Waste water management technologies

Review on Wastewater Management Technologies
Institute of Technology, Nirma University, S.G Highway, Ahmedabad
Yug Chandra Saraswat1
, Nikita P. Chokshi2
12bch040@nirmauni.ac.in, nikita.chokshi@nirmauni.ac.in
Abstract-It is no doubt that we are facing severe water crises and that efficient waste water management technologies are
needed to overcome these crises. Less than 10 countries possess 60% of the world’s available freshwater supply.1.8 billion
people still lack access to fresh water supply and 2.5 billion people need improved sanitation. Since 1940 the world’s water use
has quadrupled whilst the world’s population has only doubled. Everyone understands that water is essential to life. But many
are only just now beginning to realize how essential it is to everything in life – health, food, energy, transportation, nature,
leisure, and virtually all the products used on a daily basis. And so through this paper we review various technologies that are
employed to manage wastewater and the innovative technologies that are still underway.
Keywords: Wastewater Management, Nanotechnology, Microbial Fuel Cell, Dark Fermentation
1. Introduction
The optimist might argue that the glass is half full, while
the pessimist might think otherwise. However, both
arguments lose steam if the glass has contaminated water,
the quantity notwithstanding. Even as you read this,
millions of liters of wastewater, generated in India's urban
and rural areas on a daily basis, are getting dumped in its
already polluted water bodies. While on one hand we
aspire to be a superpower, on the other hand, we are doing
little to mitigate our water woes. Of the sewage generated
in India on a daily basis, only 30% gets treated. This means
70% of untreated sewage ends up in water bodies that serve
as sources of municipal water. No wonder, clean water is
fast becoming a scarce resource. If a checklist is to be
made of the factors that contribute to a country's progress,
efficient water management might feature right on top [1].
1.1.Why wastewater treatment does not take place?
1) India is beset by so many other problems that water and
wastewater management still doesn't seem to feature on its
priority list. Besides, the cost of land and cost of
construction and maintenance of sewage treatment plants is
quite high. As a result, wastewater treatment is often
exempt from urban planning.
2)Moreover, recycle and reuse of wastewater has not
received much attention by the policy-decision makers
perhaps because of the lack of viable models with
necessary research and technology support, strong policies
and legal framework at the national and state levels and
lack of sufficient trained manpower in the urban local
bodies.
3) One of the major problems with waste water treatment
methods is that none of the available technologies has a
direct economic return. Due to no economic return, local
authorities are generally not interested in taking up waste
water treatment [2].
1.2. Appropriate Wastewater Treatment Technologies
in India:
A single wastewater treatment technology would be
inappropriate for a country like India which has several
different geographical and geological regions, varied
climatic conditions and levels of population. It is more
appropriate to address the potential of identifying
appropriate solutions for different regions. In addition, the
solutions for wastewater treatment are a response to several
factors including:
1.The volume of wastewater
2.Type of pollutants
3.The treatment cost
4.Extent of water scarcity
5.Dilution of pollution in the water resources.
The five main wastewater treatment technologies that are
commonly used are as given below:
1.Waste stabilization ponds
2. Wastewater storage and treatment reservoir
3. Constructed wetlands
4. Chemically enhanced primary treatment
5. Up flow anaerobic sludge blanket reactors.
These are suitable for different conditions and have
advantages and disadvantages, especially in terms of
requirements for land, cost, remediation efficiency and
other factors [3].
All these solutions for wastewater treatment aim at
innovations across a broad range of environmental issues
including:
1.Reuse of wastewater;
2.Removal of nutrients from effluent;
3.Management of storm water;
1

4.Managing solid wastes
5.Flood mitigation
6. Tackling erosion around water bodies, including ponds,
lakes and riverbank.
However, from the sustainability aspect, the selection of
the appropriate solution must be balanced between simple
systems that do not require use of chemicals and those that
have high pathogen removal [3].
Figure 1: Sources of waste water
Figure 2: Basic
Municipal waste
water treatment
2. EXISTING
TECHNOLOGIES
2.1.Municipal wastewater treatment using constructed
wetlands
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• Constructed wetlands (CWs) are viable treatment
alternative for municipal wastewater, and numerous studies
on their performance in municipal water treatment have
been conducted. A good design constructed wetland should
be able to maintain the wetland hydraulics, namely
hydraulic loading rates (HLR)Hydraulic Retention
Time(HRT), as it affects the treatment performance of a
wetland.
