Different methods of urban sewage sludge energy recovery such as burning, gasification, pyrolysis and digestion based on the net energy production efficiency, advantages and disadvantages and complexity of these processes have been investigated in this article. The best method for energy production from sludge was selected among different methods according to energy and the amount of the greenh...

Seeding of nitrifying bacteria into the activated sludge process was studied both theoretically and experimentally. A simple model was developed for prediction of the effects of seeding of nitrifying bacteria from a separate stage into the activated sludge process. The purpose of seeding is to improve the treatment results and the process stability as well as to decrease the volume requirements...

This work experimentally elucidates the efficiencies of sono-alkalization treatment on municipal sewage sludge. The total solids (TS) concentration of the sewage sludge was pre-adjusted at 29.7 g/L. Two parameters such as sodium hydroxide (NaOH) dosage and sonication time were considered by the central composite design (CCD) program to investigate the effect on the degradation of phthalate acid...

Sewage sludge is generated as a result of treating municipal wastewater to remove organic and inorganic impurities from dilute solutions. The treatment results in concentrating the impurities into a smaller volume of liquid, called sludge. The main processes involve sludge stabilisation, dewatering and incineration. The major objective of stabilisation is to make the sludge less odorous and put...

Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sinteri...

How do you feel when you hear the words " wastewater, " " sludge, " " sewer, " and " sewage " ? These words may make you feel uncomfortable. However, as Victor Hugo wrote in " Les Misérables, " these words are inevitably related to human society (16): " ... The history of men is reflected in the history of sewers. The Germoniae narrated Rome. The sewer of Paris has been an ancient and formidabl...

The effects of hydraulic retention time (HRT) and influent COD concentration (CODInf) on Specific Methanogenic Activity (SMA) and the biodegradability of an anaerobic sludge need to be elucidated because of the discordant results available in literature. This information is important for the operation of anaerobic reactors and design of the sludge post-treatment unit. For this study, sludge sam...

A 69-day experimental study was conducted to investigate the treatment process of municipal wastewater using submerged membrane bioreactor technology. The results show that the average removal rate of COD and BOD5 were over 90%. The removal rate of NH3-N was 99% and the concentration of effluent NH3-N was below 0.5mg/L; because of the high DO value in the denitration sect, the denitrobacteria w...

The present work provides an overview of technological measures to increase the self-sufficiency of wastewater treatment plants (WWTPs), in particular for the largely diffused activated sludge-based WWTP. The operation of WWTPs entails a huge amount of electricity. Thermal energy is also required for pre-heating the sludge and sometimes exsiccation of the digested sludge. On the other hand, the...