207 
 

journal homepage: www.fia.usv.ro/fiajournal 
Journal of Faculty of Food Engineering,  

Ştefan cel Mare University of Suceava, Romania  
Volume XIII, Issue 3 – 2014, pag. 207 – 213 

 

 
PHYSICOCHEMICAL MONITORING AND PERFORMANCE EVALUATION OF  

SBR MUNICIPAL WASTEWATER TREATMENT 
 

*Tsvetko PROKOPOV1, Dasha MIHAYLOVA2, Nikolay MIHALKOV3 
 

1Department of Environmental Engineering, University of Food Technologies, 
26 Maritsa Blvd., 4000 Plovdiv, Bulgaria, e-mail: tsvetko_prokopov@abv.bg  

2University of Food Technologies, Department of Biotechnology, e-mail: dashamihaylova@yahoo.com    
3WWTP-Hisarya town, Bulgaria, e-mail: nmihalkov@abv.bg    

*Corresponding author 
Received August 29th 2014, accepted September 28th 2014 

 
Abstract: Hisarya town is one of the famous Bulgarian resort with mineral springs and SPA-centers 
attracting thousands of tourists where is installed one of the newly wastewater treatment plants 
(WWTP) designed on the base of sequencing batch reactor (SBR) technology. In recent years, SBR has 
been applied as an efficient technology for wastewater treatment. Monitoring and control of SBR is a 
very attractive field of research nowadays. Present study are dealt with monitoring of physicochemical 
characteristics viz. BOD5, COD, suspended solids (SS), total nitrogen (TN) and total phosphorus (TP) 
and performance evaluation of SBR municipal wastewater treatment at WWTP-Hisarya. Significant 
reduction (p<0.05) in the physicochemical characteristics of the SBR treated wastewater was 
established. The average removal of BOD5 (95.1±0.6 %), SS (95.1±0.6 %), COD (93.2±0.7 %), TN 
(80.3±8.0 %) and TP (53.4±7.2 %) were recorded. The values obtained of physicochemical 
parameters in treated wastewater were considerably below permitted emission limits which indicate 
that WWTP-Hisarya is working perfectly. Thus it is helpful in the control of the pollution of “Blue 
River” as a discharging water body. 
 
Keywords: characteristics, effluent, influent, pollutants, purification 
 
1. Introduction 
 
Water environment pollution has become a 
major environmental problem recently. 
Continuous development of urbanization, 
tourism and industry leads to increasing of 
worldwide water consumption. On the 
other hand the volume of wastewater 
effluents into water intakes containing a 
variety of pollutants is continuously 
growing. Wastewater treatment before its 
discharging into water bodies is an 
important assignment of any civilized 
society, central and local government. It is 
an urgent task for mankind to improve the 
wastewater treatment efficiency. Domestic 
and industrial wastewater incoming into 
the urban treatment plants are 
characterized by irregularity in the amount 

and type of the pollutants. Therefore, the 
facilities for the treatment of this type of 
water are combined and typically include a 
mechanical, biological and in some cases, 
chemical steps [1].  
The Sequencing batch reactor (SBR) 
represents a modern approach to 
wastewater treatment. Unlike the 
traditional continuous flow activated 
sludge process, where different reactions 
are carried out in separated tanks, SBR 
allows using a single tank for the whole 
process. SBR is a modified activated 
sludge process used to treat a variety of 
wastewaters. In recent years, SBR has been 
employed as an efficient technology for 
wastewater treatment, especially for 
domestic wastewaters, because of its 
simple configuration and high efficiency in 



Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University – Suceava 
Volume XIII, Issue 3 – 2014 

 

 
T s ve t ko P R O KOP O V,  D as ha M IH AY L O VA,  N ikol a y M IH ALK O V ,  Ph y s i c o ch e m i c a l m o n i t o ri ng  a nd  
p e r f o r m an c e  e va l u a ti o n of  SB R m un i c i p al  wa s t e wa t e r  t r e a t m e nt ,  Food and Environment Safety, Volume XIII, 
Issue 3 – 2014, pag. 207 - 213 

