ABSTRACT
An investigation of the impact of adding plant-based organic compost to clay soil from a Moringa oleifera farm focusing on the metal content, bioavailability, and accumulation of nutrients in M. oleifera leaves was conducted. Clay soil was mixed with 15%, 30%, 45% and 60% plant-based organic compost (by volume) in 20 cm wide, 2 L pots. Moringa oleifera plants were planted in four replicates of each treatment and control group. Results revealed that the addition of compost significantly (P < 0.05) altered the concentration of metals in the soil. Correspondingly, accumulation of nutrients in M. oleifera leaves increased with the addition of compost to the soil, except for cobalt and chromium. Trace elements had minimal bioavailability in the amended soils, and their presence in the leaves was lower than the permissible trace metal levels in food. The 30% combination had the highest concentration of calcium (45 042.5 mg/kg), magnesium (17430.0 mg/kg) and phosphorous (8802. 5 mg/kg) in M. oleifera leaves. The study concluded the addition of compost improved bioavailability of nutrients in the soil and their concentration in M. oleifera leaves. The target hazard quotients for heavy metals was less than one, indicating that M. oleifera leaf biomass harvested from soil amended with plant-based compost is safe for human consumption. These results serve as guidelines for recommended organic certification requiremets where plant-based compost is often used in the fast-growing herbal industry.
Subject(s)
Clay , Composting , Metals, Heavy , Moringa oleifera , Plant Leaves , Soil Pollutants , Soil , Moringa oleifera/chemistry , Soil Pollutants/analysis , Plant Leaves/chemistry , Humans , Clay/chemistry , Risk Assessment , Soil/chemistry , Metals, Heavy/analysis , BiomassABSTRACT
Nuclear energy is becoming a preferred energy source amidst rising concerns over the impacts of fossil fuel based energy on global warming and climate change. However, the radioactive waste generated during nuclear power generation contains harmful long-lived fission products such as strontium (Sr). In this study, cationic strontium uptake from solution by microbial cultures obtained from mine wastewater is evaluated. A high strontium removal capacity (q(max)) with maximum loading of 444 mg/g biomass was achieved by a mixed sulphate reducing bacteria (SRB) culture. Sr removal in SRB was facilitated by cell surface based electrostatic interactions with the formation of weak ionic bonds, as 68% of the adsorbed Sr(2+) was easily desorbed from the biomass in an ion exchange reaction with MgCl2. To a lesser extent, precipitation reactions were also found to account for the removal of Sr from aqueous solution as about 3% of the sorbed Sr was precipitated due to the presence of chemical ligands while the remainder occurred as an immobile fraction. Further analysis of the Sr-loaded SRB biomass by scanning electron microscopy (SEM) coupled to energy dispersive X-ray (EDX) confirmed extracellular Sr(2+) precipitation as a result of chemical interaction. In summary, the obtained results demonstrate the prospects of using biological technologies for the remediation of industrial wastewaters contaminated by fission products.
Subject(s)
Strontium Radioisotopes/isolation & purification , Water Pollutants, Radioactive/isolation & purification , Biodegradation, Environmental , Biomass , Cations , Microscopy, Electron, Scanning , Strontium Radioisotopes/metabolism , Water Pollutants, Radioactive/metabolismABSTRACT
An aqueous decoction of the root bark of Uapaca nitida Müll-Arg. is currently used locally at the Benedictine Mission at Peramiho in Tanzania to treat malaria. We have now demonstrated that extracts of root bark and leaves of this tree are active against the multidrug-resistant K1 strain of Plasmodium falciparum in vitro. An ethanolic extract of root bark showed activity against P. berghei in mice but at a dose which also showed toxic effects. The use of this plant in treating malaria appears to be novel and further studies would be of value.
Subject(s)
Antimalarials/pharmacology , Malaria/drug therapy , Plasmodium berghei/drug effects , Plasmodium falciparum/drug effects , Animals , Antimalarials/isolation & purification , Mice , Plant Extracts/pharmacology , TanzaniaABSTRACT
Traditional healers have a special role to play in AIDS prevention in Arica. To involve them in AIDS education requires a sensitive understanding of the roles they play in their societies. Traditional healers are capable of providing information on attitudes; practices and beliefs in relation to sexuality since most of the healers treat STDs and other venereal diseases. Traditional healers can also help control the wild notion that their conterparts claim they can cure the disease which often causes confusion for the general public. Familiarity is another advantage of the traditional healing system. Traditional practitioners are men and women who are respected and accepted by their communities. Their methods fit in more comfortably with local beliefs than do unfamiliar foreign attitudes. In addition; there is always that personal trust between the healer and his or her clients. These factors put the healers in a special key role as resource people in HIV and AIDS in their local communities. They can also negotiate sex issues with their clients in a culturally accepted manner. The author of the proposal conducted a descriptive knowledge; attitudes and practices study (KAP) in the Matebeleland and Masvingo Province. A convenience sample of fifty traditional healers from both the rural and urban areas participated in the study. The results of the survey indicate that traditional healers have many misconceptions about AIDS and information on HIV and AIDS is scanty. Therefore; a program plan to train the healers in HIV infection and other STDs is needed. The project is anticipated to be carried out in Bulilima-mangwe District; Matabeleland South
