Impact of economic capabilities and population agglomeration on PM2.5 emission: empirical evidence from sub-Saharan African countries

Environmental Science and Pollution Research - The utilization of economic capabilities to raise production in the economy enhances the industrial activities and use of transportation. These...     

Detection and removal of heavy metal ions: a review

Environmental Chemistry Letters - In aqueous systems, heavy metal ions, when present in excess than permissible limits, are dangerous for human beings and aquatic life. Heavy metals cannot be...     

Spatial assessment of groundwater quality in Guna Tana landscape

This study focuses on investigating the quality of groundwater for irrigation and drinking water purposes. Spatial distribution of physicochemical and microbiological parameters was assessed from samples collected from springs, hand‐dug wells, and boreholes found the Guna Tana landscape. A total of 70 samples were considered for physical, chemical, and bacteriological water quality determination. The results revealed that most of the groundwater quality index (WQI) values lie between good and excellent. The maximum, minimum, mean, and standard deviation of each water quality parameter were prepared for evaluating groundwater quality. According to the WQI values, more than 83% of the water samples were classified as excellent water for drinking. More than 92% of the water samples showed low sodium hazards for irrigation and about 48% and 46% of the water samples were classified as within the excellent and good water classes for irrigation based on their electrical conductance levels. Therefore, the groundwater that is found in the Guna Tana landscape could be used for drinking and irrigation purposes without any advanced treatment.     

长期施肥对棕壤有机碳储量及固碳速率的影响

利用棕壤肥料长期定位试验,研究了不同施肥条件下棕壤有机碳在0~60 cm土层的含量和储量特征以及土壤固碳速率.试验共设6个处理,即氮磷肥有机肥配施(M_2NP)、氮肥有机肥配施(M_2N)、单施有机肥(M_2)、单施氮肥(N)、氮磷肥配施(NP)和不施肥处理(CK).结果表明:经过31年长期不同施肥,各处理土壤有机碳(SOC)含量和储量的剖面分布均呈现随土层深度增加而显著降低的规律.本试验条件下M_2NP、M_2N、M_2、NP、N、CK处理的耕层有机碳富集系数分别为0.465、0.455、0.407、0.48_2、0.393、0.471,表明耕层土壤对有机碳的保持强度最强.在0~60 cm土层土壤有机碳储量表现为M_2NP、M_2NM_2、NPNCK,有机肥和化肥配施能够显著提高土壤有机碳含量和储量.与试验前相比,CK处理各土层土壤有机碳含量和储量均显著降低.各处理碳库管理指数(CPMI)表现为M_2NPM_2NM_2NNPCK.分析不同施肥处理土壤固碳速率可知,与试验前相比,CK处理表现为碳的净释放,固碳速率达-401.4 kg·hm~(-_2)·a~(-1);固碳速率最高的为M_2NP,M_2N,分别达到489kg·hm~(-_2)·a~(-1)、440._2 kg·hm~(-_2)·a~(-1).综合结果表明,化肥、有机肥配施所产生交互效应更有利于棕壤有机碳储量的增加及固碳速率的提高.     

Correlation of cadmium and aluminum in blood samples of kidney disorder patients with drinking water and tobacco smoking: related health risk

The combined exposure to aluminum (Al) and cadmium (Cd) causes more pronounced adverse health effects on humans. The kidneys are the main organs affected by internal exposure to Cd and Al via food and non-food items. The objective of present study was to measure the Al and Cd concentrations in cigarettes tobacco (branded and non-branded) and drinking water (domestic treated, ground and lake water) samples in southern part of Pakistan, to assess the risk due to ingestion of water and inhalation of cigarettes smoke containing high concentrations of both elements. The study population (kidney disorder and healthy) divided into two group based on consuming lake and ground water, while smoking non-branded cigarette as exposed, while drinking domestic treated water and smoking branded cigarette as non-exposed. Electrothermal atomic absorption spectrometry was used to determined Cd and Al concentrations in tobacco, drinking water and blood samples. The resulted data indicated that the levels of Al and Cd in lake and underground water were higher than the permissible limit in drinking water recommended by the World Health Organization. The biochemical parameters of exposed and referent patients, especially urinary N-acetyl-h-glucosaminidase, were used as a biomarkers of kidney disorder. Exposed kidney disorder patients have higher levels of Cd and Al than the exposed referents subjects, while difference was significant when compared to resulted data of non-exposed patients and referents (p = 0.01–0.001). The pearson correlation showed positive correlation between both toxic element concentrations in water, cigarettes versus blood samples of exposed subjects (r = 0.20–0.67 and 0.71–0.82), while lower values were observed for non-exposed subjects (r = 0.123–0.423 and 0.331–0.425), respectively.

