Planning approaches for sanitation systems in peri-urban areas: a case study from Tanzania

The planning and improvement of sanitation systems represents a critical problem for low - income countries, in particular in rapid growing periurban areas. This paper illustrates the assessment of the Community - Led Urban Environmental Sanitation (CLUES) and the Sanitation Safety Planning (SSP) approaches, tested for the design of an improved sanitation system in periurban areas of Iringa Municipality, in Tanzania. The application in field of the two approaches permitted to evidence and analyse their strengths and weaknesses, and possibilities to increase their potentials with an integrated use . The experience, applied to a case study, aims to be an example of application for ractitioners dealing with sanitation planning in context showing similar characteristics

Anti-collision systems in tunneling to improve effectiveness and safety in a system-quality approach: A review of the state of the art

Tunnelling and underground construction operations are often characterized by critical safety issues mainly due to poor visibility and blind spots around large vehicles and equipment. This can lead to collisions between vehicles or between vehicles and pedestrians or structural elements, causing accidents and fatalities. To improve the OS&H conditions, it is important to investigate the possible introduction of innovative techniques and technologies to reduce the occurrences and consequences of shared spaces (spaces used by both vehicles and pedestrians). For this reason, research was conducted to investigate the possible use of different technologies of anti-collision systems in tunnelling operations. First, to achieve this goal, an extensive review of the literature was carried out in accordance with the PRISMA statement to select the current techniques and technologies used by general anti-collision systems in civil and mining construction sites. Then, the operating principles, the relative advantages and disadvantages, combinations, and costs were examined for each of these. Eight types of systems and many examples of applications of anti-collision systems in underground environments were identified as a result of the analysis of the literature. Generally, it was noted that the anti-collision techniques available have found limited application in the excavation sites of underground civil works up to the present day, though the improvement in terms of safety and efficiency would be considerable

Electrochemical Treatment of Arsenic in Drinking Water: Effect of Initial As3+ Concentration, pH, and Conductivity on the Kinetics of Oxidation

Many technologies for the treatment of arsenic-containing drinking water are available, but most of them are more effective on arsenic oxidized forms. Therefore, the pre-oxidation of As3+ is necessary. The electrochemical processes represent a very promising method due to the simultaneous oxidation of compounds using electrochemical conditions and the reactive radicals produced. In this work, As3+ oxidation was experimentally studied at a pilot scale using an electrochemical oxidation cell (voltage: 10 V; current: 1.7 A). The effect of the initial arsenite concentration, pH, and conductivity of drinking water on the oxidation of As3+ into As5+ was investigated. The results showed that the initial As3+ concentration strongly directly influences the oxidation process. Increasing the initial arsenite concentration from 500 to 5000 µg L−1, the pseudo-first order kinetic constant (k) strongly decreased from 0.521 to 0.038 min−1, and after 10 min, only 21.3% of As3+ was oxidized (vs. 99.9% in the case of As3+ equal to 500 µg L−1). Slightly alkaline conditions (pH = 8) favored the electrochemical oxidation into As5+, while the process was partially inhibited in the presence of a more alkaline or acidic pH. The increase in conductivity up to 2000 µS cm−1 enhanced the kinetic of the oxidation, despite remaining on the same order of magnitude as in the case of conductivity equal to 700 µS cm−1. After 10 min, 99.9 and 95% of As3+ was oxidized, respectively. It is the opinion of the authors that the influence of other operational factors, such as voltage and current density, and the impact of the high concentration of other pollutants should be deeply studied in order to optimize the process, especially in the case of an application at full scale. However, these results provide helpful indications to future research having highlighted the influence of initial As3+ concentration, pH, and conductivity on the electrochemical oxidation of arsenic

Three-Dimensional Bioprinted Controlled Release Scaffold Containing Mesenchymal Stem/Stromal Lyosecretome for Bone Regeneration: Sterile Manufacturing and In Vitro Biological Efficacy

Recently, 3D-printed scaffolds for the controlled release of mesenchymal stem cell (MSC) freeze-dried secretome (Lyosecretome) have been proposed to enhance scaffold osteoinduction and osteoconduction; coprinting of poly(ε-caprolactone) (PCL) with alginate hydrogels allows adequate mechanical strength to be combined with the modulable kinetics of the active principle release. This study represents the feasibility study for the sterile production of coprinted scaffolds and the proof of concept for their in vitro biological efficacy. Sterile scaffolds were obtained, and Lyosecretome enhanced their colonization by MSCs, sustaining differentiation towards the bone line in an osteogenic medium. Indeed, after 14 days, the amount of mineralized matrix detected by alizarin red was significantly higher for the Lyosecretome scaffolds. The amount of osteocalcin, a specific bone matrix protein, was significantly higher at all the times considered (14 and 28 days) for the Lyosecretome scaffolds. Confocal microscopy further confirmed such results, demonstrating improved osteogenesis with the Lyosecretome scaffolds after 14 and 28 days. Overall, these results prove the role of MSC secretome, coprinted in PCL/alginate scaffolds, in inducing bone regeneration; sterile scaffolds containing MSC secretome are now available for in vivo pre-clinical tests of bone regeneration

Extraction and purification of phosphorus from the ashes of incinerated biological sewage sludge

