Performance evaluation of ceramic pot filters combined with adsorption processes for the removal of heavy metals and phenolic compounds.

It has been demonstrated that the ceramic pot filters (CPFs) with impregnated colloidal silver are efficient for the removal of turbidity and pathogens for household water treatment. This investigation evaluated the efficiency of two filter models for the removal of chemical contaminants (Hg, Pb, As and phenolic compounds) during 175 days. The first model is a traditional CPF impregnated with colloidal silver and the second consists of the ceramic silver-impregnated pot plus a post-filtration column with granular activated carbon and zeolite (CPF + GAC-Z). The results of the CPF showed average efficiencies of 91.5% (Hg), 92% (Pb), 50.2% (As) and 78.7% (phenols). The CPF + GAC-Z showed similar efficiencies for the removal of heavy metals (92.5% Hg, 98.1% Pb and 52.3% As) and a considerably higher efficiency for the removal of phenols (96.4%). The As concentration of the filtered water in both systems was higher than the regulatory limit. The ceramic pot was responsible for the highest removal of chemical compounds. It can be concluded that the traditional CPF is a viable option for water supply treatment at the household level for the removal of chemical contaminants. The efficiency of this filter can be improved with the post-filtration column mainly for the removal of organic constituents.

Assessment of Prickly Pear Fruit Peel Mucilage in Form of Gel as a Green Coagulant for the Tertiary Treatment of Domestic Wastewater.

The application of natural coagulants derived from food byproducts in domestic wastewater tertiary treatment, which contains a number of impurities as suspended colloidal particles, has a potential use as essential substitutes for traditional inorganic coagulants. These biomaterials are a sustainable and environmentally friendly alternative that can be used to improve water quality and human health. In this study, prickly pear (PP) fruit peel mucilage gel was evaluated as a novel coagulant for the tertiary stage of domestic wastewater treatment. Jar tests were performed on residual raw water at the inlet (influent) and outlet (effluent) of the tertiary wastewater treatment (constructed wetland) with a coagulant dose of 12 mg L-1 at a pH of 13. The efficiency of green (i.e., mucilage) and inorganic chemical (i.e., FeCl3) coagulants was compared on the basis of turbidity and color removal. The flocs produced by the coagulants were characterized structurally by FTIR spectroscopy and Zeta potential analysis and morphologically by scanning electron microscopy (SEM). The results showed that the turbidity and the color removal efficiency of the mucilage compared to the FeCl3 at the outlet of the treatment (effluent) were practically the same, reaching 94% turbidity and 85-87% color removal efficiency with both coagulants. The structure and morphology of the flocs generated by the coagulants showed a higher content of organic matter trapped in the flocs. The floc formation observed mechanisms were adsorption/bridging for mucilage and charge neutralization for FeCl3. The results of this study demonstrated that the PP mucilage green coagulant can be used to enhance the quality of treatment of domestic wastewater in an eco-friendly and biodegradable manner.

Removal of E. coli and Salmonella in pot ceramic filters operating at different filtration rates.

The use of pot ceramic filters PCF to improve the domestic water quality supply has been recognized as an alternative in regions where there is unsecure water treatment or contamination of the treated water during transport and storage and an absence of safe drinking water. The aim of this study was to evaluate a model of PCF impregnated with colloidal silver under three filtration rates (1.0, 2.0 and 3.0 L/h) and three E. coli and Salmonella spp concentrations (104, 103 and 102 CFU/mL). The evaluation was made using spiked water having a turbidity of 29.9 ±â€¯4.4 NTU and conductivity of 176 ±â€¯31.7 µS/cm. The results showed a turbidity removal efficiency of 97% and average effluent of 0.9 NTU. The microbiological efficiency removal was of 2 Log Reduction Value (LRV) for E. coli and 1 LRV for Salmonella spp. There were not found significant statistical differences between the filtration rates and the removal efficiencies for turbidity E. coli and Salmonella spp. It was observed that the microbiological removal efficiency was affected by biofilm formation a phenomenon that was attributed to the presence of Salmonella spp. The combination of chemical and mechanical cleaning methods contributed to the elimination of the biofilm.

[Evaluation of drinking-water treatment by Lifestraw® and Ceramic-pot filters]. / Evaluación del tratamiento de agua para consumo humano mediante filtros Lifestraw® y Olla Cerámica.

Objective To evaluate under laboratory conditions, the removal efficiency of turbidity and E. coli of two household water filters: LifeStraw® family (MF) and ceramic pot filter (CPF). Methods The two systems were operated over 6 months using two identical control units per system, treating 7.5 L/d of a synthetic substrate used as raw water. The turbidity of the substrate was adjusted with Kaolinite and the E. coli concentration, with a replica of the ATCC 95922 strain. The differences of effluent quality of the systems, in terms of turbidity and E. coli, were evaluated with Analysis of Variance (ANOVA). Operative and maintenance aspects, that could limit or enhance the use of the systems, were also considered in the evaluation. Results The water synthetic substrate quality had an average of 32.2 ± 2.8 NTU for turbidity and 3,9x105 UFC/100 mL for E. coli. Both systems reduce the turbidity to values below 2 NTU with an inactivation of 100 % of E. coli. Statistical differences were found between the systems in terms of turbidity removal, MF being more efficient than the CPF (99,2 ± 0.4 % and 97.6 % ± 1.14, respectively). Conclusions Both systems are suitable for household water supply treatment, acheiving the water quality standards established by Colombian regulations. The MF was more efficient for suspended solids removal and filtration rate, but when economic, operative, and maintenance aspects along with social acceptability and lifespan are considered, the CPF seems more suitable, especially in rural areas.

