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Abstract: Laboratory continuous flow-through riverbank filtration (RBF) models were developed to study the organic substances and ammonia nitrogen removal efficiency in the riverbank filtration process. The results indicated that the priority pollutants, organic substances and ammonia nitrogen, could be removed to a great extent. The results also indicate that the quality of the Huai River water is acceptable to operate the abstraction system with the riverbank filtration. [Copyright &y& Elsevier]

Abstract: Base on the previous study of organic substances and ammonia nitrogen removal efficiency through laboratory continuous flow-through riverbank filtration (RBF) models, field study were carried out to evaluate the results drawn from small model experiments. Five wells were selected to in this riverbank filtration process field study. The results indicated that the priority pollutants, organic substances and ammonia nitrogen, could be removed to a great extent. The results also indicate that the quality of the Huai River water is acceptable to operate the abstraction system with the riverbank filtration. [Copyright &y& Elsevier]

A flocculator-imaging system was developed to characterize the dynamics of particle size distribution (PSD) during flocculation. The system consisted of a flocculator coupled with an external flow-through cell for observation and photography, a microscopic charge-coupled device video recorder with backlighting, and an image analyzer. This nonintrusive side-stream setup was used to record the evolution of the PSD to determine the flocculation dynamics of three types of particle systems: Clean kaolin, kaolin coated with natural organic matter (NOM), and the kaolin/NOM system after ozonation. In addition to the PSD measurement, the ζ potential, NOM reduction, and turbidity removal after the jar test of flocculation and sedimentation were determined for the particle systems at various alum dosages. The results of the ζ-potential analysis and the PSD measurement indicated that flocculation takes place rapidly to form highly porous aggregates when the particle surface charge is fully neutralized. The adsorption of NOM on the particle surface stabilized the particles considerably, and thus hindered the flocculation process. Sweep flocculation using a much higher alum dosage was an effective means of process enhancement for the removal of particulates and associated organic matter. Ozonation of the kaolin/NOM solution, however, did not appear to have any positive effect on particle destabilization and flocculation. It is argued that ozonation produced more acidic functional groups in the NOM on kaolin, which increased the surface charge density and hence the stability of the particles in softer water. [ABSTRACT FROM AUTHOR]