A Review :
Finding Solution for Treating Wastewater from Floating Toilet
Dyah Wulandari Putri1, Prayatni Soewondo2, Agus Jatnika Effendi3, Tjandra Setiadi4
1Department of Environmental Engineering, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung 40132. Email : [email protected]
2 Department of Environmental Engineering, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung 40132. Email : [email protected]
3Department of Environmental Engineering, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung 40132. Email : [email protected]
4Centre for Environmental Studies (PSLH), Institut Teknologi Bandung, Jl. Sangkuriang 42 A, Bandung 40135, Indonesia. Email: [email protected]
Abstract. Floating toilets are common toilet system found in settlement near or above river, lake, swamp, estuary, and coastal area in Indonesia and some other countries in Asia. Most of them only consist of hole or toilet with short pipe that discharge wastewater directly to the water area. Consideration of the requirement to treat wastewater from floating toilet mainly appear while water quality has decreased significantly, some other considerations are about odor and estethics problem especially in area affected by tidal wave and water area without adequate flow to dilute and treat wastewater naturally. Since the applied area of floating toilet system has specific characteristics technically and non-technically, some limitation in applying wastewater treatment system need to be considered. Several works in providing adequate appropriate treatment system has been found, including three main approaches. First is to apply system that is common used for land area directly, second is to modify system by considering the specific area condition and low cost system, and third is to build system based on community development. By getting information from literature, some reports, and survey, evaluation of several applied wastewater treatment categorized based on those three approaches is implemented.
From the evaluation direct use common wastewater treatment system in land area are economically unefficient, also have higher potency of failure. The modification at least in foundation structure is required. System that innovate based on low-cost and specific area condition is promising as solution but still required further development and innovation to get better system. Community based development strategy has the challenge in getting acceptance, satisfaction and commitment of the community are the factors that lead for the successfulness of system applied and the system chosen is really specific to one community that is being included.
Keywords: floating toilet; wastewater treatment; specific area; community based development; innovation
1 Introduction
Floating toilets using stilt construction (Figure 1) are common toilet system found in slum settlement near or above river, lake, swamp, estuary, and coastal area in Indonesia and some other countries in Asia. Most of them only consist of hole or toilet with short pipe that discharge wastewater directly to the water area. The degradation of water quality, odor and estethics problem especially in area affected by tidal wave and water area without adequate flow to dilute and treat wastewater naturally make the floating toilet system become the icon of bad sanitation facilities that contribute a lot in polluted water area (Figure 1c). Nowadays, the consideration for providing the treatment system in floating toilet has been increased, but characteristic of specific area and community where floating toilet apllied in make some limitation in the option of possible and appropriate system to be applied [4][5][8]. In this paper, three approaches in finding solution for wastewater treatment in floating toilet as on-site and decentralized system are being reviewed. First approach is to apply on-site and decentralized wastewater system that commonly used in land area directly, second approach is to create or modify treatment system with the consideration of specific area condition and low cost treatment, and third approach is to develop treatment system based on community development in one study area.
Figure 1 a) Individual floating toilet in swampy area Palembang, b) Public floating toilet on the Musi river, Palembang, c) Artificial floating toilet as the icon of bad sanitation system in National Sanitation Conference Jakarta
2 Approaches in Finding Solution for Treatment in Floating Toilet – Existing Application
2.1 Applying Land Type of Wastewater Treatment System in Floating Toilet
Conventional septic tank and its modification has been applied as wastewater treatment solution for some floating toilet in several places. The first record about
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conventional septic tank application as collection tank for public toilet in Jakarta swamp area analyzed in Navarro [8]. It mentioned that the toilet was abandoned since the septic tank were flooded if rain. That become one main consideration to construct treatment system in the area with the change of water level periodically.
Anaerobic Baffled Reactor (ABR) is one of the developed conventional septic tank process that commonly use as communal treatment. ABR includes settled compartment followed by several baffled reactor. This configuration gives higher contact time to make higher efficiency than the conventional septic tank process.
