TPS/PCL Composite Reinforced with Treated Sisal Fibers: Property, Biodegradation and Water-Absorption

Sisal fibers bleached with sodium-hydroxide followed by hydrogen peroxide treatment were incorporated in a thermoplastic starch/ε-polycaprolactone (TPS/PCL) blend via extrusion processing. These samples with smooth and homogenous surfaces were examined for their property, biodegradability and water absorption. Scanning electron microscopy revealed that the fibers were well dispersed in the matrix. In addition, it was found that the fibers and matrices interacted strongly. Blends with 20 % (dry weight-basis) fiber content showed some fiber agglomeration. Whereas blends with 10 % fibers showed increased crystallinity and lower water absorption capacity. The CO₂ evolution study showed that the thermoplastic starch samples without any additives had the highest rate and extent of degradation whereas the neat PCL samples had the lowest degradation rate. Addition of fiber to the TPS/PCL blend exhibited the degradation rates and extents that were somewhere in between the pure TPS and neat PCL. This work demonstrates that TPS/PCL composites reinforced with bleached sisal has superior structural characteristics and water resistance and thus, can be used as polymeric engineering composites for different applications.     

Physicochemical characterization of industrial effluents and their effect on fish survival

Abstract

Water samples taken from selected industrial drainages and receiving streams in and around Islamabad, Pakistan, during the summers of 1987 to 1990 showed disturbances in pH and low oxygen levels. Selected metals (Fe, Pb, Zn, Cd, Cu, Ni, Hg) were higher in all effluents than in receiving waters. Static bioassays of the undiluted industrial effluents from three sites caused 100% mortality in carp during the first 24 hrs. Fishes also suffered 30 to 60% mortality when exposed to other undiluted industrial effluents and some mortality when industrial effluents were diluted by 50%.     

Biological activity and bioavailability of grain bound 14C‐malathion residues in rats

Abstract

Paddy (unmilled rice), milled rice and maize‐bound ¹⁴C residues were prepared using ¹⁴C‐succinate‐labelled malathion at 10 and 152 ppm. After 3 months, the bound residues accounted for 12%, 6.5% and 17.7% of the applied dose in paddy, milled rice and maize respectively in the grains treated at 10 ppm. The corresponding values for the 152 ppm were 16.6%, 8.5% and 18.8%. Rats fed milled rice ‐ bound ¹⁴C‐residues eliminated 61% of the ¹⁴C in the faeces and 28% in the urine. The corresponding percentages for paddy and maize were 72%, 9% and 53%, 41% respectively; indicating that bound residues from milled rice and maize were moderately bioavailable. When rice‐bound malathion residues (0.65 ppm in feed) were administered to rats in a 5 week feeding study, no signs of toxicity were observed. Plasma and RBC cholinesterase activities were slightly inhibited: blood urea nitrogen was significantly elevated in the test animals. Other parameters examined showed no or marginal changes.     

Ozone levels in the empty quarter of Saudi Arabia—application of adaptive neuro-fuzzy model

In arid regions, primary pollutants may contribute to the increase of ozone levels and cause negative effects on biotic health. This study investigates the use of adaptive neuro-fuzzy inference system (ANFIS) for ozone prediction. The initial fuzzy inference system is developed by using fuzzy C-means (FCM) and subtractive clustering (SC) algorithms, which determines the important rules, increases generalization capability of the fuzzy inference system, reduces computational needs, and ensures speedy model development. The study area is located in the Empty Quarter of Saudi Arabia, which is considered as a source of huge potential for oil and gas field development. The developed clustering algorithm-based ANFIS model used meteorological data and derived meteorological data, along with NO and NO₂ concentrations and their transformations, as inputs. The root mean square error and Willmott’s index of agreement of the FCM- and SC-based ANFIS models are 3.5 ppbv and 0.99, and 8.9 ppbv and 0.95, respectively. Based on the analysis of the performance measures and regression error characteristic curves, it is concluded that the FCM-based ANFIS model outperforms the SC-based ANFIS model.     

Environment and Mobility: A View from Four Discourses

Debate and literature on the link between degrading environments and human mobility has been increasing exponentially. There is little concrete evidence, however, of efforts or policies that support the management of environmentally influenced mobility. Through discourse analysis using Q-methodology, this research aimed to scrutinize the standoff between opposing views under a fresh lens. One-hundred and ninety-seven experts from 49 nations completed an on-line survey asking them to sort, by level of agreement, 42 statements gleaned from the literature concerning the environment-mobility nexus. Four very different discourses emerged: determined humanists, benevolent pragmatists, cynical protectionists, and critical realists. The complexity of these discourses helps explain the stalemate while confirming the inappropriateness of one-sided terminology and linear quantifications. Despite diametrically opposed viewpoints, experts unanimously agree that human mobility is connected to environmental change. Dissection of these social perspectives builds a new foundation for the Rio+20 analysis and policy deliberations related to environmentally influenced human mobility.     

Batch and continuous biosorption of Cu by immobilized biomass of Arthrobacter sp.

The ability of free and polysulphone immobilized biomass of Arthrobacter sp. to remove Cu²⁺ ions from aqueous solution was studied in batch and continuous systems. The Langmuir and Freundlich isotherm models were applied to the data. The Langmuir isotherm model was found to fit the sorption data indicating that sorption was monolayer and uptake capacity (Q^o) was 175.87 and 158.7 mg/g for free and immobilized biomass respectively at pH 5.0 and 30 °C temperature, which was also confirmed by a high correlation coefficient, a low RMSE and a low Chi-square value. A kinetic study was carried out with pseudo-first-order reaction and pseudo-second-order reaction equations and it was found that the Cu²⁺ uptake process followed the pseudo-second-order rate expression. The diffusivity of Cu²⁺ on immobilized beads increased (0.402 × 10⁻⁴ to 0.435 × 10⁻⁴ cm²/s) with increasing concentration from 50 to 150 mg/L. The maximum percentage Cu²⁺ removal (89.56%) and uptake (32.64 mg/g) were found at 3.5 mL/min and 20 cm bed height. In addition to this the Bed Depth Service Time (BDST) model was in good agreement with the experimental data with a high correlation coefficient (>0.995). Furthermore, sorption and desorption studies were also carried out which showed that polysulphone immobilized biomass could be reused for up to six sorption–desorption cycles.     

A comprehensive review on experimental,numerical and optimization analysis of EAHE and GSHP systems

Environmental Science and Pollution Research - Geothermal energy is one type of renewable source of energy that can be used as shallow geothermal system for the use of cooling and heating of...     

Introduction of Ionic Liquids as Highly Efficient Plasticizers and Flame Retardants of Cellulose Triacetate Films

Journal of Polymers and the Environment - As a promising biodegradable polymer, cellulose triacetate (CTA) was synthesized and plasticized with ionic liquids to produce flexible biocomposite films...     

Correction to: Role of casting and curing conditions on the strength and drying shrinkage of greener concrete

Environmental Science and Pollution Research -     

Temporal and spatial assessment of groundwater contamination with nitrate using nitrate pollution index (NPI), groundwater pollution index (GPI), and GIS (case study: Essaouira basin,Morocco)

Environmental Science and Pollution Research - Groundwater aquifers in Morocco’s coastal regions are under serious threat as a result of climate change. This study was conducted to evaluate...