• Indian experience with constructed wetland systems is
mostly on an experimental scale, treating different kinds of
wastewater.
• One of the major constraints to field-scale constructed
wetland systems in developing countries like India is the
requirement of a relatively large land area that is not
readily available.
• Subsurface (horizontal/ vertical) flow systems, generally
associated with about a 100 times smaller size range and 3
times smaller HRTs (hydraulic retention time, generally
2.9 days) than the surface flow systems (with about 9.3
days HRT), are therefore being considered to be the more
suitable options for the developing countries. Shorter HRTs
generally translate into smaller land requirement. Batch
flow systems, with decreased detention time, have been
reported to be associated with lower treatment area and
higher pollutant removal efficiency. Thus, batch-fed
vertical sub-surface flow wetlands seem to have an
implication for better acceptability under Indian conditions
[4].
Figure 3: Constructed Wetlands
2.2. Decentralized Wastewater Management
• Decentralized Wastewater Treatment Systems (DEWATS)
are locally organized and people-driven systems that
typically consist of a settler, anaerobic baffled septic tank,
filter bed of gravel, sand, plantation-beds and a pond. The
open pond or the polishing tank stores the remedied water
and keeps it available for re-use. The system operates
without mechanical means and sewage flows by gravity
through the different components of the system. Based on
the principle of low-maintenance. since most important
parts of the system work without electrical energy inputs
and cannot be switched off. Many of the households do
not have access to a drainage network and are connected to
natural surface drains. The assessment of open- defecation
takes a different dimension which is not discussed in this
paper.
• Thus it is evident that a large amount of human excreta
generated is unsafely disposed. This imposes significant
effect on public health, working- man days and
environmental costs resulting in loss in National revenues.
Impacts of poor sanitation are especially significant for the
rural and urban poor, women, children and the elderly.
Inadequate and un-safe discharge of untreated domestic/
municipal wastewater has resulted in contamination of 75
% of all surface water i.e. at the rivers, ponds and lakes
across India.
• The Millennium Development Goals (MDGs) enjoin upon
the signatory nations to extend access to improved
sanitation to at least half the population by 2015, and 100%
access by 2025. This calls for providing improved
sanitation, and with facilities in public places at both rural
and urban habitats [3]
3

Figure 4: Systems Concept for Decentralized Wastewater
Treatment
2.3. WASTE STABILIZATION PONDS
• Stabilization ponds [5] consist of shallow man-made basins
comprising a single or several series of anaerobic,
facultative or maturation ponds. The primary treatment
takes place in the anaerobic pond, which is mainly
designed for removing suspended solids, and some of
the soluble element of organic matter (BOD). During the
secondary stage in the facultative pond most of the
remaining BOD is removed through the coordinated
activity of algae and heterotrophic bacteria. The main
function of the tertiary treatment in the maturation pond is
4

the removal of pathogens and nutrients (especially
nitrogen).
• Stabilization ponds are particularly well suited for tropical
and subtropical countries because the intensity of the
sunlight and temperature are key factors for the efficiency
of the removal processes [6].
• It is also recommended by the WHO for the treatment of
wastewater for reuse in agriculture and aquaculture,
especially because of its effectiveness in
removing nematodes (worms) and helminth eggs [7].
Figure 5:Waste stabilization ponds
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Figure 7:Upward Flow Anaerobic Sludge Blanket
2.4.Up flow anaerobic sludge blanket (UASB)
technology
UASB uses an anaerobic process whilst forming a
blanket of granular sludge which suspends in the tank.
Wastewater flows upwards through the blanket and is
processed (degraded) by the anaerobic
6

microorganisms. The upward flow combined with the
settling action of gravity suspends the blanket with the aid
of flocculants. The blanket begins to reach maturity at
around 3 months. Small sludge granules begin to form
whose surface area is covered in aggregations of bacteria.
In the absence of any support matrix, the flow conditions
create a selective environment in which only those
microorganisms, capable of attaching to each other, survive
and proliferate. Eventually the aggregates form into dense
compact bio films[8]. Biogas with a high concentration
of methane is produced as a by-product, and this may be
captured and used as an energy source, to
generate electricity for export and to cover its own
running power. The technology needs constant monitoring
when put into use to ensure that the sludge blanket is
maintained, and not washed out (thereby losing the effect).