The requirement of infiltration construction area or wetland of conventional septic tank is reduced by applying ABR system. ABR application were founded in several coastal, river, and swamp area [4] , one of them with two steps filtration as the final treatment can be found in Tihik-tihik and Selangan coastal settlement in Bontang city (Figure 2a) [3].
Djonoputro et al. [4] analyzed that to construct septic tank system using concrete or cement material in waterlogged land or on the bottom of the water area while no land area available in the settlement area. This because of construction work itself and also the consideration of proper foundation that can support the system from pressure from water and unstable soil condition. Based on survey that was held in swamp area in Palembang city, some septic tank system that is constructed only use the common foundation use in land area cracked easily, while the system that built in the bottom of shallow sea in Bontang city was stronger by applying cerucuk construction (with long iron bar as the anchor for the additional foundation).
Rotating Biological Contactor (RBC) as other common communal wastewater treatment system were also found providing treatment for floating toilet in several household with stilt housing type (Figure 2c). This system consider not really effective since it required to be built above the water level that make the pumping system is required. Other weakness is since the material including metal, that make it cannot be applied in coastal area considering the salinity of water area that is also affected air condition make the high potency for corrosion[5].
Other land system applied based on septic tank process was fabricated biofiltration system using fiberglass as the construction material (Figure 2b) for individual floating toilet in the river in Banjarmasin[12]. First trial as floating system connected by pipe to floating toilet with the same specification as the one used in land consider as less durable system since the force between the system with bottom of the river as the effect of tidal wave make the fiberglass system cracked easily. Other evaluation by Djonoputro et al [4] is about the pipe joint that will be easily broken because of the movement of the biofiltration tank. As the alternative solution for those problem, biofiltration system constructed using heavy duty
material with hanging construction using PVC pipe. It consider become better system, but the evaluation hasn’t been established after several months after its construction.
Regarding to the sewerage system applied, there is no international standard for its application in stilt type of housing and toilet, the analysis made from the survey and also from Djonoputro et al [4], consideration of the unburried pipeline connecting from several floating toilets with stilt construction are the use of supporting material that prevent movement of the pipeline and make the strong joint between one and other pipe. Mostly the sewerage can use gravitation for flowing, but the exact criteria for placement of the sewerage pipeline has not been established.
Figure 2 a) Sewerage and ABR followed by Filtration in Tihik-tihik and Selangan Coastal Communities , b) Biofiltration in Banjarmasin[12], c) RBC in second floor in Bontang Kuala Coastal Area
2.2 Modification of Wastewater Treatment System with Specific Characteristic of Area and Low-cost Consideration
There are some wastewater treatment system that was being designed by the consideration of floating toilet condition. First is three concentric pipe-septic tank system that was developed by Civil Engineering Laboratorium, Gajah Mada University to solve sanitation problem in river communities. The system developed known as Tripikon-S (Figure 3a), which is modified septic tank by using vertical flow and pipe as construction materials. This technology consider as low cost, easy to build, easy finance, and easy replicated wastewater treatment system [9]
[11][13]. The material used is the PVC pipes with three different sizes and build concentrically each other as the place of anaerobic treatment process. Tripikon-S system has been applied and piloted in many places, such as riverbank area in
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Yogyakarta, swamp area in Palembang, also swamp area in Pontianak, Kalimantan.
Similar type of Tripikon-S system was also constructed in and developed with the name of Pinastik-A/ T-Pikon H (Figure 3b) which is use horizontal system to reduce the height of the treatment system, so the system can be applied in floating house (boat house) [5]. But the use and further research about Pinastik-A/ T-Pikon H is still rarely found. Those three concentric pipe-septic tank systems are built as hanging system that directly attached to the bottom of toilet floor. Since it easy to build, community can build it by their own resources. The problem in durability is still need to be consider also the requirement of its maintenance need to be concerned.
Figure 3 a) Tripikon-S System [13], b) T-pikon H system [5], c) Floating wetland [2][12]
Other system modified based on low cost and area condition in river is floating wetland system, also known as floating pods or floating garden (Figure 3c). This system is adapting the wetland process with floating agent such as plastic bottle or PVC frame to make it float on the surface water follow tidal wave movement. The materials used were the local and simple material such as tarpauline or any other local material [2][12]. The efficiency of system is not really high, applying the system was by combining with other treatment system is preferable.
