Ammonia volatilization from surface-applied poultry litter under conservation tillage management practices

Land application of poultry litter can provide essential plant nutrients for crop production, but ammonia (NH(3)) volatilization from the litter can be detrimental to the environment. A multiseason study was conducted to quantify NH(3) volatilization rates from surface-applied poultry litter under no-till and paraplowed conservation tillage managements. Litter was applied to supply 90 to 140 kg N ha(-1). Evaluation of NH(3) volatilization was determined using gas concentrations and the flux-gradient gas transport technique using the momentum balance transport coefficient. Ammonia fluxes ranged from 3.3 to 24% of the total N applied during the winter and summer, respectively. Ammonia volatilization was rapid immediately after litter application and stopped within 7 to 8 d. Precipitation of 17 mm essentially halted volatilization, probably by transporting litter N into the soil matrix. Application of poultry to conservation-tilled cropland immediately before rainfall events would reduce N losses to the atmosphere but could also increase NO(3) leaching and runoff to streams and rivers.     

Comparison of discharge silver concentrations from electrolytic plating and metallic replacement silver recovery units

Silver-based photographic X-ray film is made of solid crystals of silver chloride or silver bromide suspended in a gelatin and then coated on a film. During the X-ray developing process, the image is processed and the nonimage areas containing solid silver chloride or silver bromide crystals are removed in a solution called the fixer. There may be local environmental regulations that regulate the amount of silver discharged from a facility. To meet these regulations, many facilities have added silver recovery units to their processes. Two different types of recovery processes are in use in a large hospital and three clinics under study. All of the units were claimed by their respective manufacturers to be able to recover silver down to concentrations of 5 mg/L. This concentration would ensure that the building that houses each unit would meet the local county limit of 0.5 mg/L silver for total building silver discharge. The hypothesis for this research is that one system, newer and more expensive, consisting of so-called electrolytic plating units (EPUs) (which are followed by so-called metallic replacement units [MRUs] as a backup), will have better silver recovery than MRUs alone. A total of six units were sampled, three EPUs (in combination with MRUs) and three MRUs. The units were sampled once or twice a day for 10 days for a total of 17 samples from each. The samples then were analyzed by inductively coupled plasma spectroscopy, and an analysis of variance was performed on the results. The range for the electrolytic plating unit/metallic replacement unit combinations was 0.20-99.9 mg/L (mean of 35.15 mg/L; median of 33.8 mg/L). The range for the MRUs alone was 7.2-1112 mg/L (mean of 565.5 mg/L; median of 720 mg/L). Many individual results exceeded 5 mg/L, such that extensive dilution would be required to ensure the building effluent did not exceed 0.5 mg/L. It is suggested that the metallic replacement units be changed to EPUs (with metallic replacement backup units) because they had better silver recovery. Also, the EPU combinations need to be sampled regularly to ensure that their silver concentrations are at acceptable levels.     

Prenatal diagnosis of hunter syndrome

Sixteen pregnancies at risk for Hunter syndrome have been monitored by amniocentesis. Iduronate 2-sulphate sulphatase levels were measured in amniotic fluid, cultured amniotic fluid cells and cord blood. Thirteen of the pregnancies resulted in normal livebirths, two are continuing and one affected pregnancy was terminated. Reduced enzyme levels were observed in either amniotic fluid, cells or cord blood for four female fetuses. Such fetuses are likely to be carriers expressing reduced enzyme levels. The affected male fetus had reduced enzyme activity in amniotic fluid; insufficient cells were cultured for enzyme estimation, however no enzyme activity was detected in fetal liver after termination. Eight cord blood enzyme estimations have been performed, five confirming normal male infants.     

Soil carbon sequestration and associated economic costs for farming systems of the Indo-Gangetic Plain: A meta-analysis

Soil organic carbon sequestration rates over 20 years based on the Intergovernmental Panel for Climate Change (IPCC) methodology were combined with local economic data to determine the potential for soil C sequestration in wheat-based production systems on the Indo-Gangetic Plain (IGP). The C sequestration potential of rice-wheat systems of India on conversion to no-tillage is estimated to be 44.1 Mt C over 20 years. Implementing no-tillage practices in maize-wheat and cotton-wheat production systems would yield an additional 6.6 Mt C. This offset is equivalent to 9.6% of India's annual greenhouse gas emissions (519 Mt C) from all sectors (excluding land use change and forestry), or less than one percent per annum. The economic analysis was summarized as carbon supply curves expressing the total additional C accumulated over 20 year for a price per tonne of carbon sequestered ranging from zero to USD 200. At a carbon price of USD 25 Mg C⁻¹, 3 Mt C (7% of the soil C sequestration potential) could be sequestered over 20 years through the implementation of no-till cropping practices in rice-wheat systems of the Indian States of the IGP, increasing to 7.3 Mt C (17% of the soil C sequestration potential) at USD 50 Mg C⁻¹. Maximum levels of sequestration could be attained with carbon prices approaching USD 200 Mg C⁻¹ for the States of Bihar and Punjab. At this carbon price, a total of 34.7 Mt C (79% of the estimated C sequestration potential) could be sequestered over 20 years across the rice-wheat region of India, with Uttar Pradesh contributing 13.9 Mt C.     