The heat produced as a by-product of electricity generation
can be reused to heat the digestion tanks [9].
2.5. Municipal sewage treatment: the conventional
approach
A conventional sewage treatment plant is made of a series
of different treatment steps:
• Screening
Sand removal (with coupled oil and grease
removal if necessary)
• Primary sedimentation
• Biological reactor
• Secondary sedimentation
• Post-treatment if necessary (filtration, disinfection, etc.)
Municipal sewage treatment: the CEPT conception The
CEPT proposal is to enhance primary sedimentation by the
use of iron and aluminum salts, lime and polyelectrolyte’s,
in order to increase the coagulation, flocculation and
sedimentation of raw sewage. This process drastically
increases the performance of primary sedimentation
(higher removal of TSS, BOD, nutrients, etc.) without a
large increase in the amount of sludge produced. The
resulting effluents can be:
• Discharged directly to the environment if the proper
conditions are present (e.g., in the case of a marine outfall)
• Treated in a biological reactor; in this case the reactor will
be smaller with lower construction and operational costs
[7].
2.6. Wastewater storage and treatment reservoirs
While it is true that waste stabilization ponds can more
easily produce effluents suitable for agricultural reuse
(principally crop irrigation) than other wastewater
treatment processes, they share the disadvantage that their
effluent can only be used for crop irrigation during the
irrigation season. During the other months of the year, the
effluents are discharged, essentially to waste, to a surface
watercourse.
Figure 8:Wastewater storage and treatment reservoir
Wastewater storage and treatment reservoirs (WSTR), also
called effluent storage reservoirs, were used to overcome
this disadvantage and permit the whole year’s treated
wastewater to be used for crop irrigation during the
irrigation season. WSTR are especially advantageous in
arid and semi-arid areas where agricultural production is
limited by the quantity of water (including treated
wastewater) available for irrigation. Wastewater is too
valuable to waste in arid and semi-arid areas, and the use of
WSTR prevents such waste [8].
3. NEW TECHNOLOGIES
3.1. Dark Fermentation-
Utilization of wastewater as a potential substrate for bio
hydrogen production has been drawing considerable
interest in recent years especially in the dark fermentation
process. Industrial wastewater as a fermentative substrate
for H2 production addresses most of the criteria required
7

for substrate selection viz., availability, cost and
biodegradability[12,13].
1. Chemical wastewater[14,15]
2. cattle wastewater [16]
3. dairy process wastewater[17,18] ,
have been reported to produce bio hydrogen apart from
wastewater treatment from dark fermentation processes
using selectively enriched mixed cultures under acidophilic
conditions. Various wastewaters viz., paper mill
wastewater[19], starch effluent[20], food processing
wastewater[21,22], rice winery wastewater[21], distillery
and molasses based wastewater[24,25]; have been studied
as fermentable substrates for H2 production along with
wastewater treatment. The efficiency of the dark
fermentative H2 production process was found to depend
on pre-treatment of the mixed consortia used as a
biocatalyst, operating pH, and organic loading rate apart
from wastewater characteristics [26].
3.2. Microbial Fuel Cells
In past two decade high rate anaerobic processes are
finding increasing application for the treatment of domestic
as well as industrial wastewaters. Although, energy can be
recovered in the form of methane gas during anaerobic
treatment of the wastewater, but utilization of methane is
not attractive while treating small quantity of low strength
wastewater and usually it is flared. In addition, due to
global environmental concerns and energy insecurity there
is emergent interest to find out sustainable and clean
energy source with minimal or zero use of hydrocarbons.
Microbial fuel cells, used as biosensors, if used for
wastewater treatment, are capable to provide clean energy,
apart from effective treatment of wastewater [27].
3.3.Nanotechnology [28]- Table 1 shows the different
application of nano technology for waste water treatment
Table 1: Current and potential applications of nanotechnology in water and wastewater treatment.