2.3 Community Based Development For Floating Wastewater Treatment – Cambodja Case
Engineers Without Borders (EWB) and Live & Learn NGOs have been collaborating in Tonle Sap sanitation project since 2008 up until 2013 focus on Phat Sanday villages in Tonle Sape Lake, Cambodja, which consists of floating house communities. Several works including development of some pilot technologies achieved in this work. The communities were involved in concept and
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planning, design, and execution. Several focus group discussion and workshop (Figure 4a) has been hold in concept and planning stage, while community has been consulted throughout the design process and their feedback feed back into the design developed by the engineers in the design stage, and two members of the community has been employed on a part-time basis to help with execution of the project. Their assistance has enabled improved community feedback on the project and allowed to access local skills and labour during construction phase of the project [1]
First technology development that has been achived was development of floating toilet design. Based on the community discussion with the guide from the NGOs volunteer Urine Diversion Desiccation (UDD) toilet decided to be used (Figure 4b). The latrine constructed using locally available materials. Latrines contained of three holes, a straight hole for faeces, and large pan area, and hole for wash-water.
Additional of ash to increase pH of faeces collection are required in UDD toilet.
Faeces were collected in 20L bucket while urine collection using storage container (jerry can), and wash-water directy discharge into water area[1]. Similar toilet design also been achieved by Lien Aid NGOs [10] in general communities for Tonle Sap lake.
Development of UDD toilet were equipped with the existence of waste management places as the place to put full bucket to be further stabilized. In Phat Sanday communities this waste management center was developed in one large flat floating construction and stabilization occured in the bucket (Figure 4c). Urine management was developed by let the urine stabilized naturally in storage and use it for watering or direct discharge to surrounding water surface area.
Navarro [8] mention about the UDD toilet type or other kinds toilet that includes storage system and using nightsoil collection practise to other place for stabilization process is quite ideal to be applied in coastal and waterfront communities. But the main limitation in applying this system is depend on the acceptance of the communities about wastehandling as main requirement of operation and maintenance. While in Mulleger et al [7] from eighty UDD toilet applied in Ethiopia, only view of the facilities consider as success application, since in many case people reject to manage the system. To operate UDD toilet adequately, commitment of the communities is one of the main requrement since this wastewater system required exact procedure to operate the toilet and need to be maintain frequently by the communities itself. While the communities are not ready to manage the system, the potency for failure will be really high.
Work in Phat Sanday communities were continued to apply to other wastewater treatment system than has been considered also by the communities. First development is floating garden[1]. It was built with the consideration that the
community lacks access to land for most of the year, which reduces opportunities for growing vegetables and supplementing diet of fish and rice. Floating garden (Figure 4d) was developed using the stabilized faeces from wastewater management station. The other wastewater treatment system developed is floating biodigester (Figure 4e, Figure 4f) which is considered become the side source of energy for rural communities. This two wastewater treatment system development are still in prototype and testing stage[6].
Figure 4 a) Focus Group Discussion b) UDD toilet, c) Floating garden, d) e) Development of Floating Biodigester (Brown, 2010; Hughes, 2011)
3 Evaluation of The Existing Wastewater Treatment Solution For Floating Toilet
Several solution that has been applied in order to provide the treatment requirement of the wastewater in floating toilet. First approach by applying common on site and decentralized wastewater treatment system use in land area consider not effective from economical view and has high potency of failure while not consider about the requirement of different foundation stucture as adaptation to soil and water pressure condition in specific area where the floating toilet are generally applied. The change of surrounding water table is other consideration that required to make sure the system work well. Second approach by modifying wastewater treatment system by considering specific area condition and also low-cost from economical view is more promising as solution for floating toilet wastewater problem, even some development and innovation are still required to get higher durability and efficiency of treatment system. Third approach using community based development is an ideal way to provide wastewater treatment system especially in low-income settlement, but the system that appropriate in one place
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d e f
(in this case UDD Toilet in Phat Sanday community) can be adapt directly to other place regarding the acceptance of community to handle operation and maintenance of system. To make sure the community are ready, accept, and satisfy with the system provided is the challenge of this third approach that will guaratee the success of applied wastewater treatment system.
