Vol 41, No 5 (2019)

The study is aimed at investigating the efficiency of the sodium salt of maleic acid-decene-1-styrene terpolymer as a sorbent for the removal of copper ions from aqueous solution. The removal of copper ions on synthesized polymer-sorbent was carried out using a batch experiment method. Sorption of copper ions was studied at different values of the contact time, sorbent dosage, pH and initial concentrations of copper ions. The obtained results have been analyzed in Langmuir, Freundlich, and Dubinin—Radushkevich adsorption models. The equilibrium experimentally measured sorption capacity of the sorbent is 0.512 g·g⁻¹. The calculated value of the maximum experimental sorption capacity from the Langmuir and Freundlich equations is equal to 0.754 and 0.725 g·g⁻¹, respectively. The value of (1/n) in Freundlich equation is between 0 and 1, which indicates that the sorption process is governed by chemisorption. The value of the mean sorption energy calculated from Dubinin—Radushkevich equation also confirms that the sorption of copper ions by synthesized polymer salt has chemical character.

Mixed bed resin was prepared using T-46 (H⁺) and A-33 (OH⁻) through mixing their ratio 1: 1.6 and characterized by Fourier transform infrared scanning electron microscopy and energy dispersive X-Ray spectroscopy. The mixed bed resin was evaluated for the removal of cesium and strontium from contaminated water. The aim of our study was to find the suitable condition for removal of Cs and Sr ions from water under different conditions viz. initial concentration of Cs and Sr ions, contact time, dose of resin and pH. Cs and Sr ions, adsorption data are fitted well with Freundlich and Langmuir isotherm models. The adsorption capacity was 7.53 and 9.58 mg/g for Cs and Sr ions, respectively as obtained at initial concentration 10 mg/L by Langmuir isotherm. Adsorption kinetics was followed by pseudo-second order reaction. The rate constants of pseudo-second order reaction were calculated and quite high correlation coefficients R² 98–99.5 were obtained. The resin also used for removal of Cs and Sr ions from tap water (TDS—200 mg/L) and saline water (TDS—2000 mg/L), and showed 90% (Cs) and 95% (Sr) removal at 10 mg/L of each ion concentration.

Monitoring of organochlorine pesticides (OCP), polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) in surface waters, sediments and aquatic lives of the benthic layer from different water systems of Ukraine was carried out. Information about the levels of these organic contaminants was collected, summarized and presented according to universally accepted regulatory standards that determine the toxicity of compounds of these classes. Regularities of variations of ecotoxicants concentrations in five water systems of the Dnipro river and the Black Sea (Dnipro-Bug estuary, the Danube delta, Balaklava bay, Sevastopol bay) were established. It was found that in many bottom sediment samples the recorded levels of OCP, PCB, and PAH exceed the values of TEC (Threshold Effect Concentration) and PEC (Probable Effect Concentration). To assess the toxicity of hydrobionts, the content of OCP and PCB is given as relative to the toxicity equivalent factor (TEF) and toxicity equivalent (TEQ). The levels of PCB in hydrobionts are presented relative to TEQ and indicate that hydrobionts of the bottom layer are significantly contaminated with compounds of OCP and PCB and thus bioconcentration of such organic contaminants by high organisms along the trophic chain is possible.

The regeneration of used mixed sorbents (activated carbon with kieselgur) for their repeated usage in the purification of recycled water from organic impurities during the production of soft drinks has been presented in this study. The sequence of reagent interaction and the staging of acid-base processing of used sorbents allowed recovering 100% of their sorption capacity. The schematic of a three-stage adsorption device for purification of industrial water from organic impurities has been proposed and the possibility of its operation in closed circulating cycles of industrial production has been shown.

Environmental assessment using living test organisms contribute to the timely detection of negative for human health pollutants. Hydra is a small freshwater organism that has been widely used in different types of bioassays to study the toxic potential of numerous chemical substances and is recently growing in popularity for assessing the impacts of water pollutants. Under normal conditions, adult hydra has a radially symmetric body of about 5 mm long with 6–8 straightened tentacles. Hydra is an appropriate bioindicator species because of their simple anatomy, clear morphological reactions in response to alterations in the aquatic environment, high reproduction rate and simplicity of laboratory-scale cultivation. Moreover, in the optimal cultivation environment, hydra reproduces by budding that enables in a short time obtaining a large number of genetically and morphologically identical animals for a bioassay. Here we propose a rapid bioassay for the assessment of the quality of aquatic environment including drinking water, water from natural environments sources and aqueous solutions of chemicals. This bioassay is based on the registration of survival and morphological reactions in hydra (Hydra attenuata), and allows us to determine the acute and chronic toxic effect of water pollutants. We also describe the optimal laboratory-scale cultivation conditions of hydra. Hydra attenuata bioassay of an aqueous medium can be recommended as a State Standard of Ukraine for assessing the quality of natural and drinking waters.

The removal of Cu²⁺ and Zn²⁺ from industrial wastewater using the microbial desalination cell is studied. Both synthetic and industrial samples were haracterised in accordance with standard methods recommended for examination of water and wastewater. Synthetic samples used for the analysis were prepared with concentration 5; 25; 50; 75; 100 mg/L Cu²⁺ and Zn²⁺ in deionized water. The removal efficiency of each metal was analyzed after 30; 60; 90; 120; 150 min; psychrophilic, mesophilic, thermophilic and 2–3; 3–4; 4–5; 5–6 and 6–7 mg/L dissolved oxygen were monitored. The experiments were done on wastewater of electroplating industries in Isfahan, Iran, in optimum conditions. For data analysis, SPSS version 16 software was used. Optimum condition for removing Cu²⁺ and Zn²⁺ were found to be: 100 mg/L, 4.4 mg/L dissolved oxygen, 26°C and 120 min.