Carbonation of brine impacted fractionated coal fly ash: implications for CO2 sequestration

Coal combustion by-products such as fly ash (FA), brine and CO(2) from coal fired power plants have the potential to impact negatively on the environment. FA and brine can contaminate the soil, surface and ground water through leaching of toxic elements present in their matrices while CO(2) has been identified as a green house gas that contributes significantly towards the global warming effect. Reaction of CO(2) with FA/brine slurry can potentially provide a viable route for CO(2) sequestration via formation of mineral carbonates. Fractionated FA has varying amounts of CaO which not only increases the brine pH but can also be converted into an environmentally benign calcite. Carbonation efficiency of fractionated and brine impacted FA was investigated in this study. Controlled carbonation reactions were carried out in a reactor set-up to evaluate the effect of fractionation on the carbonation efficiency of FA. Chemical and mineralogical characteristics of fresh and carbonated ash were evaluated using XRF, SEM, and XRD. Brine effluents were characterized using ICP-MS and IC. A factorial experimental approach was employed in testing the variables. The 20-150 μm size fraction was observed to have the highest CO(2) sequestration potential of 71.84 kg of CO(2) per ton of FA while the >150 μm particles had the lowest potential of 36.47 kg of CO(2) per ton of FA. Carbonation using brine resulted in higher degree of calcite formation compared to the ultra-pure water carbonated residues.     

Investigating the chromium status,heavy metal contamination,and ecological risk assessment via tannery waste disposal in sub-Saharan Africa (Kenya and South Africa)

Environmental Science and Pollution Research - To mitigate the negative environmental and public health concerns associated with increased industrial discharges amid the rapid industrial growth,...     

Gender influences decisions to change land use practices in the tropical forest margins of Jambi,Indonesia

This study explores the role of gender as a factor in decision making about alternative land use options and in responses to new investment opportunities, which has received little attention to date. An observational study to determine the different factors affecting male and female decisions to change land use at the individual level in a forest margin landscape in Jambi (Sumatra, Indonesia) was combined with a set of role playing games (RPGs) designed to assess participant responses in a simulated social setting of women-only and men-only groups. The RPG included simulated agents offering new opportunities to convert or conserve agroforest. In the study area, rubber (Hevea braziliensis) agroforests that support high biodiversity and carbon storage are giving way to monoculture rubber and oil palm (Elaeis guineensis) plantations. When women from both the upland and lowland villages played the RPGs, external investors proposing logging or oil palm conversion were approached very positively and the resulting land use change was more dynamic and extensive than in the equivalent men-only groups. Consequently, women outperformed men in achieving income targets. In lowland areas gender is strongly associated with land use change, while in the uplands the level of conservation awareness plays a more crucial role in the maintenance of rubber agroforests. Based on the data, and contrary to expectations and gender stereotypes, it is expected that the greater involvement of women in landscape level decision making will increase emissions from deforestation and forest degradation in the area, posing further challenges to efforts to reduce such emissions.     

Economic use value of the Belize marine ecosystem: Potential risks and benefits from offshore oil exploration

The announcement of plans for exploratory oil drilling at a number of offshore sites in Belize raised concerns about the risks associated with drilling, particularly given the socio‐economic importance of the marine ecosystem. The current economic value of fisheries and marine ecotourism is estimated, along with the potential revenue from offshore oil and potential economic losses stemming from oil pollution, under various assumptions on risk and uncertainty. Marine fisheries and ecotourism are estimated to generate around US$ 183 million per year. Single‐year estimated maximum revenue is higher for oil extraction initially but quickly declines; during a 50 year (two generation) period, total discounted benefits from marine fisheries and ecotourism are estimated at US$ 5.1 billion, compared to US$ 3.2 billion from offshore oil revenue. Following a hypothetical oil spill, discounted losses in marine fisheries and ecotourism due to perception and ecological impacts are estimated at US$ 912 million, with clean‐up costs and capital losses of US$ 6.1‐10.4 billion. Considering the short extraction life of oil resources compared to fisheries and ecotourism, the difference in benefits increases substantially in favour of the latter with a longer time horizon. A recent public referendum resulted in a 98% vote against oil exploration and a subsequent annulment of oil concessions pending environmental impact assessments.     

Effects of radiation exposure on brain health: a state of the art and new challenges

Environmental Science and Pollution Research - Good brain health refers to a condition in which a person may fully realize their talents and improve their psychological, emotional, cognitive, and...     

Effectiveness of photocatalytic filter for removing volatile organic compounds in the heating, ventilation, and air conditioning system

Nowadays, the heating, ventilation, and air conditioning (HVAC) system has been an important facility for maintaining indoor air quality. However, the primary function of typical HVAC systems is to control the temperature and humidity of the supply air. Most indoor air pollutants, such as volatile organic compounds (VOCs), cannot be removed by typical HVAC systems. Thus, some air handling units for removing VOCs should be added in typical HVAC systems. Among all of the air cleaning techniques used to remove indoor VOCs, photocatalytic oxidation is an attractive alternative technique for indoor air purification and deodorization. The objective of this research is to investigate the VOC removal efficiency of the photocatalytic filter in a HVAC system. Toluene and formaldehyde were chosen as the target pollutants. The experiments were conducted in a stainless steel chamber equipped with a simplified HVAC system. A mechanical filter coated with Degussa P25 titania photocatalyst and two commercial photocatalytic filters were used as the photocatalytic filters in this simplified HVAC system. The total air change rates were controlled at 0.5, 0.75, 1, 1.25, and 1.5 hr(-1), and the relative humidity (RH) was controlled at 30%, 50%, and 70%. The ultraviolet lamp used was a 4-W, ultraviolet-C (central wavelength at 254 nm) strip light bulb. The first-order decay constant of toluene and formaldehyde found in this study ranged from 0.381 to 1.01 hr(-1) under different total air change rates, from 0.34 to 0.433 hr(-1) under different RH, and from 0.381 to 0.433 hr(-1) for different photocatalytic filters.