Abstract

Aim: The paper examines the sources of explosion hazard, which are related to the operation of wastewater treatment plant as well as the measures and solutions applied for the reduction of these hazards.

Introduction: Progress of urbanization is accompanied by an increased demand for water of proper quality water for living purposes. The amount of municipal waste also increases. Guaranteeing the supply of water in the required amount and of required quality is connected with proper treatment of water obtained from river or lakes. A certain kind of prelude to the process of water treatment for the next recipient is the treatment of wastewater discharged by a previous recipient (in accordance with the flow of the river). Wastewater treatment is carried on using mechanical, physical, chemical and biological methods. Municipal waste, due to its composition, creates a perfect environment for the development of microbiological processes, resulting in gases which can create explosible atmospheres: methane and hydrogen sulfide.

Methodology: The analysis of available information on treatment processes of municipal waste used to write this article was applied as well as the analysis of information on the operation of wastewater treatment plant and hazards connected with water treatment processes. Information on indicators of explosive substances formed during wastewater treatment was also used. Le Chatelier’s rule was referred to which allows the estimation of lower explosive limit for mixtures of many flammable gases with air. Source materials were presented which were helpful in determining explosion hazard zones as well as effective ignition sources in these zones.

Conclusions: National statistics show that every year several cases of explosions (with casualties) occur, in connection with wastewater treatment and water supply. Therefore, in addition to typical risks associated with toxic gases generated in the process of municipal wastewater treatment, also the problem of hazardous areas must be taken into consideration when designing and operating wastewater treatment plants in order for them to function effectively and safely (both for the environment and for the personnel). A key factor in this matter is to identify sources of danger, determine endangered areas, indicate and properly enforce rules of conduct (work) in endangered areas.

Keywords: wastewater treatment plant, explosion hazard

Type of article: review article