208 
 

BOD5 and suspended solids removal, 
nitrification, denitrification and 
phosphorus removal [2]. There are several 
literatures supporting the applicability of 
this promising reactor in different 
wastewater treatment [3-15].  
Monitoring and control of SBR is a very 
active field of research nowadays. The 
quality and quantity of influent wastewater 
are floating with season, temperature and 
weather. Meanwhile wastewater treatment 
systems have characteristics of high 
dimensional data and strong nonlinearity. 
Therefore precise monitoring and control 
for SBR is still complex for research and 
practice [16].  
The efficiency of wastewater treatment 
plant (WWTP) can be illustrated by a study 
on the evaluation of pollution levels of the 
influent and the effluent at the treatment 
plant discharging into the environment 
[17]. On the other hand, process 
monitoring of wastewater treatment 
systems can be used successfully for the 
WWTP optimization [18]. 
In the town of Hisarya, which is one of the 
famous Bulgarian resorts with its mineral 
springs and SPA-centers attracting 
thousands of tourists especially in summer, 
is installed one of the newly wastewater 
treatment plants designed on the base of 
SBR-technology. Bulgarian experience in 
wastewater treatment for complete removal 
of BOD5, nitrogen and phosphorus is 
relatively new and limited. Recent projects 
for new WWTP are developed by 
mathematical models and programs. These 
plants are not susceptible to mathematical 
verification. For examination of plant’s 
design and efficiency of operation can only 
be used the results from the wastewater 
analysis at the inlet and the outlet of the 
already constructed plant during its 
exploitation. Monitoring and performance 
evaluation will also help for the better 
understanding of design and operating 

difficulties in WWTP and also to assess 
reuse potential of treated water.  
This work aimed the monitoring of 
physicochemical characteristics of 
municipal wastewater before and after 
treatment at SBR plant installed in Hisarya 
town, Bulgaria and the performance 
evaluation of SBR treatment.    
 
2. Materials and methods 
 
Wastewater treatment plant (WWTP) 
general description 
The object of this study was WWTP 
designed on the base of SBR-technology 
installed in Hisarya town, Bulgaria (Fig. 
1). The plant was put into operation in 
2011. Design values of the performance of 
the plant are: load 10000-25000 PE, 
wastewater dry weather flow 7250 m3/d, 
wastewater wet weather flow up to 2000 
m3/h, daily treatment volume in wet 
weather 1080 m3/h, organic load as BOD5 
up to 1500 kg/d, total nitrogen load 275 
kg/d and total phosphorus load 45 kg/d. 
WWTP includes three aeration basins 
(SBRs), aerobic stabilization of sludge, 
dewatering machine (centrifuge) and lime 
conditioning, with installed capacity of 
about 430 kW, daily consumption of 
electricity at full load about 2000 kWh/d, 
specific consumption of electric energy per 
unit volume of wastewater 0.27 kWh/m3 
and specific electricity consumption 
equivalent per capita per year 29 kWh/PE.  
 
Analytical methods 
Wastewater sampling was conducted 
according to BDS ISO 5667-10 standard. 
Samples were collected automatically into 
the plastic bags and were brought to the 
laboratory for analysis. 
Physicochemical monitoring of the 
wastewater treatment was carried out by 
the values of the following standard 
parameters: five-day biological oxygen 
demand (BOD5), chemical oxygen demand 



Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University – Suceava 
Volume XIII, Issue 3 – 2014 

 

 
T s ve t ko P R O KOP O V,  D as ha M IH AY L O VA,  N ikol a y M IH ALK O V ,  Ph y s i c o ch e m i c a l m o n i t o ri ng  a nd  
p e r f o r m an c e  e va l u a ti o n of  SB R m un i c i p al  wa s t e wa t e r  t r e a t m e nt ,  Food and Environment Safety, Volume XIII, 
Issue 3 – 2014, pag. 207 - 213 

209 
 

(COD), total nitrogen (TN), total 
phosphorus (TP) and suspended solids 
(SS). Values of COD, TN and TP were 
determined, spectrophotometrically by 
using of standard cuvette tests (HACH 
LANGE), according ISO 6060, EN ISO 
11905-1 and ISO 6878-1, respectively and 
DR3900 spectrophotometer acomplished 
with Termostat LT200. Values of BOD5 
were determined by using of BODTrakTM 
II Respirometric BOD apparatus (HACH 
LANGE). Quantity of suspended solids 
was measured by filtration through glass 
filter, according to BDS EN 872 standard.  

