The Business Model as a technique for problem identification and scoping: a case study of Brazilian drinking water quality assessment sector

In this case study, a Business Model Canvas (BMC) was used as a technique for problem identification and scoping for the introduction of a new technology or methodology for water quality assessment. Therefore, information about the Brazilian water supply sector was used for the application of a BMC based on technological innovations for coliform analysis. The innovations proposed in the study include faster results, internet connection, and portability. To populate the model, data regarding the drinking water quality from Brazil were used from public data banks and reports. Also, a group of accountable representatives from diverse water supply systems and water quality laboratories reported their experience with the new coliform analysis and their perception of its technological improvement. The major gaps identified in this study were simplicity and faster results. These may be associated with technological improvements such as portability and internet connection. It was possible to conclude that the segment is diverse, and the BMC highlighted that value might differ for different niches. The results emphasized that the application of a BMC may be more than a business tool. It can also be used by developers or scientists to understand and improve both technology concepts and applications. HIGHLIGHTS A Business Model was applied to structure coliform analysis in drinking water.; Characteristics of water supply systems influence value proposition priorities.; Legal demands have influences in different levels and applications.; Technological innovation and advantages alone may not fit customer needs.; Information gathered reveals a technological gap in coliform analysis.

Exploring challenges in Giardia cyst visualisation by common microscopy methods

Giardia spp. is an intestinal parasite responsible for worldwide disease outbreaks. Guiding researchers and practitioners to choose among current methods for microscopy detection of the infectious forms may be directly beneficial to public health and the environment. This study provides an overall comparison of brightfield (BF), fluorescence and darkfield (DF) microscopies for detecting Giardia duodenalis and Giardia muris cysts, by illustrating micrographs of such protocols applied to purified samples, as well as discussing advantages and constraints based on secondary information and collected data. BF analysis included Lugol's iodine staining. In fluorescence microscopy, samples were processed by immunofluorescence assay (IFA) with DAPI and by standalone DAPI dye. Cyst suspensions were also analysed by DF microscopy using a recently developed low-cost system. The three techniques enabled detecting Giardia spp. cysts, although they did not provide species identification by morphology. The overview of each method points out some relevant aspects to consider when selecting common optical microscopy techniques, and includes challenges and advantages regarding each of them. HIGHLIGHTS Comparisons of BF, DF, standalone DAPI and IFA-combined are provided.; BF and DF may be alternatives for low-cost detection of Giardia cysts.; Combinations of at least two diagnostic methods are recommended to minimise inherent errors.

Household slow sand filters in intermittent and continuous flows to treat water containing low mineral ion concentrations and Bisphenol A

Household slow sand filter (HSSF) has been used as an alternative to drinking water treatment in rural communities worldwide; however, its performance to treat influent water with quality similar to rainwater still needs further studies. Rainwater presents low pH and slight mineral ion concentrations, an aspect that can modify the filter media and consequently the HSSF efficiency. Furthermore, house roofs used in rainwater harvesting can be made of plastic. Therefore, it can introduce chemicals such as Bisphenol A (BPA) in the water. In this context, two pilot-scale HSSFs operated in continuous and intermittent flows were evaluated to treat water containing BPA and low mineral ion concentrations in order to assess the filter performance. Filter media leaching was noticed in the trials; thus, filter media and construction material selection must be carefully evaluated to eliminate risks of pollutant occurrence in drinking water. Operational differences between continuous and intermittent flows influenced the HSSF efficiency for BPA and DOC removals; even so, the filters' performance was low probably due to the slow schmutzdecke development. According to tracer test results, HSSF can be classified as a plug flow reactor and strategies to improve its hydraulic performance are not required