Nitrogen And Phosphorus Removal In Substrate-Free Pilot Constructed Wetlands With Horizontal Surface Flow In Uganda

Kyambadde, Joseph; Kansiime, Frank; Dalhammar, Gunnel

doi:10.1007/s11270-005-4643-6

Cited by 74 publications

(37 citation statements)

References 46 publications

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“…The Netherlands-funded ECOLIVE project (2009-2013) involved a transdisciplinary study of the Nyando wetland in Kenya, incorporating hydro-logical, ecological and socioeconomic sub-projects (van Dam et al 2011. In addition to studies of the natural wetland environment, there were also various studies on papyrus in constructed wetlands for water quality regulation (Chale 1985(Chale , 1987Okurut et al 1999;Okurut 2001;Kyambadde et al 2005;Abira et al 2005). A number of economic valuation studies of papyrus wetlands were done (e.g.…”

Section: Research On Papyrus Wetlandsmentioning

confidence: 99%

A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa

Dam

Kipkemboi

Mazvimavi

et al. 2014

Wetlands Ecol Manage

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Van Dam, A.A. et al. (2014). A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L. Papers from the session, combined with additional contributions, were collected in a special issue of Wetlands Ecology and Management. The current paper reviews ecological and hydrological characteristics of papyrus wetlands, summarizes their ecosystem services and sustainable use, provides an overview of papyrus research to date, and looks at policy development for papyrus wetlands. Based on this review, the paper provides a synthesis of research and policy priorities for papyrus wetlands and introduces the contributions in the special issue. Main conclusions are that (1) there is a need for better estimates of the area covered by papyrus wetlands. Limited evidence suggests that the loss of papyrus wetlands is rapid in some areas; (2) there is a need for a better understanding and modelling of the regulating services of papyrus wetlands to support trade-off analysis and improve economic valuation; (3) research on papyrus wetlands should include assessment of all ecosystem services (provisioning, regulating, habitat, cultural) so that trade-offs can be determined as the basis for sustainable management strategies ('wise use'); (4) more research on the governance, institutional and socio-economic aspects of papyrus wet-lands is needed to assist African governments in dealing with the challenges of conserving wetlands in the face of growing food security needs and climate change. The papers in the special issue address a number of these issues.

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Section: Research On Papyrus Wetlandsmentioning

confidence: 99%

A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa

Dam

Kipkemboi

Mazvimavi

et al. 2014

Wetlands Ecol Manage

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“…In this study, EC was reduced significantly in the three systems (p < 0.05) reaching similar values. According to some authors [41], a decrease in EC despite significant water losses is explained by uptake of micro and macroelements and ions by plants and their removal through adsorption to plant roots, litter and settled suspended particles. Moreover, the ground tezontle rock used as the media in the CWs has demonstrated a high capacity for total dissolved solid removal in previous studies [42].…”

Section: Electrical Conductivity (Ec)mentioning

confidence: 99%

Comparative Study of Three Two-Stage Hybrid Ecological Wastewater Treatment Systems for Producing High Nutrient, Reclaimed Water for Irrigation Reuse in Developing Countries

Zurita¹,

White²

2015

Water Treatment in Developed and Developing Nations

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In this study, three different two-stage hybrid ecological wastewater treatment systems (HEWTS) with combinations of horizontal flow (HF) constructed wetlands (CWs), vertical flow (VF) CWs and stabilization ponds (SP) were evaluated for the removal of Organic-N, NH 4 + , NO 3 − , Total N, Total P, Total Coliforms (TCol) and Escherichia Coli, BOD, COD and TSS. The overall goal of the study was novel in comparison to most other studies in that we sought to evaluate and compare the efficiency of the three HEWTSs for water quality improvements, while minimizing nutrient removal from the wastewater in order to generate high quality reclaimed water for reuse for irrigation of crops. The most effective systems were those systems containing a vertical flow component, either HF-VF or VF-HF. In these two HEWTS, NH 4 + was reduced by 85.5% and 85.0% respectively, while NO 3 − was increased to 91.4 ± 17.6 mg/L and to 82.5 ± 17.2 mg/L, respectively, an artifact of nitrification. At the same time, E. coli was reduced by 99.93% and 99.99%, respectively. While the goal of most wastewater treatment is focused on reducing nutrients, the results here demonstrate that two-stage HEWTSs containing VF components can be used to produce a high quality effluent while retaining inorganic nutrients, thereby conserving this valuable resource for reuse as irrigation water for agriculture in subtropical developing countries where water and fertilizer resources are scarce or expensive.

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“…Most wetlands in Uganda are, however, being degraded due to extensive encroachment for agricultural activities and infrastructure development. This has hampered their ability to retain nutrients, resulting in deterioration of adjacent water bodies such as Lake Victoria due to eutrophication Kansiime and Nalubega, 1999;Kelderman et al, 2007;Kyambadde et al, 2005;Mugisha et al, 2007). …”

Section: Catchment Descriptionmentioning

confidence: 99%

Phosphorus transport and retention in a channel draining an urban, tropical catchment with informal settlements

Nyenje

Meijer

Foppen

et al. 2014

Hydrol. Earth Syst. Sci.

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Abstract. Urban catchments in sub-Saharan Africa (SSA) are increasingly becoming a major source of phosphorus (P) to downstream ecosystems. This is primarily due to large inputs of untreated wastewater to urban drainage channels, especially in informal settlements (or slums). However, the processes governing the fate of P in these catchments are largely unknown. In this study, these processes are investigated. During high runoff events and a period of base flow, we collected hourly water samples (over 24 h) from a primary channel draining a 28 km 2 slum-dominated catchment in Kampala, Uganda, and from a tertiary channel draining one of the contributing slum areas (0.54 km 2 ). The samples were analysed for orthophosphate (PO 4 -P), particulate P (PP), total P (TP), suspended solids (SS) and hydrochemistry. We also collected channel bed and suspended sediments to determine their geo-available metals, sorption characteristics and the dominant phosphorus forms. Our results showed that the catchment exported high fluxes of P (0.3 kg km 2 d −1 for PO 4 -P and 0.95 for TP), which were several orders of magnitude higher than values normally reported in literature. A large proportion of P exported was particulate (56 % of TP) and we inferred that most of it was retained along the channel bed. The retained sediment P was predominantly inorganic (> 63 % of total sediment P) and consisted of mostly Ca and Fe-bound P, which were present in almost equal proportions. Ca-bound sediment P was attributed to the adsorption of P to calcite because surface water was near saturation with respect to calcite in all the events sampled. Fe-bound sediment P was attributed to the adsorption of P to iron oxides in suspended sediment during runoff events given that surface water was undersaturated with respect to iron phosphates. We also found that the bed sediments were P-saturated and showed a tendency to release P by mineralisation and desorption. During rain events, there was a flushing of PP which we attributed to the resuspension of P-rich bed sediment that accumulated in the channel during low flows. However, firstflush effects were not observed. Our findings provide useful insights into the processes governing the fate and transport of P in urban slum catchments in SSA.

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Nitrogen And Phosphorus Removal In Substrate-Free Pilot Constructed Wetlands With Horizontal Surface Flow In Uganda

Cited by 74 publications

References 46 publications

A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa

A synthesis of past, current and future research for protection and management of papyrus (Cyperus papyrus L.) wetlands in Africa

Comparative Study of Three Two-Stage Hybrid Ecological Wastewater Treatment Systems for Producing High Nutrient, Reclaimed Water for Irrigation Reuse in Developing Countries

Phosphorus transport and retention in a channel draining an urban, tropical catchment with informal settlements

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