Agriculture Reference
In-Depth Information
12.5.3 Biological Technology
Biological treatment technology is commonly used for livestock wastewater treat-
ment and includes anaerobic treatment, aerobic treatment, and anaerobic-aerobic
treatment. Anaerobic treatment is suitable for livestock wastewater containing high
concentrations of organic matter. The common anaerobic treatment methods
include the use of anaerobic baffled reactor (ABR), upflow anaerobic sludge
blanket (UASB), microbial fuel cell (MFC), etc.
A study from Wu et al. (
2013
) was designed regarding orthogonal experiments
to operate the four-compartment ABR with a hydraulic retention time (HRT)
¼
1
C and discovered the
24 h, influent COD
4,600 mg/L, and temperature
¼
35
¼
¼
optimal parameters with pH
7, C/N
44, and 2-bromoethanesulfonate (BES)
¼
concentration
20 mmol/L to achieve the high acetic acid accumulation of efflu-
ent. Dias et al. (
2014
) presented a broad evaluation of one particular system (UASB
reactor, three shallow ponds, and a coarse rock filter in series) in Brazil treating
sewage from 250 inhabitants over a period of 10 years. They found that even with
short HRTs in each pond (2-6 days), the results endorse the good capacity for
organic matter and ammonia removal and excellent removal of coliforms, helminth
eggs, and sulfides.
It can be observed that the COD volumetric loading of ABR is adequately high,
and the HRT is sufficiently long to treat wastewater containing high concentrations
of organic matter. This new high-rate anaerobic reactor was developed by McCarty
and Bachmaann in 1982, and has good adaptability to shock load. The character-
istics of UASB include engineering expertise, steady operation, good results, high
efficiency, cost-effectiveness, and small size. On the other hand, the MFC can
convert chemical energy into electricity while achieving sewage treatment and has
become the focus of current studies. The MFC can remove organics at a high rate
and is particularly suitable for wastewater with high concentrations of organic
matter. Anaerobic treatment technology is widely applied for the treatment of
wastewater with high concentrations of organics, such as pharmaceutical, chemical,
and farming wastewater, with advantages of good COD removal efficiency and
utilizing small area. However, the effluent formed after anaerobic treatment does
not meet the quality standards, and often, further treatment is required if odor is
emitted from the non-closed reactor.
The common livestock wastewater aerobic treatment technologies include
sequencing batch reactor (SBR), sequencing batch biofilm reactor (SBBR), biofilm,
biological filter, moving bed biofilm reactor (MBBR), membrane bioreactor
(MBR), and anoxic/oxic (A/O) method.
Effects of dilution rates, glucose supplementation, and HRTs on the efficiency
and performance of the SBR system with electroplating wastewater (EPWW)
solutions containing CN
and Zn
2+
were conducted by Sirianuntapiboon (
2013
).
The system showed that the highest COD, BOD
5
, TN, TKN, CN
, and Zn
2+
removal efficiencies were 91
2, 71
6, 48.6
1.0, 56.9
5.3, 62.4
3.0, and
88.0
0.6 %, respectively, at the 1:5 diluted EPWW solution containing 100 mg/L