H ISTORICALLY, wastewater treatment plants (WWTPs) have acted as a readily identifiable conduit for the environmental introduction of toxic chemicals from industrial and residential discharges and urban runoff. However, technological improvements in wastewater treatment processes since the enactment of the Clean Water Act of 1972 have resulted in greatly improved pollutant removal efficiencies....

The lack of fresh water is one of the major threats for people. The extremely sufficient and cost saving methods for water and wastewater treatment must be applied. The paper shows possibility of using traditional Dissolved Air Flotation method (DAF) with alternation of feeding gas by ozone (Dissolved Ozone Flotation – DOF) instead of air to obtain better treatment results and possibilities of ...

The management of wastewater sludge, now often referred to as biosolids, accounts for a major portion of the cost of the wastewater treatment process and represents significant technical challenges. In many wastewater treatment facilities, the bottleneck of the sludge handling system is the dewatering operation. Advanced sludge treatment (AST) processes have been developed in order to improve s...

Activated Sludge Treatment is a biological wastewater treatment process which speeds up waste decomposition by adding Activated sludge into wastewater, and the mixture is aerated and agitated for a specified amount of time there by allowing the activated sludge to settle out by sedimentation and is disposed of (wasted) or reused (returned to the aeration tank). It is to everyone’s advantage for...

From a theoretical investigation of the continuity of wastewater organic (COD) and N compounds along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) treating raw and settled wastewater and aerobic digestion unit operations, it was found that the PS characteristics, viz. the biodegradable and unbiodegradable soluble and particulate COD and N...

UNITANK is a biological wastewater treatment process that combines the advantages of traditional activated sludge process and sequencing batch reactor, which is divided into Tank A, B and C. In this study, the sludge distribution and its impact on performance of UNITANK were carried out in Liede Wastewater Plant (WWTP) of Guangzhou, China. Results showed that there was a strong affiliation betw...

An enhanced electrokinetic process for removal of metals (Cr, Cu, Fe, Ni, Pb, Zn) from an industrial wastewater sludge was performed. The electrokinetic experiments were conducted under a constant potential gradient (1.25 V cm(-1)) with processing fluids of tap water (TW), sodium dodecylsulfate (SDS) and citric acid (CA) for 5 days. Results showed that metal removal efficiency of heavy metals f...

Introduction There is a significant and inevitable fact in Turkey which is the “sludge problem” generated from the wastewater treatment plants. There are many sludge disposal techniques currently applied in Turkey such as incineration, landfilling, composting, etc.; but the disposal of sludge with those conventional methods is difficult and expensive, often requiring over 50 per cent of the ope...

A survey of wastewater treatment facilities in the Federated States of Micronesia revealed a lack of fully functional treatment systems and conditions that potentially could lead to adverse environmental impacts and public health concerns. Due to inadequate facilities, the amount and composition of wastewater entering the plants as well as the degree of treatment being achieved is largely unkno...

Solid/liquid separations are a mature technology area and few new developments occurred in seventies and eighties. However, last decade witnessed appearance of a significant number of new innovative systems in this field. (Rubio et al., 2002) This paper describes new developments in mixing, coagulation, flocculation and flotation systems for industrial wastewater treatment. (Ross et al., 2000; ...