 
Fig. 1. Schematic flow diagram of the WWTP-

Hisarya: 1 - input shaft, 2 - mechanical pre-
treatment units, 3 - SBRs, 4 - UV-disinfection, 5 - 
excess sludge stabilization tanks, 6 - excess sludge 
dewatering machine, 7 - conditioning of dewatered 

excess sludge, 8 - pumping station 
 
Performance evaluation 
Performance evaluation of the SBR 
wastewater treatment was carried out by 
assessment of percentage degree of 
purification (DP, %) calculated by the 
following equation: 

100.
С
СС

DP
inlet

outletinlet=   (1) 

where: inletС  – concentration of the 
respective pollutant at the inlet of the SBR, 
mg/L; outletС  – concentration of the 
respective pollutant at the outlet of the 
SBR, mg/L. 

Individual emission limits for controlled 
pollutants which are specified in the permit 
for the use of water body "Blue River" – 
Hisarya for discharge of the wastewater 
were used for the WWTP performance 
evaluation. 
 
Statistical analysis 
All experiments were performed in 
triplicate. The data were analyzed and 
presented as mean values with standard 
deviation. Statistical analysis was 
conducted by using of Statgraphics 
Centurion XVI Version 16.2.04 software. 
Values are considered at a significance 
level of 95 %.    
 
3. Results and discussion 
 
The processes in the WWTP and the 
sequence are presented in the schematic 
flow diagram shown in Fig. 1. 
Results for average wastewater influent in 
the WWTP for 2013 year are presented in 
Fig. 2. The established average wastewater 
daily influent for 2013 year was 
2995.3±614.2 m3/d. For monitoring of the 
SBR operation and to calculate pollutants 
degree of purification, physicochemical 
characteristics of the wastewater influent 
and effluent were determined. Table 1 
presents physicochemical characteristic of 
the SBR wastewater influent. Average 
BOD5 of the inlet was 100.1±11.7 mg/L 
with maximum 121 mg/L and minimum 90 
mg/L. Average values of the inlet for 
COD, TN, TP and SS were 272±26 mg/L, 
25.3±2.0 mg/L, 3.65±0.27 mg/L and 
74.1±8.2 mg/L respectively. The results in 
Fig. 2 and Table 1 show that the actual 
load of the WWTP is less than the design, 
which allows for the treatment of 
additional volumes of wastewater if any 
expansions of the business in the town and 
to increase the number of tourists. 



Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University – Suceava 
Volume XIII, Issue 3 – 2014 

 

 
T s ve t ko P R O KOP O V,  D as ha M IH AY L O VA,  N ikol a y M IH ALK O V ,  Ph y s i c o ch e m i c a l m o n i t o ri ng  a nd  
p e r f o r m an c e  e va l u a ti o n of  SB R m un i c i p al  wa s t e wa t e r  t r e a t m e nt ,  Food and Environment Safety, Volume XIII, 
Issue 3 – 2014, pag. 207 - 213 

210 
 

 
Fig. 2. Average wastewater influent in the WWTP-Hisarya for 2013 year  

 
Table 1 

Physicochemical characteristic of the SBR wastewater influent 
 

Month/ 
Year 
2013 

BOD5 
(mg/L) 

COD 
(mg/L) 

TN 
(mg/L) 

TP 
(mg/L) 

SS 
(mg/L) 

January 119±23 302±34 24.5±2.4 3.3±0.5 82.6±13.3 
February 121±14 310±35 23.5±2.9 3.4±0.4 76.0±17.0 
March 98±7 299±40 25.0±1.4 3.4±0.3 77.8±12.6 
April 117±29 282±27 23.8±1.8 3.4±0.2 75.0±13.0 
May 90±3 258±26 24.4±2.7 3.7±0.2 71.0±18.0 
June 92±6 261±24 23.7±2.0 3.4±0.3 64.0±12.0 
July 92±9 236±28 22.0±1.9 3.7±0.3 63.0±12.0 
August 93±9 285±51 28.7±3.0 3.8±0.1 80.0±30.0 
September 98±9 291±23 27.2±1.2 3.7±0.1 89.0±38.0 
October 95±6 257±43 26.2±2.8 3.9±0.2 75.1±13.8 
November 93±6 244±37 27.0±1.9 4.0±0.2 73.8±14.8 
December 93±6 239±35 27.5±1.3 4.1±0.1 61.8±16.3 

