Long-term Environmental Pollution Research Articles

Wool keratin total solubilisation for recovery and reintegration - An ecological approach

Abstract Organic waste is a valuable raw material with potential for replacing synthetic products of petroleum origin in a more sustainable economy. Such a material is unmarketable wool, which is a growing resource in many countries and has recently concerned authorities because of the low degree of biodegradation of keratin and the potential for long-term environmental pollution. At the same time keratin represents a smart protein with high compatibility for cell growth and with high sulphur content which can be used for plant treatment in a circular economy. In this respect the aim of this research was to develop a facile and versatile method for total solubilisation of keratin from unmarketable wool which was experimented at pilot level with high potential for reintegration in ecological agriculture. The original investigations indicated that different properties can be tailored by alkaline or alkaline-enzymatic hydrolysis of wool waste with preservation of 9.2–19.2% of cystine sulphur as compared to raw wool. The measurement of particle sizes, zeta potential and contact angle demonstrates that the keratin peptides are able to associate and self assemble with influence on particle size, stability and hydrophilic properties. FTIR-ATR, CP/MAS 13C-NMR and Cryo-STEM-EDX analyses highlighted specific chemical modification of keratin polypeptide with cleavage of disulphide bonds and dehydroalanine generation only in alkaline hydrolysates and with more alkyl species and oxidized sulphur in enzymatic hydrolysates. The results indicated that different compositions of keratin hydrolysates can be modulated through alkaline and enzymatic hydrolysis with release of metabolism precursors for plant growth which can be alternatives to the use of synthetic products. Preliminary tests on foliar fertilization of wheat plants opened the path for large scale application of keratin hydrolysate solubilised with zero waste from wool by-products, in a more ecological agriculture.

Natural Chlordecone Degradation Revealed by Numerous Transformation Products Characterized in Key French West Indies Environmental Compartments.

Production and use of the insecticide chlordecone has caused long-term environmental pollution in the James River area and the French West Indies (FWI) that has resulted in acute human-health problems and a social crisis. High levels of chlordecone in FWI soils, even after its ban decades ago, and the absence of detection of transformation products (TPs), have suggested that chlordecone is virtually nonbiodegradable in the environment. Here, we investigated laboratory biodegradation, consisting of bacterial liquid cultures and microcosms inoculated with FWI soils, using a dual nontargeted GC-MS and LC-HRMS approach. In addition to previously reported, partly characterized hydrochlordecones and polychloroindenes (families A and B), we discovered 14 new chlordecone TPs, assigned to four families (B, C, D, and E). Organic synthesis and NMR analyses allowed us to achieve the complete structural elucidation of 19 TPs. Members of TP families A, B, C, and E were detected in soil, sediment, and water samples from Martinique and include 17 TPs not initially found in commercial chlordecone formulations. 2,4,5,6,7-Pentachloroindene was the most prominent TP, with levels similar to those of chlordecone. Overall, our results clearly show that chlordecone pollution extends beyond the parent chlordecone molecule and includes a considerable number of previously undetected TPs. Structural diversity of the identified TPs illustrates the complexity of chlordecone degradation in the environment and raises the possibility of extensive worldwide pollution of soil and aquatic ecosystems by chlordecone TPs.

A conceptual model of organochlorine fate from a combined analysis of spatial and mid- to long-term trends of surface and ground water contamination in tropical areas (FWI)

Abstract. In this study, we investigated the management of long-term environmental pollution by organic pollutants such as organochlorine pesticides. We set out to identify conditions that are conducive to reducing pollution levels for these persistent molecules and then propose a conceptual model of organochlorine fate in water. Our approach looked at spatio-temporal changes in pollutant contents in surface water (SW) and groundwater (GW) on a large scale, in order to decipher the respective roles of soil, geology, hydrology and past treatment practices. The case of chlordecone (CLD) on the island of Martinique (1100 km2) was selected given the sampling campaigns carried out since 2007 over more than 150 sites. CLD, its metabolite chlordecone-5b-hydro (5bCLD) and the metabolite-to-parent-compound ratio were compared. As regards the spatial variability of water contamination, our results showed that banana cropping areas explained the location of contaminated SW and GW, whereas the combination of soil and geology factors explained the main spatial variability in the 5bCLD∕CLD ratio. For temporal variability, these conditions defined a high diversity of situations in terms of the duration of pollution, highlighting two groups: water draining old geological formations and ferralsols or vertisols vs. recent geology and andosols. A conceptual leaching model provided some key information to help interpret downward trends in CLD and 5bCLD observed in water. Lastly, a conceptual model of organochlorine fate is proposed to explain the diversity of the 5bCLD∕CLD ratio in water. Our conclusions highlight the combined role of soil and groundwater residence time for differentiating between conditions that are more conducive, or not, to the disappearance of CLD from the environment. This paper presents a model that provides an overall perception of organochlorine pesticide fate in the environment.

