Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): hydrochemistry and water quality

Arabian Journal of Geosciences - This paper presents the results of a groundwater hydrochemical assessment in the urban area of Khan Younis City in the southern Gaza Strip by measuring its...     

Heavy metal resistant endophytic fungi isolated from Nypa fruticans in Kuching Wetland National Park

Heavy metal pollution is an environmental issue globally and the aim of this study was to isolate endophytic fungi from mangrove wetlands of Sarawak to assess and test their ability to grow in the presence of various heavy metals (copper (Cu), zinc (Zn), lead (Pb), and chromium (Cr)). Samples of Nypa fruticans were collected from Kuching Wetland National Park (KWNP) for subsequent endophyte isolation. Ninety-three (93) isolates were obtained and assessed and the most resistant isolates (growing at concentrations up to 1000 ppm) were identified using fungal primers ITS 1 and ITS 4. All of the endophytic fungi were identified to be closely related to Pestalotiopsis sp. and this is to our knowledge the first study reporting the ability of Pestalotiopsis sp. to grow at high concentrations of copper, lead, zinc and chromium. Our results highlight the potential of using endophytic fungi for the treatment of heavy metal pollution, for example as biosorbents.

     

The impact of climate change on sea level rise at Peninsular Malaysia and Sabah–Sarawak

The sea level change along the Peninsular Malaysia and Sabah–Sarawak coastlines for the 21st century is investigated along the coastal areas of Peninsular Malaysia and Sabah–Sarawak because of the expected climate change during the 21st century. The spatial variation of the sea level change is estimated by assimilating the global mean sea level projections from the Atmosphere–Ocean coupled Global Climate Model/General Circulation Model (AOGCM) simulations to the satellite altimeter observations along the subject coastlines. Using the assimilated AOGCM projections, the sea level around the Peninsular Malaysia coastline is projected to rise with a mean in the range of 0.066 to 0.141 m in 2040 and 0.253 m to 0.517 m in 2100. Using the assimilated AOGCM projections, the sea level around Sabah–Sarawak coastlines is projected to rise with a mean in the range of 0.115 m to 0.291 m in 2040 and 0.432 m to 1.064 m in 2100. The highest sea level rise occurs at the northeast and northwest regions in Peninsular Malaysia and at north and east sectors of Sabah in Sabah–Sarawak coastline. Copyright © 2012 John Wiley & Sons, Ltd.     

Leaching of Lisan Marl and its consequences on the engineering behavior of dikes,studied by finite elements modeling

Leaching of Lisan Marl, Dead Sea, Jordan increased the soil compressibility and cohesion intercept. Back analysis using the Plaxis finite element code was successfully implemented. The Finite element modeling of dike construction showed a significant increase of total settlement and negligible effect on the strength as calculated by the φ/c reduction method. The height of dikes to be constructed on Lisan Marl as foundation material, should be optimized to account for the effect of soluble salts leaching. For this to take place, an accurate calculation of settlement is crucial.     

Drinking quality assessment of some groundwater sources along the stretch of Jhelum River in Kashmir Himalaya

The physicochemical properties and major ion chemistry of the groundwater sources from alluvial aquifers along the stretch (60 km) of Jhelum River in Kashmir Himalaya were determined in order to identify hydro-geochemical processes and their suitability for drinking purposes. The data depicted that calcium and bicarbonates were dominating among the cations and anions. The results indicate the trend of cation dominance as Ca²⁺ > Na⁺ > Mg²⁺ > K⁺, whereas anion dominance was in the order of HCO₃ ^? > Cl^? > SO₄ ^2?. Ratio of calcium to magnesium indicated the dissolution of Ca²⁺ from CaCO₃, which results in an increased levels of Ca²⁺ in the groundwater. Interpretation of Piper Trilinear plot understands the various geochemical processes affecting the groundwater quality and shows groundwater was dominated by Ca–HCO₃ type. The pH was recorded in the slightly alkalinity range 7.2–7.8 and was showing positive correlation with HCO₃ ^?. The chloro-alkaline indices revealed 86% of the sources exchange by a type of base-exchange reactions, rest by cation–anion exchange. Gibbs diagram revealed groundwater sources fall in the category of rock dominance. The concentration of the nitrogen compounds was in the progression of NO₃–N > NH₄–N > NO₂–N, and the PO₄ ^? fluctuated from 0.12 to 0.22 mg/L. Moreover, corrosivity ratio indicated that water from the majority of sources (71%) is safe to supply using pipes without any corrosive effects, while 29% of sources are corrosive in nature and need non-corrosive pipes for transporting and lifting of groundwater. The results revealed, groundwater samples were within permissible limits as prescribed by International and National standards, for drinking purposes. The State government and NGO’s can show their interest in utilizing such water resources to overcome the shortage of drinking water in a sustainable way for the daily consumption of the people living in the vicinity of Jhelum River.     

