Short communication: Industrial effluent treatments using heavy-metal removing bacterial bioflocculants

Bioflocculants produced by Herbaspirillium sp. CH7, Paenibacillus sp. CH11, Bacillus sp. CH15 and a Halomonas sp. were preliminarily evaluated as flocculating agents in the treatment of industrial wastewater effluents. Industrial (1 local chemical-industry and 2 textile-industry: Biavin 109-medium blue dye and Whale dye) effluent (9 m.) containing various heavy metals was vortexed with 1 m. of bioflocculant in a 25 m. test tube. One m. of water (Millipore Elix purification system, 17 megaƒ¶) was substituted for the bioflocculant in the control. After 5 min, the heavy metal concentrations, the microbial population and the turbidity of the top layer of the industrial effluent were determined using ICP-OES, spread-plate technique and a turbidity meter respectively. The flocculating activity was calculated based on absorbance at a wavelength of 550 nm.Bioflocculants produced in this study were capable of removing several heavy metals from industrial effluents simultaneously and effectively. This was significant (p < 0.05) when applied to Biavin medium blue dye, with 95% of Cr2+ and 94% of Ni2+ removed by the presence of bioflocculants. Bioflocculants also removed almost all of the bacteria and reduced 50-80%of the turbidity of the chemical effluent sample, simultaneously. Bacterial  bioflocculants may provide an alternative means of treating industrial wastewater resulting in environmental and economical benefits. However, our findings suggest that the treatment of industrial effluents using bioflocculants might be effluent-dependent. In order to explore the potential of bioflocculants in the treatment of industrial effluents, a preliminary study to determine the optimal conditions is crucial

Participant verification: Prevention of co‑enrolment in clinical trials in South Africa

Background. As KwaZulu-Natal Province is the epicentre of the HIV epidemic both in South Africa (SA) and globally, it is an ideal location to conduct HIV prevention and therapeutic trials. Numerous prevention trials are currently being conducted here; the potential for participant co-enrolment may compromise the validity of these studies and is  therefore of great concern.Aim. To report the development and feasibility of a digital,  fingerprint-based participant identification method to prevent co-enrolment at multiple clinical trial sites.Methods. The Medical Research Council (MRC) HIV Prevention Research Unit (HPRU) developed the Biometric Co-enrolment Prevention System (BCEPS), which uses fingerprint-based biometric technology to identify participants. A trial website was used to determine the robustness and usability of the system. After successful testing, the BCEPS was piloted in July 2010 across 7 HPRU clinical research sites. The BCEPS was pre-loaded with study names and clinical trial sites, with new participant information  loaded at first visit to a trial site.Results. We successfully implemented the BCEPS at the 7 HPRU sites. Using the BCEPS, we performed real-time ‘flagging’ of women who were already enrolled in another study as they entered a trial at an HPRU site and, where necessary, excluded them from participation on site.Conclusion. This system has promise in reducing co-enrolment in clinical trials and represents a valuable tool for future implementation by all groups conducting trials. The MRC is currently co-ordinating this effort with clinical trial sites nationally

Acceptability of a tablet-based application to support early HIV testing among men in rural KwaZulu-Natal, South Africa: a mixed method study

Uptake of HIV testing remains low among men in South Africa. As part of a trial, we assessed the acceptability of a theoretically derived and adapted tablet-based-application (EPIC-HIV1) in rural South Africa. We conducted 20 in-depth interviews with men aged ≥18 years and offered a tablet-based survey to all men aged ≥15 years who received EPIC-HIV1 (Sep-Dec 2018). We conducted a descriptive analysis of the survey and used Self-Determination Theory (SDT) to guide our thematic analysis. A total of 232/307 (75%) completed the survey, 55% of whom were aged 15–24 years. 96%[ CI: 92.8–98.2%; n = 223] found EPIC-HIV1 acceptable and 77% [95% CI: 71.8–82.6%; n = 179] found it user-friendly. 222 [96%] reported that EPIC-HIV1 motivated them to test; 83% (192/232) tested for HIV, of which 33% (64/192) were first time testers. Those who did not consent (n = 40) were more likely to have had an HIV-positive test result. Participants reported that the app boosted their confidence to test. However, they were unsure that the app would help them overcome barriers to test in local clinics. Given reach and usability, an adapted SDT male-tailored app was found to be acceptable and could encourage positive health-seeking behavioural change among men

Production and characterization of heavy-metal removing bacterial bioflocculants

Bioflocculants produced by Herbaspirillium sp. CH7, Paenibacillus sp. CH11, Bacillus sp. CH15 and Halomonas sp. are potential flocculanting agents in the treatment of industrial wastewater effluents. Up to 250% increases in bioflocculant production were achieved by manipulation of the media composition. Increases in peptone and glycerol contents, up to 2 and 3%, respectively enhanced the bioflocculants production. With the exception of Herbaspirillium sp. CH7, all isolates preferred higher yeast extract content for bioflocculant production. Physicochemical analysis showed most of bioflocculants produced appeared to contain high protein content, then carbohydrate. All bioflocculants contained similar hexosamine and uronic acid contents in the range of 0.0115 to 0.0150 mM and 0.0054 to 0.0068 mM, respectively. Purified bioflocculants produced under optimized conditions possessed higher flocculating activities (up to 14-fold increases) in comparison to those under the control conditions with the exception of that from Herbaspirillium sp. CH7. A decrease in bioflocculant concentration from 10000 ppm to 1 ppm resulted in a significant increase in the removal percentages of Pb+2, Zn+2 and Hg+2 with the optimal dosage of 1 to10 ppm. Bioflocculants in this study removed Cd+2 effectively only at 10000 ppm, but not at the lower concentrations. This Cd+2-removing capacity of bioflocculant could be further stimulated by an increase in temperature. The pH requirement for maximum flocculating activity seems to be varied for different strains of microorganisms.Key words: Bioflocculant, heavy metal removal, physiochemical properties, pH, temperature