An assessment of effluent treatment to reduce heavy metal levels in effluent from a battery manufacturing concern

The study area is one of the point water pollution sources for chemical waste because this is a battery manufacturing concern. The city of Gweru is currently not monitoring the heavy metal levels in industrial waste, except for biological oxygen demand and pH. Heavy metals are bio-accumulative and hence are a health threat to humans, and to microorganisms and aquatic life in general. The battery manufacturing concern uses both borehole water and tap water in its processes. In this study, borehole. Water was also analysed in order to assess whether pollution at the surface was percolating downwards. Tap water was used as a control because the dam from which municipal water is drawn lies in an area far removed from pollution sources

Selective froth flotation concentration of antimonite ore from a mixture of antimony, lead and arsenic ores

Mineral ore beneficiation and value addition has become a key factor for economic growth in Africa. Froth flotation process is used to concentrate relatively low grade ores. In Zimbabwe antimonite is mined together with lead and arsenic which are regarded as contaminants and hence the need to selectively remove them. We report on the selective concentration of antimonite at the expense of lead and arsenic by use of a depressant. Starting with an containing antimony (5.89%), lead (0.34%) and arsenic (0.25%) a concentrate containing antimony 30.68%, lead 1.52% and arsenic 0.85% was obtained without an depressant in a Devnver flotation cell. The addition of a depressant resulted in a concentrate with antimony 24.89%, lead 0.90% and arsenic 5.89%. The Flame Atomic Absorption Spectroscopy (FAAS) and X-Ray Florescence (XRF) analytical techniques were used to measure the changes in concentrations of antimony, lead and arsenic during this research

Recombinantly produced phenylalanine pminomutase (PAM) shows increased activity in E. Coli grown under light illumination

The effect of light on the activity of phenylalanine aminomutase was determined by measuring the expression and activity of the recombinantly expressed enzyme in E. coli. The variation of phenylalanine aminomutase activity over time in response to light and the effect on cell viability was also determined. The type of radiation responsible for phenylalanine aminomutase activation was determined by irradiating the cell cultures with blue light. Phenylalanine ammonia lyase has been shown to increase in activity when exposed to light in whole organisms. No similar studies have been carried out with heterologously expressed recombinant protein. Phenylalanine ammonia lyase is mechanistically similar to phenylalanine aminomutase and would be expected to behave similarly. The aim of this study was to demonstrate whether light can increase the activity and expression of phenylalanine aminomutase. The results show that phenylalanine aminomutase from cells exposed to white light had a more than fourfold increase in activity compared to cells kept in the dark. The time course assay of the activity show that the change in activity is cyclic and over a long period of incubation there seem to be no major difference between light and dark. Total white increases the growth rate of E. coll. compared to cultures kept in the dark or where the infrared light had been cut off. This study will provide an easy and inexpensive way of producing more efficient enzymes per gram of cell pellet without increasing the culture volumes

The optimization of lead electrodeposition from leachant of lead laden cupels

Disposal of lead laden cupels is proving problematic to mining and metallurgical companies due to environmental and health issues. In this study the optimization of operation parameters for the electrode position of lead metal from acetic acid leachant was carried out. The effects of voltage, temperature, concentration, size of electrode and the effect of the space between the electrodes were investigated. Acetic acid (10%) was used as a leachant in the optimization process. The optimum voltage was found to be 6 V, with the best operating temperature of 20°C. The amount of lead deposited increased with increase in concentration of the lead in solution up to an optimum concentration of 2271.1 ppm. However the extraction efficiencies tended to decrease with increase in concentration. The optimum inter-electrode distance was observed to be 4 cm with 0.5 cm radius electrodes that gave the largest extraction efficiency (70.9%). Acetic acid (10%) was preferred as a leachant compared to EDTA (0.1 M) because it gave higher leaching and electrode position efficiencies (73.3% vs 68.1) and (95% vs 90.8) respectively. EDTA (0.1 M) was however found to be less corrosive to the carbon electrodes as observed with acetic acid. Other advantages of acetic acid are that it is cheaper, can be obtained from renewable sources and is easy to use because there is no need for constant pH monitoring and adjustments

