bbk 000000

UDC 628.312:54.01

Kofman V. Ya.

«Emerging contaminants» in water environment: international studies (review)

Summary

The scientific developments over a period of the late 1990-ies up to nowadays in the field of studies of the «emerging contaminants» presence in water environment are considered. Emerging contaminants include mainly pharmaceuticals, illegal drugs, ultraviolet filters, artificial sugar substitutes, biocides, their metabolites and transformation products as well as nanomaterials and micro(nano)-plastics. The progress in this field is now possible owing to the introduction of analytical methods based on liquid chromatography/mass-spectrometry into the laboratory practice. The method provides for identifying and determining polar contaminants in water environment, their metabolites and transformation products at the concentration level of ng/l. The applied mass-spectrometric detectors are characterized by the high sensitivity and selectivity. The improved techniques that provide for the higher efficiency of removing emerging contaminants from wastewater compared to the traditional processes are presented. Modern approaches to the evaluation of the toxicity of the contaminants under consideration in the situations when low concentrations of these substances in mixtures have a long-term impact on non-target organisms are discussed.

Key words

wastewater , aquatic environment , emerging contaminants , liquid chromatography/mass-spectrometry , contaminant transformation products

bbk 000000

UDC 504.054

Kofman V. Ya.

«New pollutants» in aquatic environment. Drugs, ultraviolet filters, artificial sugar substitute products (review)

Summary

The data on the concentrations of illegal drugs (cocaine and its metabolites, opioids, marihuana derivatives, amphetamine and ecstasy group compounds), ultraviolet filters found in sun protection creams (titanium dioxide, para-aminobenzoates, cinnamates, benzophenones, dibenzoylmethanes, camphor derivatives, benzimidazoles), and artificial sugar substitute products (sucralose, aspartame, saccharin, acesulfame) in waste, surface, ground and drinking water are presented. As a result of incomplete removal in the processes of physical, chemical and biological treatment at the traditional wastewater treatment facilities the given pollutants get into the natural aquatic environment where can be found in concentrations mainly of nanograms per liter of water. In foreign countries a marked increase of studies in the field of aquatic environment pollution with illegal drugs, UV filters and artificial sugar substitute products dates back to the beginning of the 2000-ies. Herewith the main attention is paid to improving the efficiency of degradation of these substances at the treatment facilities; to the transformation in aquatic environment resulted from the impact of the natural factors with possible formation of products more toxic than the original substances; to the potential role of these substances as precursors of water disinfection byproducts; to the mechanism of toxicological effect and related risks for aquatic organisms and human beings; to the development of analytical methods.

Key words

toxicological effect , drugs , ultraviolet filters , artificial sugar substitute products , aquatic environment , photodegradation

bbk 000000

UDC 628.1/.2 (98)

Kofman V. Ya.

Water supply and wastewater disposal in the Arctic region:
Greenland, Canada, USA (a review)

Summary

The specific features of the water supply and sanitation infrastructure in the Arctic Region are determined by the extreme dramatically changing climatic conditions, scattering throughout the vast territory of separate communities; the lack, with a few exceptions, of road communication between settlements; differences in the views of traditional and modern culture on the role of water supply and sanitation systems. The transport infrastructure involves the prevailing use of ships, aircraft and helicopters. In light of this almost all communities have autonomous systems of power supply, water supply and sanitation. Public water supply is provided only in some of the largest cities; in most cases, the water transported in tanks is stored by residents in tanks or independently delivered from water distribution points. Wastewater is either discharged untreated or passes passive purification under natural conditions organized in stabilization ponds and/or in marshy areas where self-purfication takes place due to sedimentation, biodegradation and inactivation of microorganisms under the impact of sunlight. After passive treatment the effluent is discharged into estuaries or the sea. In households of small settlements bio toilets with removable plastic bags are widely used. These bags are collected, transported and emptied at sea by municipal services, outsourcing companies or individual collectors. Recently local wastewater treatment and reuse systems have become common; monitoring of anthropogenic pollution of the natural aquatic environment is becoming regular.

Key words

water supply , anthropogenic pollution , aquatic environment , the Arctic Region , Greenland , Canadian Arctic , Alaska

DOI 10.35776/MNP.2019.09.03
УДК 543.3:544.576

Vikulina Vera, Кирошка Стефания

Change in ζ-potential of aquatic environment in ultrasonic field

Summary

At the boundary of the adsorption layer of the micelle an electrokinetic potential arises named ζ-potential. The numerical value of ζ-potential produces a significant impact on the processes that occur during water treatment, namely, coagulation and sedimentation. The influence of ultrasonic cavitation on the change in ζ-potential of aquatic environment is considered. Ultrasonic equipment and instruments for determining ζ-potential are presented. Experimental data on the effect of ultrasonic field on the electrophoretic mobility of particles in water is presented. The dependence of ζ-potential on the duration of ultrasonic treatment is obtained. The conducted experimental studies confirm the use of the ultrasonic method of water treatment for the enhancement of water treatment processes.

Key words

water treatment , aquatic environment , ζ-potential , ultrasonic field

bbk 000000

UDC 504.4.054

Kofman V. Ya.

Microplastics – a new threat for the aquatic environment? (review)

Summary

Plastic debris components with a size from microns to meters are found in the pelagic and benthic zones of all the seas and oceans. Fine plastic fractions get to the municipal wastewater treatment facilities and water treatment plants with water and wastewater after pretreatment. By microplastics particles with a size less than 5 mm are implied. By origin they are classified as primary and secondary. Microplastic materials that are a part of industrial products are classified as primary; the secondary microplastics are formed as a result of bigger microplastics fragmentation. In municipal wastewater secondary microplastics prevail in the form of fibers; their concentration can reach 100 particles/l. Incomplete removal of microplastics at the treatment facilities is considered an accepted fact. Effluent discharge results in the rivers becoming the main source of these pollutants entering seas and oceans. The growth trend of sea water pollution with microplastics is considered absolute. Besides, the tendency of their reduction in size is noted. Microplastics are characterized by bioaccessibility for the wide range of marine biota. In animal organisms microplastics can cause physical damages or become sources of toxic impact as a result of monomers and different additives used in the production of plastics migrating from their structure. High sorption activity of microplastics in the sea water is also noted; it results in the concentration of resistant organic substances in them sixfold exceeding the concentration in sea water. High probability of bioaccumulation and trophic transfer of a whole number of toxic substances adsorbed by microplastics exists.

Key words

treatment facilities , toxicological effect , aquatic environment , primary and secondary microplastics , sorption activity