| The main excess pollutants commonly found in wastewater from fertilizer plants are arsenic,sulfides and ammonia nitrogen.Wastewater contains high levels of ammonia and nitrogen and contains toxic arsenic and sulfides.Therefore,in addition to the production process,the analysis of the effluent quality data of the treatment facility is even more important.This article first uses basic descriptive statistical methods to analyze the effluent concentration of various pollutants,and studies the mean,extreme value,median,data distribution characteristics,etc.;then the concentration data is divided according to the seasons,and firstly descriptive The statistical method analyzes the data of each season and draws a conclusion to test the difference of the effluent concentration of each season in a non-parametric test in combination with the test results of the data distribution characteristics,and comprehensively draws the following conclusions:1.The maximum effluent chemical oxygen demand concentration is 76.20 mg/L,and the minimum effluent chemical oxygen demand concentration is 49.04 mg/L,which deviates from the effluent standard by-23.8%--50.96%.The mean value is 61.845 mg/L,the standard deviation is 8.030,the variance is 64.489,and the coefficient of variation is 12.98.It is concluded that the water chemical oxygen demand concentration data is highly dispersed.The skewness is 0.21,showing a right skewness,and most of the concentration data is higher than the overall mean.The kurtosis is-1.24,indicating that the overall distribution of the data is flatter than the normal distribution and is a flat-topped peak.Through the Anderson-Darling test,the P value is less than 0.005,and the concentration distribution of the chemical oxygen demand of the effluent does not conform to the normal distribution.In addition,the Mann-Whitney test was performed on the data at a confidence level of 95%,and it was concluded that there was no significant difference in the effluent chemical oxygen demand concentration in each season.2.The maximum effluent ammonia nitrogen concentration is 14.97mg/L,and the minimum effluent ammonia nitrogen concentration is 1.00mg/L,which deviates from the effluent standard by-0.6%--94.6%.The average value of ammonia nitrogen concentration is 8.027mg/L,the standard deviation is 3.871,the variance is 14.985,and the coefficient of variation is 48.23.The skewness is-0.11,showing a left skewness,and most of the concentration data is lower than the overall mean.The kurtosis is-1.04,indicating that the overall distribution of the data is flatter than the normal distribution and is a flat-topped peak.Through the Anderson-Darling test,the P value is greater than 0.005,and the concentration distribution of the chemical oxygen demand of the effluent conforms to the normal distribution.In addition,the Mann-Whitney test was performed on the data when the confidence level was 95%,and it was concluded that there were significant differences in the effluent chemical oxygen demand concentration in each season.3.The maximum effluent phosphate concentration is 19.88 mg/L,and the minimum effluent phosphate concentration is 1.08 mg/L,which deviates from the effluent standard by-0.6%--94.6%.The average phosphate concentration is 10.53mg/L,the standard deviation is 5.415,the variance is 29.323,and the coefficient of variation is 51.42.The effluent phosphate concentration data is more scattered.The skewness is-0.07,showing a left skewness,and most of the concentration data is lower than the overall mean.The kurtosis is-1.16,indicating that the overall distribution of the data is flatter than the normal distribution and is a flat-topped peak.By Anderson-Darling test,the P value is less than 0.005,and the distribution of phosphate concentration in the effluent does not conform to the normal distribution.In addition,the Mann-Whitney test was performed on the data at a confidence level of 95%,and it was concluded that there was no significant difference in the effluent phosphate concentration in each season.4.The maximum effluent fluoride concentration is 10.00mg/L,the minimum effluent fluoride concentration is 1.07mg/L,and the deviation from the effluent standard is between-0% and 89.3%.The average value of fluoride concentration is 5.736 mg/L,the standard deviation is 2.498,the variance is 6.241,and the coefficient of variation is 43.55.It is concluded that the fluoride concentration data of the effluent is more scattered,but the concentration is improved compared with the phosphate and ammonia nitrogen data.The mode is 3.42,which appears 4 times.The skewness is-0.06,showing a slight left skewness,indicating that most of the concentration data is lower than the overall mean,but the difference between the two is not obvious.The kurtosis is-1.11,indicating that the overall distribution of the data is flatter than the normal distribution and is a flat-topped peak.Through Anderson-Darling test,the P value is less than 0.005,and the water fluoride distribution does not conform to the normal distribution.In addition,the Mann-Whitney test was performed on the data at a confidence level of 95%,and it was concluded that there was no significant difference in effluent fluoride in each season.5.The maximum arsenic concentration of effluent is 0.045mg/L,the minimum arsenic concentration of effluent is 0.02mg/L,and the deviation from the effluent standard is between-1% and-60.0%.The average value of arsenic concentration is 0.0327mg/L,the standard deviation is 0.0076,the variance is 0.000058,and the coefficient of variation is 23.25.From the statistical data,it can be seen that the concentration of arsenic data is high and the dispersion is low.The skewness is 0.05,showing a weak right skewness,and more of the concentration data is higher than the overall mean.The kurtosis is-1.23,indicating that the overall distribution of the data is flatter than the normal distribution and is a flat-topped peak.Through the Anderson-Darling test,the P value is less than 0.005,and the arsenic concentration distribution in the water does not conform to the normal distribution.In addition,the Mann-Whitney test was performed on the data at a confidence level of 95%,and there was no significant difference in the arsenic concentration in the effluent of each season. |
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