Dephenolization and detoxification of olive-mill wastewater (OMW) by purified biotic and abiotic oxidative catalysts

The capability of two oxidative catalysts, a laccase from Rhus vernicifera and birnessite, a manganese oxide, in the dephenolization and detoxification of two olive-mill wastewater (OMW) samples, C1 and C2, differing for complexity and composition, was evaluated. OMW phenolic extracts (EC1 and EC2) and mono-substrate solutions of phenols mostly present in OMW samples were also tested. Birnessite was more effective than laccase in removing the phenolic content from mono-substrate solutions (more than 70% of each initial phenolic concentration) and of either OMW samples or EC1 and EC2 extracts. For instance, 60% of the total phenolic content of EC1 was removed after 48-h treatment with 5 mg mL(-1) birnessite and the efficiency was lower as greater was the complexity of the OMW sample (only 17% removal from EC2 over the same time span). Phytotoxicity tests with Lepidium sativum and Lycopersicon esculentum seeds and antibacterial toxicity tests with Bacillus megaterium were performed on crude OMW samples and their extract and exhausted fractions before and after the catalytic treatment. Results demonstrated that (a) monomeric phenols were certainly but not exclusively responsible of OMW phytotoxicity, whereas their removal led to a quite complete elimination of the toxicity toward bacterial growth; (b) other components not removable by the oxidative catalysts very likely contribute to OMW phytotoxicity; and (c) the choice of the vegetal species to use in toxicity tests might be crucial for correct and easily interpretable results. Overall the results provided useful information on the possible use of oxidative catalysts for the efficient treatment of complex aqueous wastes such as those deriving from olive industry.     

Assessment of large-scale deforestation of Nawarangpur district, Orissa, India: a remote sensing based study

The Nawarangpur district, Orissa, a tropical region with Sal mixed moist deciduous and Sal mixed dry deciduous forests, has been affected by extensive deforestation. The district was surveyed using Landsat MSS (1973), Landsat TM (1990) and IRS P6 LISS III (2004) satellite imagery. From 1973 to 1990, more than 888.6 km(2) of dense forest (rate of deforestation = 3.62) and from 1990 to 2004, 429.7 km(2) (rate of deforestation = 3.97) were found to have been deforested. The analysis of results identified the reduction in area of dense forest and increase of agricultural land, degraded areas of abandoned agricultural land and unproductive scrub. There is an urgent need for rational management of the remaining forest for it to be able to survive beyond next decades. From this study it can be concluded that temporal changes and the factors affecting these changes should be determined for sustainable management of natural resources.     

Accumulation of organic and inorganic contaminants in shellfish collected in estuarine waters near Pensacola, Florida: contamination profiles and risks to human consumers

We conducted a screening level assessment of contaminants in blue crabs (Callinectes sapidus) and oysters (Crassostrea virginica) from bays and bayous in the Pensacola, FL area. Tissue samples were analyzed for 17 dioxins/furans, 12 dioxin-like PCB (DL-PCBs) congeners, mercury, and various metals. Contaminant levels were compared to screening values (SV) calculated using U.S. EPA recommendations for establishing consumption advisories. All sampling locations exceeded the SV (0.098pgg(-1)) for dioxins/furans/DL-PCBs, based on a Florida-specific consumption rate (46gday(-1)). Arsenic (inorganic), mercury, cadmium, and zinc levels exceeded SVs in samples from select locations, and with the exception of mercury, these locations were generally downstream of known contaminated areas. We also assessed potential human health risks from consumption of these species. Risks to human health were greatest from consumption of crab hepatopancreas, suggesting that consumption of hepatopancreas, whether directly or indirectly, from crabs collected anywhere in the Pensacola Bay region should be avoided.     

A comprehensive review of hydrophobic silica and composite aerogels: synthesis,properties and recent progress towards environmental remediation and biomedical applications

Environmental Science and Pollution Research - The hydrophobicity of silica and composite aerogels has enabled them to acquire applications in a variety of fields. With remarkable structural,...     

