Graphical effluent quality control for compliance monitoring: What is a violation?

Demonstration of compliance with discharge (effluent) requirements suffers because Discharge Monitoring Reports (DMRs) give neither the discharger nor the regulator information on the process mean which ensures compliance. To obtain this information, a simple graphical method is presented which takes into account process variability. This technique provides quality control specifications for the monitoring data and the process itself.     

The oxidative polymerization of aromatic molecules in the interlayer of montmorillonites studied by resonance Raman spectroscopy

The adsorption and reaction of aromatic molecules in the interlayer of transition-metal ion(Cu²⁺, Fe³⁺, Ru³⁺)-exchanged montmorillonites have been investigated by resonance Raman spectroscopy. Some mono-substituted benzenes are found to form cation radicals of 4,4′-substituted biphenyl together with those having the composition of the parent molecules. Benzene, biphenyl and p-terphenyl polymerize to form the poly-p-phenylene cation. Thus, the cation radicals or cations may remain stable when para-positions of the benzene ring are occupied by a stable substituent, or undergo polymerization when the para-position is open. Phenols behave differently in that the polymerization via the ortho-position also occurs and the reaction is faster in aerobic than in anearobic conditions.     

Seasonal variations of natural ventilation and radon-222 exhalation in a slightly rising dead-end tunnel

The concentration activity of radon-222 has been monitored, with some interruptions, from 1997 to 2005 in the end section of a slightly rising, dead-end, 38-m long tunnel located in the Phulchoki hill, near Kathmandu, Nepal. While a high concentration varying from 6 x 10(3) Bq m(-3) to 10 x 10(3) Bq m(-3) is observed from May to September (rainy summer season), the concentration remains at a low level of about 200 Bq m(-3) from October to March (dry winter season). This reduction of radon concentration is associated with natural ventilation of the tunnel, which, contrary to expectations for a rising tunnel, takes place mainly from October to March when the outside air temperature drops below the average tunnel temperature. This interpretation is supported by temperature measurements in the atmosphere of the tunnel, a few meters away from the entrance. The temporal variations of the diurnal amplitude of this temperature indeed follow the ventilation rate deduced from the radon measurements. In the absence of significant ventilation (summer season), the radon exhalation flux at the rock surface into the tunnel atmosphere can be inferred; it exhibits a yearly variation with additional transient reductions associated with heavy rainfall, likely to be due to water infiltration. No effect of atmospheric pressure variations on the radon concentration is observed in this tunnel. This experiment illustrates how small differences in the location and geometry of a tunnel can lead to vastly different behaviours of the radon concentration versus time. This observation has consequences for the estimation of the dose rate and the practicability of radon monitoring for tectonic purposes in underground environments.     

Human health risk assessment due to dietary intake of heavy metals through rice in the mining areas of Singhbhum Copper Belt,India

Environmental Science and Pollution Research - The study was intended to investigate heavy metal contamination levels in the rice grown in the vicinity of the mining areas of Singhbhum Copper Belt,...     

The determination of carbonyl compounds in air using a robotic sampling preparation system integrated to a gas chromatograph with a nitrogen-phosphorus detector

A totally automated solid phase extraction gas chromatography procedure was developed for the sampling and analysis of carbonyl compounds in air. In this system, two PrepStation modules were used, one for the preparation and elution of 2,4-dinitrophenylhydrazine silica cartridges, and the other for air sampling. The sample collected by the sampling module was eluted to an autosampler vial in the PrepStation module and then transferred to the gas chromatograph for analysis via a robotic arm. The sampling module was modified to enable air sampling via an external pump. A typical run by this technique required 142 min, 100 min for air sampling and 42 min for the other operations, including a GC analysis time of 25 min. Recoveries of at least 85% were obtained for all compounds studied. The detection limits for formaldehyde, acetaldehyde and acetone were 2.2, 2.7 and 2.2 ppbv, respectively. All operations, including the conditioning of the cartridges, were performed without any intervention from the analyst.     

Risk assessment due to intake of heavy metals through the ingestion of groundwater around two proposed uranium mining areas in Jharkhand,India

Heavy metal pollution of water resources can be apprehended in East Singhbhum region which is a highly mineralised zone with extensive mining of copper, uranium and other minerals. Ten groundwater samples were collected from each site and the heavy metal analysis was done by atomic absorption spectrophotometer. Analysis of the results of the study reveals that the concentration of iron, manganese, zinc, lead, copper and nickel in groundwater of Bagjata mining area ranged 0.06–5.3 mg l^− 1, 0.01–1.3 mg l^− 1, 0.02–8.2 mg l^− 1, 1.4–28.4 μg l^− 1, 0.78–20.0 μg l^− 1 and 1.05–20.1 μg l^− 1, respectively. In case of Banduhurang mining area, the range was 0.04–2.93 mg l^− 1, 0.02–1.1 mg l^− 1, 0.01–4.68 mg l^− 1, 1.04–33.21 μg l^− 1, 1.24–18.7 μg l^− 1 and 1.06–14.58 μg l^− 1, respectively. The heavy metals were found to be below the drinking water standards (IS:10500 1993) except iron (0.3 mg l^− 1) and manganese (0.1 mg l^− 1). The hazard quotients of the heavy metals for drinking water were below 1 posing no threat due to intake of water to the people for both the areas.     

