Sandbar-regulated hydrodynamic influences on river hydrochemistry at Mengabang Telipot River, Peninsular Malaysia

Influences of river hydrodynamic behaviours on hydrochemistry (salinity, pH, dissolved oxygen saturations and dissolved phosphorus) were evaluated through high spatial and temporal resolution study of a sandbar-regulated coastal river. River hydrodynamic during sandbar-closed event was characterized by minor dependency on tidal fluctuations, very gradual increase of water level and continual low flow velocity. These hydrodynamic behaviours established a hydrochemistry equilibrium, in which water properties generally were characterized by virtual absence of horizontal gradients while vertical stratifications were significant. In addition, the river was in high trophic status as algae blooms were visible. Conversely, river hydrodynamic in sandbar-opened event was tidal-controlled and showed higher flow velocity. Horizontal gradients of water properties became significant while vertically more homogenised and with lower trophic status. In essence, this study reveals that estuarine sandbar directly regulates river hydrodynamic behaviours which in turn influences river hydrochemistry.     

Food additives for the synthesis of metal nanoparticles: a review

Environmental Chemistry Letters - Metal nanoparticles have found applications in many fields such as molecular diagnostics, electronic devices and environmental remediation. Nonetheless,...     

The relative importance of factors influencing the adoption of sustainable agricultural practices: a factor approach for Malaysian vegetable farmers

This study develops the understanding of the adoption of sustainable agricultural practices (SAPs) by investigating the relative importance of a set of multidimensional factors in the Malaysian vegetable production sector. A factor approach is deployed to identify explanatory indicators within an integrative framework that is synthesized from the theory of interpersonal behavior and the theory of diffusion of innovation. We achieved this by analyzing a logistic regression model for the adoption of six individual SAPs (conservation tillage, intercropping, cover crops/mulches, crop rotation, organic fertilizers/composts, and integrated pest management). The findings indicate that adoption depends on a range of socio-economic, agro-ecological, institutional, informational, and psychological factors, as well as the perceived attributes of SAPs. Fundamental policy understanding of the issue should, therefore, be multidisciplinary. In addition, standardized coefficients reveal that the impact of statistically significant factors on adoption is unequal. In general, the most influential factor is the asymmetric distribution of resources across geographical locations. This is followed by financial capital and a number of factors, including the workforce size, the usefulness of information, Chinese ethnicity, and the perceived relative advantage of SAPs. Guided by this prioritization understanding, future SAPs promotion now has a better opportunity to target the more important areas. Similar research effort should be made to steer sustainable agriculture internationally.     

Enhancing Performance of Sphingobacterium spiritivorum in Bioremediation Phenanthrene Contaminated Sand

Many biodegradation studies have focused on survival of isolated bacteria to increase the bacteria population and subsequently enhance the efficiency of polycyclic aromatic hydrocarbon (PAH) biodegradation. However, there is limited research on enhancing the performance of isolated bacteria through reinoculation. Thus, this study was designed to evaluate the effects of reinoculation on the performance of Sphingobacterium spiritivorum in degradation of phenanthrene contaminated sand. Experiments were performed in three different reactors. Inoculation was performed once (day 0) in reactor 1. In reactor 2, inoculation was performed twice (day 0 and day 5). The bacteria was isolated from reactor 2 and inoculated into reactor 3. The study results show reactor 3 having the highest degradation rate (13.61 mg/kg/day) and percentage removal (95.36 percent). In contrast, without reinoculation in reactor 1, 68.93 percent of phenanthrene was removed. Thus, the performance of S. spiritivorum in phenanthrene degradation can be enhanced through reinoculation. © 2014 Wiley Periodicals, Inc.     

Pesticide risk assessment: A study on inhalation and dermal exposure to 2,4-D and paraquat among Malaysian paddy farmers

A cross-section analytical study was conducted to evaluate the risk of pesticide exposure to those applying the Class II pesticides 2,4-D and paraquat in the paddy-growing areas of Kerian, Perak, Malaysia. It investigated the influence of weather on exposure as well as documented health problems commonly related to pesticide exposure. Potential inhalation and dermal exposure for 140 paddy farmers (handlers of pesticides) were assessed. Results showed that while temperature and humidity affected exposure, windspeed had the strongest impact on pesticide exposure via inhalation. However, the degree of exposure to both herbicides via inhalation was below the permissible exposure limits set by United States National Institute of Occupational Safety and Health (NIOSH). Dermal Exposure Assessment Method (DREAM) readings showed that dermal exposure with manual spraying ranged from moderate to high. With motorized sprayers, however, the level of dermal exposure ranged from low to moderate. Dermal exposure was significantly negatively correlated with the usage of protective clothing. Various types of deleterious health effects were detected among users of manual knapsack sprayers. Long-term spraying activities were positively correlated with increasing levels of the gamma-glutamyl transpeptidase (GGT) liver enzyme. The type of spraying equipment, usage of proper protective clothing and adherence to correct spraying practices were found to be the most important factors influencing the degree of pesticide exposure among those applying pesticides.     

