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Schmutzdecke, the biofilm formed on the top of the sand bed in household slow sand filters (HSSF) is a key factor for the filters’ high efficiency in removing particles and microorganisms from water. This paper aims to investigate the extracellular polymeric substances composition (carbohydrates and proteins), biomass, dissolved oxygen, and microbial community in two types of HSSFs and identify a correlation between them and their efficiency. A continuous- and an intermittent-HSSF (C-HSSF and I-HSSF) were studied to treat river water for 48 days. Their efficiencies for bacteria (E. coli and total coliforms), turbidity, and apparent color removals were analyzed. Results clearly showed an increase of carbohydrates (from 21.4/22.5 to 101.2/93.9 mg·g−1 for C-/I-HSSF) and proteins (from 34.9 to 217/307.8 mg g−1 for C-/I-HSSF), total solids (from 0.03/

Ao redor do mundo, 2,1 bilhões de pessoas não tem acesso a água segura em quantidade e qualidade adequadas, apesar de ser considerado um direito humano. Dessa forma, existe demanda para o desenvolvimento e o aprimoramento de tecnologias de tratamento de água em escala domiciliar. Entre essas tecnologias, o Filtro Lento Domiciliar (FLD) tem apresentado resultados promissores; entretanto, ainda possui limitações que carecem de solução (e.g., limitação ao tratar água com elevada turbidez e baixa eficiência durante os períodos nos quais a camada biológica – schmutzdecke – não está totalmente desenvolvida). Nesse contexto, um sistema em múltiplas etapas foi construído e avaliado durante 442 dias ininterruptos, tratando água superficial natural. Tal sistema contava com 3 etapas: pré-tratamento por sedimentação e filtração em tecido, filtração lenta em FLD e desinfecção com hipoclorito de sódio. Durante o período de operação, cada etapa foi avaliada individualmente na remoção de parâmetros físico-químicos e microbiológicos. Ainda, dois modelos distintos de FLD foram comparados. O FLD-d possuía um difusor, enquanto o FLD-b contou com um reservatório equipado com uma boiam, visando a melhoria da eficiência do filtro. A remoção de cistos de Giardia e oocistos de Cryptosporidium pelos FLDs também foi avaliada. Os resultados mostraram que o sistema foi capaz de produzir água com turbidez média abaixo de 3 UNT, cor aparente média abaixo de 12 UH e ausência de Escherichia coli em mais de 70% das amostras, sendo todas caracterizadas como de baixo risco (

