The infiltration rate and therefore the principal function of a sand based vertical flow constructed wetland (VFCW) is influenced by the content of suspended solids (SS) and chemical oxygen demand (COD) of the waste water supply. In this study there were three operating conditions defined as “No Clogging”; “Partly Clogging” and “Clogging”. Investigations on 21 VFCWs approved analytical differen...

Ferrihydrite is effective in arsenic removal because of the considerable amount of active hydroxyl groups. Solid–liquid separation of the arsenic adsorbed ferrihydrite from aqueous solution is important for the arsenic treatment technology. Coagulation is a promising process for ferrihydrite separation. Effects of different coagulants on arsenic adsorbed ferrihydrite settlement were investigate...

Elevated deer densities have led to reports of forest regeneration failure and ecological damage. However, there is growing evidence that the biophysical conditions of a forest thatmake it attractive to deermay be a contributing factor in determining browsing levels. Thus, an understanding of settling stimulus—how attractive an area is to deer in terms of food-independent habitat requirements— ...

This study aims at evaluating the impacts of PAM addition on activated sludge performance. Four lab-scale sequencing batch reactors (SBRs), each with a working volume of 3L, were investigated with different PAM concentrations. Experiments were conducted with varying organic loading rate and the sludge volume index (SVI), particle size, zeta potential, specific oxygen uptake rate (SOUR), mixed l...

The present study was aimed at the development of aerobic granules in a sequencing batch reactor for the biodegradation of m-cresol. The reactor was started with 100 mg L(-1)of m-cresol. Aerobic granules first appeared within 1 month of the start-up of the reactor. The granules were large and strong and had a compact structure. The diameter of stable granules on day 200 was in the range of 1.5 ...

This paper presents a study of the effect of settling error due to finite gain-bandwidth product (GBW) and slew-rate (SR) of opamps in SC Σ∆ A/D modulators. Based on the theoretical point of view, a new architecture for cascade multibit Σ∆ A/D modulators is proposed to achieve better performances at low oversampling ratio. The performance improvement is analyzed and compared with traditional ca...

Aerobic granulation is a promising biotechnology for wastewater treatment. The formation and development of granules and the pollutant removal are closely associated with hydrodynamic shear force, settling time and volume exchange ratio (VER), which are proved to be the selection pressures. Three different values of shear force (2, 3 and 4 cm/s), settling time (3, 5 and 10 min) and VER (25, 50 ...

The present study was aimed at the development of aerobic granules in sequencing batch reactor (SBR) for the biodegradation of p-nitrophenol (PNP). The reactor was started with 50 mg L 1 of PNP. Aerobic granules first appeared within 1 month of the start up of the reactor. The granules were large and strong and had a compact structure. The diameter of stable granules on day 200 was in the range...

A field experiment was conducted to quantify settling velocities, aggregate states, and flocculation within a hopper dredge plume. Particular interest was in determining the abundance of dense, bed aggregates suspended from the consolidated bed during dredging. A suspended sediment plume from the hopper dredge Essayons was sampled for a period of 90 min after dredging. Settling velocities and s...