Monitoring and identification of airborne asbestos in unorganized sectors, India

Rajasthan state in India is credited to cater more than 90% of total production of asbestos in this country, of which around 60% is processed there in unorganized sectors including milling and manufacturing of asbestos-based products. Unorganized asbestos units particularly mills showed unhealthy occupational conditions, therefore industrial hygiene study was carried out focusing on the prevalence of asbestos fibres in air at work zone area of asbestos milling units. Fibre levels were in the range of 2.00-5.09f/cm(3) and 4.07-15.60f/cm(3) in unorganized asbestos mills of Rajasthan located at Beawer and Deogarh districts, respectively. Like asbestos concentration, fibre type and length are also vital factors in the health risk assessment of industrial workers. Phase contrast and polarized light microscopic study of asbestos fibres showed their amphibole nature registering about 90% as tremolite and rest as anthophyllite. Fibre length measured micrometrically were sub-grouped in <10microm, 11-20microm, 21-30microm and >30microm. About 30-40% fibres belonged to sub-group <10microm. It is concluded that unorganized asbestos mills bear poor industrial unhygienic conditions reflected specifically from their manyfold higher fibre concentrations than the Indian and International standards. Poor industrial unhygienic conditions are attributable to obsolete milling technology, lack of pollution control devices and escape from regulatory control.     

Source Apportionment of Particulate Matter (PM10) and Indoor Dust in a University Building

A study on source apportionment of indoor dust and particulate matter (PM₁₀) composition was conducted in a university building by using chemometrics. The objective of this study was to investigate the potential sources of selected heavy metals and ionic species in PM₁₀ and indoor dust. PM₁₀ samples were collected using a low-volume sampler (LVS) and indoor dust was collected using a soft brush. Inductively coupled plasma spectrometry (ICP-MS) was used to determine the concentration of heavy metals, while the concentration of cations and anions was determined by atomic absorption spectrometer (AAS) and ion chromatography (IC), respectively. The concentration of PM₁₀ recorded in the building throughout the sampling period ranged from 20 ± 10 μgm^?3 to 80 ± 33 μgm^?3. The composition of heavy metals in PM₁₀ and indoor dust were dominated by zinc (Zn), followed by lead (Pb), copper (Cu), and cadmium (Cd). Principle component analysis (PCA) and multiple linear regression (MLR) showed that the main sources of pollutants in PM₁₀ came from indoor renovations (73.83%), vehicle emissions (16.38%), earth crust sources (9.68%), and other outdoor sources (0.11%). For indoor dust, the pollutant source was mainly earth crust. This study suggests that chemometrics can be used for forensic investigation to determine the possible sources of indoor contaminants within a public building.     

Optimising of Scenedesmus sp. biomass production in chicken slaughterhouse wastewater using response surface methodology and potential utilisation as fish feeds

Production of Scenedesmus sp. biomass in chicken slaughterhouse wastewater (CSWW) is a promising alternative technique for commercial culture medium due to the high nutritional content of the generated biomass to be used as fish feeds. The current work deals with optimising of biomass production in CSWW using response surface methodology (RSM) as a function of two independent variables, namely temperature (10–30 °C) and photoperiod (6–24 h). The potential application of biomass yield as fish feeds was evaluated based on carbohydrate, protein and lipid contents. The results revealed that the best operating parameters for Scenedesmus sp. biomass production with high contents of carbohydrates, proteins and lipids were determined at 30 °C and after 24 h. The actual and predicted values were 2.47 vs. 3.09 g, 1.44 vs. 1.27 μg/mL, 29.9 vs. 31.60% and 25.75 vs. 28.44%, respectively. Moreover, the produced biomass has a high concentration of fatty acid methyl ester (FAME) as follows: 35.91% of C15:1; 17.58% of C24:1 and 14.11% of C18:1N9T. The biomass yields have 7.98% of eicosapentaenoic acid (EPA, C20:5N3) which is more appropriate as fish feeds. The Fourier transform infrared (FTIR) analysis of biomass revealed that the main functional groups included hydroxyl (OH), aldehyde (=C–H), alkanes and acyl chain groups. Scanning electron micrograph (SEM) and energy-dispersive X-ray spectroscopic analysis (EDS) indicated that the surface morphology and element distribution in biomass produced in BBM and CSWW were varied. The findings have indicated that the biomass produced in CSWW has high potential as fish feeds.

     

Low-carbon energy strategies and economic growth in developed and developing economies: the case of energy efficiency and energy diversity

Environmental Science and Pollution Research - There has been growing interest in studying the relationship between energy strategies (energy efficiency and energy diversity) and economic growth to...