pH dependence of sorption of Cd2+, Zn2+, Cu2+ and Cr3+ on crude water and sodium chloride extracts of Moringa stenopetala and Moringa oleifera,/i>

The ability of crude water and sodium chloride extracts of partially defatted powder of Moringa stenopetala (MS) and Moringa oleifera (MO) to remove heavy metals (Cd2+, Zn2+, Cu2+ and Cr3+) fromsingle ion solution was investigated. At initial metal concentration of about 4 ppm, the extracts showed complete sorption for Cd2+, Zn2+ and Cr3+ ions at pH above 7.8, 4.0 and 4.0, respectively, at a dose of 1.0 ml of sorbent in 9.50 ml of metal solution. Cu2+ sorption increases slightly with pH to about 60% for MS at pH 6 and then becomes constant up to pH 8 when sorption rises to completion. Preliminarycharacterization of the actual powder by proton nuclear magnetic resonance showed clear presence of amide (-CO-N-H), benzenoid (Ar-H), saturated alkyl and unsaturated fragments in both MS and MO. The mass spectrum showed the presence of amino (R-NH2) fragments. The remarkable heavy metal sorption ability of M. stenopetala and M. oleifera could thus be attributable to, among other mechanisms,coordination or complex formation between the metal cations and pH dependent oxygen and nitrogen anionic sites of the Moringa proteins

Use of indigenous knowledge and traditional practices in fisheries management: a case of Chisi Island, Lake Chilwa, Zomba

This paper presents results of a study, which examined local ecological knowledge and traditional management practices in lake resources management on Chisi Island. A combination of household questionnaires, semi structured interviews with key informants and focus group discussions were used to collect the required data for the study. The paper also includes review of other scientific studies done in the area to validate the survey results. The study found that Chisi inhabitants have developed and maintained some local ecological knowledge and practices that can have significant implications in scientific studies and on the management of lake resources on the Island. The practices included restricted cutting of Typha, fishing and access in sacred sites and conservation of mabawe. These traditional practices encouraged regeneration and sustainable utilisation of fish. The knowledge systems have been conserved and passed on from generation to generation through religious beliefs, taboos and myths. Some indigenous knowledge systems have been eroded over the past years due to changes in social structures, immigration and advent of new religions, adoption of new resource harvesting techniques and changes in life styles. Although these knowledge systems were not specifically meant for conservation of natural resources, the study argues that to achieve sustainable designs or implementation of natural resource management projects, there is need to integrate relevant existing indigenous knowledge systems that promote conservation of resources.Keywords: sustainable utilisation and conservation

Empowering communities to manage natural resources: where does the power lie?: the case of Malawi

Effective community-based natural resource management (CBNRM) has been practiced for decades in Malawi where traditional leaders command much power over their subjects. Political and economic changes over the years have weakened the powers of the local leaders, and made it difficult for them to mobilise their people towards CBNRM. A multi sectoral approach by a number of players, aimed at capacity building combined with strong traditional leadership and appropriate legal framework would provide the necessary conditions to restore community confidence and commitment for successful CBNRM. This paper describes such a process

Modelling Sustainable Harvesting Lebels of Timber in the Zomba Plantation: A Logistic Modelling Approach

No Abstract

Removal of Cd2+, Cr3+, Cu2+, Hg2+, Pb2+ and Zn2+ cations and AsO43- anions from aqueous solutions by mixed clay from Tundulu in Malawi and characterisation of the clay

Water and wastewater studies in Malawi have revealed very high levels of heavy metals in most streams and other water bodies particularly within urban areas. The metals are produced and released during industrial and agricultural activities, and also in vehicular emissions. These metals may pose serious threats to both human health and the environment. This study investigated the potential of mixed clay, obtained from the Tundulu area, in removing, Cd2+, Cr3+, Cu2+, Hg2+, Pb2+ and Zn2+ cations and AsO43- anions from aqueous solutions using batch equilibrium technique. Qualitative mineralogical characterisation of the clay revealed that the clay contains illite, distorted kaolinite, mixed layer minerals and non-clay mineral carbonate fluoroapatite. pHpzc for the raw clay, as determined by potentiometric titrations, was 9.66 while pHpzc of pretreated clay was 9.63. Pretreatment of the clay involved removal of carbonates, iron oxides and organic matter. Initial total metal concentrations ranged from 3 to 5 mg/ℓ. pH metal sorption dependence of the clay revealed Cr3+ removal from pH of 3 to complete removal at pH 5 with over 90% of the removal attributable to adsorption on the clay while the remaining 10% attributable to both adsorption and Cr(OH)3 precipitation. Zn2+ complete removal occurred at pH above 7 with 92% attributable to adsorption while the rest could be from both adsorption and hydroxide precipitation. Cu2+ was removed from pH 4 and completely above pH 6.8 with 50% due to adsorption. Cd2+ removal was between pH of 6 and 9 with 85% due to adsorption to the clay. Lead was completely removed at pH greater than 7.67. Removal of Hg2+ at total Hg2+ concentration of 0.023 mM was pH independent fluctuating between 30 and 60%. No effective removal of AsO43- anion was observed. Water SA Vol.32 (4) 2006: pp.519-52

Factors influencing implementation of bylaws on sustainable crop intensification: Evidence from potatoes in southwestern Uganda

The study examined the factors for the successful implementation of bylaws on sustainable crop intensification. The study used the new institutionalism theory to examine the implementation of bylaws in the potato cropping system in southwestern Uganda. A mixed model featuring both qualitative and quantitative approaches was used in the study. This involved analysis of primary data. The primary sources were key informants, focus group discussions, and face to face interviews with individual farmers, as well as secondary data sources. Factors influencing the effective implementation of bylaws on sustainable crop intensification at community level included awareness of existing bylaws, availability of extension agents to sensitize and train farmers on bylaws, power relations and conflicts among farmers, and availability of financial resources for procurement of agro-inputs. The factors influencing implementation of bylaws on sustainable crop intensification at the individual level included farmers’ knowledge on bylaws (P = 0.03), farmers’ participation in activities organised by government agencies (P = 0.01), the farmers’ village/location (P = 0.03), farmers’ gender (P = 0.001), farmers’ other occupations (P = 0.01), and income earnings (P = 0.02), support of local councils and technical persons to implement bylaws (P = 0.01), and knowledge on soil and water conservation laws (P = 0.03). Thus, there is need to protect land rights (regardless of gender), create awareness on best practices and bylaws among farmers, and mobilize resources to strengthen formal and informal farmer groups to enhance sustainable crop intensification and economic development of the potato sector

Music advocacy, the media and the Malawi political public sphere, 1958–2007

Journalists and writers in Malawi were crucial in the resistance to Dr Banda's hegemony between 1964 and 1993. The contested terrain was orality. This paper concentrates on the role of musicians and asserts that musicians in Malawi were, and arguably are, much braver and more persistent political critics and social change advocates than their counterparts in print journalism. While journalists censored themselves, and were censored, oral practitioners' lyrics and texts were usually much more explicit. Musicians exploited aspects of traditional culture to point out the political-economic suffering of the peasantry. While journalists' critiques and analyses have, since 1995, become more muted, musicians have continued to provide more independent, forceful voices on behalf of the poor in a country where literacy levels remain low and English is the official legislative, political and economic voice. This paper argues that an assessment of Malawi's public sphere excluding oral critiques misses significant and critical inputs important for social and developmental change