scholarly journals Effects of total suspended solids, particle size, and effluent temperature on the kinetics of peracetic acid decomposition in municipal wastewater

2019 ◽  
Vol 80 (12) ◽  
pp. 2299-2309 ◽  
Author(s):  
Tasnim Amerian ◽  
Ramin Farnood ◽  
Siva Sarathy ◽  
Domenico Santoro

Abstract In this study, the influence of total suspended solids (TSS) and particle size as well as effluent temperature on peracetic acid (PAA) decomposition kinetics in municipal wastewater was investigated. PAA decomposition was best described following second order kinetics in primary effluent (PE) and first order kinetics in secondary effluent (SE) samples. For synthetic samples prepared by varying TSS levels, PAA demand increased on average by about 0.042 mg/L in PE and 0.034 mg/L in SE for every 10 mg/L increase in TSS. Similarly, the PAA decay rate constant in these samples increased at a rate of 0.0014 L/mg.min and 0.00039 min−1, respectively, per 10 mg/L TSS. To examine the effect of particle size, synthetic samples with narrow size fractions (20–45, 45–75, and 75–90 μm) were prepared. It was found that samples with smaller particle size fractions had a greater PAA demand and decay rate constant. Effluent temperature also enhanced the PAA decomposition rate with the calculated activation energies for PE and SE samples being 29,980 J/mol and 34,860 J/mol, respectively.

2010 ◽  
Vol 27 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Aldo Leal-Egaña ◽  
Aránzazu Díaz-Cuenca ◽  
Augustinus Bader

2000 ◽  
Vol 42 (1-2) ◽  
pp. 337-340 ◽  
Author(s):  
H.Q. Shaheen

Wastewater flow samples were collected at 2-hour intervals for one week during the month of October 1998 at the Irtah wastewater pumping station in the Tulkarem city. The station collects about 32% of the wastewater of the Tulkarem city and 25% of the Tulkarem camp. The samples were mixed on 24-hour basis and tested for the pollution parameters BOD5, COD, total suspended solids, orthophosphate, total Kjeldahl nitrogen, ammonia nitrogen, nitrate, calcium, sodium and potassium. At the 2-hour intervals the wastewater flow was tested for conductivity, temperature, pH, and dissolved oxygen. The variation of the strength of these parameters and its relation to the flow values are observed and evaluated. The produced organic strength versus the flow and the 24-hour mixed samples are presented and commented upon.


2015 ◽  
Vol 73 (6) ◽  
pp. 1320-1332 ◽  
Author(s):  
Jueying Qian ◽  
Evelyn Walters ◽  
Peter Rutschmann ◽  
Michael Wagner ◽  
Harald Horn

Following sewer overflows, fecal indicator bacteria enter surface waters and may experience different lysis or growth processes. A 1D mathematical model was developed to predict total suspended solids (TSS) and Escherichia coli concentrations based on field measurements in a large-scale flume system simulating a combined sewer overflow. The removal mechanisms of natural inactivation, UV inactivation, and sedimentation were modelled. For the sedimentation process, one, two or three particle size classes were incorporated separately into the model. Moreover, the UV sensitivity coefficient α and natural inactivation coefficient kd were both formulated as functions of TSS concentration. It was observed that the E. coli removal was predicted more accurately by incorporating two particle size classes. However, addition of a third particle size class only improved the model slightly. When α and kd were allowed to vary with the TSS concentration, the model was able to predict E. coli fate and transport at different TSS concentrations accurately and flexibly. A sensitivity analysis revealed that the mechanisms of UV and natural inactivation were more influential at low TSS concentrations, whereas the sedimentation process became more important at elevated TSS concentrations.


2009 ◽  
Vol 59 (4) ◽  
pp. 723-728 ◽  
Author(s):  
P. Castilla ◽  
L. Aguilar ◽  
M. Escamilla ◽  
B. Silva ◽  
Z. Milán ◽  
...  

Municipal wastewater was amended with organic garbage leachates at a concentration around 700 mgCODsoluble/L and fed to three different anaerobic systems to compare their performance: a down flow fluidized bed (DFFB), an expanded granular sludge bed (EGSB) and a zeolite-packed anaerobic filter reactor (ZPF). The DFFB and EGSB reactors were operated at HRT of 6 and 4 h and the ZPF reactor at 12 and 36 h. Organic loads rate for the DFFB reactor were 2.3±0.9 and 4.8±1.8 gCOD/L·d, with removal efficiencies around 40% and a methane productivity of 0.2±0.03 L/Lreactor·d. For the EGSB reactor, organic loads tested were 2.1±0.9 and 4.3±1.3 gCOD/L·d, removal efficiencies attained were of 77.6±12.7% and 84.4±4.9%, respectively at both conditions and total suspended solids were removed in 54.6±19.3%, while methane productivity at 4 h HRT was of 1.29±0.4 L/Lreactor·d. The ZPF reactor was operated at lower organic loading rates, 1.4±0.27 and 0.42±0.13 gCOD/L·d and attained removal efficiencies of 48±18% and 83±8%, respectively, reaching a methane productivity of 0.21±0.09 and 0.12±0.04 L/Lreactor·d, 83±8.0% of total suspended solids were retained in the reactor and as HRT was increased ammonium concentrations increased in 39%. Specific methanogenic activity in all systems was around 0.2 gCOD-CH4/gVSS d.


2017 ◽  
Vol 8 (2) ◽  
pp. 234-243 ◽  
Author(s):  
Mohini Verma ◽  
R. Naresh Kumar

Abstract Landfill leachate and municipal wastewater at various ratios (1:20, 1:10, 1:7 and 1:5) were subjected to coagulation and electrocoagulation (EC). Alum was used in conventional coagulation at pH 6 and aluminum plate as electrode was used in EC at a current density of 386 A/m2 with 5 cm inter electrode spacing. Treatment efficiency was assessed from removal of chemical oxygen demand (COD), total suspended solids (TSS), turbidity, ammonia, nitrate and phosphate. At 1:5 ratio of landfill leachate to municipal wastewater, highest COD removal was with 3.8 g/L alum whereas highest turbidity removal was with 3.3 g/L alum during coagulation. EC exhibited almost similar removal efficiency for all the parameters at different ratios tested except for COD which was considerably higher at 1:20 ratio. Aluminum consumption from electrode was 0.7 g/L following EC as compared to 3.8 g/L alum used in coagulation. The amount of sludge produced was found to be higher with EC as compared to coagulation which could be due to the fact that the electrochemical method was performed for a longer duration than conventional coagulation. For minimal sludge generation, EC reaction time should be ∼30 min. Further studies with EC process on costing and sludge generation will help to advance the technology for wastewater treatment.


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