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G J Hatziconstantinou

Publications and source records attributed to G J Hatziconstantinou.

2 recordsLinked to original sources

Sludge dewatering and disposal practices for small activated sludge wastewater treatment plants.

Sludge dewatering is a decisive step in the reduction of waste sludge volume, thus considerably affecting total sludge treatment and disposal costs. The construction of sludge dewatering facilities in small WwTPs though, is generally not cost effective. In this paper some experimental evidence is presented, that waste sludge dewatering in small WwTPs of the activated sludge extended aeration type, can be effectively achieved by a centrifuge type of equipment withdrawing sludge directly from the aeration tank; an economic evaluation of the possibility to employ a transportable type of similar equipment mounted on a truck, to serve a number of small WwTPs located in remote or isolated areas is also presented and discussed.

Costs and Cost Analysis↗

Differences in nitrification potential between fully aerobic and nitrogen removal activated sludge systems.

Experimental observations made on two pilot plants, showed that nitrogen removal activated sludge systems, operating under favourable conditions, seem to develop increased nitrification potential compared to fully aerobic systems under similar conditions. This increased potential, which cannot be detected by simple nitrification performance evaluations, is attributed to higher autotrophic populations sustained--developed in similar systems employing anoxic reactors or phases. A reduced autotrophic decay rate under anoxic conditions as reported by some researchers, seems to play a significant role in such a response, most likely together with a more efficient use of available nitrogen for additional nitrifying microorganisms production, resulting from a reduced nitrogen loss to autotrophic biomass maintenance needs and heterotrophic biomass synthesis requirements.

Bacteria, Aerobic↗