a Dissolved Ave 51.3 mg/L 2345678910I12131415l6171819202122 Fig 2 Suspended and dissolved fractions of BOD, in the raw sewag d Dissolved Ave 4.06 mg/ D Suspended Ave, 4. 10 mg/L IAnihhnllbhilnhhi Fig 3 Suspended and dissolved fractions of total phosphorus in the raw sewage 3.3 Total phosphorus and total nitrogen 3.4 Composition of nitrogen Figure 3 shows the fractions of dissolved and suspended Figure 5 shows the composition of nitrogen in the raw phosphorus in the raw sewage. In most measurements, the sewage. Inorganic nitrogen took 68.8% of the tn while concentration of the suspended fraction was higher than that organic nitrogen took 31.2%. Of the inorganic nitrogen, the of the dissolved fraction, while they were about the same dissolved and suspended fractions were 87.8% and 12.2%, on average(50.2% and 49.8%, respectively ) Regarding total respectively. And of the organic nitrogen, the dissolved and nitrogen(TN), the dissolved fraction was much larger than suspended fractions were 59.6% and 40.4%, respectively the suspended fraction in each water sample( Fig 4), while on The inorganic nitrogen mostly took the form of NH3-N average, the percentage of the dissolved fraction and that of(about 98%)with the other as no3-N. There was no NO2-N the suspended fraction were 79.6% and 20.4%, respectively. detected from the raw sewage O Dissolved Ave 30.9 mg/ D Suspended Ave. 7.9 mg/ 1234567891011213141516171819202 Sample number Fig.4 Suspended and dissolved fractions of total nitrogen in the raw sewage59 3.3 Total phosphorus and total nitrogen Figure 3 shows the fractions of dissolved and suspended phosphorus in the raw sewage. In most measurements, the concentration of the suspended fraction was higher than that of the dissolved fraction, while they were about the same on average (50.2% and 49.8%, respectively). Regarding total nitrogen (TN), the dissolved fraction was much larger than the suspended fraction in each water sample (Fig. 4), while on average, the percentage of the dissolved fraction and that of the suspended fraction were 79.6% and 20.4%, respectively. 3.4 Composition of nitrogen Figure 5 shows the composition of nitrogen in the raw sewage. Inorganic nitrogen took 68.8% of the TN while organic nitrogen took 31.2%. Of the inorganic nitrogen, the dissolved and suspended fractions were 87.8% and 12.2%, respectively. And of the organic nitrogen, the dissolved and suspended fractions were 59.6% and 40.4%, respectively. The inorganic nitrogen mostly took the form of NH3 + –N (about 98%) with the other as NO3 − –N. There was no NO2 − –N detected from the raw sewage. Fig. 2 Suspended and dissolved fractions of BOD5 in the raw sewage Fig. 3 Suspended and dissolved fractions of total phosphorus in the raw sewage Fig. 4 Suspended and dissolved fractions of total nitrogen in the raw sewage