Synthetic Media: A Promising New Treatment Technology for 1,4‐Dioxane

1,4‐Dioxane (14DX) is classified as a probable human carcinogen by the US Environmental Protection Agency (EPA), and it has toxic effects on the kidney and liver. EPA's Health Advisory Level (HAL) for 14DX is 0.35 micrograms per liter (μg/L). Accordingly, several states have lowered their drinking water advisory levels and site cleanup levels. The widespread occurrence of 14DX in contaminated groundwater has contributed to a growing demand for remediation services. Treating 14DX is a challenge due to its very low Henry's law constant, low sorption potential, and strong ether linkages. The primary solution for 14DX remediation has been various forms of advanced oxidation processes (AOP), namely pump and treat followed by ex situ treatment with catalyzed ultraviolet light oxidation or ozone‐peroxidation. Many of the available advanced oxidation systems are complex, requiring careful monitoring and maintenance to adjust for variable source water and operating conditions. Synthetic media is a relatively new 14DX treatment technology that overcomes many of the operating challenges faced by existing technologies. AMBERSORB? 560 (AMBERSORB) has recently demonstrated the effective removal of 14DX over a wide range of concentrations and operating conditions, including those created by in situ thermal remediation. Consistent and reliable treatment down to sub‐0.3 μg/L levels differentiates synthetic media technology from other 14DX treatment technologies. AMBERSORB provides a solution to the problem of “stranded capital” by offering a 14DX treatment system capable of meeting regulatory standards today and in the foreseeable future. © 2014 Wiley Periodicals, Inc.     

Evaluation of different isotherm models,kinetic, thermodynamic,and copper biosorption efficiency of Lobaria pulmonaria (L.) Hoffm.

The biosorption characteristics of Cu(II) ions from aqueous solution using Lobaria pulmonaria (L.) Hoffm. biomass were investigated. The biosorption efficiency of Cu(II) onto biomass was significantly influenced by the operating parameters. The maximum biosorption efficiency of L. pulmonaria was 65.3% at 10 mg/L initial metal concentration for 5 g/L lichen biomass dosage. The biosorption of Cu(II) ions onto biomass fits the Langmuir isotherm model and the pseudo-second-order kinetic model well. The thermodynamic parameters indicate the feasibility and exothermic and spontaneous nature of the biosorption. The effective desorption achieved with HCl was 96%. Information on the nature of possible interactions between the functional groups of the L. pulmonaria biomass and Cu(II) ions was obtained via Fourier transform infrared (FTIR) spectroscopy. The results indicated that the carboxyl (–COOH) and hydroxyl (–OH) groups of the biomass were mainly involved in the biosorption of Cu(II) onto L. pulmonaria biomass. The L. pulmonaria is a promising biosorbent for Cu(II) ions because of its availability, low cost, and high metal biosorption and desorption capacities.

Implications: Lobaria pulmonaria is a promising biosorbent for Cu(II) ions because of its availability, low cost, and high metal biosorption and desorption capacities. To the best of our knowledge, this is the first paper on the biosorption Cu by L. pulmonaria.     

In vitro effects of citrus oils against Mycobacterium tuberculosis and non-tuberculous Mycobacteria of clinical importance

We evaluated the in vitro activity of citrus oils against Mycobacterium tuberculosis and other non-tuberculous Mycobacterium species. Citrus essential oils were tested against a variety of Mycobacterium species and strains using the BACTEC radiometric growth system. Cold pressed terpeneless Valencia oil (CPT) was further tested using the Wayne model of in vitro latency.

Exposure of M. tuberculosis and M. bovis BCG to 0.025 % cold pressed terpeneless Valencia orange oil (CPT) resulted in a 3-log decrease in viable counts versus corresponding controls. Inhibition of various clinical isolates of the M. avium complex and M. abscessus ranged from 2.5 to 5.2-logs. Some species/strains were completely inhibited in the presence of CPT including one isolate each of the following: the M. avium complex, M. chelonae and M. avium subsp. paratuberculosis. CPT also inhibited the growth of BCG more than 99 % in an in vitro model of latency which mimics anaerobic dormancy thought to occur in vivo. The activity of CPT against drug-resistant strains of the M. avium complex and M. abscessus suggest that the mechanism of action for CPT is different than that of currently available drugs. Inhibition of latently adapted bacilli offers promise for treatment of latent infections of MTB. These results suggest that the antimycobacterial properties of CPT warrant further study to elucidate the specific mechanism of action and clarify the spectrum of activity.     

Effect of ozonization in degradation of trifluralin residues in aqueous and food matrices

Abstract

This study investigates the oxidation of trifluralin residues during ozonation in aqueous and food matrices (tomato). Domestic ozonation equipment with average production of 23.9?mg O₃ L^?1 h^?1 was used in the tests. Modern chromatographic systems (SPME-GC-IT/MS/MS and QuEChERS-GC-IT/MS/MS) were applied for extraction and detection of trifluralin residue in fortified samples of ultrapure water, tap water, superficial water and tomato fruit. The samples were submitted to the ozonation process during 0, 5, 10 and 20?min. Treatment at 5?min was able to degrade 71.5% of herbicide trifluralin in surface water. The removal (%) in ultrapure water reached 83.4% after 20?min of ozonation. The degradation of trifluralin in fortified tomato samples (0.025–0.1?mg kg^?1) were conducted with ozonation at 20?min, and it ranged from 84.4 to 92.7%. After treatment, levels of trifluralin in tomato remained within the established MRLs to EU, USEPA and ANVISA (Brazil). The data provided evidence that ozone is effective for removing trace trifluralin from water and foods.     