4 Conclusion
From the review of three approach in providing wastewater treatment system as solution for the wastewater treatment requirement in floating toilet, direct use common wastewater treatment system in land area are economically unefficient, also have higher potency of failure. The modification at least in foundation structure is required. System that innovate based on low-cost and specific area condition is promising as solution but still required further development and innovation to get better system. Wastewater system selected by community based development strategy in one place, can not be adapted directly to other place. In the practise of community based development strategy to get the acceptance, satisfaction and commitment of the community are the factors that lead for the successfulness of system applied.
5 References
[1] Brown, M., 2010, “Sanitation on Floating Communities in Cambodia”.
Report for the Ministry of Rural Development - Live&Learn Environmental Education Cambodia Engineers Without Borders Australia
[2] Chakraborty, I., Jennings, W., Khon, P., Hand, T. 2012. “Floating Treatment Pods for Lake Communities”. Presentation for International Faecal Sludge Management Conference, South Africa
[3] Dinas Perikanan, Kelautan, dan Pertanian Kota Bontang, 2009. “Pembuatan Sanmasir dan MCK di Kampung Tihik-Tihik”, Laporan Kegiatan Peningkatan Sarana & Prasarana Permukiman Masyarakat Nelayan dan Pesisir, Bontang
[4] Djonoputro, E.R., Blackett, I., Rosenboom, J.-. & Weitz, A. 2010,
"Understanding sanitation options in challenging environments", Waterlines, vol. 29, no. 3, pp. 186-203.
[5] Djonoputro, E. R. Blackett, I. Weitz, A., Lambertus, A., Siregar, R., Arianto, I., Supangkat, J. 2011. “Opsi Sanitasi yang Terjangkau Untuk Daerah Spesifik”, Water and Sanitation Program- East Asia & the Pacific (WSP- EAP)
[6] Hughes, R, 2011, “CAMBODIA Floating Community Ecological Sanitation Project on the Tonle Sap Lake”. Project of Phat Sanday floating communities on the Tonle Sap Lake, Cambodia
[7] Mulleger, E., Olto, E., Bulbo, M. B., Wolde, A., 2013, “Operation and maintenance strategies for a sustainable dry sanitation system in Arba Minch (Ethiopia)”. 3rd IWA Development Congress Paper, Kenya
[8] Navarro. R. G. 1994. “Improving Sanitation in Coastal Communities with Special Reference to Puerto Princesa, Palawan Province, Philippines”, PhD Thesis McGill University, Montreal
[9] Nurmandi, A. 2012. “Toward Community-based Wastewater Management Experience from Urban River Side in Yogyakarta City Indonesia”. Working Paper. Muhammadiyah Yogyakarta University
[10] Sanyal, S. 2009. “CAMBODIA Case Study 1: Floating Toilets for the Floating Villages in Tonle Sap Lake”. Lien Aid Report- Project of Phat Sanday floating communities on the Tonle Sap Lake, Cambodia
[11] Saraswati, S.P., Nizam, Darmanto. 2009. “Design and Reviewing the Work of a Rural Sanitation – Tripicon System : An Application in Coastal Area”.
International Conference on Sustainable Development for Water and Wastewater Treatment, MUWAREC YK09-Muslim Water Researches Cooperation, Yogyakarta
[12] Sumidjan, I. Y. 2012. “Efisiensi Sistem Biosanter dalam Pengendalian Pencemaran Kawasan Permukiman di Sekitar Bantaran Sungai (Draft)”.
Pusat Penelitian dan Pengembangan Permukiman
[13] Wijaya, A. W., Dewi, N. P. 2010. “Tripikon-S as A Appropriate Technology for Sustainable Sanitation Along Riverbank Area at Tropical Developing Country”. International Conference on Sustainable Future for Human Security, Kyoto, Jepang
6 Acknowledgements
Bill & Mellinda Gates Foundation in “Stimulating Local Innovation on Sanitation for Urban Poor in Sub-Saharan Africa and South East Asia”
research project.
