Distribution and transportability of hexabromocyclododecane (HBCD) in the Asia-Pacific region using skipjack tuna as a bioindicator

The geographical distribution of hexabromocyclododecane (HBCD) was investigated through analysis of muscle tissue of skipjack tuna (Katsuwonus pelamis) collected from offshore waters of Asia-Pacific region (Japan, Taiwan, Philippines, Indonesia, Seychelles, Brazil, Japan Sea, East China Sea, South China Sea, Indian Ocean and North Pacific Ocean). HBCD was detected in almost all samples analyzed (<0.1 to 45 ng/g lipid weight basis), indicating widespread presence of this compound in the marine environment. Elevated concentrations of HBCD were found in skipjack tuna from areas around Japan, which have the larger modern industrial/urban societies, and implicated these areas as primary regional sources. All three individual HBCD isomers (alpha-, gamma- and beta-HBCD) were detected in almost all samples; the percentage contribution of the alpha-isomer to total HBCD increased with increasing latitude. The estimated empirical 1/2 distance for alpha-HBCD was 8500 km, which is one of the highest atmospheric transportability among various halogenated persistent organic pollutants (POPs).     

Modified SBA-15 mesoporous silica for heavy metal ions remediation

N-Propylsalicylaldimino-functionalized SBA-15 mesoporous silica was prepared, characterized and used as an adsorbent for heavy metal ions. The organic-inorganic hybrid material was obtained using successive grafting procedures of SBA-15 silica with 3-aminopropyl-triethoxysilane and salicylaldehyde, respectively. For comparison an amorphous silica gel was functionalized using the same procedure. The structure and physicochemical properties of the materials were characterized by means of elemental analysis, X-ray diffraction (XRD), nitrogen adsorption-desorption, thermogravimetric analysis and FTIR spectroscopy. The organic functional groups were successfully grafted on the SBA-15 surfaces and the ordering of the support was not affected by the chemical modification. The behavior of the grafted solids for the adsorption of heavy metals ions from aqueous solutions was investigated. The hybrid materials showed high adsorption capacity and high selectivity for copper ions. Other ions, such as nickel, zinc, and cobalt were adsorbed by the modified SBA-15 material. The adsorbent can be regenerated by acid treatment without altering its properties.     

An advanced study on the hydrometallurgical processing of waste computer printed circuit boards to extract their valuable content of metals

This study refers to two chemical leaching systems for the base and precious metals extraction from waste printed circuit boards (WPCBs); sulfuric acid with hydrogen peroxide have been used for the first group of metals, meantime thiourea with the ferric ion in sulfuric acid medium were employed for the second one. The cementation process with zinc, copper and iron metal powders was attempted for solutions purification. The effects of hydrogen peroxide volume in rapport with sulfuric acid concentration and temperature were evaluated for oxidative leaching process. 2 M H₂SO₄ (98% w/v), 5% H₂O_2, 25 °C, 1/10 S/L ratio and 200 rpm were founded as optimal conditions for Cu extraction. Thiourea acid leaching process, performed on the solid filtrate obtained after three oxidative leaching steps, was carried out with 20 g/L of CS(NH₂)₂, 6 g/L of Fe³⁺, 0.5 M H₂SO₄, The cross-leaching method was applied by reusing of thiourea liquid suspension and immersing 5 g/L of this reagent for each other experiment material of leaching. This procedure has lead to the doubling and, respectively, tripling, of gold and silver concentrations into solution. These results reveal a very efficient, promising and environmental friendly method for WPCBs processing.     

Poly(Lactic Acid)-co-Aspartic Acid Copolymers: Possible Utilization in Drug Delivery Systems

The synthesis and characterization of poly(lactic acid)-co-aspartic acid copolymers (PLA-co-Asp) were presented. Subsequently, the synthesized PLA-co-Asp copolymers were tested as biodegradable carriers in drug delivery systems. PLA-co-Asp copolymers were synthesized by solution polycondensation procedure, using different molar ratios PLA/l-aspartic acid (2.33/1, 1/1, 1/2.33), manganese acetate and phosphoric acid as catalysts and N,N′-dimethyl formamide (DMF)/toluene as solvent mixture. The copolymers were characterized by FT-IR and ¹H-NMR spectroscopy, gel permeation chromatography (GPC), DSC and TG-DTG analyses. Diclofenac sodium, a non steroidal anti-inflammatory drug was subsequently loaded into PLA-co-Asp copolymers. The in vitro drug release experiments were done by dialysis of the copolymer/drug systems, in phosphate buffer solution (pH = 7.4, at 37 °C) and monitored by UV spectroscopy.     

