Phosphorus runoff from agricultural land and direct fertilizer effects: a review

Phosphorus (P) is one of the most important mineral nutrients in agricultural systems, and along with nitrogen (N), is generally the most limiting nutrient for plant production. Farming systems have intensified greatly over time, and in recent years it has become apparent that the concomitant increase in losses of N and P from agricultural land is having a serious detrimental effect on water quality and the environment. The last two decades have seen a marked increase in research into the issues surrounding diffuse losses of P to surface and ground water. This paper reviews this research, examining the issue of P forms in runoff, and highlighting the exceptions to some generally held assumptions about land use and P transport. In particular the review focuses on P losses associated with recent P fertilizer application, as opposed to organic manures, both on the amounts and the forms of P in runoff water. The effects of the physicochemical characteristics of different forms of P fertilizer are explored, particularly in relation to water solubility. Various means of mitigating the risk of loss of P are discussed. It is argued that the influence of recent fertilizer applications is an under-researched area, yet may offer the most readily applicable opportunity to mitigate P losses by land users. This review highlights and discusses some options that have recently become available that may make a significant contribution to the task of sustainable management of nutrient losses from agriculture.     

Nanotechnology for improved production of algal biofuels: a review

Environmental Chemistry Letters - Fossil fuel depletion and carbon dioxide emissions are calling for carbon neutral energies such as algal biofuels, yet actual production of agal biofuels is...     

Factors affecting urban electricity consumption: a case study in the Bangkok Metropolitan Area using an integrated approach of earth observation data and data analysis

Environmental Science and Pollution Research - Urbanization induces shifts in surface environmental factors, including impervious surface expansion, green space loss, and temperature increase in...     

Arsenic-contaminated groundwater and its potential health risk: A case study in Long An and Tien Giang provinces of the Mekong Delta,Vietnam

Environmental Science and Pollution Research - The occurrence of arsenic (As) in groundwater (drilled well water) that were used for drinking, cooking, and personal hygiene and its risks to human...     

Use of an exchange method to estimate the association and dissociation rate constants of cadmium complexes formed with low-molecular-weight organic acids commonly exuded by plant roots

Organic acids released from plant roots can form complexes with cadmium (Cd) in the soil solution and influence metal bioavailability not only due to the nature and concentration of the complexes but also due to their lability. The lability of a complex influences its ability to buffer changes in the concentration of free ions (Cd); it depends on the association (, m mol s) and dissociation (, s) rate constants. A resin exchange method was used to estimate and (m mol s), which is the conditional estimate of depending on the calcium (Ca) concentration in solution. The constants were estimated for oxalate, citrate, and malate, three low-molecular-weight organic acids commonly exuded by plant roots and expected to strongly influence Cd uptake by plants. For all three organic acids, the and estimates were around 2.5 10 m mol s and 1.3 × 10 s, respectively. Based on the literature, these values indicate that the Cd- low-molecular-weight organic acids complexes formed between Cd and low-molecular-weight organic acids may be less labile than complexes formed with soil soluble organic matter but more labile than those formed with aminopolycarboxylic chelates.     

Enteric Viruses in a Large Waterborne Outbreak of Acute Gastroenteritis in Finland

In Nokia city about 450,000 l of treated sewage water was for 2 days allowed to run into the drinking water supplies of the city due to a personal error of one employee. Within the next 5 weeks about 1,000 people sought care at the municipal health centre or regional hospital because of gastroenteritis. Here we report the results of viral analyses performed by gene amplification assays from the earliest water and sewage samples as well as from close to 300 patient samples. The contaminating treated sewage was shown to harbour several enteric viruses known to cause acute gastroenteritis. Likewise, the drinking water sample was positive for noro-, astro-, rota-, entero- and adenoviruses. Noroviruses were also found in 29.8% of stool samples from affected patients, while astro-, adeno-, rota- and enteroviruses were detected in 19.7, 18.2, 7.5 and 3.7% of the specimens, respectively. An erratum to this article can be found at     

Simulation of retention and transport of copper,lead and zinc in a paddy soil of the Red River Delta,Vietnam

Heavy metal (HM) contaminations in the topsoil around handicraft villages with non-ferrous heavy metal recycling in the Red River Delta can impose serious threats to the subsoil as well as to the groundwater quality. This feature is very important for paddy soils due to relatively high leaching rates and the dissolution of Fe–Mn oxides under reducing conditions which can accelerate the amount of HM translocated to the subsoil and groundwater.The transport of Cu, Pb and Zn in paddy soils was simulated by numerical modeling of non-equilibrium solute transport with an adaptation of the Hydrus-1D model. For the simulation, a water layer on the soil surface was included, from which HM can infiltrate into the soil depending on the soil hydraulic properties. Sorption coefficients, obtained from batch experiments were used as input data for the simulations. Calculated leaching rates were compared with the binding forms of HM in the samples.The simulations show that leaching rates decrease in the order: Zn > Cu > Pb. This order is confirmed by the results of sequential extractions. Under constant flooded conditions at a water table of 20 cm, Cu, Pb and Zn were estimated to reach the soil depth of 1 m within 470, 495 and 370 days, respectively, emphasizing that reactive pollutants can reach groundwater in a relatively short time. A change of the water layer from 1 to 30 cm can accelerate the leaching rate of HM up to 36%. The hard pan layer was observed to induce a hysteresis in hydraulic conductivity and slow down the movement of HM. Uncertainties in modeling arise as several parameters in the simulation can be determined only with significant errors. However, Hydrus-1D is a suitable tool for simulation of the transport of HM in paddy soils.     

Biocatalytic polymeric membranes to decrease biofilm fouling and remove organic contaminants in wastewater: a review

The presence of recalcitrant contaminants in wastewater is major challenge to decrease pollution and associated health issues. As a consequence, membrane technologies have recently attracted industrial attention, yet a major setback of membrane employment is membrane fouling which leads to frequent discarding of membrane modules. More than 45% of all membrane fouling cases are caused by biofilms that are resistant to antimicrobial agents. Here we review polymeric membranes with antifouling properties, with focus on surface properties, fabrication, characterization, biocatalysis using enzymes and application towards the removal of dyes, phenol, pesticides and fertilizers. Nano-engineered fabrication of polymeric membranes allow to decrease fouling by 80–90%. Immobilized oxidoreductases in polymeric membranes allow 65–98% removal contaminants in wastewater.

     

Formation,antimicrobial activity,and biomedical performance of plant-based nanoparticles: a review

Environmental Chemistry Letters - Because many engineered nanoparticles are toxic, there is a need for methods to fabricate safe nanoparticles such as plant-based nanoparticles. Indeed, plant...