Made available in DSpace on 2021-06-25T15:05:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-18 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) There is increasing evidence showing positive association between changes in oral microbiome and the occurrence of oral squamous cell carcinoma (OSCC). Alcohol- and nicotine-related products can induce microbial changes but are still unknown if these changes are related to cancerous lesion sites. In an attempt to understand how these changes can influence the OSCC development and maintenance, the aim of this study was to investigate the oral microbiome linked with OSCC as well as to identify functional signatures and associate them with healthy or precancerous and cancerous sites. Our group used data of oral microbiomes available in public repositories. The analysis included data of oral microbiomes from electronic cigarette users, alcohol consumers, and precancerous and OSCC samples. An R-based pipeline was used for taxonomic and functional prediction analysis. The Streptococcus spp. genus was the main class identified in the healthy group. Haemophilus spp. predominated in precancerous lesions. OSCC samples revealed a higher relative abundance compared with the other groups, represented by an increased proportion of Fusobacterium spp., Prevotella spp., Haemophilus spp., and Campylobacter spp. Venn diagram analysis showed 52 genera exclusive of OSCC samples. Both precancerous and OSCC samples seemed to present a specific associated functional pattern. They were menaquinone-dependent protoporphyrinogen oxidase pattern enhanced in the former and both 3 ',5 '-cyclic-nucleotide phosphodiesterase (purine metabolism) and iron(III) transport system ATP-binding protein enhanced in the latter. We conclude that although precancerous and OSCC samples present some differences on microbial profile, both microbiomes act as iron chelators-like potentially contributing to tumor growth. Univ Fed Rio Grande do Sul, Fac Dent, Prevent & Community Dent Dept, BR-90035003 Porto Alegre, RS, Brazil Univ Sao Paulo, Fac Med Ribeirao Preto, Postgrad Program Clin Oncol Stem Cells & Cell The, BR-14049900 Ribeirao Preto, SP, Brazil Reg Blood Ctr Ribeirao Preto, Natl Inst Sci & Technol Stem Cell & Cell Therapy, Ctr Cell Based Therapy CEPID FAPESP, Mol Genet & Bioinfonnat Lab MGBL, Rua Tenente Catao Roxo 2501, BR-14049900 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Ribeirio Preto Med Sch, Dept Genet, BR-14049900 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Entomol & Acarol, BR-13418900 Piracicaba, SP, Brazil Univ Sao Paulo, Ribeirao Preto Med Sch, BR-14049900 Ribeirao Preto, SP, Brazil Univ Sao Paulo, Sch Publ Hlth, Dept Nutr, BR-01246904 Sao Paulo, SP, Brazil Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul & Sanitat, BR-13563120 Sao Carlos, SP, Brazil Inst Canc Res IPEC, BR-85015430 Guarapuava, PR, Brazil Univ Estadual Centro Oeste, Dept Med, BR-85015430 Guarapuava, PR, Brazil Sao Paulo State Univ, Sch Pharmaceut Sci, Dept Food & Nutr, Araraquara, SP, Brazil Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Biochem & Immunol, Ribeirao Preto, SP, Brazil Univ Paulista, Inst Hlth Sci, Undergrad Biol Sci, Ribeirao Preto, SP, Brazil Univ Fed Parana, Grad Program Bioinformat Profess & Technol Educ S, Curitiba, Parana, Brazil Univ Fed Amapa, Dept Biol Sci & Hlth, Macapa, AP, Brazil Embrapa Southeast Livestock EMBRAPA, Sao Paulo, Brazil FARVET, Labs Invest & Desarrollo, Chincha Alta, Ica, Peru Univ San Martin de Porres, Ctr Invest Genet & Biol Mol CIGBM, Lima, Peru Para State Univ, Grad Program Parasit Biol Amazon, Belem, Para, Brazil Para State Univ, Inst Technol, Dept Elect & Biomed Engn, Belem, Para, Brazil Fundacao Ctr Controle Oncol Estado Amazonas, Dept Educ & Res, Manaus, Amazonas, Brazil Univ Fed Goias, Inst Pathol Trop & Publ Hlth, Goiania, Go, Brazil Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Oral Maxillofacial Surg & Periodontol, Ribeirao Preto, SP, Brazil Univ Sao Paulo, Sch Arts Sci & Humanities, Sao Paulo, Brazil Blood Ctr Ribeirao Preto, Ctr Cell Based Therapy CEPID FAPESP, Mol Genet & Bioinformat Lab MGBL, Rua Tenente Catao Roxo 2501, BR-14051140 Ribeirao Preto, SP, Brazil Sao Paulo State Univ, Sch Pharmaceut Sci, Dept Food & Nutr, Araraquara, SP, Brazil CNPq: 465539/2014-9 FAPESP: 2013/08135-2 FAPESP: 17/23205-8 FAPESP: 19/08528-0

This study evaluated the impact of a 50% reduction of filter media depth in Household Slow Sand Filters (HSSFs) on continuous flow to remove physicochemical and microbiological parameters from river water. Furthermore, simple pre-treatment and disinfection processes were evaluated as additional treatments. Two filter models with different filtration layer depths were evaluated: a traditional one with 50 cm media depth (T-HSSF) and a compact one (C-HSSF) with 25 cm. HSSFs were fed with pre-treated river water (24-h water sedimentation followed by synthetic fabric filtration) for 436 days at a constant filtration rate of 0.90 m3 m−2 day−1 with a daily production of 48 L day−1. Sodium hypochlorite (2.0 mg L−1 of NaOCl 2.5% for 30 min) was used to disinfect the filtered water. Water samples were analysed weekly for parameters such as turbidity, organic matter, colour and E. coli, among others. Removal of protozoan cysts and oocysts by the HSSFs were also evaluated. After pretreatment, turbidity from the HSSF river water was reduced to 13.2 ± 14.6 NTU, allowing the filters to operate. Statistical analysis indicated no significant difference (p > 0.05) between T-HSSF and C-HSSF efficiencies in all evaluated parameters throughout operation time. Hence, media depth reduction did not hinder continuous HSSF performance for almost all the evaluated parameters. However, it may have affected Giardia cysts retaining, which passed through the thinner media on one evaluation day. Disinfection was effective in reducing remaining bacteria from filtered water; however, it was ineffective to inactivate protozoa. The reduction in the filtration layer did not affect the overall filtered water quality or quantity showing that a compact HSSF model may be a viable option for decentralized water treatment.

