Major and trace element partitioning between dissolved and particulate phases in Antarctic surface snow

In order to provide a new insight into the Antarctic snow chemistry, partitioning of major and trace elements between dissolved and particulate (i.e. insoluble particles, >0.45 μm) phases have been investigated in a number of coastal and inland snow samples, along with their total and acid-dissolvable (0.5% nitric acid) concentrations. Alkaline and alkaline-earth elements (Na, K, Ca, Mg, Sr) were mainly present in the dissolved phase, while Fe and Al were predominantly associated with the particulate matter, without any significant difference between inland and coastal samples. On the other hand, partitioning of trace elements depended on the sampling site position, showing a general decrease of the particulate fraction by moving from the coast to the plateau. Cd, Cu, Pb and Zn were for the most part in the dissolved phase, while Cr was mainly associated with the particulate fraction. Co, Mn and V were equally distributed between dissolved and particulate phases in the samples collected from the plateau and preferentially associated with the particulate in the coastal samples. The correlation between the elements and the inter-sample variability of their concentration significantly decreased for the plateau samples compared to the coastal ones, according to a change in the relative contribution of the metal sources and in good agreement with the estimated marine and crustal enrichment factors. In addition, samples from the plateau were characterised by higher enrichment factors of anthropogenic elements (Cd, Cr, Cu, Pb and Zn), compared to the coastal area. Finally, it was observed that the acid-dissolvable metal concentrations were generally lower than the total concentration values, showing that the acid treatment can dissolve only a given fraction of the metal associated with the particulate (<20% for iron and aluminium).     

Will ASEAN countries be a potential choice for the export of pollution intensive goods?

Environmental Science and Pollution Research - China, being the world’s largest exporter, has now certain environmental commitments such as to achieve carbon neutrality before 2060. These...     

Bioaccessibility of metals in soils: comparison between chemical extractions and in vitro tests

It is well-known that the total metal content in soils is not a good indicator of their harmful effects, leading to an overestimation of risks. Toxicological and environmental hazards depend on the chemical species and on its bioavailability to target organisms. Because a good estimation of bioavailability is difficult, a good compromise is to assess bioaccessibility, defined as the maximum amount of a pollutant which is potentially absorbable by a target organism. This study presents a comparison of different strategies to measure metal bioaccessibility in soils. Three procedures were applied to real soil samples with different levels of metal contamination: pseudo-total metal attack, selective sequential extractions and in vitro tests (deliberately developed to simulate human or mammals digestion). Considering the first step of the selective extraction procedure, which can provide the bioaccessible fraction for deposit-feeder organisms, data obtained for each metal were lower than those obtained from in vitro tests. Therefore, it is possible to highlight that this extraction tends to underestimate metal bioaccessibility in soils for humans, while in vitro tests certainly will overestimate bioaccessibility for organisms as invertebrates. If the sum of first and second step of sequential procedure is considered, results are quite similar to those obtained from in vitro tests, but this kind of procedure would require two days of work rather than a few hours required to perform an in vitro test. Results highlight the diversity among the differently defined bioaccessible fractions and the need to apply the most suitable procedure depending on the target organism.     

Electrochemical reduction of carbon dioxide into valuable chemicals: a review

Environmental Chemistry Letters - Global warming is partly caused by massive emissions of carbon dioxide (CO2), a greenhouse gas, in the atmosphere by industrial and other human activities....     

Site selection in CO2 ocean sequestration: Dependence of CO2 injection rate on eddy activity distribution

Site selection in CO₂ ocean sequestration is examined based on the idea that a site where injected CO₂ is efficiently diluted is favourable in reducing/avoiding biological impacts. Simulations of CO₂ injection into several sites by an eddy-resolving oceanic general circulation model (OGCM) show that the maximum CO₂ concentration differs by a factor of 10 among sites. The distribution of eddy activity is the most important causative factor producing the geographical differences in CO₂ dilution. Based on the relationship between the maximum CO₂ concentration and eddy activity, we estimated the distribution of the maximum CO₂ injection rate by a proposed method, which does not cause chronic impacts on biota. Around Japan, extensive ocean volume has the potential to dilute 20 million tonnes per year without chronic impacts, and some areas can be injected with 80 million tonnes per year.     

