2021/42

PERFORMANCE EVALUATION OF FAECAL SLUDGE TREATMENT PLANT AT LUBHU, LALITPUR

4 Poster Track: Applied Research » 4 Innovative technology aspects

Speaker: Sabuna Gamal


Summary – for publication in conference brochure:


The study aims to understand the performance of Lubhu FSTP in terms of O&M practices. BOD, COD, TS, Nitrate, TKN, TP, E. coli. and Helminths eggs were analyzed in the laboratory. Field observation, key informant interview, questionnaire survey was also carried out. COD (94%) and BOD (92.18%) removal efficiency were high. Helminths eggs removal efficiency was very high but E. coli. (on average 900 CFU/ml) was detected in effluents. About 77.51 % respondents weren’t aware about FSTP but about 77.4 % respondents want FSTP at their locality. O&M and monitoring guidelines should be prepared and regulated to enhance performance.


Introduction, methods, results and discussion:


 

Proper management of the Faecal Sludge (FS) is a growing issue particularly in developing countries including Nepal. Unsafe disposal of FS into the open environment has adverse impact on public health and the environment. Faecal Sludge Treatment Plant (FSTP) at Lubhu was established in 2016 to treat FS generated from temporary latrines during the earthquake. It is now receiving the FS from households (6 m3/week). While there are very limited FSTP in Nepal, sustainable operation and maintenance (O&M) of the system is another challenge. The study aims to understand the performance of Lubhu FSTP with respect to the existing O&M procedures and practices, measuring the effectiveness based upon the final effluent quality and resource recovery along with people’s knowledge, perception, and acceptability.

The sample of untreated FS was taken directly from de-sludging vehicle. The sample of treated effluent was taken from outlet of planted gravel filter. The sample of treated dried sludge was taken from planted sludge drying bed. Major constituents such as BOD, COD, TS, TSS, Nitrate, TKN, TP, K, E.coli, and Helminths eggs were analyzed in the laboratory. A questionnaire survey was conducted and analyzed using SPSS.  In addition, field observation and key informant interviews were carried out.

The removal efficiency of VS and TS were 92.53% and 87. 44 % respectively. While it has highest removal efficiency of TSS (97.7%). TP (86.66 %) has highest removal efficiency while lowest for TKN (57.14 %) among nutrients. Compared to previous analysis by Rajbhandari and Dangol (2017), there is increase on TS, VS, TSS, COD, K and TP removal efficiency. The increase in efficiency could be result of major maintenance of modules. However, there is decrease in Nitrate removal efficiency. Thus, further study is recommended to figure out fluctuation. Absence of Helminths at effluent and dried sludge indicates safe use for farming (WHO, 2006). Presence of E. coli. (900 CFU/ml) create the risk however E. coli.  ˂105 CFU/100 ml is considered safe for restricted irrigation (Blumenthal et al., 2000).

All treatment products form Lubhu FSTP have been used.  About 1103 m3 biogas produced was being used. The treatment products such as treated effluent and treated dried sludge have been used for farming. Drying beds have low operating costs whereas anaerobic digestion (biogas) have high operating cost (Strande et al., 2014). Selling of end product support to manage O& M costs. Funds generated from biogas, compost, selling vegetables, saving from buying vegetables, visitor’s charge, discharge fee and municipal matching fund have supported for regular operation. Proper training to caretaker on O&M procedure has been contributed to proper functioning.

 

The 50.5% of respondents (n=93) know about FSTP. Nevertheless, most of the people (77.51%. n=93) don’t know that there is FSTP in their locality. Most of the people (77.4%. n=93) want to accept FSTP in their locality. Similarly, half of people (53.8%, n=93) have a willingness to use treated FS as soil conditioners. The acceptance of wastewater reuse varies widely depending on reuse purposes (Saad et al. 2017). 

 

 

 


Conclusions and implications:


 

Based on the study, the following conclusions are obtained:

 

 

 

1)    Based on the removal efficiencies of different physiochemical parameters, the faecal sludge treatment plant at Lubhu is operating well and demonstrates a successful system for treating faecal sludge at the municipal level.

2)     The current model of operation involving a well-trained care-taker, backed by financial incentives and backstopping of a technical partner has worked well to sustainably operate the Lubhu FSTP.

3)   The survey reflects the gap in knowledge sharing as most of the people are unknown about the FSTP in their locality but encouraging for replicating the FSTP in other locations due to acceptability by most of the people. 

·     Regular monitoring should be conducted to monitor the treatment performance and efficiency. This will allow making timely corrections for the sustainable operation of the plant. Further research should be conducted on performance of each treatment module and the impact of the application of treated effluents and dried sludge in agriculture products. Moreover, the awareness should be raised for enhancing social knowledge, perception, and acceptance along with promotion and capacity building of stakeholders for further replication and scaling up.

 

 

 

 


Relevant references:


APHA
AWWA
WEF (2012): Standard Methods for examination of water and wastewater. 22nd ed. Washington: American Public Health Association; 2012
1360 pp. ISBN 978-087553-013-0
Rajbhandari R and Dangol B (2017): Faecal Sludge Treatment and reuse system in Mahalaxmi Municipality
Nepal. Journal of Environment and Public Health
1(1)
59- 63.Published by ENPHO
Nepal.
Saad D
Byrne D and Drechsel P (2017): Physico-Chemical Wastewater Treatment and Resource Recovery; Chapter 12; Social Perspectives on the Effective Management of Wastewater; Available on: https://www.intechopen.com/books/physico-chemical-wastewater-treatment-and-resource-recovery
Strande L
Ronteltap M and Brdjanovic D (2014): Faecal Sludge Management: Systems Approach for Implementation and Operation. IWA Publishing. ISBN: 9781780404738 http://www.eawag.ch/en/department/sandec/publications/faecal-sludge-management-fsm-book/
Tilley E
Ulrich L
Lüthi C
Reymond P and Zurbrügg C (2014): Compendium of Sanitation Systems and Technologies. Dübendorf: Swiss Federal Institute of Aquatic Science & Technology (EAWAG) 2nd revised edition.

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