An evaluation of occupational accidents in the wooden furniture industry - A regional study in South East Asia

Studies on the rate of occupational accidents among workers in the wooden furniture industry is sparse, although the industry is deemed to be highly accident prone. Therefore, the rate of occupational accidents among workers in the wooden furniture industry in Malaysia, Thailand, Indonesia and Vietnam were studied, in 240 furniture manufacturing factories, using a structured questionnaire. The findings of the study suggest that contract workers are less prone to occupational accidents compared to their permanent counterparts, and hence, are more productive. Further, the results also revealed that the contract workers have a more positive attitude towards the work, and hence, pick up the essentials of safe working practices quickly. It must therefore be recognized that the “production oriented mentality” prevalent in the wooden furniture industry, which has been argued to compromise occupational safety and health standards in the industry may be debatable. In this context, it is essential for the policy makers to re-examine the employment of contract workers for the furniture manufacturing industry, as changing the psycho-economic parameters of the industry may be warranted before the industry is deemed attractive to a permanent workforce.     

Novel Glycopolymers Based on d-Mannose and Methacrylates: Synthesis, Thermal Stability and Biodegradability Testing

This paper presents the synthesis, thermal stability and biodegradability of new d-mannose glycopolymers. These glycopolymers have been obtained by free radical bulk copolymerization of d-mannose based glycomonomer, 1-O-(2′-hydroxy-3′-methacryloyloxypropyl)-2,3:5,6-di-O-isopropylidene-d-mannofuranose (Mm), and respectively d-mannose derived oligomer (Mo) with methyl methacrylate and respectively 2-hydroxypropyl methacrylate. The chemical structures of Mm and Mo have been confirmed via FTIR, ¹H-NMR and HPLC–MS spectroscopy. The copolymerization process has been investigated using differential scanning calorimetry, which allowed calculating the activation energies by applying Kissinger–Akahira–Sunose method. The glycopolymers are thermally stable, fact assessed by TG analysis; their glass transition temperature exceeds 50 °C, so they are part of the glassy class of polymers. The biodegradability of these glycopolymers has been investigated in vitro, using pure cultures of Zymomonas mobilis and Trichoderma reesei. The glycopolymers lose up to 55 % weight in just 14 days of incubation as their surface and composition is altered by colonies of microorganisms that grow on/into them, fact demonstrated using SEM/EDX.     

Effect of some environmentally degradable materials on the pyrolysis of plastics II: influence of cellulose and lignin on the pyrolysis of complex mixtures

Pyrolysis of polymer mixtures with a composition similar to that of municipal plastic waste containing polyvinyl chloride (PVC) and of municipal plastic waste free of PVC was performed in the presence of components of biomass, namely lignin, cellulose, or both. The pyrolysis products were characterized by standard methods utilized in the petrochemical industry, i.e., paraffins-isoparaffinsolefins-naphthenes-aromatics analysis, proton nuclear magnetic resonance and infrared spectroscopy, and gas chromatography-mass spectrometry. Up to 3 wt% lignin, cellulose, or both in mixed polymers changed the material balance of pyrolysis by decreasing the amount of waxy products. The presence of both PVC and biomass components significantly changed the material balance by decreasing the waxy product yield and increasing the gas and coke yield. The composition of all pyrolysis products was also modified with the addition of PVC, components of biomass, or both.     

Feedstock recycling from plastic and thermoset fractions of used computers (I): pyrolysis

The increasing production of computers, the progress in their performance, and the shorter time between innovation and production has led to increasing numbers of obsolete products. It has thus become necessary to recover some materials from old computers and to protect the environment from a new type of pollution. Such recycling is difficult because of the diversity of polymeric materials used, e.g., thermoplastics (polystyrene or acrylonitrile-butadiene-styrene) and thermosets (epoxy resins), and the relatively high levels of flame retardants (halogen- and nitrogen-containing compounds) added during production. Pyrolysis seems to be a suitable way to recover materials and energy from such waste without component separation if an efficient method for reducing toxic compounds can be applied. In this study, the pyrolysis of plastic and thermoset fractions (keyboards, casings, printed circuit boards, and mixtures thereof) of used computers was studied by thermogravimetry and batch reactor pyrolysis. The degradation products were separated into three fractions, solid, liquid, and gaseous, each of them being characterized by suitable methods such as gas chromatography (GC-MSD, gas chromatography-mass spectrometry detection; GC-AED, gas chromatography-atomic emission detection), infrared (FT-IR) and 1H-NMR (nuclear magnetic resonanace) spectroscopy, and elemental analysis. It has been established that most of the halogens, nitrogen, and sulfur is concentrated in the residue. However, the elimination of hazardous toxic compounds, mainly those containing bromine, is necessary before being able to safely use the pyrolysis oils as fuels or in refinery or petrochemical industry flows.     