 
Values of standard parameters of the SBR 
treated wastewater for the investigated 
period of time are presented in Tables 2 
and 3. Statistical analysis indicated that 
there are not significant differences 
(p>0.05) between the average values of 
physicochemical parameters determined 
for the effluents from SBR 1 and SBR 2, 
respectively. Contrary, values of BOD5, 
COD, TN, TP and SS were decreased to be 
significantly (p<0.05) in finally treated 
(outlet) wastewater (Tables 2 and 3) in 
comparison to inlet (Table 1). For 
example, the average BOD5 decreasing 

was from 100.1±11.7 mg/L to 4.7±0.7 
mg/L. For COD, TN, TP and SS it was 
from 272±26 mg/L to 18.2±1.4 mg/L, from 
25.3±2.0 mg/L to 4.4±1.6 mg/L, from 
3.65±0.27 mg/L to 1.67±0.15 mg/L and 
from 74.1±8.2 mg/L to 3.5±0.2 mg/L, 
respectively. The obtained results are in 
accordance to [4, 7, 9, 14, 17] which 
described such significantly decreasing of 
pollutants after SBR treatment of different 
wastewaters.  
Table 4 presents percentage degree of 
purification of SBR municipal wastewater 
treatment. Reached degree of purification 

0

500

1000

1500

2000

2500

3000

3500

4000

Ja
nu

ary
Fe

br
ua

ry
M

arc
h

Ap
ril

M
ay

Ju
ne Ju
ly

Au
gu

st
Se

pte
mb

er
Oc

tob
er

No
ve

mb
er

De
se

mb
er

A
ve

ra
ge

 w
as

te
at

er
 fl

ow
, m

3/
d



Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University – Suceava 
Volume XIII, Issue 3 – 2014 

 

 
T s ve t ko P R O KOP O V,  D as ha M IH AY L O VA,  N ikol a y M IH ALK O V ,  Ph y s i c o ch e m i c a l m o n i t o ri ng  a nd  
p e r f o r m an c e  e va l u a ti o n of  SB R m un i c i p al  wa s t e wa t e r  t r e a t m e nt ,  Food and Environment Safety, Volume XIII, 
Issue 3 – 2014, pag. 207 - 213 

211 
 

for BOD5 was in the range from 93.2 % to 
95.9 %, average 95.1±0.6 %. For COD this 
degree was in the range from 92.1 % to 
95.0 % (93.2±0.7 %). For TN it was from 
60.0 % to 94.5 % (80.3±8.0 %). Such 
intervals for TP and SS were from 44.5 % 
to 66.8 % (53.4±7.2 %) and from 93.7 % 
to 96.2 % (95.1±0.6 %), respectively. 
Similar degree of purification of municipal 
wastewater treatment plant as follow: 
BOD5 (91.31 %), COD (91.84 %), TN 
(71.40 %) and SS (88.37 %) was reported 
by [7]. Recently, degree of purification of 
SBR municipal wastewater treatment of 
BOD5 (89-98 %), COD (80 %), total SS 

(85 - 97 %), TN (>75 %) and Bio-P (57-69 
%) was reported by [8] also.  
Fig. 3 represents the results for 
performance evaluation of SBR municipal 
wastewater treatment based on the average 
pollutant’s concentration in the wastewater 
and emission limit. The average values of 
standard parameters BOD5, COD, TN and 
SS of treated wastewater were 
considerably below emission limits (25 
mg/L, 125 mg/L, 15 mg/L and 35 mg/L, 
respectively) specified in the discharge 
limit. Average values of TP of the effluents 
from SBR 1 (1.69±0.17 mg/L) and SBR 2 
(1.67±0.15 mg/L) were closed to the 
permitted emission limit (2 mg/L). 

