Removal of pharmaceuticals and personal care products (PPCPs) from drinking water is usually enhanced by advanced oxidation which is not affordable in low income countries. Slow sand filtration has been found to be capable of removing anti-inflammatory compounds, and its low maintenance costs and easy operation make it an attractive technology for treating drinking water in many parts of the world. In addition, slow sand filters can be used at both large and household scales. The biofilm (i.e. schmutzdecke) developed on the top of the sand and within the upper layers of the sand is acknowledged to be responsible for the water purification. However, it is possible that the PPCPs may affect the schmutzdecke development and microbial community within the filters, and consequently the performance of the filter. This study investigated two household slow sand filters (for water purification) operated intermittently with and without contamination by six PPCPs. Eleven parameters were monitored in the affluent and effluent water, including bacterial species present and schmutzdecke biomass development. Results demonstrated that the household slow sand filter performance was not affected by the 2μgL of PPCPs in the water. There was no significant difference between filters for total coliforms and E. coli removal, but there was considerable difference between sampling times. Biomass considerably increased with the number of filtrations in both filters and there was no significant difference between filter biomass. However, it was found that more bacterial species were present in the period with no contamination than during the contamination period. Bacillus anthracis and Exiguobacterium sp. showed to be resistant to the effects of the PPCPs. These suggest there are effects of PPCPs on bacterial species within the filter. However, the effect of the PPCPs on biomass was not conclusive in this study and needs to be further investigated.

The presence of PPCPs (Pharmaceuticals and Personal Care Products) in water sources and drinking water has concerned researchers in recent times. This study was carried out to evaluate the occurrence of 6 PPCPs (namely paracetamol, diclofenac, naproxen, ibuprofen, benzophenone-3 and methylparaben) in the Lobo reservoir, their degradation products, and how efficienctly they were removed by 22 ecological filters, considering individual and mixtures of compounds. There were 3 spiking events of PPCPs (2 μg L-1) in the ecological filter influents conducted with a lag period of 15 days between spikes. Water sample were collected from the influent and effluent of the filters at 3, 6 and 24 hours after each spiking event. All target PPCPs were identified in the Lobo reservoir water in the range of µg L-1. The personal care products were detected with 100 % frequency in the samples, and in higher concentrations compared to the pharmaceuticals. Degradation products of diclofenac and benzophenone-3 were identified in the water samples. Results of this investigation show that an ecological filter was an effective process (70-99 %) to remove 2 μg L-1 of the selected PPCPs, and demonstrated that the filters were resilient to individual compounds and to their mixtures.

Recently, special attention has been given to low-cost technologies for water treatment, with the aim of serving remote communities and thus enabling everyone to have access to drinking water and basic sanitation. In that context, the ecological filter is an alternative for treating water for human consumption. Some studies show that climate change and meteorological parameters can influence the water quality of water bodies and the water supply system. However, most of the papers deal with model projections and therefore do not show real situations. The aim of this study was to determine the impact of meteorological variables (e.g. atmospheric pressure, evaporation, wind speed, radiation, precipitation) on the physicochemical and biological parameters (e.g. turbidity, apparent colour, pH, total coliforms, Escherichia coli) of Lobo reservoir water treated by 22 ecological filters during a period of 4 months. Statistically significant correlations were found between the water from the Lobo reservoir and the weather variables, and between the water quality parameters of the 22 ecological filters and the average weather variables. The results from the statistical analysis indicate that climatic variations may influence treatment performance.

Toxicities of bisphenol A (BPA) and nonylphenol (NP) to the neotropical freshwater cladocerans Ceriodaphnia silvestrii and Daphnia similis were studied under laboratory conditions. Acute exposures to BPA generated mean 48-h EC values of 14.44 (6.02-22.85) mg L for C. silvestrii and 12.05 (1.73-22.37) mg L for D. similis. When the organisms were exposed to acute doses of NP, mean 48-h EC values were 0.055 (0.047-0.064) mg L (C. silvestrii) and 0.133 (0.067-0.200) mg L (D. similis). Ceriodaphnia silvestrii was also tested in chronic bioassays, which resulted in mean 8-d IC values of 2.43 (2.16-2.69) mg L BPA [no observed effect concentration (NOEC): 1.38 mg L] and 0.020 (0.015-0.026) mg L NP (NOEC: 0.015 mg L). These laboratory tests are valuable to broaden the understanding of the environmental threat posed by BPA and NP in aquatic ecosystems, and to increase the knowledge about the sensitivity of neotropical indigenous species to these contaminants. In addition to the laboratory bioassays, species sensitivity distributions were used to suggest protective concentrations of BPA and NP to prevent adverse effects on freshwater organisms. According to the obtained results, concentrations lower than 36.47 µg L BPA and 1.39 µg L NP are not expected to adversely impact aquatic organisms in natural ecosystems.

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