Many larger wastewater treatment plants use Anaerobic Digestion, a bacterial process that is carried out in the absence of oxygen. Compared to the conventional activated sludge process, Anaerobic Digestion is more energy efficient, reduces dewatered biosolids by 7-12 times (as compared to conventional processes) and produces useful methane gas (biogas). Gardner Denver Nash liquid ring pumps and...

INTRODUCTION Small wastewater treatment plants (SWTP) are here defined as plants with a size less than about 2000 p.e., or with a daily load less than 1000 m/d and 200 kg BOD/d. There are, however, no such exact limits in reality. Therefore, plants up to 5000 p.e. are some times included. The interesting thing is that several practical conditions are more or less of the same type for this class...

background wastewaters with high salt content disturb the metabolic function of microorganisms causing plasmolysis or activity loss in microorganisms, so the efficiency of biological treatment of saline wastewater by conventional microorganisms will decrease. objectives this study aimed to find the outbreak of disorder in the biological wastewater treatment process and how much salt leads to lo...

Three full-scale Australian wastewater treatment plants are reviewed to present the ‘lessons learnt’ so far in developing an improved design and operating strategy able to efficiently achieve biological nitrogen removal and phosphorus removal. The success of the ‘state of the art’ wastewater treatment plants is based on the development and refinement of existing nutrient removal process models,...

A new biofilm reactor for wastewater treatment, the moving bed biofilm reactor (MBBR), is discussed. A general description of the reactor is given. Results from investigations of different applications (carbonaceous removal, nitrification and nitrogen removal) when used for municipal wastewater treatment, are discussed. Design values are given and it is demonstrated that use of this reactor res...

BACKGROUND In recent years, decreasing annual rainfalls in some countries and population growth have led to a shortage of freshwater resources. Thus, recycled wastewaters has been suggested for agricultural activities. Contamination of wastewaters with pathogens is a major concern for the use of these waters. This study aimed to (i) investigate the occurrence of helminth eggs and protozoan (oo)...

The development of titrimetric sensor applications to monitor biological wastewater treatment processes is shortly described, and the measurement principle (based on a pH controller) is illustrated. 3 applications that were developed during the past years are used to illustrate the capabilities of titrimetric sensors. The ammonium and the nitrate concentration can be measured to monitor the nit...

In the contribution a (non-exhaustive) overview is given on the use of mathematical models in control systems of wastewater treatment plants. As a starting point, the four building blocks of any controlled process are used, 1) the process itself, 2) the actuators that allow manipulation of the process, 3) the control algorithm that calculates a proper action for disturbance rejection or setpoin...

The occurrence of Clostridium difficile in nine wastewater treatment plants in the Ticino Canton (southern Switzerland) was investigated. The samples were collected from raw sewage influents and from treated effluents. Forty-seven out of 55 characterized C. difficile strains belonged to 13 different reference PCR ribotypes (009, 010, 014, 015, 039, 052, 053, 066, 070, 078, 101, 106, and 117), w...