ENVIRONMENTAL BENEFITS OF THE INTRODUCTION AND IMPLEMENTATION OF ISO 14001 STANDARD IN THE MEAT INDUSTRY EXPRESSED THROUGH THE CONCENTRATIONS OF NITROGEN COMPOUNDS IN WASTE WATER

Abstract

The nitrogen compounds that were the subject of research are as follows: nitrate nitrogen (NO -N), ammonia nitrogen (NH -N) and total nitrogen (N). The values of the 3 4 mentioned parameters weremonitored before the introduction and implementation of the ISO14001 standard (period January-June) and after the introduction and implementation (period July-December). The values of nitrate nitrogen (NO -N), ammonia nitrogen (NH -N) and total nitrogen (N) are expressed in mg/l (their minimum and maximum values) with the associated limit values. Also, the average values of concentrations of nitrogenous compounds (Me, mg/l) with standard deviations (SD, mg/l) and errors of average assessment (SE, mg/l) were recorded. The daily load of wastewater with total nitrogen per day, as well as the equivalent of harm from total nitrogen expressed in the equivalent number of inhabitants, were the subject of calculations. Before the aforementioned calculations, the calculation of deviations from the limit values was started. The obtained results of the evaluation of the equivalent of harm were processed with a t-test (comparison before and after the introduction and implementation of the ISO 14001 standard). The daily load of wastewater with ammonia nitrogen and nitrate nitrogen was calculated taking into account the average values of the concentrations of thementioned compounds and the daily flow, and before that, the calculation of deviations fromthe limit values was started. The T-test was used to compare the harmfulness of the mentioned compounds before and after the introduction and implementation of the ISO 14001 standard. The Mann-Whitney U test was used to test the average values of the median daily load of ammonia and nitrate nitrogen. The hypotheses were also tested: the distribution of the daily load of wastewater with ammonia nitrogen is the same before and after the introduction of the ISO 14001 standard, and the distribution of the daily load of wastewater with nitrate nitrogen is the same before and after the introduction of the ISO 14001 standard.