their energy content by 4-36% per mg dry weight as compared with the energy content of food. The excretion of ammonium considerably increased, implying that the oxidisation of proteins increased in the process of respiration. Oxygen consumption increased with acidification only in young fishes.