CC BY
61
YflK 551.509 (628.39)
DANGER OF GASEOUS COMPOUNDS OF WATER REMOVAL
DRAINING
K. Vasilenko, student, E. Voronova, ass. prof., V. Yurchenko, ass. prof.,
KhNAHV
Abstract. It is shown that gaseous emissions from networks of water removal create environmental problem for cities. The highest danger to a city atmosphere and durability of the sewerage networks among emissions components is presented by hydrogen sulphide.
Key words: environment protection, sewer network, hydrogen sulphide, gas purification.
Introduction
Constructions of sewerage are technical devices to protect the environment from pollution by liquid wastes. However the operation of water removal systems creates environmental problems connected with the formation of toxic gaseous compounds (hydrogen sulphide, mercaptan, sulfur dioxide, carbon monoxide, carbon dioxide, methane, nitrogen monoxide, ammonia, etc.) which pollute the atmosphere of city regions.
Gaseous emissions of water removal draining
In Kharkiv various carbon-, nitrogen- and sulfur-containing compounds penetrate into the structure of gaseous emissions from sewerage networks. The concentration of these compounds exceeds their maximum concentration limits essentially [1] and represents a source of constant pollution of city air.
The greatest environmental problems are caused by hydrogen sulphide. It is connected with frequency and the excess of its maximum concentration limit, with toxic influence of this gas on a man and with its initialization of concrete pipelines water destruction removal.
Hydrogen sulphide is a gas which actively participates in the geochemical cycle of sulfur. In biosphere the geochemical cycle of sulfur is controlled basically by biological processes [2]. So the formation of H2S occurs mainly at micro-
biological sulfate reduction. Detoxication of hydrogen sulphide is carried out in biosphere by sulphurous bacteria oxidizing H2S to elementary sulfur and sulfate.
The basic source of formation of sulfur-containing compounds at the gaseous phase of sewer networks is the microbiological processes in sewage.
To decide the environmental problem of water removal system in Kharkiv it has been developed and constructed the equipment for clearing gaseous emissions by a method of dry chemical filtration. As the data of the operation testify this installation clears off gas emissions from shafts of sewage collectors methyl mer-captan, hydrogen sulphide and ammonia but ineffectively removes methane. Besides the sorb-ent (the activated coal) in such equipment is destroyed during 1-1,5 years of operation and the effect of gas purification decreases greatly [3].
The reasons of filters low operational durability for gas purification were based on the chemical analysis of structure of emissions the chemical and microbiological analysis of the loading material of filters.
Gas emissions from the sewerage networks have a high humidity therefore in the process of operation of the filter on the sorbent it is formed the water skin that changes the principle of clearing off a dry filtration incorporated in the construction. At the same time humidity initiates fission
and vital activity of spontaneous microbic communities.
As the investigations showed during the operation of the filter it is accumulated acids (decrease pH), sulfates and thionic bacteria (tab. 1) in the activated coal. Humidity of coal has increased (apparently owing to the destruction of the sorbent).
Table 1 Characteristics of a sorbent from the filter of gas purification [3]
Thus the destruction of a sorbent in filters is caused by the development of thiobacillus bring-
ing to accumulation of sulfuric acid in layer moisture at the activated coal to decrease рН of the environment.
To increase the efficiency of operation and life durability of a filter it is necessary to replace acid-nonresistant of a sorbent (the activated coal) on acid-resistant (granules the filter from polythene). The active influence of thiobacillus on these carriers provides deep removal of hydrogen sulphide as it has been confirmed by experimental researches.
References
1. Юрченко В.О. Розвиток науково-техно-
лопчних основ експлуатаци споруд каналiзащi в умовах бiохiмiчного окислення неоргашчних сполук: Автореф. дис. д-ра техн. наук: 05.23.04 / УДНД1 «УкрВОДГЕО». - Харюв, 2007. - 36 с.
2. Грабович М.Ю. Участие прокариот в кру-
говороте серы // Соросовский Образовательный Журнал. - 1999. - № 12. - С. 19.
3. Юрченко В.А., Лобкова Е.К., Василенко
Е.А., Черемных Е.Ю. Проблема запахов в канализационных сетях / Сб. научн. Трудов XV междунар. научно-технич. конф. // Под ред. Разметаева С.В., Ко-стенко В.Ф.: В 2-х т. Том 2. - Харьков: УкрВОДГЕО, 2007.- 376 с.
Рецензент: Е.И. Позднякова, доцент, к.х.н., ХНАДУ.
Статья поступила в редакцию 23 мая 2007 г.
of the filter, monthDuration of operation рН Humidity, % extract, (1:10), mg/lConcentration of sulfates in water Concentration of thiobacillus, oxidizing S2- to SO42-
1 7,4 10,0 10 104
2 6,0 13,2 78 105
3 4,5 15,9 150 107
Conclusions
