Treated wastewater discharged from more than 400 onsite wastewater treatment systems (OWTS) near the Civic Center area of Malibu, California, 40 km west of downtown Los Angeles, composes 28% of the recharge to a 3.4 km(2) alluvial aquifer. On the basis of δ(18) O and δD data, the fraction of wastewater in some samples was >70%. Ammonium and nitrate concentrations in water from 15 water-table we...

Zero-valent iron (ZVI) application in groundwater remediation is limited by its vulnerability to passivation, which significantly decreases its surface reactivity. Both biological and chemical processes can potentially passivate ZVI, although the understanding of biological passivation is limited. This study was conducted in bench-scale reactors packed with fresh ZVI or ZVI pre-exposed to nitra...

Although interest in biomarkers in the nitrate-nitrite-NO pathway has recently increased, associations between nitrite (NO2(-)) and nitrate (NO3(-)), and asthma, allergic sensitisation and rhinitis remain unclear. The study aimed to evaluate the associations between NO2(-)/NO3(-) and exhaled fraction of nitric oxide (FeNO) levels with asthma, allergic sensitisation and rhinitis. Plasma and exha...

The advantages of using multispectral remotely sensed data instead of CORINE Land Cover for the modelling of nitrate concentrations in the leachate of the Rur catchment are presented and discussed in this paper. In this context it has been shown that the identification of main crops and annual crop rotation in the Rur catchment by SPOT, LANDSAT and ASTER imagery provides the key for a spatial a...

Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO3) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable is...

Agricultural-induced increase of nitrate (NO3) loading in groundwater is a worldwide problem. This study investigates the impacts of agricultural activities on groundwater NO3 pollution in a Yellow River irrigated region. The agricultural land use patterns are dependent on the land and water conditions. Besides wheat–maize rotation, the most popular cultivation pattern, other patterns with high...

Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewater with high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO) and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal from synthetic wastewater was investigated. Experiments were conducted in mov...

In the framework of understanding the transport mechanism that governs the filtration of NO3- solution through a γ-Al2O3 membrane with a nominal pore size of 5 nm at low ultrafiltration, a series of various types of nitrate solutions and operating conditions were investigated. The effect of filtration parameters such as pH, applied pressure and NO3- concentration on the selectivity and permeabi...

The removal of nitrate (NO3−-N) and antibiotics in aquaculture tail water is urgent necessary. A lab-scale up-flow immobilized biofilter (I-BF) filled with polyurethane foam (PUF) carriers a microbial consortium was developed for simultaneous tetracycline (TC). denitrification TC performance the I-BF reactor investigated under different concentrations (0, 10, 50, 100 mg·L−1), carbon/nitrogen (C...

Excessive nitrate leaching from the U.S. Corn Belt has created serious water quality problems and contributed to the expansion of the hypoxic zone in the Gulf of Mexico. We evaluated the effect of implementing the late spring nitrate test (LSNT) for corn (Zea mays L.) grown within a 400-ha, tile-drained subbasin in central Iowa. Surface water discharge and NO3 concentrations from the treated su...