Clinical effects and cholinesterase activity changes in workers exposed to phorate (Thimet)

Abstract

Phorate (Thimet), an aliphatic derivative of phospnorus is a hignly toxic insecticide. In order to implement the safety measures, the clinical manifestations and cholinesterase (ChE) activity were evaluated before and after 2 weeks of exposure to this insecticide in 40 male tormulators.

The 2 week's exposure reveal signs and symptoms of toxicity in 60% of the formulators. Gastrointestinal symptoms and lowering of heart rate (bradycardia) were more prominent as compared to the neurological symptoms. A significant depression in plasma ChE activity was observed at the end of 1st week (55%) and 2nd week (71%) as compared to the respective pre‐exposure values. A recovery up to 79% of the pre‐exposure activity of this enzyme was noticed 10 days after cessation of the above exposure.     

Deposition of aerially sprayed mexacarbate on balsam fir canopy and the forest floor: Relevance to ULV applications

Abstract

Spray deposit patterns were measured on aluminum coils and live balsam fir needles at different canopy heights, following aerial application of mexacarbate (4‐dimethylamino‐3,5‐xylyl N‐methylcarbamate) over a conifer forest in New Brunswick. Droplet size spectra of the spray cloud were determined on cylindrical Kromekote® cards placed at the corresponding crown heights. Ground deposits were collected on cylindrical Kromekote cards, aluminum coils and natural balsam fir foliage placed In forest clearings and under different types of vegetation.

Canopy deposits decreased progressively from the top to the bottom level of the tree crown. This trend was observed on aluminum coils, live fir foliage, and Kromekote cards. Droplet size spectra were similar at all sampling heights of the tree crown, and were comparable to those obtained on the ground cards placed in the forest clearings. Deposits of mexacarbate obtained on ground samplers on the open forest floor were markedly lower than those found at the top canopy but were similar to those at the mid or bottom canopy level. Droplet size spectra and mexacarbate deposits obtained on samplers placed under different types of forest vegetation indicated a selective filtration of the large droplets present in the spray cloud by plant canopies.     

Persistence and biodegradation of carbaryl in soils

Abstract

The persistence of the methylcarbamate pesticide carbaryl was studied in four soils under flooded conditions. A substantial portion of the pesticide was recovered from all soils even after 15 days of its application, with the recovery ranging from 37% in an alluvial soil to 73% in an acid sulfate soil. The degradation of carbaryl was more rapid under flooded conditions than under nonflooded conditions. A bacterium, Pseudomonas cepacia, isolated from a flooded soil amended with a related methylcarbamate pesticide carbofuran, degraded carbaryl in a mineral medium supplemented with yeast extract.     

Measurements of surface contamination of spray equipment with pesticides after various methods of application

Abstract

A traditional method to determine operator dermal exposure is to quantify the amount of pesticide coming into contact with specific body regions and then to integrate the deposition density values with the total body surface. It is known that extremely high deposition values may occur in the hand region; however, the source of contamination is generally assumed to be direct splash or contact with the pesticide container. One of the parameters affecting operator/pilot exposure could be the transfer of pesticide residue, particularly in the case of pesticides with a longer half‐life, from contaminated surfaces of spray equipment by direct contact over extended periods. If the rate of skin absorption of pesticide is readily known, the expected values of daily dose for an operator or pilot may significantly rise due to the extended contact period. This study produced field data on the surface contamination of spray equipment used for ground and aerial applications. If field data on precise work practice (time‐motion) observations are incorporated, it may be possible to estimate the potential exposure of operator/pilot due to hand contact with contaminated surfaces.     

Effect of maternal dietary hexachlorocyclohexane exposure on pup survival and growth in albino rats

Abstract

In adult albino rats, maternal dietary. ß‐ and ?‐hexachlorocyclohexane (HCH) intake during gestation upto 400 ppm level did not affect the number of litters produced. But about 50 and 100% pup mortality was found in 200 and 400 ppm ß ‐HCH group within 5 days of birth. Maternal mortality was observed in 800 ppm ß ‐HCH group during third week of gestation. The effect of maternal dietary intake of HCH isomers at 50 and 250 ppm level during gestation and/or lactation on perinatal development was also studied. The body weights and sizes of the newborn litters of mother rats exposed to dietary HCH isomers did not. differ from controls. Similarly, the growth and development of the litters of HCH exposed mother rats that survived 28 day lactation period were found to be comparable to controls as evidenced by the body weight and weight of vital organs. However, liver weight increases were found in the 28 day weaned litters wherever the mothers had been exposed to HCH isomers during lactation. Lowered kidney weight was seen in litters of mother rats fed 250 ppm ?‐HCH during gestation and lactation. The brain and testis weights were not affected in the litters of any experimental groups.     

Feasibility of vermicomposting dairy biosolids using a modified system to avoid earthworm mortality

Abstract

A laboratory study was conducted to examine the feasibility of vermicomposting dairy biosolids (dairy sludge), either alone or with either of the bulking agents ‐ cereal straw or wood shavings, using the epigeic earthworm ‐ Eisinea andrei. Earthworms added directly to these three substrates died within 48 hours. A system was developed to overcome the toxic effect of unprocessed dairy biosolids. The substrates were placed over a layer of vermicomposted sheep manure into which the earthworms were inoculated. Within two weeks, all earthworms were within the upper layer of substrate. Compared to sheep manure which is a favourable substrate for vermicomposting, the three substrates containing dairy biosolids were more effective in supporting earthworm growth and reproduction. The final products obtained after 63 days of vermicomposting had 39–53% less organic carbon than the initial substrates. Organic fractionation indicated that vermicomposting increased the stability of the materials to biological decomposition. The vermicomposts obtained from the three substrates with dairy biosolids had low heavy metal contents and electrical conductivities, and did not inhibit plant growth when compared with a commercial vermicompost in a bioassay.