An experimental design for the optimization of the extraction methods of metallic mobile fractions from environmental solid samples

The evaluation of the cadmium and lead mobile forms from environmental solid samples provides information about their mobility and bioavailability. In the present study, the Cd and Pb mobile fractions were obtained by two modified extraction methods applied to industrial and acidic pH soils or to polluted sediments. In order to highlight that the extraction procedure does not significantly influence the quantitative atomic absorption spectrometric determination of cadmium and lead, the robustness of the extraction methods was evaluated and proven applying a Youden and Steiner factorial design. Within this experimental design, the shaking rate, the shaking time, and the solid/liquid extraction ratio were modified. The measurement uncertainty of the whole analytical procedure was assessed, the contribution of the factors involved in the extraction process being insignificant compared to the other uncertainty sources. The importance of the study is related to the fact that it proves the applicability in the routine laboratory practice of the modified extraction methods by increasing the extraction ratio following thorough optimization and robustness studies.     

Heavy metal contamination in the vicinity of an industrial area near Bucharest

Background, aim, and scope

Heavy metals such as lead are well known to cause harmful health effects. Especially children are particularly susceptible to increased levels of lead in their blood. It is also a fact that lead concentration is increasing in the environment due to increased anthropogenic activity. The risk of heavy metal contamination is pronounced in the environment adjacent to large industrial complexes. In a combined case study, the environmental pollution by heavy metals was related to children’s health in the vicinity of an industrial area located 4 km south-east from Bucharest about 2 km east from the nearest town—Pantelimon. This site includes companies processing different, nonferrous solid wastes for recovery of heavy metals and producing different nonferrous alloys and lead batteries. In this paper, mainly the results of environmental sampling and analyses are summarized.

Materials and methods

Water, soil, and atmospheric deposition samples were collected from different locations within 3 km from the industrial area. For comparison, samples were also taken from Bucharest. Water samples were filtered (<0.45 μm), extracted by salpetric acid, and quantified by ICP-OES and ICP-MS. Soil samples were dried, sieved (<2 mm), extracted by aqua regia and analyzed by AAS. In order to quantify the atmospheric deposition, three kinds of permanently open collecting pots were used on nine different sites between August and November 2006.

Results

At most sampling locations, the heavy metal concentrations in soil decrease with increasing distance to the presumably major source of pollution. Highest heavy metal concentrations were found in 10–20 cm soil depths. There were also decreasing heavy metal concentrations for atmospheric deposition with increasing distance to the industrial site. In surface and groundwater samples, traces of zinc, copper and lead were detected.

Discussion

The heavy metal concentrations in soil were increased in the study area, mostly under legal action limits in low-concern areas (e.g., 1,000 mg Pb/kg dry soil), but often above action limits for high-concern areas (100 mg Pb/kg dry soil) such as populated areas. The soluble lead concentrations in water samples indicate a need for monitoring and assessing water quality in more detail. The results for atmospheric deposition showed increased dust precipitation and heavy metal loads in the study area compared to Bucharest. However, based on mass flow balance calculations, the actual atmospheric deposition of heavy metals must be much lower than it was in the past decades.

Conclusions

It was shown that highest lead values in water, soil and atmospheric deposition are rather to be found near the investigated industrial site than at the control sites in Bucharest. Our results correspond very well with results that show that children from Pantelimon have significantly increased lead concentrations in their blood compared to children in Bucharest. The increased lead contamination around the investigated industrial area is likely to have caused the increased exposure for children living in Pantelimon.

Recommendations and perspectives

In high-concern areas, such as found in populated areas, further measures have to be taken to avoid health risks for people living in these areas. The measures already taken to reduce emissions from the industrial site will help to avoid further increases in heavy metal concentrations. In areas with exceeded action limits, measures have to be taken as required by law. Detailed risk assessments could help to take necessary actions to protect public health in this area. The public should be informed about the potential hazards of eating plants grown in that area. Educational programs for schools, informing children about the contamination, should lead to a better understanding of environmental problems and a more sustainable behavior in the future.