Potential application of LDPE plastic waste into tiles

Plastic has interesting characteristics which makes it the most used material in the world. However, plastic is known to be a non-biodegradable material which unable to naturally decompost in soil and thus contribute to environmental issue. As alternative, plastic waste has been recycled to produce quality and sustainable construction materials as the source is abundant. Thus, this study is carried out to utilize plastic waste particularly low density polyethylene (LDPE) and with sand in manufacturing tiles in two different sand and plastic waste ratios of 2:1 and 2:2. The tiles manufactured were further analyzed for their water absorption and compressive strength. It was found that the tiles made of mixture ratio of 2:2 have higher compressive strength and lower weight compared to that of 2:1 ratio. The average weight of tiles for 2:1 ratio was 891.59 g, while ratio 2:2 produced tiles with weight of 1319.5 g. Tiles manufactured from the plastic waste also showed better water absorption and compressive strength compared to normal cement tiles

Integral application of electrical resistivity tomography, geochemistry and borehole data in groundwater seepage assessment

Electrical resistivity tomography (ERT) has increasingly adopted as an alternative approach in engineering, environmental and archeological studies. In the past, several limitation of conventional method in groundwater mapping was always relative to the high cost, time consuming and limited data coverage. Hence, this study adopted an ERT in order to identify the unknown problematic zone due to the excessive groundwater seepage occurrences. During data acquisition, five (five) ERT spread lines was conducted using ABEM SAS4000 equipment set. Then, field raw data was processed using RES2DINV and ROCKWORKS software to generate 2-D and 3- D of the inverse model resistivity section respectively. Engineering properties and information related to the borehole and geochemistry results was also used for interpretation and verification purposes. Geochemistry test was performed to identify groundwater sources using Atomic Absorption Spectrometer (AAS) and Ion Chromatography (IC) in order to determine the elements of cation (sodium, potassium, calcium and magnesium) and anions (chloride, bicarbonate, nitrate and sulfate) respectively. Based on ERT results, it was found that low electrical resistivity value (10 ~ 100 Ωm) which commonly associated to groundwater was detected at ground surface (0 m) until greater depth (> 10 m). Furthermore, it was found that the groundwater was classified as Ca-HCO that indicates the water was originally come from a typical shallow of the fresh groundwater. Finally, this study has successfully demonstrate that the integral application of ERT, geochemistry and borehole data was applicable to produced comprehensive outcome with particular reference to the problematic groundwater seepage assessment

Time-lapse resistivity investigation of salinity changes at an ex-promontory land: A case study of Carey Island, Selangor, Malaysia

Time-lapse resistivity measurements and groundwater geochemistry were used to study salinity effect on groundwater aquifer at the ex-promontory-land of Carey Island in Malaysia. Resistivity was measured by ABEM Terrameter SAS4000 and ES10-64 electrode selector. Relationship between earth resistivity and total dissolved solids (TDS) was derived, and with resistivity images, used to identify water types: fresh (ρ e > 6.5 Ω m), brackish (3 Ω m < ρ e < 6.5 Ω m), or saline (ρ e < 3 Ω m). Long-term monitoring of the studied area’s groundwater quality via measurements of its time-lapse resistivity showed salinity changes in the island’s groundwater aquifers not conforming to seawater-freshwater hydraulic gradient. In some aquifers far from the coast, saline water was dominant, while in some others, freshwater 30 m thick showed groundwater potential. Land transformation is believed to have changed the island’s hydrogeology, which receives saltwater pressure all the time, limiting freshwater recharge to the groundwater system. The time-lapse resistivity measurements showed active salinity changes at resistivity-image bottom moving up the image for two seasons’ (wet and dry) conditions. The salinity changes are believed to have been caused by incremental tide passing through highly porous material in the active-salinity-change area. The study’s results were used to plan a strategy for sustainable groundwater exploration of the island

Evaluating freshwater lens morphology affected by seawater intrusion using chemistry-resistivity integrated technique: a case study of two different land covers in Carey Island, Malaysia

Freshwater lenses are vital to small island communities but are susceptible to seawater intrusion due to the physical changes in the shoreline land cover. The effect of seawater intrusion and irrigation water on a coastal unconfined aquifer beneath naturally preserved mangrove and deforested mangrove-barren belt was investigated in Carey Island. Analysis of the total dissolved solids (TDS) and earth resistivity (ER) using a geochem�istry-electrical integrated technique gave a TDS–ER rela�tionship capable of predicting freshwater lens morphology affected by sea-irrigation water. The study result shows freshwater was fourfold thicker in close proximity of the mangrove forest than the mangrove barren area; the further the shoreline from the mangrove thickest section, the less vulnerable was the seawater intrusion and the more fresh the irrigation water, and hence the greater the freshwater availability potential

Water quality under the changing climatic condition: a review of the Indian scenario

The current work reviews the state of Indian water quality under the climate change regime. Rising temperatures will lead to higher concentration of pollutants like nutrients (nitrates, phosphates etc.), persistent organic pollutants and pesticides. Probable negative consequences include increase in harmful algal blooms, toxicity hazards in people etc. Rising temperatures could lead to release of higher amounts of fluoride and uranium due to prevalence of drier oxic conditions, and also arsenic due to release from iron (hydr)oxides. Implications on emerging contaminants, a new class of pollutants without any regulatory status, is not clearly understood. Prevalence of microbes in water is also predicted to increase. Coastal aquifers appear to be at risk from salt water intrusion. Conflicts on the international and national platform is predicted to rise due to issues with sharing of water. Lastly, we also discuss the sustainability options for water in India under a changing climatic regime, under three broad subcategories signifying the roles of (1) science, (2) policies and legal framework and the (3) people perspective, while also highlighting the existing lacunae.by Nilotpal Das, Chandan Mahanta and Manish Kuma