Degradation kinetics of forchlorfenuron in typical grapevine soils of India and its influence on specific soil enzyme activities

The rate of degradation of forchlorfenuron, a cytokinin-based plant growth regulator (PGR) was explored in typical grapevine soils of India with simultaneous evaluation of its effect on biochemical attributes of the test soils in terms of the activities of specific soil microbial enzymes. In all the test soils, namely clay, sandy-loam and silty-clay, the dissipation rate was faster at the beginning, which slowed down with time, indicating a non-linear pattern of degradation. Degradation in soils could best be explained by two-compartment 1st + 1st order kinetics with half-life ranging between 4–10 days. The results suggest that organic matter might be playing a major role in influencing the rate of degradation of forchlorfenuron in soil. The rate of degradation in sandy-loam soil was fastest followed by clay and silty-clay soils, respectively. Comparison of the rate of degradation in natural against sterilized soils suggests that microbial degradation might be the major pathway of residue dissipation. Changes in soil enzyme activities as a consequence of forchlorfenuron treatment were studied for extra-cellular enzymes namely acid phosphatase, alkaline phosphatase and β -glucosidase and intracellular enzyme-dehydrogenase. Although small changes in enzyme activities were observed, forchlorfenuron did not have any significant deleterious effect on the enzymatic activity of the test soils. Simple correlation studies between degradation percentage and individual enzyme activities did not establish any significant relationships. The pattern and change of enzyme activity was primarily the effect of the incubation period rather than the effect of forchlorfenuron itself.     

Temporal signatures of advective versus diffusive radon transport at a geothermal zone in Central Nepal

Temporal variation of radon-222 concentration was studied at the Syabru-Bensi hot springs, located on the Main Central Thrust zone in Central Nepal. This site is characterized by several carbon dioxide discharges having maximum fluxes larger than 10 kg m⁻² d⁻¹. Radon concentration was monitored with autonomous Barasol™ probes between January 2008 and November 2009 in two small natural cavities with high CO₂ concentration and at six locations in the soil: four points having a high flux, and two background reference points. At the reference points, dominated by radon diffusion, radon concentration was stable from January to May, with mean values of 22 ± 6.9 and 37 ± 5.5 kBq m⁻³, but was affected by a large increase, of about a factor of 2 and 1.6, respectively, during the monsoon season from June to September. At the points dominated by CO₂ advection, by contrast, radon concentration showed higher mean values 39.0 ± 2.6 to 78 ± 1.4 kBq m⁻³, remarkably stable throughout the year with small long-term variation, including a possible modulation of period around 6 months. A significant difference between the diffusion dominated reference points and the advection-dominated points also emerged when studying the diurnal S₁ and semi-diurnal S₂ periodic components. At the advection-dominated points, radon concentration did not exhibit S₁ or S₂ components. At the reference points, however, the S₂ component, associated with barometric tide, could be identified during the dry season, but only when the probe was installed at shallow depth. The S₁ component, associated with thermal and possibly barometric diurnal forcing, was systematically observed, especially during monsoon season. The remarkable short-term and long-term temporal stability of the radon concentration at the advection-dominated points, which suggests a strong pressure source at depth, may be an important asset to detect possible temporal variations associated with the seismic cycle.     

Gifting,ridding and the “everyday mundane”: the role of class and privilege in food waste generation in Indonesia

Current research on household food waste has not considered the impact of the inter-class power dynamics between employers and domestic helpers on food waste management and generation in the Global South. This article focuses on the issue of food justice and will demonstrate that it is important to reconsider household food practices within the framework of unequal power dynamics in household units – especially between employers and their domestic helpers. Informed by food waste regime conceptual framework, this paper will examine the complex food provisioning practices of Indonesian households. The research draws on 21 in-depth interviews with households of varying incomes, multiple site visits, participant observation and going along on grocery trips to better understand the power dynamics and practices that result in, or prevent the generation of household food waste. In addition, 12 key informant interviews with government officials, traditional food vendors, supermarket managers, and a waste collector was also conducted. In an Indonesian context, understanding the interclass dynamics of the household, namely, who gets to define what is “food” and what is “waste” is key to understanding the broader phenomenon of food waste in order to promote solutions to food waste prevention and food insecurity that is socially and environmentally just.     

Statistical tools for analysing the data obtained from repeated dose toxicity studies with rodents: a comparison of the statistical tools used in Japan with that of used in other countries

In the present study, an attempt was made to compare the statistical tools used for analysing the data of repeated dose toxicity studies with rodents conducted in 45 countries, with that of Japan. The study revealed that there was no congruence among the countries in the use of statistical tools for analysing the data obtained from the above studies. For example, to analyse the data obtained from repeated dose toxicity studies with rodents, Scheffé's multiple range and Dunnett type (joint type Dunnett) tests are commonly used in Japan, but in other countries use of these statistical tools is not so common. However, statistical techniques used for testing the above data for homogeneity of variance and inter-group comparisons do not differ much between Japan and other countries. In Japan, the data are generally not tested for normality and the same is true with the most of the countries investigated. In the present investigation, out of 127 studies examined, data of only 6 studies were analysed for both homogeneity of variance and normal distribution. For examining homogeneity of variance, we propose Levene's test, since the commonly used Bartlett's test may show heterogeneity in variance in all the groups, if a slight heterogeneity in variance is seen any one of the groups. We suggest the data may be examined for both homogeneity of variance and normal distribution. For the data of the groups that do not show heterogeneity of variance, to find the significant difference among the groups, we recommend Dunnett's test, and for those show heterogeneity of variance, we recommend Steel's test.