Table 2  
Physicochemical characteristic of wastewater effluent from SBR 1 

 

Month/Year 2013 BOD5 (mg/L) 
COD 

(mg/L) 
TN 

(mg/L) 
TP 

(mg/L) 
SS 

(mg/L) 
January 5.3±0.7 17.9±8.5 7.43±0.97 1.83±0.05 4.2±1.1 
February 5.4±0.8 17.5±1.5 9.40±2.20 1.85±0.07 3.6±0.5 
March 4.9±0.1 18.1±1.3 5.80±2.70 1.78±0.09 3.5±0.5 
April 5.5±1.3 20.1±3.2 7.95±4.98 1.87±0.13 3.7±0.3 
May 4.1±0.4 19.6±1.2 3.75±1.37 1.70±0.42 3.7±0.6 
June 3.8±0.3 16.9±0.1 4.72±0.48 1.81±0.12 3.4±0.4 
July 4.8±0.6 18.7±1.6 4.37±1.11 1.75±0.15 3.3±0.4 
August 4.1±0.7 20.8±3.8 4.11±0.76 1.72±0.14 3.6±0.4 
September 4.0±0.3 18.6±3.1 3.17±0.96 1.76±0.11 3.6±0.6 
October 5.1±0.5 18.2±1.5 5.07±1.79 1.51±0.03 3.6±0.5 
November 4.7±0.1 17.7±1.3 3.72±0.97 1.40±0.16 3.8±0.6 
December 4.7±0.1 18.8±1.2 4.85±0.48 1.36±0.16 3.9±0.6 

 
Table 3 

Physicochemical characteristic of wastewater effluent from SBR 2 
 

Month/Year 2013 BOD5 (mg/L) 
COD 

(mg/L) 
TN 

(mg/L) 
TP 

(mg/L) 
SS 

(mg/L) 
January 5.9±0.6 15.2±3.0 5.8±2.0 1.82±0.13 3.8±0.6 
February 5.4±2.1 18.2±1.9 7.2±3.3 1.86±0.04 3.3±0.5 
March 5.5±0.4 18.3±1.2 3.8±2.4 1.78±0.12 3.5±0.6 
April 5.4±0.9 19.2±2.2 6.9±4.0 1.59±0.08 3.6±0.4 
May 6.1±0.1 19.5±1.9 3.2±0.3 1.61±0.43 3.7±0.6 
June 4.1±0.4 19.3±2.0 4.4±1.3 1.79±0.11 3.2±0.4 
July 4.6±0.4 17.1±2.9 3.8±1.3 1.72±0.18 3.3±0.5 
August 4.2±0.3 20.0±2.6 4.0±0.7 1.79±0.14 3.4±0.4 
September 4.2±0.1 18.6±1.0 1.5±0.1 1.72±0.07 3.4±0.4 
October 4.6±0.4 18.2±1.8 4.2±0.9 1.49±0.05 3.5±0.5 
November 5.2±0.1 16.4±1.8 3.9±1.2 1.44±0.19 3.8±0.4 
December 5.2±0.1 17.8±0.9 4.6±0.4 1.46±0.09 3.7±0.1 



Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University – Suceava 
Volume XIII, Issue 3 – 2014 

 

 
T s ve t ko P R O KOP O V,  D as ha M IH AY L O VA,  N ikol a y M IH ALK O V ,  Ph y s i c o ch e m i c a l m o n i t o ri ng  a nd  
p e r f o r m an c e  e va l u a ti o n of  SB R m un i c i p al  wa s t e wa t e r  t r e a t m e nt ,  Food and Environment Safety, Volume XIII, 
Issue 3 – 2014, pag. 207 - 213 

