Inclined plate settling for emergency water treatment

Adequate water supply is a public health intervention aimed at preventing diarrhoeal diseases in relief operations. Based on humanitarian water treatment objectives in which supplied water quantities should be prioritised (whilst safeguarding minimum quality standards) an inclined plate settler (IPS) was tested. Preliminary testing revealed that the IPS was capable of stable turbidity reductions at several tested conditions, but further optimisation was required to reach the treatment objectives with regards to turbidity reductions (i.e. 5 NTU). The simplicity and relative low-cost of manufacturing makes this process a potentially cost-effective solution for emergency water treatment

Comparison of scales for faecal sludge gravimetric characterization in low-resource settings

Physical and chemical properties of faecal sludge (FS) samples must be routinely measured for FS characterization as well as for design treatment and monitoring purposes. Many of the parameters of interest for FS rely on gravimetric methods of measurement (e.g. total solids, total volatile solids, etc.). As such, they require the use of weighing scales of sufficient reliability, accuracy and precision. Laboratory-grade analytical scales can be difficult to use in remote areas because of their bulk and price point. This study aims to compare two relatively low-cost, off-the-shelf electronic scales to a laboratory-grade analytical (reference) scale. Three scales were compared using their bias, load eccentricity errors and sensitivity errors. The comparison showed that the low-cost scales exhibit a positive bias and are more prone to eccentricity errors than the reference scale. However, they perform well enough to warrant further investigation into whether they can be an acceptable alternative to laboratory scales in field or low-resource settings for faecal sludge characterization

Inclined plate settler for emergency water treatment: final design

Previously we reported on the proof-of-concept and initial optimisation work on an inclined plate settler (IPS) for water treatment in humanitarian situations. Whilst promising results (i.e. effluent turbidity < 5 NTU) were obtained, further work was warranted to better control and design the hydraulic flocculation (floc conditioning) stage of the treatment system. This paper reports on such work. A scaled-down version of the IPS was tested in parallel with several hydraulic flocculation configurations. The first deployment of the IPS is planned for 2015

Sachet-type point-of-use (POU) water treatment product comparison for emergencies

Point-of-use (POU) water treatment and safe storage techniques are effective in improving microbial water quality and decreasing diarrhoeal disease incidence and have potential to be effective interventions in humanitarian emergency contexts. Coagulant/disinfection products (CDPs) can provide microbial quality improvement, turbidity reductions, and a protective post-treatment free chlorine residual. The objective of this study was to compare the treatment performance of 4 commercially-available CDPs with regards to humanitarian water treatment objectives. This is the first comparison of its kind it was demonstrated the (at times significant) inter- and intra-variability of CDP treatment performance between products and with regards to varying water quality, respectively. It is recommended that implementing agencies should conduct field testing for context specific assessments of product performance and acceptability by beneficiaries. Knowledge of product formulation can also help in evaluating its treatment potential

The potential for a simple method for in-situ faecal sludge pH determinations

pH is a critical parameter for faecal sludge characterisation. However, basic laboratory facilities with such instrumentation are not always available in resource limited contexts. Furthermore, the operational importance (e.g. during lime stabilisation) of this parameter warrants a method that can be applied in situ. This study assesses the potential of a method for in faecal sludge pH determinations using a commercially-available soil pH meter. Results reveal that this simple and low-cost method can relatively reasonably estimate pH when compared to a conventional laboratory pH meter. Further work is necessary to better characterise its limitations

Collection time inequalities: fetching water in Ethiopia

In 2015, WHO and UNICEF reported that only 12% of Ethiopia’s population have access to water on premises. High proportion of the population thus needs to fetch water for their survival. Considering the importance of time to fetch water on an individual’s health and well-being, we aim to demonstrate where water fetching issues are the most prevalent. This study highlights the widespread burden of fetching water and the significant disparities in terms of accessibility with regards to the location of the source within population groups. Characterization of collection time by regions, type of source, education level and water fetcher illustrated where work mostly remains to reach universal access to drinking water

Revisiting MDGs in view of accessibility with particular attention to distance: examples in Eastern Africa

Data from WHO and UNICEF Joint Monitoring Programme (JMP) for Water Supply and Sanitation show that 91% of the worldwide population have access to an improved source of water in 2015. However, this indicator does not reflect the definition of water access considering distance to the source. This is an important factor to take into account considering that 42.5% of the world population don’t have access to water on their premises in 2015. This study examined accessibility data from the JMP by taking distance into account for 5 Eastern African countries. As reported by JMP, 72,6% of these countries population have access to an improved water source while our analysis revealed that this figure falls to 58,5 % when considering distance in the access criterion. To achieve universal and equitable access to safe and affordable drinking water for all, as desired in the new Sustainable Development Goals, this impact must be considered to ensure reasonable access to water

Inclined plate settling for emergency water treatment: towards optimisation

Previous work revealed the potential of an inclined plate settler (IPS) for water treatment in emergency relief applications. Whilst preliminary data demonstrated the tested IPS prototype’s capacity to achieve stable turbidity reductions, further optimisation was warranted. This paper reports on the optimisation and preliminary field testing of an IPS prototype. Trials revealed that after system modification, treatment objectives with regards to turbidity reductions (i.e. < 5 NTU) could be achieved. Such positive results were largely due to the addition of a hydraulic flocculation (conditioning) stage