Optimization of biodiesel production from waste cooking oil using ion-exchange resins

Waste cooking oil is a potential substitution of refined vegetable oil for the production of biodiesel due to the low cost of raw material and for solving their disposal problem. In this study, optimization of esterification process of free fatty acids in artificially acidified soybean oil with oleic acid has been carried out using methanol as an agent and ion exchange resin as a heterogeneous catalyst. The esterification reaction has been investigated based on the mass balance of the developed model. The model has been validated against experimental data and effects of temperature and catalyst weight have been analyzed. Thereafter, optimization process has been fulfilled for two different objective functions as conversion of acid oil and benefit. Optimization results indicated that the maximum conversion of acid is 95.95%, which is achievable at 4.48-g catalyst loading and reaction temperature of 120°C. Maximum benefit was obtained as US$0.057 per batch of reaction at a catalyst amount of 1 g and temperature of 120°C.     

Pesticide residues in fruits and vegetables from Pakistan: a review of the occurrence and associated human health risks

The main objective of the review is to document, assess and analyze the results of the previously reported data on levels of different pesticides in selected fruits and vegetables from Pakistan. The findings of the previous studies clearly indicated that more than 50 % of the samples were contaminated with organophosphate, pyrethroids and organochlorine pesticides. Many studies reported that among fresh fruits and vegetables tomato, apple, melon, mango, grapes, and plum crossed the FAO/WHO permissible limits for these contaminants residual levels. The comparison of other regions showed that observed levels were found above maximum residue limits (MRLs) in 50 % of the samples but were in agreement with the studies from neighboring countries like China and Bangladesh. Higher hazard risk index (HRI) values were calculated for dieldrin, methamidophos, o,p′-DDT, diazinon and p,p′-DDT in apple, mango, banana, melon, potato and onion. The review also highlights that data on pesticide residues in foodstuff is scarce which should be overcome by further extending studies from different areas of Pakistan. In order to ascertain the provision of food suitable for human consumption, it is imperative to monitor pesticides in food commodities by the country’s authorities and enforce guidelines based on permissible limits.     

Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters

The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatment plan. Preliminary hazard analysis is used as a technique to identify and assess the hazards that threaten the reliability and maintainability of a bioremediation treatment technology. Some key parameters with regard to the feasibility of the suggested preventive/corrective measures are described as well.     

Cattle egret (Bubulcus ibis) and Little egret (Egretta garzetta) as monitors of mercury contamination in Shadegan Wetlands of south-western Iran

Mercury concentrations in feather, liver, kidney, and muscle tissue of Little egret (n?=?8) and Cattle egret (n?=?3) from Shadegan Wetlands in south-western Iran were examined. Liver of Little egret had significantly higher mercury compared to Cattle egret (p?<?0.05). In addition, mercury values were consistently larger in Little egret when compared to Cattle egret, but mercury levels found in feather, kidney, and muscle did not differ statistically between the two bird species (p?>?0.05). The small Cattle egret sample size, however, makes it difficult to conclude that the same trend would persist had we been able to include more Cattle egrets in this study. An interesting regional comparison between mercury concentrations in the feather of Little egret chicks, from China, Hong Kong, and Pakistan, and adult Little egrets, from Shadegan wetlands, revealed higher mercury in the adult of the species, as one would expect. Conversely, feathers of adult Cattle egrets form Shadegan had less mercury than values reported for young birds of the same species from Aswan in Egypt; but our Cattle egrets had higher or similar mercury concentrations to Cattle egrets from Pakistan, New York, Delaware, Puerto Rico, Hong Kong, and Cairo in Egypt.     

Changes in urinary catecholamines in response to noise exposure in workers at Sarcheshmeh Copper Complex, Kerman, Iran

Noise is one of the most harmful agents in the workplace. In addition to the adverse effects of noise on the auditory system, as a stressor it may cause increased blood pressure, cardiovascular disease, anxiety, and impaired secretion of hormones. The purpose of this study was to evaluate changes in urinary catecholamines in workers exposed to industrial noise. This is an experimental study of the workers at the smelter section of Sarcheshmeh Copper Industries done on two separate days. During the first day, urine samples from 20 workers who did not use any hearing protection device, were collected during an 8-h work shift and on the second day the same was done but they were asked to use earplugs. Also 20 people were selected as a control group from people who were not exposed to noise at work. Urinary catecholamine levels were measured with ELISA kits. The mean urinary epinephrine and norepinephrine levels in the workers (without earplugs) was respectively 8.69 and 35.56 μg/8h on the first day and on the second day (with earplugs) dropped to 6.45 and 30.95 μg/8h. Noise reduction by earplugs led to almost significant reductions in urinary epinephrine (p?=?0.05) and significant reductions in norepinephrine (p?=?0.02). The results showed that with noise reduction the urinary excretion of stress hormones, especially norepinephrine significantly decreases and workers are probably less prone to stress-related disorders.     

Factors affecting incentive dependency of residents to participate in e-waste recycling: a case study on adoption of e-waste reverse supply chain in Iran

Modern societies face a dilemma called electronic waste (e-waste). This waste, which may contaminate the soil or cause unwanted impacts on human health when treated improperly, is one of the fastest growing waste streams in developed as well as developing countries and has brought great environmental impacts. Developing countries like Iran also face this modern waste management challenge. In order for more appropriate disposal or, if possible, recycling of this waste, more attention has been paid to reverse logistics as the most appropriate way to manage them. The first and most important action to address e-waste and implementation of reverse logistics is to persuade residents to bring back their obsolete electronic products. This paper attempts to understand significant factors affecting residents’ incentive dependency to participate in e-waste recycling program. Socioeconomic and demographic information of different residents is discussed by means of logistic regression for the first time in Iran. The results show that about 58.7 % of residents will participate even if no incentive is given. Household income, household size, education, e-waste concern level, and marital status are the significant factors affecting the incentive dependency of respondents.     

A multivariate statistical analysis of the composition of rainwater near Cubatão, SP, Brazil

With the aim of estimating the chemical composition of bulk precipitation (wet + dry) in Cubat?o, rainwater samples were collected at several localities in the Cubat?o region from May 1984 to October 1985. The levels of some inorganic ions (Na+, Ca2+, K+, Mg2+, Cl-, SO4(2-), NH4+, PO4(3-)) were measured by atomic absorption spectrophotometry, turbidimetry and titration analysis. Correlation and Fisher discrimination indices, principal component and varimax loading and scores were determined in the multivariate statistical data treatment. The results showed that ionic concentrations in rainwater from Vila Parisi are significantly higher than those of Cubat?o Centro, Santos and Serra do Mar. The ionic compositions of the Vila Parisi rainwater seem to be mainly determined by local anthropogenic activities (industrial pollution). Besides the influence of this factor on water quality, there is also a natural oceanic contribution involving Cl- and Na+ at the other locations.     

Spatial analysis of drought severity and magnitude using the standardized precipitation index and streamflow drought index over the Upper Indus Basin,Pakistan

Environment, Development and Sustainability - Droughts are one of the multidimensional extreme events that negatively influence agriculture, water availability and food security in the World. The...