212 
 

Table 4 
Degree of purification of SBR municipal wastewater treatment 

 
Month/Year 

2013 
DPBOD5 (%) DPCOD (%) DPTN (%)) DPTP (%) DPSS (%) 

SBR 1 SBR 2 SBR 1 SBR 2 SBR 1 SBR 2 SBR 1 SBR 2 SBR 1 SBR 2 
January 95.5 95.0 94.1 95.0 69.7 76.3 44.5 44.8 94.9 95.4 

February 95.5 95.5 94.4 94.1 60.0 69.4 45.6 45.3 95.3 95.7 
March 95.0 94.4 93.9 93.9 76.8 84.8 47.6 47.6 95.5 95.5 
April 95.3 95.4 92.9 93.2 66.6 71.0 45.0 53.2 95.1 95.2 
May 95.4 93.2 92.4 92.4 84.6 86.9 54.1 56.5 94.8 94.8 
June 95.9 95.5 93.5 92.6 80.1 81.4 46.8 47.4 94.7 95.0 
July 94.8 95.0 92.1 92.8 80.1 82.7 52.7 53.5 94.8 94.8 

August 95.6 95.5 92.7 93.0 85.7 86.1 54.7 52.9 95.5 95.8 
September 95.9 95.7 93.6 93.6 88.3 94.5 52.4 53.5 96.0 96.2 

October 94.6 95.2 92.9 92.9 80.6 84.0 61.3 61.8 95.2 95.3 
November 94.9 94.4 92.7 93.3 86.2 85.6 65.0 64.0 94.9 94.9 
December 94.9 94.4 92.1 92.6 82.4 83.3 66.8 64.4 93.7 94.0 

 

 
Fig. 3. Performance evaluation of SBR municipal wastewater treatment 

 
Recorded maximum values of the standard 
parameters for discharged wastewater 
(Tables 2 and 3) during the investigated 
period of time were below emission limits 
also. These results indicates a significantly 
better performance of SBR wastewater 
treatment compared the requirements for 
the discharge into the water body and also 
potential of treated water for non-potable 
reuses, like gardening, cooling water and 
etc.     
 
4. Conclusion  
 
The results obtained in present research 
and performance evaluation of the SBR 
municipal wastewater treatment indicated 

that WWTP installed in Hisarya town, 
Bulgaria is working perfectly. The 
significant reduction (p<0.05) was 
observed in the physicochemical 
characteristics viz. BOD5, COD, TN, TP 
and SS. The average removal of BOD5 
(95.1±0.6 %), SS (95.1±0.6 %), COD 
(93.2±0.7 %), TN (80.3±8.0 %) and TP 
(53.4±7.2 %) of municipal wastewater 
were recorded after SBR treatment. The 
values obtained of standard parameters for 
treated wastewater were considerably 
below emission limits which indicate a 
significantly better performance of SBR 
wastewater treatment compared the 
requirements for the discharge into the 
water body and also reuse potential of 

0
20
40
60
80

100
120
140
160
180
200
220
240
260
280

BOD5 COD TN TP SS

C
on

ce
nt

ra
ti

on
 o

f 
po

llu
ta

nt
, 

m
g/

L
 Influent

Effluent from SBR 1
Effluent from SBR 2
Emission limit



Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University – Suceava 
Volume XIII, Issue 3 – 2014 

 

 
T s ve t ko P R O KOP O V,  D as ha M IH AY L O VA,  N ikol a y M IH ALK O V ,  Ph y s i c o ch e m i c a l m o n i t o ri ng  a nd  
p e r f o r m an c e  e va l u a ti o n of  SB R m un i c i p al  wa s t e wa t e r  t r e a t m e nt ,  Food and Environment Safety, Volume XIII, 
Issue 3 – 2014, pag. 207 - 213 

213 
 

treated water. Thus it is helphul in the 
control of the pollution of “Blu River” – 
Hisarya. 
 
5. Acknowledgments 
  
The authors express their most sincere 
gratitude to the Municipality and Mayor of 
Hisarya town, Bulgaria for their kind 
assistance and permission to access the 
WWTP. 
 
