Conditions for the development of anaerobic digestion technologies using the organic fraction of municipal solid waste: perspectives for Poland

This article outlines problems related to the location of facilities designed to treat the organic fraction of municipal solid waste (OFMSW). Anaerobic digestion (AD) facilities are investigated as a treatment option, while taking into account the aspects of renewable energy generation. This research has been spurred on by the relationship between waste management, energy generation issues and spatial planning procedures. The analysis is focused on urban and semi-urban areas of medium and large cities. One of the most difficult issues associated with siting of waste processing plants is its integration with local infrastructures, avoiding conflicts and negative environmental impacts at the same time. This research aims to analyse possible locations for AD plants fuelled by OFMSW in Poland. Based on the experience gained from other countries and lessons learnt from the analysis of existing facilities in Europe, conditions for the location of this type of waste treatment plants have been defined, with the focus on economic, environmental and social issues. Most likely, the results of the multicriteria decision analysis for siting of municipal solid waste AD plants (M-BIST tool) could be transferred to other countries, especially those with a comparable GDP level and a similar framework for a waste management system.     

A Comparative Study of Doum fiber and Shrimp Chitin Based Reinforced Low Density Polyethylene Biocomposites

The aim of this paper was to study the effects of reinforcing low density polyethylene (LDPE) by using bio-fillers (Doum cellulose or Shrimp chitin) on the mechanical properties. Both, Doum cellulose extracted frsom Doum leaves and Shrimp chitin extracted from shrimp co-products were compounded with LPDE without and with compatibilizer. The biocomposites were prepared by melt blending in a twin-screw extruder. Torsion and flexural tests were performed to investigate the impact of each reinforcement on the biocomposite mechanical properties. The SEM was carried out to study the filler/polymer interface adhesion. The present study has demonstrated that Doum fibers and shrimp chitin succeed in improving the mechanical properties of LPDE bio-composites. The results also showed that the use of maleic anhydride-grafted polyethylene as a compatibilizer improves filler adhesion/matrix and mechanical properties. This study exhibits that polyethylene composites based on Doum fibers or shrimp chitin can be used to replace the polyethylene materials in several fields like packaging and automotive industries.     

Physiological and biochemical defense reactions of Vicia faba L.–Rhizobium symbiosis face to chronic exposure to cyanobacterial bloom extract containing microcystins

The presence of cyanotoxins, mainly microcystins (MCs), in surface freshwater represents a serious health risk to aquatic organisms living in the water body, as well as terrestrial animals and plants that are in contact with contaminated water. Consequently, the use of MCs contaminated water for irrigation represents a hazard for cultivated plants and could induce severe economical losses due to crops’ yield reduction. The experimental approach undertaken in this work was exposing Vicia faba seedlings (inoculated with a Rhizobium strain resistant to MCs), to water supplemented with cyanobacterial crude extract containing total microcystins at a concentration of 50 and 100 μg/L (environmental relevant concentrations of MCs dissolved in the raw irrigation water from Lalla Takerkoust Lake-Marrakesh region). After chronic MCs exposure (2 months), biological and physiological parameters (plant growth, nitrogen uptake, mineral assimilation, and oxidative defense mechanisms) were evaluated. The results obtained showed evidence that chronic exposure to cyanobacterial bloom extract containing MCs strongly affected the physiological and biological plants activities; reduction of dry matter, photosynthetic activity, nodule number, and nitrogen assimilation. At the same time, an increase of oxidative stress was observed, as deduced from a significant increase of the activities of peroxidase, catalase, polyphenoloxidase, and phenylalanine ammonia lyase in leaves, roots, and nodules of faba bean plants exposed to cyanotoxins, especially at 100 μg/L of MCs. This experimentation constitutes a simulation of the situation related to cyanotoxins chronic exposure of seedlings—plants via the contaminated irrigation water. For this reason, once should take into consideration the possibility of contamination of agricultural crops and the quality of irrigation water should be by the way monitored for cyanotoxins biohazard.     

Introduction

Abstract

Eight pairs of O‐methyl and O‐ethyl O‐(substituted‐phenyl) phenylphosphonothionates were evaluated with respect to their delayed neurotoxic activity in hens. O‐methyl compounds were in all cases more active than their O‐ethyl analogs. The neurotoxic potential of the O‐methyl phenylphosphonothionates was 2,5‐diCl >4‐NO₂ >2,4,5‐triCl and 2,4,6‐triCl >2,4‐diCl >2,5‐diCl‐4‐Br >4‐CN, when single oral doses were given. Both EPN‐ethyl and leptophos‐raethyl were more neurotoxic in multiple dermal than multiple oral dosing regimens. LD₅₀s for mice and flies were established.     

Biochemical effects of some organo‐phosphorus insecticides on new targets in white rats

Abstract

The three S‐n‐propyl phosphates and phosphothioates: RH 218, profenofos and prothiophos were compared with fenitrothion in their potential as inhibitors of rat liver and brain AChE. Fenitrothion was more potent as an inhibitor than the three S‐n‐propyl derivatives. Incubation of hepatic protein enhanced ChE inhibition in brain in the case of fenitrothion, while it reduced the inhibitory effect of the S‐n‐propyl derivatives. On the other hand, the four organophosphorus esters caused hypoglycemia in both male and female rats and also reduced their blood urea with different degrees.     