Household Water Treatment and Safe Storage (HWTS) are recommended to supply the demand for drinking water in communities without conventional water supply systems. However, there is a lack of long-term laboratory studies regarding such technologies. We evaluated the contributions of each step of a multi-barrier system with pretreatment (sedimentation and fabric filtration), filtration in Household Slow Sand Filters (HSSFs) and disinfection (sodium hypochlorite) treating surface water for more than 14 consecutive months. Removal of turbidity, colour, organic matter, coliform group bacteria and protozoa were evaluated. Two HSSF models were compared, one with a diffuser vessel (HSSF-d) and one with a gravity float equipped vessel (HSSF-f). Correlations between efficiency and operational parameters were assessed. Overall, the multi-barrier system removed more than 90% of turbidity and more than 3.5 log of Escherichia coli. HSSF removed up to 3.0 log of Giardia spp. and 2.4 log of Cryptosporidium spp. HSSF-f presented significantly higher removal rates for turbidity, apparent colour and E. coli. Disinfection resulted in water with E. coli concentration lower than 1 CFU 100mL−1, however it was not able to inactivate protozoa. The evaluated system was able to reduce microbiological risks from water and could indeed be an alternative to communities that depend on surface water as their main source of supply. Nevertheless, further studies are recommended to include a low-cost disinfectant for protozoa inactivation.

This study aimed to evaluate the efficiency of four household slow sand filter (HSSF) models for the removal of microorganisms from river water throughout the development of their biological layers (schmutzdecke). Two models were designed to be operated continuously (HSSF-CC and HSSF-CT) and two intermittently (HSSF-ID and HSSF-IF). Filters were fed daily with 48 L pre-treated river water (24 h sedimentation followed by filtration through a non-woven synthetic blanket). Water samples were quantified by coliform group bacteria and analysed by bright field microscopy to visualize the microorganisms. Total coliform reduction was between 1.42 ± 0.59 log and 2.96 ± 0.58 log, with continuous models showing a better performance (p-values < 0.004). Escherichia coli reduction varied from 1.49 ± 0.58 log to 2.09 ± 0.66 log and HSSF-IF, HSSF-CC and HSSF-CT presented a similar performance (p-values > 0.06), slightly better than the one presented by HSSF-ID (p-value=0.04). Microorganisms, such as algae, protozoa and helminths were detected by microscopy in raw water and pre-treated water. Algae were the most significant group in these samples, although they were not visualized by bright field microscopy in the filtered water. Results showed the potential of HSSF in microbiological risk reduction from river water, which increases the range of point-of-use water treatments in rural communities. However, additional studies of the HSSF biological layer must be performed.

Household, or point-of-use (POU), water treatments are effective alternatives to provide safe drinking water in locations isolated from a water treatment and distribution network. The household slow sand filter (HSSF) is amongst the most effective and promising POU alternatives available today. Since the development of the patented biosand filter in the early 1990s, the HSSF has undergone a number of modifications and adaptations to improve its performance, making it easier to operate and increase users' acceptability. Consequently, several HSSF models are currently available, including those with alternative designs and constant operation, in addition to the patented ones. In this scenario, the present paper aims to provide a comprehensive overview from the earliest to the most recent publications on the HSSF design, operational parameters, removal mechanisms, efficiency, and field experiences. Based on a critical discussion, this paper will contribute to expanding the knowledge of HSSF in the peer-reviewed literature.

A household slow sand filter (HSSF) is a widely used water treatment technology recognized as one of the most effective and sustainable in reducing waterborne diseases. However, there is a lack of knowledge concerning its behaviour in the presence of cyanobacteria and cyanotoxins. In this context, the study aimed to evaluate HSSF ability to remove Microcystis aeruginosa cells (stain BB005) and microcystin-LR from water, among other parameters, when operated under continuous (C-HSSF) and intermittent (I-HSSF) flows. C HSSF was operated at a constant filtration rate (1.22 m3 m−2 day−1), while I-HSSF was operated at a variable filtration rate (starting at 2.95 m3 m−2 day−1 and finishing at zero). Each filter produced 60 L day−1. The influence of the pause period was also tested in the I-HSSF. The water from the study was prepared by inoculating M. aeruginosa culture in water from a well to a final cell density of ± 1 × 105 cells mL−1. M. aeruginosa removal rates were 2.39 ± 0.34 log and 2.01 ± 0.43 log by C HSSF and I-HSSF, respectively. Microcystin-LR concentration in studied water was 5.55 μg L−1, and both filters produced filtered water with microcystin concentrations below 1.0 μg L−1, the maximum value recommended by the World Health Organization (WHO), for most of the samples. Turbidity and apparent colour were also within WHO guidelines. Filters operating with different flow regimes and distinct residence times did not statistically influence treatment efficiencies. Both filters showed promising results in the M. aeruginosa and microcystin-LR removals from water; nevertheless, more research is needed to understand the mechanisms involved in the reduction of both cyanobacteria and cyanotoxin through household slow sand filtration.