Long-term purification efficiency and factors affecting performance in peatland-based treatment wetlands: An analysis of 28 peat extraction sites in Finland

Peatland-based treatment wetlands that purify incoming water by means of natural physical, chemical and biological processes belonging to the peatland ecosystem are widely used at Finnish peat extraction sites. They can comprise either undrained or drained overland flow areas (OFAs or DOFAs), with the OFAs representing the best available technology (BAT) for peat extraction. We analyse here the long-term treatment performance of these OFAs and DOFAs and factors affecting this performance. Data on 14 OFAs and DOFAs in different parts of Finland were taken from the extensive long-term environmental pollution control databases. Nearly half of these wetlands had been monitored for at least 4 years and seven for 8–23 years. The results indicated that peatland-based treatment wetlands purify drainage water as efficiently as other natural treatment wetlands on soils in general, the common challenge being phosphorus retention. Iron was also efficiently retained. The average reductions were highest in OFAs with good hydraulic function, and these also showed long-term water protection performance. An important factor affecting purification efficiency was the hydraulic loading rate. Important system design elements in this regard were the size of the wetland in relation to its catchment area, its gradient, the length of the water flow route within the wetland, and the efficient flow area of the wetland. The results regarding the latter two design elements strongly indicate that not all the areas potentially suitable in DOFAs for water purification are yet being used efficiently.

Environmental Remediation of Chlorinated Hydrocarbons Using Biopolymer Stabilized Iron Loaded Halloysite Nanotubes

Dense nonaqueous phase chlorinated compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE) are widespread groundwater and soil contaminants which cause long-term environmental pollution. Extensive efforts have been carried out to develop materials for in situ remediation particularly using nanoscale zerovalent iron (NZVI) to reduce TCE to relatively innocuous products such as ethane and ethylene. A novel technology is described here that uses earth-abundant natural tubular aluminosilicate clays known as halloysite (HNT) to support NZVI. These systems are efficient at the reductive dechlorination of such chlorinated hydrocarbons indicating a pseudo-first order rate constant of 0.1 L g–1 h–1 with NZVI particle size between 5 and 10 nm. The adsorption of the naturally derived polyelectrolytes chitosan and carboxymethyl cellulose on the surface of HNT provides easy dispersibility in aqueous solutions and colloidal stability to the NZVI supported on HNT, with chitosan adsorption leading to stab...

Investigation on white coconut oil to use as a metal working fluid during turning

Almost all machining industries in Sri Lanka use mineral oil–based and synthetic oils as metal working fluids during machining. But their usage has potential for long-term environmental pollution and threat to workers’ health. Therefore, much effort has been focused on research and development of eco-friendly and hazard-free alternatives to mineral oil–based metal working fluids, and the use of vegetable oils is one such alternative. This study was focused on investigating the easy access of vegetable oils in Sri Lanka and most commonly machined metals in the local industry, so that the outcome would be much more beneficial to the local industries. After several tests with 10 candidate vegetable oils, white coconut oil is selected as base oil and the results of a successful questionnaire survey directed to select mild steel and AISI 304 steel as the machining metals. Machining experiments were planned using Taguchi methods, and the variation of the surface roughness was tracked with respect to four variable parameters depth of cut, feed rate, spindle speed and metal working fluid. Two mathematical models were developed to predict the surface roughness and optimize the parameters. Further experiments were conducted to investigate the effects of metal working fluid for smooth- and rough-cut conditions. These experiments revealed that white coconut oil is a better metal working fluid for mild steel, while soluble oil favors AISI 304 steel. Different thermal conductivities of metals cause the coconut oil to act differently while machining two metal types.

An approach to low-density polyethylene biodegradation by Bacillus amyloliquefaciens.

