The objective of this research was to advance a fundamental understanding of a unique post-anoxic denitrification process for achieving biological nutrient removal (BNR), with an emphasis on elucidating the impacts of surface oxygen transfer (SOT), variable process loadings, and bioreactor operational conditions on nitrogen and phosphorus removal. Two sequencing batch reactors (SBRs) were opera...

Fish-meal factories generate waste waters with high chemical oxygen demand (COD), suspended solids (SS), fats and protein concentrations. After their treatment by anaerobic digestion, effluents with high ammoniaand organic-nitrogen contents and a fraction of residual COD are produced. A biological nitrification/denitrification process is proposed to reduce both the residual carbon and the nitro...

As a first step of treatment of landfill leachates (total COD – 1,430-3,810 mg/l, total nitrogen 90162 mg/l), a performance of laboratory UASB reactors has been investigated under mesophilic (30 C), sub-mesophilic (20 C) and psychrophilic (10 C) conditions. Under hydraulic retention times (HRT) of around 7 h, when the average organic loading rates (OLR) were around 5 g COD/l/day, the total COD ...

In this research, constructed wetlands were applied to remove the nitrogen of lightly polluted wastewater from a wastewater treatment plant in Tangshan. The results showed that a favorable removal effect of nitrogen could be obtained through constructed wetland. Moreover, the aeration device added to the bottom could increase the removal rates of ammonia nitrogen in lightly polluted wastewater,...

The advantages associated with the use of membrane bioreactors (MBR) in wastewater treatment are widely known [1]. MBR have been recently applied to the biological nutrients removal from wastewater, especially nitrogen and phosphorus. Recent studies [2; 3] have demonstrated that the operation of MBR in sequencing batch results in benefits to the treatment system and can be an interesting altern...

In order to deal with the environmental problems associated with animal production industrialization and at the same time considering energy costs increasing, a piggery wastewater treatment process consisting of combined anaerobic digestion and biological nitrogen removal by activated sludge was developed. This contribution presents a modelling framework in order to optimize this process. Modif...

Over the past few years, new technologies for nitrogen removal have been developed mainly because of the increasing financial costs of the traditional wastewater treatment technologies. Newly discovered pathways, like the anaerobic oxidation of ammonium (ANAMMOX), and uses for nitrogen removal technologies are under discussion. Processes and technologies such as: Partial nitrification; Single r...

This study describes the biological degradation of TNT by using induced aeration. Three plastic reactors were used. In each reactor 3 kg of soil were used. In order to increase the porosity of the soil, sawdust was added to soil. Textile wastewater treatment plant sludge was also added to soil. TNT at the concentrations of 1000 mg/kg of soil was added thereafter. Rhamnolipid biosurfactant at th...

Denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (N2) through a series of intermediate nitrogen compounds.Vermiculite is a hydrous phyllosilicate mineral (Mg, Fe+2,Fe+3)3[(Al,Si)4O10](OH)2·4H2O with several layers for bacterial immobilization. The goal of this study was removal of nitrate from water with vermiculi...

In Korea, more than 80% of municipal wastewater treatment plants (WWTPs) with capacities of 500 m3·d-1 or more are capable of removing nitrogen from wastewater through biological nitrification and denitrification processes. Normally, these biological processes show excellent performance, but if a toxic chemical is present in the influent to a WWTP, the biological processes (especially, the nitr...