REVIEW ON WATER RESOURCES MANAGEMENT AND KEY THREATS IN RWANDA, EAST AFRICA

Water is important for human health, industry, agriculture and ensuring the integrity and sustainability of the ecosystem. The water resources are the top affected by climate variability and population growth. The current population of Rwanda is about 12 million heading to about 25 million in 2050 under the changing climate, where since 1970 temperature rose by 1.4°C and is predicted that in 2050 to be about 2.5°C with severe effects on water resources in Rwanda. Thereby, this study reviewed the status and causes of water quality problems and suggested appropriate options to undertake for sustainable water resources access, employ and management in Rwanda. It was noticed that among others, the key threats to water quality in Rwanda, include not limited to climate change causing rainfall patterns which generated flooding, landslides and periodic droughts, which loaded pollutants into water. In addition, water quality is jeopardized by the rapid population growth, agrochemicals, industrialization, urbanization, soil steepness and land mismanagement. Accordingly, the reviewed water quality indicate that the water quality pollution likelihood is increasing over time. These facts reveal that the water quality soon or late will be highly polluted and calls for further adaptation and management measures.

PERFORMANCE AND SHORT TERM DURABILITY OF PALM KERNEL SHELL AS A SUBSTRATE MATERIAL IN A PILOT HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLAND TREATING SLAUGHTERHOUSE WASTEWATER

Wastewater treatment using constructed wetlands is one of the effective and low-cost technologies to improve the quality of slaughterhouse effluent. This study was carried out to investigate the suitability of palm kernel shell as a substrate material for constructed wetlands treating slaughterhouse wastewater. Rhizomes of Thalia Geniculata and Typha Latifolia were grown in four pilot horizontal subsurface flow constructed wetland beds filled with palm kernel shell and grave, and their growth and treatment performance evaluated. The results of the study showed that Thalia Geniculata survives and proliferates in palm kernel shell bed. The mean removal rates of 72.81% (BOD5), 89.87% (TSS), 39.42% (NH4-N), 60.79% (NO3-N) and 42.52% (PO43-) for the palm kernel shell were comparable to the values obtained for the gravel bed. The study proved that palm kernel shell, as a substrate material in constructed wetlands had the potentials to sustain the growth of some macrophytes, as well as the capacity to remove contaminants from wastewater.

WATER GOVERNANCE IN RAPIDLY URBANISING SMALL TOWN: A CASE OF DHULIKHEL IN NEPAL

Small towns in the mid-hills of Nepal rely on springs, streams and rivers in surrounding catchments for drinking water. The rapidly growing population in these towns has put increasing stresses on limited water resources. The inverse relationship between supply and demand of water has created challenges to the water security in these towns. In the absence of elected local government, decision making processes, including the management and governance of water at local level were directly affected. There were some unanswered questions – who are the leaders? who sets agendas? How do they formulate and implement strategies and make decisions? This paper aims to analyse the context of water governance in rapidly urbanising small town in Nepal, focusing on actors and institutions. Primary data were collected through semi-structured interviews, focused group discussions and key informant surveys from Dhulikhel municipality and its upstream communities. This paper argues that the local level water governance practices in rapidly urbanising small towns in Nepal are still evolving. During the political transition and vacuumed local jurisdictions, the real decisions to manage and govern water were made in an informal way. The formal course of making decisions by authorised actors and institutions has been curtailed significantly.

POTENTIAL OF AQUATIC MACROPHYTES EICHHORNIA CRASSIPES, PISTIA STRATIOTES AND SALVINIA MOLESTA IN PHYTOREMEDIATION OF TEXTILE WASTEWATER

Phytoremediation is an emerging low cost green technology, which uses plants for treating contaminant in the environment. Phytoremediation potential of locally available aquatic plants Eichhornia crassipes (water hyacinth), Pistia stratiotes (water lettuce) and Salvinia molesta (water fern) in the treatment process of textile wastewater was investi-gated. The reduction efficiencies of chemical oxygen demand (COD), total solids (TS), total suspended solids (TSS), total dissolved solids (TDS), nitrates, phosphates, heavy metals (Cd, Ni and Zn) and total and fecal coliform from the waste-water by each plant species were estimated. Bioconcentration factors (BCF) and translocation factors (TF) of three plant species for Cd, Ni and Zn were also estimated in order to identify their heavy metal absorption and translocation capacity. The results of the study indicated that greater reduction of COD, nitrates, phosphates, total coliform and Zn from the ini-tial wastewater by the three plant species. The results of the study also suggested that the selected aquatic plants are hy-peraccumulators of Cd, Ni and Zn metals. The findings of this study suggest that E. crassipes, P. stratiotes and S. molesta are potential aquatic plants for treating textile waste water.