Phosphorus depletion represents a significant problem. Ash of incinerated biological sewage sludge (BSS) contains P, but the presence of heavy metals (e.g., Fe and Al) is the main issue. Based on chemical characterization by SEM-EDS, ED-XRF and ICP-OES techniques, the characteristics and P content of bottom ash (BA) and fly ash (FA) of incinerated BSS were very similar. On BA, P extraction carried out in counter-current with an S:L ratio of 1:10 and H2SO4 0.5 M led to better extraction yields than those of a similar test with H2SO4 1 M and an S:L ratio of 1:5 (93% vs. 86%). Comparing yields with H2SO4 0.5 M (S:L ratio of 1:10), the counter-current method gave better results than those of the crossflow method (93% vs. 83.9%), also improving the performance obtained with HCl in crossflow (93% vs. 89.3%). The results suggest that the purification of the acid extract from heavy metals with pH variation was impractical due to metal precipitation as phosphates. Extraction with H2SO4 and subsequent treatment with isoamyl alcohol represented the best option to extract and purify P, leading to 81% extraction yields of P with low amounts of metals

Comparison of different primer sets for use in automated ribosomal intergenic spacer analysis of complex bacterial communities

ITSF and ITSReub, constituting a new primer set designed for the amplification of the 16S-23S rRNA intergenic transcribed spacers, have been compared with primer sets consisting of 1406F and 23Sr (M. M. Fisher and E. W. Triplett, Appl. Environ. Microbiol. 65:4630-4636, 1999) and S-D-Bact-1522-b-S-20 and L-D-Bact-132-a-A-18 (L. Ranjard et al., Appl. Environ. Microbiol. 67:4479-4487, 2001), previously proposed for automated ribosomal intergenic spacer analysis (ARISA) of complex bacterial communities. An agricultural soil and a polluted soil, maize silage, goat milk, a small marble sample from the fac\ub8ade of the Certosa of Pavia (Pavia, Italy), and brine from a deep hypersaline anoxic basin in the Mediterranean Sea were analyzed with the three primer sets. The number of peaks in the ARISA profiles, the range of peak size (width of the profile), and the reproducibility of results were used as indices to evaluate the efficiency of the three primer sets. The overall data showed that ITSF and ITSReub generated the most informative (in term of peak number) and reproducible profiles and yielded a wider range of spacer sizes (134 to 1,387) than the other primer sets, which were limited in detecting long fragments. The minimum amount of DNA template and sensitivity in detection of minor DNA populations were evaluated with artificial mixtures of defined bacterial species. ITSF and ITSReub amplified all the bacteria at DNA template concentrations from 280 to 0.14 ng l 1, while the other primer sets failed to detect the spacers of one or more bacterial strains. Although the primer set consisting of ITSF and ITSReub and that of S-D-Bact-1522-b-S-20 and L-D-Bact-132-a-A-18 showed similar sensitivities for the DNA of Allorhizobium undicula mixed with the DNA of other species, the S-D-Bact-1522-b-S-20 and L-D-Bact-132-a-A-18 primer set failed to detect the DNA of Pseudomonas stutzeri

The challenge of sharing data in cooperation projects: cause for reflection.

The collection of data and  their management  remain a never-ending challenge within projects carried out in low-income countries.  Data collection requires high investments, and even if great efforts have been done in building tools for data sharing, these processes need to be improved at local level in developing countries. Data are valuable items  for developing strategies leading to more effective local development. The CeTAmb LAB, on the basis of its experience, proposes a reflection on the role of the academia, which is based on principles of capacity building and sharing knowledge, in promoting the importance of data collection, conservation and sharing

Molecular Tools for Monitoring the Ecological Sustainability of a Stone Bio-Consolidation Treatment at the Royal Chapel, Granada

Background: Biomineralization processes have recently been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). While this promising method has demonstrated its efficacy regarding strengthening of the stone, little is known about its ecological sustainability.Methodology/Principal Findings: Here, we report molecular monitoring of the stone-autochthonous microbiota before and at 5, 12 and 30 months after the bio-consolidation treatment (medium/long-term monitoring), employing the well-known molecular strategy of DGGE analyses. Before the bio-consolidation treatment, the bacterial diversity showed the exclusive dominance of Actinobacteria (100%), which decreased in the community (44.2%) after 5 months, and Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) appeared. After 12 months, Gamma-proteobacteria vanished from the community and Cyanobacteria (22.1%) appeared and remained dominant after thirty months, when the microbiota consisted of Actinobacteria (42.2%) and Cyanobacteria (57.8%) only. Fungal diversity showed that the Ascomycota phylum was dominant before treatment (100%), while, after five months, Basidiomycota (6.38%) appeared on the stone, and vanished again after twelve months. Thirty months after the treatment, the fungal population started to stabilize and Ascomycota dominated on the stone (83.33%) once again. Members of green algae (Chlorophyta, Viridiplantae) appeared on the stone at 5, 12 and 30 months after the treatment and accounted for 4.25%, 84.77% and 16.77%, respectively.Conclusions: The results clearly show that, although a temporary shift in the bacterial and fungal diversity was observed during the first five months, most probably promoted by the application of the bio-consolidation treatment, the microbiota tends to regain its initial stability in a few months. Thus, the treatment does not seem to have any negative side effects on the stone-autochthonous microbiota over that time. The molecular strategy employed here is suggested as an efficient monitoring tool to assess the impact on the stone-autochthonous microbiota of the application of biomineralization processes as a restoration/conservation procedure.This work was supported by the European Regional Development Fund (ERDF), Junta de Andalucía (Spain) and the “Fortalecimiento de la I+D+i” program from the University of Granada, co-financed by grant RNM-3493 and Research Group BIO-103 from Junta de Andalucía, as well as by the Spanish Government through “José Castillejo” program from the “Ministerio de Educación, Cultura y Deporte” (I+D+i 2008-2011), and by the Austrian Science Fund (FWF) under Grant “Elise-Richter V194-B20”