Long-term evaluation of the performance of four point-of-use water filters.

Despite technological advances water supply quality and poor access to safe water remain a major problem in developing countries, especially in rural areas. Point-of-use (POU) water treatment has been shown to be a viable option to produce safe drinking water quality. The aim of this study was to evaluate, under laboratory conditions over 14 months, the performance of four household filtration systems: membrane filter (MF), one-candle ceramic filter (1CCF), two-candle ceramic filter (2CCF) and pot ceramic filter (PCF). The evaluation was made using spiked water having the required concentrations of turbidity, Escherichia coli and Total Dissolved Solids (TDS). The results show that all systems have high removal efficiencies for turbidity (98-99%), and E. coli 4-5 Log Reduction Value (LRV). The poorest efficiency was for TDS (9-18%). The MF and the CCF displayed no significant difference in efficiencies for these parameters. The PCF had less significant differences for turbidity removal than the other systems. The average filtration rate for all systems decreased during the operation time. The CPF showed the major potential to be used in rural communities mainly for its low operational level and maintenance requirements as well as its local craftsmanship. It was observed that the efficiency of the systems is highly sensitive to cleaning and maintenance activities and therefore, the system sustainability will depend considerably on the training and education of the potential users.

Evaluación del tratamiento de agua para consumo humano mediante filtros Lifestraw® y Olla Cerámica / Evaluation of drinking-water treatment by Lifestraw® and Ceramic-pot filters

Objetivo Evaluar la eficiencia de dos sistemas de filtración casera: LifeStraw® family (FM) y Filtro de Olla Cerámica (FOC) en el tratamiento del agua para consumo humano bajo condiciones controladas de laboratorio y en términos de remoción de Turbiedad y E.coli. Métodos Ambos sistemas se operaron durante 6 meses tratando diariamente 7,5 litros de sustrato sintético. La turbiedad del sustrato se ajustó con Caolín y la concentración de E.coli con la réplica de la cepa ATCC 95922. Los resultados obtenidos en términos de remoción de turbiedad y E. coli fueron evaluados con un análisis de varianza (ANOVA) y considerando aspectos operativos y de mantenimiento. Resultados La turbiedad del sustrato sintético presentó un promedio 32,3 ± 2,8 UNT y la concentración de E. coli 3,9 x105 UFC/100mL. Ambos sistemas de filtración disminuyeron la turbiedad a niveles menores de 2 UNT y lograron la inactivación del 100 % de E.coli. Se encontraron diferencias significativas en la remoción de turbiedad siendo más eficiente el FM (99,2 % ± 0,4) que el FOC (97,6 % ± 1.14). Conclusiones Los dos sistemas de filtración son adecuados para el tratamiento del agua a nivel casero, cumpliendo con la reglamentación Colombiana. El FM resultó más eficiente en remoción de turbiedad y tasa de filtración; Sin embargo, cuando se tienen en cuenta aspectos como aceptabilidad social operación, mantenimiento y vida útil, el filtro de olla cerámica parece más apropiado especialmente en áreas rurales.(AU)

Objective To evaluate under laboratory conditions, the removal efficiency of turbidity and E. coli of two household water filters: LifeStraw® family (MF) and ceramic pot filter (CPF). Methods The two systems were operated over 6 months using two identical control units per system, treating 7.5 L/d of a synthetic substrate used as raw water. The turbidity of the substrate was adjusted with Kaolinite and the E. coli concentration, with a replica of the ATCC 95922 strain. The differences of effluent quality of the systems, in terms of turbidity and E. coli, were evaluated with Analysis of Variance (ANOVA). Operative and maintenance aspects, that could limit or enhance the use of the systems, were also considered in the evaluation. Results The water synthetic substrate quality had an average of 32.2 ± 2.8 NTU for turbidity and 3,9x105 UFC/100 mL for E. coli. Both systems reduce the turbidity to values below 2 NTU with an inactivation of 100 % of E. coli. Statistical differences were found between the systems in terms of turbidity removal, MF being more efficient than the CPF (99,2 ± 0.4 % and 97.6 % ± 1.14, respectively). Conclusions Both systems are suitable for household water supply treatment, acheiving the water quality standards established by Colombian regulations. The MF was more efficient for suspended solids removal and filtration rate, but when economic, operative, and maintenance aspects along with social acceptability and lifespan are considered, the CPF seems more suitable, especially in rural areas.(AU)