Low-density polyethylene (LDPE) is a major cause of persistent and long-term environmental pollution. In this paper, two bacterial isolates Bacillus amyloliquefaciens (BSM-1) and Bacillus amyloliquefaciens (BSM-2) were isolated from municipal solid soil and used for polymer degradation studies. The microbial degradation LDPE was analyzed by dry weight reduction of LDPE film, change in pH of culture media, CO2 estimation, scanning electron microscopy (SEM), and fourier transform infrared FTIR spectroscopy of the film surface. SEM analysis revealed that both the strains were exhibiting adherence and growth with LDPE which used as a sole carbon source while FTIR images showed various surface chemical changes after 60 days of incubation. Bacterial isolates showed the depolymerization of biodegraded products in the extracellular media indicating the biodegradation process. BSM-2 exhibited better degradation than BSM-1 which proves the potentiality of these strains to degrade LDPE films in a short span of time.

Variation in prevalence and intensity of two avian ectoparasites in a polluted area

We counted the numbers of pupae of two ectoparasitic flies (Protocalliphora sp. and Ornithomyia sp.) in the nests of a passerine bird, the pied flycatcher (Ficedula hypoleuca) to find out if their prevalence or intensity are affected by long-term environmental pollution by a copper smelter and whether such an interaction would have impacts on birds' breeding success. Fecal metal concentrations of F. hypoleuca nestlings were used to explore direct association between metal levels and parasite prevalence, but we also included other explanatory factors in our analysis, such as timing of breeding, brood size, ambient temperature, habitat quality and host population density. We found that environmental pollution decreased the prevalence of Protocalliphora via changed habitat quality but did not affect the prevalence of Ornithomyia. The prevalence of neither ectoparasite was, however, directly related to ambient metal levels. Both ectoparasites showed higher prevalence when ambient temperature during the nestling period was high, emphasizing the potential of climate change to modify host–parasite relationships. The prevalence of Ornithomyia was further highest in dense F. hypoleuca populations and late broods. Nestling survival decreased with increasing infestation intensity of Ornithomyia while no association was found for Protocalliphora. Despite relatively low numbers and overall weak effect of parasites on survival, the possible delayed and/or sublethal effects of these ectoparasites call for further studies. Our results suggest that pollution-related effects on avian ectoparasite numbers are species-specific and reflect habitat changes rather than direct toxic effect of heavy metals.

Distribution of hexachlorocyclohexane isomers in soil samples from a small scale industrial area of Lucknow, North India, associated with lindane production

Concentrations of hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH, and δ-HCH) were studied in soils samples collected from a small scale industrial unit of Lucknow associated with lindane production. All four isomers were detected from ten sites and the total HCH isomers in the analyzed samples varied from 53 to 99 mg kg −1. Cluster analysis was performed to group the soil sites in terms of their HCH contamination level. Low α/γ HCH ratios were found and they indicate recent input of HCH. There is an urgent need for the on-site remediation of these contaminated sites in order to prevent the long-term environmental pollution.

Long-term Hg pollution induced Hg tolerance in the terrestrial isopod Porcellio scaber (Isopoda, Crustacea)

The aim of our work was to assess the pollution-induced community tolerance (PICT) of isopod gut microbiota and pollution-induced isopod population tolerance (PIPT). Animals collected from a chronically Hg polluted and an unpolluted location were exposed for 14 days to 10 μg Hg/g dry food under laboratory conditions. The lysosomal membrane stability, hepatopancreas epithelium thickness, feeding activity and animal bacterial gut microbiota composition were determined. The results confirm the hypothesis that the response to short-term Hg exposure differs for animals from the Hg polluted and the unpolluted field locations. The animals and their gut microbiota from the Hg polluted location were less affected by Hg in a short-term feeding experiment than those from the unpolluted environment. We discuss the pollution-induced population tolerance of isopods and their gut microbiota as a measure of effects of long-term environmental pollution. The ecological consequences of such phenomena are also discussed.

Residue Analysis of Chlorinated Pesticides in Jordanian Human Adipose Tissues

Abstract To study the long-term environmental pollution in Jordan, thirty two adipose tissue samples were analysed for 15 Organochlorine Compounds using the capillary GC-ECD. The results were discussed in terms of clinical aspects and in terms of environmental and hygienic effects. To explain the sources of pollution, the major fat-containing food stuffs usually used in Jordan were analysed. It has been found that most of the imported foods are contaminated, especially with heptachlor and heptachlorepoxide.