6. References 
 
[1]. DAVIS M.L., Water and wastewater 
engineering: design principles and practice. 
McGraw-Hill Inc., USA, (2010). 
[2]. MAHVI A.H., Sequencing batch reactor: a 
promising technology in wastewater treatment. 
Iran. J. Environ. Health Sci. Eng. Vil. 5, No 2. 79-
90, (2008). 
[3]. DE NARDI I.R., DEL NERY V., AMORIM 
A.K.B., DOS SANTOS N.G., CHIMENES F., 
Performances of SBR, chemical-DAF and UV 
disinfection for poultry slaughterhouse wastewater 
reclamation. Desalination 269. 184-189, (2011). 
[4]. ELMOLLA E.S., RAMDASS N., 
CHANDHUR M., Optimization of sequencing 
batch reactor operating conditions for treatment of 
high-strength pharmaceutical wastewater. Journal 
of Environmental Science and Technology Vol. 5, 
Issue 6. 452-459, (2012). 
[5]. JANCZUKOWICZ W., SZEWCZYK M., 
KRZEMIENIEWSKI M., PESTA J., Settling 
properties of activated sludge from a sequencing 
batch reactor (SBR). Polish Journal of 
Environmental Studies Vol. 10, No. 1. 15-20, 
(2001). 
[6]. JIA Y., GAO CH., ZHANG L., JIANG G., 
Effects of pre-fermentation and influent 
temperature on the degree of purification of COD, 
NH4+-N and PO43—P in slaughterhouse wastewater 
by using SBR. Energy Procedia 16. 1964-1971, 
(2012). 
[7]. KUMAR V., CHOPA A.K., Monitoring of 
physico-chemical and microbiological 
characteristics of municipal wastewater treatment 
plant, Haridwar city (Uttarakhand) India. Journal of 
Environmental Science and Technology 5(2). 109-
118, (2012). 

[8]. KUMBHAR S., MAIN J., DESAI M., Reuse 
potential of treated sewage from sequencing batch 
reactor. International Journal of Applied 
Engineering Research 8(7). 2011-2016, (2013).     
[9]. KUNDU P., DEBSARKAR A., MUKHERJEE 
S., Treatment of slaughter house wastewater in a 
sequencing batch reactor: performance evaluation 
and biodegradation kinetics. BioMed Research 
International Volume 2013, Article ID 134872. 11 
p., (2013). http://dx.doi.org/10.1155/2013/134872.  
[10]. MACE S. MATA-ALVAREZ J., Utilization 
of SBR technology for wastewater treatment: an 
overview. Ind. Eng. Chem. Res. 41. 5539-5553, 
(2002). 
[11]. MOHAN S.V., RAO N.CH., PRASAD K.K., 
MADHAVI B.T.V., SHARMA P.N., Treatment of 
complex chemical wastewater in a sequencing 
batch reactor (SBR) with an aerobic suspended 
growth configuration. Process Biochemistry 40. 
1501-1508, (2005).   
[12]. MOJIRI A., AZIZ H.A., AZIZ S.Q., ZAMAN 
N.Q., Review on municipal landfill leachate and 
sequencing batch reactor (SBR) technique. Archives 
Des Sciences 65(7). 22-31, (2012). 
[13]. OBAJA D., MACE S., MATA-ALVAREZ J., 
Biological nutrient removal by a sequencing batch 
reactor (SBR) using an internal organic carbon 
source in digested piggery wastewater. Bioresource 
Technology 96. 7-14, (2005). 
[14]. SATHIAN S., RAJASIMMAN M., RADHA 
G., SHANMUGAPRIYA V., KARTHIKEYAN C., 
Performance of SBR for the treatment of textile dye 
wastewater: optimization and kinetic studies. 
Alexandria Engineering Journal 53. 417-426, 
(2014).   
[15]. SPANGI A., MARSILI-LIBELLI S., 
Nitrogen removal via nitrite in a sequencing batch 
reactor treating sanitary landfill leachate. 
Bioresource Technology 100. 609-614, (2009). 
[16]. FAN L., XIE Y., Optimization control of 
SBR wastewater treatment process based on pattern 
recognition. Procedia Environmental Sciences 10. 
20-25, (2011). 
[17]. WAKODE P.N., SAYYAD S.U., 
Performance evaluation of 25 MLD sewage 
treatment plant (STP) of Kalyan. American Journal 
of Engineering Research Vol. 03, Issue 03. 310-
316, (2014). 
[18]. YOO CH.K., VILLEZ K., VAN HULLE 
S.W.H., VANROLLEGHEM P.A., Enhanced 
process monitoring for wastewater treatment 
systems. Environmetrics 19. 602-617, (2008).