Applications
Representative Desirable nanomaterial Enabled technologies
nanomaterials properties
1) Adsorption
Carbon
nanotubes
High specific surface area, highly
assessable adsorption sites, diverse
contaminant-CNT,interactions,
tunable surface chemistry easy reuse
Contaminant
preconcentration/detection,
adsorptioin of recalcitrant
contaminants
2) Membranes and
membranes processes
Nano-zeolites Molecular sieve, hydrophilicity
High permeability thin film
nanocomposite
Nano-Ag
Strong and wide-spectrum
antimicrobial activity, low toxicity
to humans
Anti-biofouling membranes
Carbon
nanotubes
Antimicrobial activity (unaligned
carbon nanotubes)
Anti-biofouling membranes
Small diameter, atomic smoothness
of inner
Aligned carbon nanotube
membranes
surface, tunable opening
Nano-
magnetite
Tunable surface chemistry, super
paramagnetic
Forward osmosis
Disinfection and
microbial control
Nano-Ag Strong and wide-spectrum
antimicrobial activity, low toxicity
to humans, easy to use
POU water disinfection, anti-
biofouling surface
Carbon
nanotubes
Antimicrobial activity, fiber shape POU water disinfection, anti-
biofouling surface
4. Conclusion
At the end we conclude that technological advancement can
improve the waste water treatment technologies but at the
same time it is important that we change the mindset of the
people, making them understand that waste water is not
useless but a resource that can be reused, recycled and has
the potential of getting rid of our country’s water woes.
Further, there is a need to support implementation of projects
8

which demonstrate not only low-cost treatment of
wastewater, but also demonstrate how communities and local
administration can partner to implement ways that make the
facilities more durable and sustainable in the long run. The
wastewater generated in India is so huge that public
investment alone will not help. Private-public partnerships
(PPP) are then the way out. Hence, adequate incentives are
needed. If India has to ensure overall progress, it must
manage its water resources efficiently and this is only
possible if we take wastewater treatment seriously.
5. References
[1]
http://www.moneycontrol.com/news/features/why-
india-lagswastewater-management_961087.html-By
Avinash Iyer
[2]http://www.indiawastemanagementportal.org/inde
x.php?
option=com_content&view=article&id=49&Itemid=14
8-India Waste Management Portal
[3]Decentralized_Wastewater_Management.pdf -
Decentralized Wastewater Management – An overview of
community initiatives -Er. Ajit Seshadri, Head- Environment
, The Vigyan Vijay Foundation, New Delhi
[4]Wastewater production, treatment and use in India R
Kaur1
, SP Wani2
, AK Singh3
and K Lal1
Water Technology
Centre, Indian Agricultural Research Institute, New Delhi,
India ,International Crops Research Institute for the Semi-
Arid Tropics, Hyderabad Indian Council of Agricultural
Research, New Delhi, India Email: rk132.iari@gmail.com;
pd_wtc@iari.res.in
[5]Design and Performance of Waste Stabilization Ponds,
Hamzeh H. Ramadan & Victor M. Ponce
[6]IRC Waste stabilization ponds for wastewater treatment,
May 2004, prepared by Cinara, Colombia
[7]WHO: Guidelines for the safe use of wastewater, excreta
and greywater
[8]What are sludge granules? UASB Homepage Finstein,
M.S., Zadik, Y., Marshall, A.T., Brody, D. (2004). "The
ArrowBio Process for Mixed Municipal Solid Waste –
Responses to “Requests for Information”" (PDF).
