linear alkylbenzene sulfonate (labs) is an anionic surfactant widely used all over the world. they will eventually end-up and accumulate in household or industrial sewage. due to their high foaming capabilities which can cause numerous problems in sewage treatment facilities as well as direct toxic effects on many different organisms in ecosystem they are generally considered as serious polluta...

the activated sludge process simply involves bringing together wastewater and a mixed culture of microorganisms under aerobic conditions. the system usually includes a secondary treatment given to the settled sewage, and requires an environment in which active microorganisms are maintained in intimate contact with wastewater in the presence of sufficient oxygen. in this study, the treatment of ...

Fats and oils are the most common contaminants in wastewater and are usually discarded 17 through physical processes. This paper studies its elimination through an environmentally friendly 18 biological treatment, yielding good results on both laboratory scale and in the field. In this study a 19 comparative evaluation of the biodegradation of fats and oils in two scenarios were developed in 20...

This paper presents three new approaches to reduce excess sludge production in activated sludge systems: 1) modification of conventional activated sludge process with insertion of a sludge holding tank in the sludge return line; 2) chlorination of excess sludge so as to minimize excess sludge production; and 3) utilization of a metabolic uncoupler, 3, 3', 4', 5-Tetrachlorosalicylanilide (TCS) t...

Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results ind...

It is important to understand the adsorption mechanism of chemicals and active pharmaceutical ingredients (API) on sewage sludge since wastewater treatment plants are the last barrier before the release of these compounds to the environment. Adsorption models were developed considering mostly hydrophobic API-sludge interaction. They have poor predictive ability, especially with ionisable compou...

Continuous monitoring of ammonia removal by microbial complexes and observation of their morphology were carried out using a microdevice. Consumption of NH(4)(+) ions by active sludge could clearly be recorded over 48 h. Aggregation of the sludge could be observed in parallel by using confocal reflection microscopy.

The mechanical properties of dewatered, anaerobically digested sewage sludge were determined from soil laboratory tests. The sludge material is largely composed of organic clay sized-particles, a sizable fraction of which is in an active state of biological digestion which can continue over many years under field conditions. Moderately digested sludge material was found to have a typical specif...

Formation of excessive sludge and fuel filter clogging were experienced in using biodiesel blends under marine environment. In this study, a field test was conducted in a marine ferry boat fueled by canola-based biodiesel blends. The sludge materials collected in the fuel purifier were characterized using inductively coupled plasma (ICP), pyrolysis-GC/MS (Py-GC/MS), thermogravimetric analysis (...

The agent in wastewater sludge previously shown to reduce the heat required to inactivate reovirus (R. L. Ward and C. S. Ashley, Appl. Environ. Microbiol. 34:681--688, 1977) was "separated" from other sludge components and analyzed by infrared spectroscopy. The infrared spectrum of this material was quite similar to the spectra of commercial anionic detergents, and subsequent analyses of the fr...