华东某铀矿区周边河流表层沉积物的天然放射性评价

利用高纯锗γ能谱分析仪测量中国华东某铀矿区附近河流沉积物的放射性核素比活度,计算γ辐射吸收剂量率(D)、有效镭浓度(Ra_(eq))、外照射指数(H_(ex))、内照射指数(H_(in))、年有效剂量当量(AEDE(室内和室外))和年性腺剂量当量(AGDE)等放射性参数,并开展沉积物的放射性危害评估,最后通过Pearson线性系数确定放射性核素比活度之间的相关性。结果表明,河流沉积物中放射性核素~(238)U、~(226)Ra、~(232)Th和40K的平均比活度分别为51.55、37.32、57.63和756.86 Bq·kg~(-1),除~(226)Ra外,其他放射性核素的比活度均高于中国平均值;距离污染区较远或存在河流稀释作用的区域,沉积物的天然放射性核素处于正常水平,作为建筑材料使用时比活度不存在超标;放射性核素~(238)U、~(226)Ra和~(232)Th之间存在显著相关性。     

Fuelwood assessment at micro-watershed level in Northeast Himalaya:a case study in Manipur,India

Fuelwood is one of the major sources of energy in the domestic sector across the rural areas,especially in the developing regions across the world.The Northeastern Himalayan state of Manipur is dominated by the tribal population that largely depends on fuelwood from the nearby forest area.The entire dependence on forests for energy resources is affecting the sustainability of the forest ecosystem in the region,thus indicating the livelihood conditions.Since land-use land-cover change is the key driver to the change in resource availability of a region,the present study has tried to analyze the landcover changes over a period 28 years.The second major component affecting resource availability is the increasing population pressure that leads to changes in the land dynamics,which directly affect the resource production.Based on the existing consumption pattern,the total consumption of fuelwood in the watershed ranges fiom a minimum of 289.992 tons/year to a maximum of 3545.719 tons/year with an average of 1561.956 tons/year in the year 2009 and simulated fuelwood consumption for the year 2021 is around 1469.260 tons/year.Nine different probable scenarios of resource are proposed to calculate the stress value that can be used by the policy-makers and planners for suitable policy implementation at the micro level with a complex social system.     

Ozone Air Quality over North America: Part II—An Analysis of Trend Detection and Attribution Techniques

ABSTRACT

Assessment of regulatory programs aimed at improving ambient O₃ air quality is of considerable interest to the scientific community and to policymakers. Trend detection, the identification of statistically significant long-term changes, and attribution, linking change to specific clima-tological and anthropogenic forcings, are instrumental to this assessment. Detection and attribution are difficult because changes in pollutant concentrations of interest to policymakers may be much smaller than natural variations due to weather and climate. In addition, there are considerable differences in reported trends seemingly based on similar statistical methods and databases. Differences arise from the variety of techniques used to reduce nontrend variation in time series, including mitigating the effects of meteorology and the variety of metrics used to track changes. In this paper, we review the trend assessment techniques being used in the air pollution field and discuss their strengths and limitations in discerning and attributing changes in O₃ to emission control policies.     

Increased urinary 8-hydroxy-2��-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China

Background

Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.

Methods

The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.

Results

Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?p?p?Conclusions The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.     

De-fluoridation of groundwater using magnesium oxide

Fluorosis, which severely affects teeth and bones, is one of the common water-related diseases listed by the World Health Organization. Fluorosis is caused by ingestion of groundwater containing fluoride in excess of 1.5 mg/l and is widespread in about 25 countries. As majority of fluorosis affected regions occur in arid or semi-arid regions of the world, de-fluoridation of the limited available water resource forms the viable solution. Though several methods of de-fluoridation have been proposed, only few are implemented in field. Further, the existing field methods have various limitations such as cost, efficiency, quality of treated water and disposal of byproducts of treatment. In search of a sustainable solution towards mitigating the fluorosis problem, a new method of de-fluoridation using magnesium oxide has been developed in laboratory. Present study addresses issues that will assist in successful implementation of the new de-fluoridation method in field, using a domestic de-fluoridation unit.