[9] In Papadimitriou, E.K., Stentiford, E.I. Biodegradable
and Residual Waste Management. 1st UK Conference and
Exhibition on Biodegradable and Residual Waste
Management, February 18–19, 2004, Harrogate, UK. Leeds:
CalRecovery Europe Ltd. pp. 407–413. ISBN 0-9544708-1-
8
[10]http://www.juanico.co.il/Main%20frame%20-
%20English/Issues/CEPT.htm- Juanicó - Environmental
Consultants Ltd. International consulting firm on high-tech
low-cost low-energy solutions for warm climate
[11]http://www.bt.slu.se/eas/Litterature/WSP_IndiaM
an/IPDMc9.pdf
[12]Angenent, L.T., Karim, K., Al-Dahhan, M.H., Wrenn,
B.A., Domíguez-Espinosa, R., 2004. "Production of
bioenergy and biochemicals from industrial and agricultural
wastewater". Trends in Biotechnology 22, 477-85
[13] Kapdan, I. K., Kargi, F., 2006. "Bio-hydrogen
production from waste materials", Enzyme Microb Technol
38, 569–82
[14] Venkata Mohan, S., Vijaya Bhaskar, Y., Sarm, P.N.,
2007a. "Biohydrogen production from chemical wastewater
treatment by selectively enriched anaerobic mixed consortia
in biofilm configured reactor operated in periodic
discontinuous batch mode". Water Res 41, 2652-64
[15]Venkata Mohan, S., Mohanakrishna G., Veer Raghuvulu
S., Sarma, P.N., 2007b. "Enhancing biohydrogen production
from chemical wastewater treatment in anaerobic sequencing
batch biofilm reactor (AnSBBR) by bioaugmenting with
selectively enriched kanamycin resistant anaerobic mixed
consortia". Int J Hydrogen Energy 32, 3284–92
[16] Tang, G., Huang, J., Sun, Z., Tang, Q., Yan, C., Liu, G.,
2008. "Biohydrogen production from cattle wastewater by
enriched anaerobic mixed consortia: Influence of
fermentation temperature and pH". J Biosci Bioengng., 106,
80-7
[17] Venkata Mohan, S., Lalit Babu, V., Sarma, P.N., 2007c.
"Anaerobic biohydrogen production from dairy wastewater
treatment in sequencing batch reactor (AnSBR): Effect of
organic loading rate". Enzyme and Microbial Technology
41(4), 506-15
[18] Rai, Pankaj K, Singh, S.P & Asthana, R.K .
"Biohydrogen production from cheese whey wastewater in a
two-step anaerobic process". Applied Biochemistry and
Biotechnology 2012, 167 (6) 1540-9
[19] Idania, V.V., Richard, S., Derek, R., Noemi, R.S.,
Hector, M.P.V., 2005. "Hydrogen generation via anaerobic
fermentation of paper mill wastes". Biores Technol 96, 1907-
13
[20] Zhang, T., Liu, H., Fang, H.H.P., 2003. "Biohydrogen
production from starch in wastewater under thermophilic
condition". J Environ Manag 69, 149-56
[21] Shin, H.S., Youn, J.H., Kim, S.H., 2004. "Hydrogen
production from food waste in anaerobic mesophilic and
thermophilic acidogenesis". Int J Hydrogen Energy 29, 1355-
63
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[22] van Ginkel, S.W., Oh, S.E., Logan. B. E., 2005.
"Biohydrogen gas production from food processing and
domestic wastewaters". Int. J. Hydrogen Energy 30, 1535-42
[23] Yu, H., Zhu, Z., Hu, W., Zhang, H., 2002. "Hydrogen
production from rice winery wastewater in an upflow
anaerobic reactor by using mixed anaerobic cultures", Int J
Hydrogen Energy 27, 1359-65
[24] Ren, N.Q., Chua, H., Chan, S.Y., Tsang, Y.F., Wang,
Y.J., Sin, N., 2007. "Assessing optimal fermentation type for
bio-hydrogen production in continuous flow acidogenic
reactors", Biores Technol 98, 1774-80
[25] Venkata Mohan, S., Mohanakrishna, G., Ramanaiah,
S.V, Sarma, P.N., 2008a. "Simultaneous biohydrogen
production and wastewater treatment in biofilm configured
anaerobic periodic discontinuous batch reactor using
distillery wastewater". Int J Hydrogen Energy 33(2), 550-8
[26] Vijaya Bhaskar, Y., Venkata Mohan S, Sarma, P.N.,
2008. "Effect of substrate loading rate of chemical
wastewater on fermentative biohydrogen production in
biofilm configured sequencing batch reactor". Biores
Technol 99, 6941–8
[27]
http://www.microbialfuelcell.org/publications/env-ce-
iitkgp/p-37-mfc-mmg.pdf-MICROBIAL FUEL CELL:
A NEW APPROACH OF WASTEWATER
TREATMENT WITH POWER GENERATION M.M.
GHANGREKAR AND V.B. SHINDE
[28]
http://alvarez.blogs.rice.edu/files/2013/06/159.pdf-
Xiaolei Qu, Pedro J.J. Alvarez, Qilin Li
Department of Civil and Environmental Engineering,
Rice University, Houston, TX 77005, USA
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