Applying the scores of multivariate statistical analyses to characterize the relationships between the hydrochemical properties and groundwater conditions in respect of the monsoon variation in Kapas Island,Terengganu, Malaysia

The different factors (seasonal changes) and variables (physicochemical) controlling the groundwater hydrochemistry of Kapas Island were identified using multivariate techniques principal component analysis (PCA), discriminant analysis (DA) and hierarchy cluster analysis (HCA). In the present study, the hydrochemistry of 216 groundwater samples, consisting of information concerning the in situ parameters and major ions in six monitoring boreholes, was studied and compared in two different monsoon seasons. The dominant variables derived from four components by PCA in the pre-monsoon indicated the influence of the salinity process, while the dominant variables derived from three components in the post-monsoon mostly indicated on the mineralization process. The DA gave the final variables after discriminating the insignificant variables based on the pre- and post-monsoon classifications. This provided important data reduction in terms of the mineralization process, as it only discriminated physical variables (TDS, EC, salinity, DO and temperature). Based on the HCA result, samples belonging to stations KW 3 and KW 4 were under Ca-rich water, while the remaining boreholes were grouped in Na-rich water.     

Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): assessment for multi-domestic purposes

The present study research investigation is aimed to assess the groundwater quality for the urban area in Khan Younis City, southern Gaza Strip, for multi-domestic purposes. The physicochemical analysis of the groundwater wells shows the major ions in the order of Na⁺ > Mg²⁺ > Ca²⁺ > B³⁺ > K⁺ and Cl^? > HCO₃ ^? > SO₄ ^2? > NO₃ ^2? > F^? > PO₄ ^3?. Groundwater quality is classified as very hard-brackish water type. Ninety-five percent of the wells are classified as saline water type with high NO₃ ^2? concentrations. Based on water quality index (WQI), the groundwater falls into one of three categories: fair water (10%), poor water (15%), very poor (45%), and worst (30%). The high WQI values are because of high Na⁺, Cl^?, SO₄ ^2?, and NO₃ ^2? concentrations, while synthetic pollution index (SPI) values indicate that most about 80% of the wells are seriously polluted. Langelier Saturation Index (LSI) indicates that most of data are either slightly scale forming or corrosive water or slightly corrosive but non-scale forming, and 75% of the wells are suitable for construction purposes (have SO₄ ^2? concentrations <300 mg/L). The groundwater reaches alarming situation, where almost chemically unsuitable for drinking purposes and the water to be used after proper treatment such as desalination.     

Saturation states of carbonate minerals in a freshwater-seawater mixing zone of small tropical island’s aquifer

Groundwater is a crucial resource on the Manukan Island as it is the only source of freshwater available on the island. The aquifer has deteriorated to a high degree, during the last decade. Nine domestic wells were sam-pled from March 2006 to January 2007 to probe the hydrochemical components that influence the water quality. Geochemical data on dissolved major constituents in groundwater samples from the Manukan Island revealed the main processes responsible for their geochemical evolution. The results using statistical analyses, graphical method and numerical model output (PHREEQC) showed that the groundwater was chemically highly enriched in Na and Cl, indicative of seawater intrusion into the aquifer as also supported from the Na-Cl signature on the Piper diagram. From the PHREEQC simulation model, calcite, dolomite and aragonite solubility showed positive values of the saturation indices (SI), indicating supersaturation which led to mineral precipitation condition of water by these min-erals.     

Spatial trends of dry spells over Peninsular Malaysia during monsoon seasons

This study aims to trace changes in the dry spells over Peninsular Malaysia based on the daily rainfall data from 36 selected rainfall stations which include four subregions, namely northwest, west, southwest, and east for the periods of 1975 to 2004. Six dry spell indices comprising of the main characteristics of dry spells, the persistency of dry events, and the frequency of the short and long duration of dry spells will be used to identify whether or not these indices have increased or decreased over Peninsular Malaysia during the monsoon seasons. The findings of this study indicate that the northwestern areas of the Peninsular could be considered as the driest area since almost all the indices of dry spells over these areas are higher than in the other regions during the northeast (NE) monsoon. Based on the individual and the field significant trends, the results of the Mann–Kendall test indicate that as the total number of dry days, the maximum duration, the mean, and the persistency of dry days are decreased, the trend of the frequency of long dry spells of at least 4 days is also found to decrease in almost all the stations over the Peninsula; however, an increasing trend is observed in the frequency of short spells in these stations during the NE monsoon season. On the other hand, during the southwest monsoon, a positive trend is observed in the characteristics of dry spells including the persistency of two dry days in many stations over the Peninsula. The frequency of longer dry periods exhibits a decreasing trend in most stations over the western areas during both monsoon seasons for the periods of 1975 to 2004.