Radiant Domestic Combustion Stove System: Experimental and Simulated Study of Energy Use and Thermal Comfort

A steady-state space radiant heat model and a stove combustion model are developed to simulate the heat exchanges between various surfaces in the room and the stove and stack surfaces, assuming stiochiometric combustion inside the stove and the exhaust gases flow out through the stack by natural convection. The space heat model calculates the fuel consumption, the stove, stack temperatures, and the mass flow rate of exhaust gases, and provides an opportunity to study the energy efficiency of the stove, while satisfying the constraints of thermal comfort. Fanger (1982) Fanger, P. O. 1982. Thermal Comfort Analysis and Applications in Engineering, 156–198. New York: McGraw Hill.  [Google Scholar] model and a radiation exchange model between various surfaces of the space, the thermal building energy balance, and stove combustion process is applied to determine the mean radiant temperature (MRT) and the extent of thermal comfort as determined by predicted mean vote (PMV).

The overall model is validated by performing experiments in a room placed inside a controlled outdoor environment. The room is heated using a domestic stove common for rural areas of Lebanon and the MRT, the room air temperature, the walls and window temperatures are measured at two stove positions. The measured MRT, the average room temperature, and the wall surface temperatures agreed within ±7% of values predicted by the numerical model.

A parametric study is performed to optimize the stove and occupant locations in the room where adequate comfort level can be maintained at lower fuel consumption levels. The values of MRT and PMV depend strongly on the position of the radiant stove heater and stack with respect to the cold window and the occupant location. It is shown that it is possible to save up to 15% in stove fuel consumption by changing the stove position in the room with respect to the window and to the person, while maintaining the same level of comfort.     

Effect of MBT on landfill behavior: an Italian case study

Bad choices in municipal waste (MW) management cause negative effects on sustainability. Evolving regulation has identified prevention and recycling as the best strategies; nevertheless, disposal in landfilling sites plays an essential role since a complete zero-waste scenario is not realistic, currently. Nowadays, policies require a preliminary waste stabilization to decrease the putrescible content. Therefore, mechanical biological treatment (MBT) has replaced the previous crushing, aimed at simple volume reduction. Literature has proved the effectiveness of MBT when MW collection system is ineffective. The present paper considered a facility in an area with a high-performance MW collection system. A long-term (1999–2019) on-site sampling allowed the comparison between two sites of the facility: the old site (before the MBT activation) and the new area, where the stabilized waste is disposed of. Monitoring of biogas, leachate (analyzed parameters: pH, BOD₅, COD, ammonia-nitrogen) and odorous emissions was performed to verify the effect of the stabilization process. The considered long period and the on-site sampling support the relevance of the results, compared to the available literature, often referred to as laboratory scale. The results proved the relatively low benefit of stabilization at the considered facility, which cannot justify the energy consumption of MBT.

     

Do voluntary pollution reduction programs (VPRs) spur or deter environmental innovation? Evidence from 33/50

We study whether a government-sponsored voluntary pollution reduction program (VPR) promotes or deters the development of new environmental technologies that yield future emission reduction benefits. Using a panel of 127 U.S. manufacturing industries defined by 3-digit SIC classifications over the 1989–2004 period, we estimate impacts of industry-level participation in the 33/50 program, a VPR initiated by government regulators in 1991, on industry-level rates of environmental patenting. We find that higher rates of 33/50 program participation are associated with significant reductions in the number of successful environmental patent applications five to nine years after the program ended.     

Cost-effective treatment of sludge conditioning using supernatant fluid polyelectrolyte

Environmental Science and Pollution Research - Treatment of activated sludge using pure polyelectrolyte and its supernatant fluids for sludge dewatering was examined. The supernatant was used for...     

Sediment microbial fuel cells for bioremediation of pollutants and power generation: a review

Environmental Chemistry Letters - Worldwide pollution of almost all natural media by toxic compounds is a major public health issue requiring the development of advanced remediation techniques such...