abstract   background: the compounds which contain nitrogen entering the environment can cause some problems, such as eutrophication for water resources and potential risk for human health because of methemoglobinemia and cancer. biological techniques are effective in removing nitrate. the aim of this study was to remove nitrate from groundwater using denitrification. the main objectives of thi...

background: the modeling aims to simulate or optimize a process in physical, chemical or biological environments and the derived model will provide a considerable assistance to generate data and predict unknown condition, in case of sufficient suitability. unsuitable disposal and elimination of waste tires have polluted the environment and human life areas, it also have caused removal of a huge...

backgrounds and aims: ammonia removal from air to prevent severe damage to the environment and living organisms is very important. biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. the aim of this study is to investigate the efficiency of biological filtration using a compost and scallop bed for ammonia removal. ...

The ever-expanding world-wide application of biological nutrient removal (BNR) technology is generating a greater appreciation for the performance of BNR processes under different operating conditions. This paper examines the effects of high process temperature on the biological phosphorus and nitrogen removal mechanisms and the sludge settling properties in BNR activated sludge processes. Thes...

This paper deals with control of bulking by chlorination in a laboratory-scale (15l/ d) biological nutrient removal system. Bulking was caused by filamentous organisms characteristic of nutrient removal systems, i.e. Type 0092, Microthrix parvicella and Type 0914. Over a continuous dosing period of 19 d, at 8 mgCl2 /gMLSS.d the diluted sludge volume index (DSVI) decreased from 230 to 48 ml/g. N...

introduction: antibiotics as a  type of pharmaceutical compounds are widely used in modern medicine and veterinary industries. they enter the environment in different ways, including agricultural runoff, direct discharge of urban wastewater treatment or human waste, direct disposal of medical, veterinary industrial waste and etc. antibiotics have been able to influence the microbial population....

[1] We present a conceptual approach for evaluating the biological and hydrological controls of nutrient removal in different sized rivers within an entire river network. We emphasize a per unit area biological parameter, the nutrient uptake velocity (nf), which is mathematically independent of river size in benthic dominated systems. Standardization of biological parameters from previous river...