A combinação de coagulação/floculação/sedimentação, filtração lenta em escala domiciliar e adsorção foi ponderada como alternativa de tratamento de águas com Microcystis aeruginosa e microcistina para comunidades isoladas. As Cactáceas Opuntia cochenillifera e Opuntia ficus-indica foram estudadas como coagulantes e a espécie Luffa cylindrica foi estudada como adsorvente. Os coagulantes foram avaliados em ensaios em bancada com água contendo M. aeruginosa. O extrato de O. cochenillifera apresentou melhor desempenho por isso foi selecionado para ensaios de bancada em jarteste seguidos por filtração. Os filtros operados em regime contínuo apresentaram melhores resultados, na remoção de microcistina (75,79%), cor aparente (79,68%) e turbidez (79,15%). Entretanto, os filtros operados em regime intermitente demonstraram melhor eficiência na remoção de M. aeruginosa (96,62% - 1,985 Log). Os ensaios de adsorção mostraram que Luffa cilyndrica in natura, temperatura ambiente e pH neutro não apresentou potencial na adsorção de microcistina. Para os ensaios em escala plena, dois filtros lentos em escala domiciliar (FLD) em policloreto de polivinila (polyvinyl chloride - PVC) foram construídos tomando-se por base o modelo do Centre for Affordable Water and Sanitation Technology (CAWST). Um filtro foi operado em regime contínuo e o outro em regime intermitente. O coagulante e o adsorvente não foram utilizados nessa etapa do trabalho. O filtro operado em fluxo contínuo apresentou resultados superiores para a remoção de M. aeruginosa (99,59% - 1,998 log), cor aparente (97,73%) e turbidez (84,39%). O regime de operação e o tempo de residência nos filtros não influenciaram na eficiência do tratamento. A água filtrada apresentou características em consonância com as previstas na legislação para cor aparente, porém, não para turbidez. A água filtrada apresentou concentrações de microcistina abaixo de 1,0 μg L-1 para ambos os filtros, valor máximo permitido pela Portaria MS 2914/2011 e pelas diretrizes da Organização Mundial da Saúde. Em ensaios ecotoxicológicos com Chironomus xanthus, a água filtrada não apresentou toxicidade. The combination of coagulation/flocculation/sedimentation, slow sand filtration at home scale and adsorption was evaluated as an alternative treatment for waters with Microcystis aeruginosa and microcystin for isolated communities. The Cactaceae Opuntia cochenillifera and Opuntia ficus-indica were evaluated as coagulants and the species Luffa cylindrica was evaluated as adsorbent. The coagulants were evaluated in bench tests with a study water containing M. aeruginosa cells. O. cochenillifera extract presented better removal performance so it was selected for jartest bench tests followed by filtration. The filters operated in continuous flow showed better results in microcystin removal (75.79%), apparent color (79.68%) and turbidity (79.15%). However, the intermittent flow filters demonstrated a better removal of M. aeruginosa cells (96.62% - 1985 Log). The adsorption tests showed that the use of Luffa cylindrica fibers, at ambient temperature and neutral pH had no potential in microcystin adsorption. In full-scale trials, two PVC home scale slow sand filters were constructed based on the CAWST (Center for Affordable Water and Sanitation Technology) Biosand filter model. One home scale slow sand filters was operated on a continuous flow and another on an intermittent flow. The coagulant and the adsorbent were not used at the fullscale trials. The continuous flow filter showed superior results for cyanobacteria removal (99.59% - 1.998 log), apparent color removal (97.73%) and turbidity removal (84.39%). The filters operating regime and residence time do not influenced the efficiency of the treatment. The filtered water showed characteristics in line with the legislation for apparent color, but not for turbidity. The filtered water had microcystin concentrations below 1.0 μg L-1 for the two filters, maximum value allowed by Directive 2914/2011 and by guidelines of the World Health Organization. In ecotoxicological tests with Chironomus xanthus, filtered water showed no toxicity.