Small effects of a large sediment contamination with heavy metals on aquatic organisms in the vicinity of an abandoned lead and zinc mine

The effects of the long-term contamination of water reservoirs with mine effluents were investigated at an abandoned mine site in Upper Silesia, southern Poland. The studies covered metal content and mobility in bottom sediments as well as water chemistry in relation to the content of metals in selected macrophytes and their physiology and the composition of phyto- and zooplankton communities. Although it is 40 years since mining ceased, reservoir sediments are still heavily contaminated with cadmium, zinc and lead with concentrations (mg/kg), which vary roughly between 130–340, 10,000–50,000 and 4,000–12,000, respectively. About 50–80 % of these elements are associated with the reducible phase, and only a small percentage, <10 %, is present in the most mobile exchangeable phase. Despite the high total metal concentration in sediments, their content in the submerged plants Myriophyllum spicatum and the emerged plants Phragmites australis was low. The observed effects of heavy metal contamination on photosynthetic activity in the leaves of P. australis were negligible, whereas those in M. spicatum show up only as a difference in the distribution of photosynthetic activity in leaves of different ages, which seems to be related to the very good water quality and to the generally small concentrations of metals in pond water. The physicochemical properties of water also seem to control the presence of planktonic species more than does sediment contamination. However, a shift toward groups of species known to be more resistant to heavy metals (diatoms, green algae and Rotifera) indicates some adaptative changes related to the long-lasting contamination of ponds.     

Trihalomethanes formation in water treatment plants and distribution lines: a monitoring and modeling scheme

Monitoring and modeling of the concentrations of trihalomethanes (THMs) within four water treatment plants (WTPs) and distribution lines in Fayoum City, Egypt, were studied. Sampling sites for raw and treated waters were determined by global positioning system and the Arc geographic information system software was used for mapping. THMs were monitored using 25 sampling points located at the plant exit and through the distribution lines up to the plant extremity. Results indicated that the THMs concentration varied significantly but it was very rarely higher than the allowed maximum contaminant level of 100 μg L^?1. However, at the dead zones in the distribution lines, the THMs increased by about 160% compared to in-plant level. Furthermore, the level of THMs in hot months was about 1.3 times higher than in cold ones. The influence of some independent variables such as temperature, pH, ammonia concentration, total organic carbon and color were investigated by Pearson model to find their correlation with the rate of THMs formation in WTPs. The resulted R values ranged from 0.81 to 0.98. Successful application of the model to a selected region on the distribution lines has resulted in a correlation coefficient of 0.98.     

Occupational Exposure to Natural UV Radiation and Premature Skin Ageing

The skin is the part of the human body most vulnerable to ultraviolet (UV) radiation. The spectrum of the negative effects of UV radiation on the skin ranges from acute erythema to carcinogenesis. Between these extreme conditions, there are other common skin lesions, e.g.,photoageing. The aim of this study was to assess the skin for signs of photoageing in a group of 52 men occupationally exposed to natural UV radiation. There were 2 types of examinations: an examination of skin condition (moisture, elasticity, sebum, porosity, smoothness, discolourations and wrinkles) with a device for diagnosing the skin, and a dermatological examination. The results of both examinations revealed a higher percentage of skin characteristics typical for photoageing in outdoor workers compared to the general population.     

Efficiency and degradation products elucidation of the photodegradation of mefenpyrdiethyl in water interface using TiO2 P-25 and Hombikat UV100

The photodegradation of mefenpyrdiethyl (MFD), an herbicide safener, was investigated in aqueous suspensions by using Degussa P-25 and Hombikat UV100 titanium oxide under simulated sunlight irradiation. The effects of initial concentration of the herbicide, pH, catalysts and hydrogen peroxide doses as well as their combinations were studied and optimized. Accordingly, the kinetic parameters were determined and the effectiveness of the processes was assessed by calculating the rate constants. A pseudo first-order kinetics was observed. Under experimental conditions, the degradation rate constants were strongly influenced using P-25 and no noticeable effect was observed for Hombikat UV100. DFT calculations with B3LYP/6-311+G(2d,p)//B3LYP/6-31+G(d,p) level of theory were performed to check whether significant conformational changes occur when the charge state of the MFD substrate changes and whether these changes could play a role in the dependency of photodegradation rate constant on the studied pH. High resolution mass spectrometry (FT-ICR/MS) was implemented to identify the main degradation products.     

TiO2 nanotubes as solid-phase extraction adsorbent for the determination of polycyclic aromatic hydrocarbons in environmental water samples

An analytical method based on TiO2 nanotubes solid-phase extraction (SPE) combined with gas chromatography (GC) was established for the analysis of seven polycyclic aromatic hydrocarbons (PAHs): acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors a ecting the extraction e ciency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01–0.8 g/mL, repeatability of the extraction (RSD were between 6.7% and 13.5%, n = 5) and satisfactory detection limits (0.017–0.059 ng/mL). The developed method was successfully applied to the analysis of surface water (tap, river and dam) samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.