Evaluation of anti-microbial, anti-inflammatory and anti-oxidative properties artemisia afra, gunnera perpensa and eucomis autumnalis

Infectious disease is an illness resulting from the invasion of the host species by a pathogenic microbial agent, and outcome of the disease depends on the degree of success of the invading pathogen and immune system of the host [1]. They are considered a major threat to human health, because of the unavailability of vaccines or limited chemotherapy even in the developed parts of the world, although developing countries are carrying the major part of the burden Sub Saharan African countries, including South Africa are mostly affected by respiratory infections, diarrhea, HIV/AIDS, tuberculosis and malaria [2,3] The continued resurfacing of antibiotic- resistant infections drives research to produce better drugs to combat the more resistant pathogens [4]. Auto immune diseases such as lupus are becoming a major concern in both the developed and third world countries [5]. Investigating plants that could be included in affected people’s diet would assist in managing such diseases

Free radical scavenging and antibacterial activity of crude extracts from selected plants of medicinal value used in Zululand

Ledebouria revoluta, Berkheya setifera and Carissa bispinosa are some of the medicinal plants used in South African traditional medicine. An investigation to evaluate antimicrobial, anti-inflammatory and free radical scavenging activities of the root crude extracts and fractions from the three plants was carried out. Reduction by 2, 2-azinobis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS.+) and 2, 2-di (4-tertoctylphenyl)- 1-picrylhydrazyl (DPPH.) radicals were used to assess antioxidant capacities by change in absorbance in a UV-VIS spectrophotometer. Anti-inflammatory activity of the plant extracts against 15- soybean derived lipoxygenase (15-LOX) enzyme was evaluated as increase in absorbance at 234 nm after addition of soya bean derived 15-LOX, using linoleic acid (134 μM) as substrate. Anti-microbial activities were determined by assessing the plant samples’ Minimum Inhibitory Concentrations (MICs) by a micro dilution method. Carissa bispinosa and Berkheya setifera have shown good to moderate antimicrobial activity. Ledebouria revoluta displayed good activities (20 μg/mL) for both acetone and methanol fractions against E. coli and good-moderate activity (160-320 μg/mL) against the rest of the bacterial strains used. Anti-fungal activity for Ledebouria revoluta methanol fraction (20 μg/mL) is high against Candida albicans. Percentage inhibition of 15-soybean lipoxygenase enzyme by the crude extracts at concentration of 25 μg/mL was for Berkheya setifera, 80%, Carissa bispinosa, 65% and Ledebouria revoluta, 40%

Pharmacological properties of Pomaria sandersonii, Pentanisia prunelloides and Alepidea amatymbica extracts using in vitro assays

The antimicrobial, anti-inflammatory and free radical scavenging activities of root crude acetone extracts and fractions of different polarities from Pomaria sandersonii (Fabaceae), Pentanisia prunelloides (Rubiaceae) and Alepidea amatymbica (Apiaceae) were determined using in vitro assays. The antioxidant properties of extracts and fractions were assessed by reduction of 2, 2´-azinobis (3-ethylbenzothiazoline)-6-sulfonic acid and 2, 2-di (4-tert-octylphenyl)-1-picrylhydrazyl radicals which was measured by changes in absorbance using an ultraviolet-visible spectrophotometer. Anti-inflammatory activity of the plant extracts against 15 soybean lipoxygenase enzyme was measured by monitoring the change in absorbance at 234 nm after incubation of 15-LOX with linoleic acid (134 µM) as substrate. The anti-microbial activities were determined by measuring the minimum inhibitory concentrations using a serial dilution microplate method with terazolium violet as a growth indicator. The minimal inhibitory concentration (MIC) value of the dichloromethane (DCM) and ethyl acetate fractions (1 mg/ml) of P. sandersonii was 80 µg/ml in each case against Staphylococcus aureus and Escherichia coli. The inhibition activity of 15 soybean lipoxygenase enzyme by the crude extracts at concentration of 25 μg/ml was 97% for P. sandersonii, 79% for P. prunelloides and 55% for A. amatymbica. This indicates that extracts for these plants can be used as dietary supplements in the management of inflammation related conditions