     

Behaviour of Rice-Byproducts and Optimizing the Conditions for Production of High Performance Natural Fiber Polymer Composites

This present study deals with evaluating some available rice by-products, such as rice straw and rice husks, as a fiber component in manufacturing of high performance natural fiber polymer composites (NFPC). The utilization of these undesirable wastes will contribute to the reduction of the environmental impact of waste disposal by burning. Two matrices (thermoset and thermoplastic) were used. Optimization of manufacture conditions of polyester-based thermosetting polymer composites was carried out through examine the effects of fibers to polymer ratio, amounts of catalyzed and initiator, fraction size of fibers and substituting one fibers by another, as well as time, temperature and pressure of pressing. The possibility of styrene containing polyester solution on improving the fiber interface via in situ grafting and enhancing the strength and water resistance of the produced NFPC was also evaluated, in comparison with that produced from using thermoplastic matrix (polypropylene) in presence of coupling agent. The production of this valuable product (NFPC) by this simple procedure, which not needs special devices (twin extrusion with heater), and chemicals to improve the compatibility between fibers and polymer matrix, will ensure reasonable profits and direct impacts on the Egyptian economy in general and rice growers in particular.     

Effect of calcium against salinity-induced inhibition in growth, ion accumulation and proline contents in Cichorium intybus L

This study assesses the effect of NaCl (80 and 160 mM) and CaCl2 (10 mM) solutions, alone and in combination, to 30-day-old seedlings of Cichorium intybus L. Observations were made at 30 day intervals from the time of treatment till harvest (180 days after sowing). Application of NaCI resulted in significant decreases in lengths of root and stem, in dry weights of root, stem and leaves and in the leaf area, as compared with control. The reduction was less with the combined application of NaCI and CaCI2 than with the NaCI treatment alone. On the contrary treatment of CaCl2, alone promoted the above variables. Proline content in the leaves was enhanced with NaCl and CaCI, alone as well as with the NaCI + CaCI2 treatments; the maximum (six-fold) enhancement was observed with the combined treatments, compared with NaCl (four-fold increase) and CaCl2 (two-fold increase) alone. The sodium (Na+) and Chloride (CI) contents in different plant parts increased both with NaCI and with NaCI+ CaCI2 treatments. The maximum accumulation was observed in leaves, followed by that in stem and root. The potassium (K+) and calcium (Ca2+) contents decreased under NaCl stress, but increased with CaCI2 treatment. Thus, calcium ameliorated the deleterious effects of NaCI stress and stimulated the plant metabolism and growth.     

Spatial assessment of groundwater quality in Mamundiyar basin, Tamil Nadu, India

Understanding the groundwater quality is important as it is the main factor determining its suitability for drinking, domestic, agricultural, and industrial purposes. In order to assess the groundwater quality, 30 groundwater samples have been collected in year 2008. The water samples collected in the field were analyzed for electrical conductivity, pH, total dissolved solids (TDS), major cations like calcium, magnesium, sodium, potassium, and anions like bicarbonate, carbonate, chloride, nitrate, and sulfate, in the laboratory using the standard methods given by the American Public Health Association. The groundwater locations were selected to cover the entire study area and attention was been given to the area where contamination is expected. The expected groundwater contaminants were chloride, nitrate, TDS, etc. The results were evaluated in accordance with the drinking water quality standards given by the World Health Organization (WHO 1993). To know the distribution pattern of the concentration of different elements and to demarcate the higher concentration zones, the contour maps for various elements were also generated, discussed, and presented.     

ModelOps for enhanced decision-making and governance in emergency control rooms

Environment Systems and Decisions - For mission critical (MC) applications such as bushfire emergency management systems (EMS), understanding the current situation as a disaster unfolds is critical...     

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

The shrinkage of cement-based materials is a critical dimensional property that needs proper attention as it can influence the corresponding characteristics especially when the preparation of such cement-based material is done in hot weather. Studies have shown that the casting or curing conditions influence the performance of concrete. However, there is limited understanding of the combined role of casting temperature and curing conditions, especially for concrete made with unconventional binders. In this study, five supplementary cementitious materials (SCMs) were utilized as the substitute of the ordinary Portland cement (OPC) at different ratios to produce greener concrete and improve its characteristics and sustainability. The influence of four casting temperatures (i.e., 25 °C, 32 °C, 38 °C, and 45 °C) and two curing regimes (i.e., covering of samples using wet burlap and applying curing compound on the surface of samples) on the corresponding compressive strength and drying shrinkage at various ages was studied. The outcomes of this research revealed that the composition of the binders has a substantial impact on the characteristics of concrete. In addition, the casting temperature and curing regimes also have a huge role on the compressive strength of concrete produced with binary binders. For example, the compressive strength at 3 days of concrete made at 25 °C made with binary binders was reduced up to 31% compared to that made with only OPC as the binder when cured using wet burlap. Nonetheless, less than 38 ℃ was suitable to minimize the durability issues in the studied blended cement mixes.