Use of bank filtration (BF) to improve water quality is of great importance for public water supply. The BF technique consists of the use of wells situated near riverbanks with sediment materials from the banks and bed as a natural filter, which significantly reduces pollutant concentration found in surface water. The objective of this study was to analyse the ability of the BF technique to improve water quality in a study performed on the Beberibe River, Pernambuco State, Brazil. At a pilot scale, physical structure in the experimental module comprises one production well and seven observation wells. Groundwater levels and physical-chemical monitoring were conducted both at the Beberibe River and a production well, to evaluate the effectiveness of the BF technique. In addition, coliforms group and cyanobacteria removal were also analysed. The BF technique at the Beberibe River effectively improved water quality in terms of physical-chemical and bacteriological parameters and pumped water complies with potability standards required by Brazilian law and the rules of the World Health Organization.

The hyporheic environment is composed of a rich meiofauna that depends on water flow, organic matter, and oxygen. The concentration of meiofauna varies spatially (horizontal and vertical) and temporally. Several processes occur at this interface (groundwater and surface water), including biogeochemical processes involving meiofauna. A study of the hyporheic meiofauna community in the sediments of the Beberibe River, in Brazil, was conducted. Meiofauna attained peak densities of 942.8 organisms/10 cm2, with organisms distributed over six taxa, with 98% of them represented by rotifers, nematodes, and annelids. Density was higher in the dry season with an average of 653.1 organisms/10 cm2, and in more superficial sediments with an average of 739.6 organisms/10 cm2. Greater densities were found in coarser sediment with a higher percentage of organic matter. A river bank filtration (RBF) pilot project has been installed, with good results in the attenuation of contaminants and pathogens.

Introduction: Transmission of pathogenic protozoa and helminths by water is a serious public health problem. In this study, we analyzed the presence of these organisms in the Beberibe River in Pernambuco, Brazil. Methods: Parasite analysis was performed using the Hoffman, Pons, & Janer method followed by centrifugation and preparation of slides by staining with acetic acid and Lugol's solution. Protozoan oocysts were isolated by the modifi ed Ziehl Neelsen method. Results: Cryptosporidium spp., Giardia spp. and other parasites were found in the Beberibe River. Conclusions: Sanitation companies must assess pathogenic intestinal parasites in water basins providing public water and subsequently develop improved treatment systems for removal of such parasites.

In bank filtration (BF) technology, a production well is pumped near surface water and induces water flow from the river through a porous medium to the well by percolation into the soil.Several physical, chemical, and biological processes occur, providing a natural water treatment along the river banks. An experimental area was installed on the Beberibe River with 2 production wells and 7 monitoring wells. The BF potential in removing pathogenic intestinal parasites and analysis of physical-chemical and bacteriological parameters was evaluated, according to Standard Methods. River-aquifer interaction was characterized by piezometric levels of production wells. Monitoring of the wells was correlated with the water depth of the river and precipitation. Parasite analysis was performed using Hoffman, Pons, and Janer's methods of spontaneous sedimentation, followed by centrifugation and preparation of slides stained with acetic Lugol. Protozoa oocysts were isolated by a modified Ziehl-Neelsen method, preceded by sedimentation and centrifugation. The pathogenic protozoa found in samples from Beberibe River were Cryptosporidium spp., Giardia spp., Entamoeba histolytica/dispar complex, and Isospora belli. Pathogenic helminths were also detected: Ascaris lumbricoides, Strongyloides stercoralis, and hookworm eggs and larvae, Hymenolepis nana. In water samples from the production wells, no waterborne pathogens were found. The BF pilot project was effective in reducing levels of turbidity and color. Total coliforms and Escherichia coli were absent in the production wells.Piezometric levels of production wells and monitoring wells correlated with water depth of Beberibe River show hydraulic connection between the production wells and river, thus featuring a river-aquifer interaction. The BF pilot system showed potential for reduction or elimination of pathogenic intestinal parasites.

Alluvium at Beberibe river at "Caixa d'Água" neighborhood between Olinda and Recife municipality has been researched for analyzing Bankfiltration technique as an efficient and suitable water treatment method. An important point to evaluate bankfiltration performance is the understanding of the alluvium hydraulics and hydrodynamics. Four pumping wells have been drilled and seven observations wells were installed. Hydraulic head have been monitored and pumping tests were performed. This work presents the results of pumping test and head monitoring. Potentiometric map shows that natural groundwater flow has the direction of river flow, with small inflexions of hydraulic head isolines, indicating that before pumping Beberibe river is effluent at that site. Drawdown surfaces are elliptic with larger axis parallel to river. Aqu ifer tests were interpreted by Theis and Thiem methods. Hydrogeologic representative parameters are transmissivity: 2,3x10-3 m 2 /s, hydraulic conductivity: 2,03x10-4 m/s and storage coefficient: 1,02x10-3. The aquifer hydrodinamics is similar to a confined aquifer with recharge from Beberibe river during well pumping.