1. Using PC simulation for flow sensitivity analysis with application to a wastewater treatment plant Panaitescu Ileana-Irina, Panaitescu Mariana, Panaitescu Fanel-Viorel, Enache Iulia-Alina

2. Problem Statement  simulation flow using STOAT program to assess variation in settling solids concentration in wastewater from a primary tank of a urban waste water treatment plant.  Our case study is based on sensitivity analysis of solids change depending on the flow of wastewaters from a urban wastewater treatment plant.

3. Purpose of Study  In this paper we demonstrate how to use the simulation flow sensitivity analysis within STOAT program to evaluate the effect of variation of the constant, “k” in the equation v= kC h settling on fixed concentration of suspended solids in sewage water from a primary tank of physical- biological step.

4. Methods  We use the STOAT program with input and output data for primary tank and parameters of wastewater.  We generated a file for influent data using a sinusoidal model and we accepted defaults STOAT data.  After this, we get spreadsheet data for various characteristics of wastewater for 48 hours:flow, temperature, pH, volatile fatty acids, soluble BOD, COD inert soluble particulate BOD, COD inert particles, volatile solids, volatile solids, ammonia, nitrate and soluble organic nitrogen.

5. Findings and Results: 1. Graphics after 48 hours  To wire the primary tank and effluent fluid of variation of parameters we chose for each run. Playing involve graphical representation of the variation coefficient k depending settling suspended solids and flow regime, depending on speed and coefficient.

6. 2.Graphics for flow,temperature, hours:flow,temperature,pH,solids, total BOD,total COD,ammonia, nitrate

7. 3. Graphics of phosphate, total phosphorus, total nitrogen, BOD of volatile fatty acids, soluble BOD, inert soluble COD, BOD particles and COD inert particles

8. 4. Graphics of volatile solids, non-volatile, solid soluble organic nitrogen, particulate organic nitrogen, dissolved oxygen, PHB in removing phosphorus, viable PHB in removing phosphorus viable, sustainable phosphorus phosphorus removal

9. 5. Timeseries data and summary statistics

10. Results  Using sensitivity analysis to see the variation and elimination and other elements such as phosphorus, poly- phosphorus, autotrophic viable and non-viable heterotrophic viable, nonviable, metal hydroxide, metal phosphate, alkalinity, total dissolved solids, nitrates, soluble metals, glycogen, glycogen in bacteria-G viable, unviable glycogen in bacteria- G, G-viable bacteria, viable bacteria-G, PHA-G in bacteria viable, unviable PHA-G in bacteria, dissolved organic carbon, soluble organic nitrogen degraded paticule degradable organic nitrogen, particulate phosphorus degradable, non-degradable particulate phosphorus, soluble organic phosphate degradable and non-degradable soluble phosphate.

11. Conclusions and Recommendations  For every variation of the parameter we are running with P = parameter number chosen for this rollover, for example P = 3 is running where settling coefficient K was set at 3.  When K = 3, suspended solids in the effluent are approximately 290 mg/l.  When K = 5, suspended solids in the effluent are about 270 mg/l.  When K = 7, suspended solids in the effluent are about 250 mg/l.  When K = 9, suspended solids in the effluent are about 240 mg/l.  When K = 11, suspended solids in the effluent are approximately 220 mg/l.  It is observed that for an increase of K from the 3 to 11 and has the effect of reducing suspended solids in the effluent, from about 290 mg/l at a value of K = 3, approximately 220 mg/l at a value of K = 11.  This demonstrates how sensitive are visualized in the effluent suspended solids, when settling coefficient K varies.  Using sensitivity analysis to see the variation sensitive and accurate graphics wastewater characteristics, while failing this analysis leads to an almost linear variation graphs, due to the large data.

12. Thank you for your attention!  More details:  Prof.Dr.eng. Mariana Panaitescu  marianapan@yahoo.com