Assessment of groundwater quality in Kavaratti Island in the Lakshadweep Archipelagos,India

This study attempts to address the processes controlling the chemical composition of the Kavaratti aquifer system of Lakshadweep Island in India. Major ions and other physico-chemical parameters were determined for the premonsoon period in the Kavaratti of the Lakshadweep Island system. The trilinear diagram confirms the ingress of sea water into the shallow lens of freshwater in the islands by the changing water types. The abundance of major cations varied in the order Na>Ca>Mg>K and anions in the order Cl>HCO₃>SO₄. The ionic relations suggest that the higher concentration Na and Cl are the results of ion exchange and evaporation. The plots of data on the Gibbs diagram suggest that chemical weathering of rock-forming minerals and evaporation are the dominant factors controlling groundwater chemistry in the area. The hydrochemistry concept was deduced by the multivariate analysis for better understanding on the dynamic and complexity of the groundwater chemical processes. By the multivariate analytical techniques, the samples were grouped into two: one with saline water dominance and the other with freshwater characteristics. Thus proper management of these aquifers should be assured to retain their freshwater yield in the future.     

Anaerobic treatment of slaughterhouse wastewater: a review

This article presents a review of anaerobic treatment technologies to treat slaughterhouse wastewater including its advantages and disadvantages. Physico-chemical characteristics and biochemical methane potential (BMP) of slaughterhouse wastewater are addressed. Various anaerobic treatment technologies are presented with the related operating parameters, viz., hydraulic retention time (HRT), organic loading rate (OLR), upflow velocity (V_up), and biogas yield vis-a-vis treatment efficiency in terms of chemical oxygen demand (COD). In addition, various factors that affect the anaerobic treatment of slaughterhouse wastewater such as high oil & grease (O & G) concentration in influent, inhibitors, volatile fatty acids (VFAs), and the loading rate are also addressed. The literature review indicated that the slaughterhouse wastewater can be treated effectively by employing any anaerobic treatment technologies at OLRs up to 5 kg COD/m³.d with more than 80% COD removal efficiency without experiencing operational problems. Anaerobic hybrid reactors (AHRs) were found the most effective among various reviewed technologies because of their ability to operate at higher OLRs (8 to 20 kg COD/m³.d) and lower HRTs (8 to 12 hrs).

     

Critical coastal issues of Sagar Island, east coast of India

Sagar Island, situated in the east coast of India and one of the biggest deltas in Sundarban group, faces coastal erosion and degradation of coastal vegetation and various natural hazards. Erosion is mainly due to clay mining, wave activities, and the impact of river and tidal currents of Muri Ganga and Hugly Rivers. Further, the coastal zone of Sagar Island faces increasingly severe problems of rapidly growing human population, deteriorating environmental quality, and loss of critical habitats. Sagar Island has been victimized several times by tropical cyclones and influenced daily by tidal fluctuations. The island needs immediate attention on the coastal zone in order to protect the shoreline and ecosystem. The capability of satellite remote sensing to provide synoptic, repetitive, and multispectral data has proved to be very useful in the inventory and monitoring of critical coastal issues. Sagar Island and its environs are subjected to both natural and anthropogenic activities that continuously modify the region.     

Assessment on Seasonal Variation of Groundwater Quality of Phreatic Aquifers – a River Basin System

Spatial distribution of pH, electrical conductivity (EC), total dissolved solids (TDS), fluoride and total iron content of ground water samples collected from the muvattupuzha river basin, Kerala, India, has been studied for pre monsoon and post monsoon periods of year 2001. Results showed the groundwater of the basin is acidic for which the pH values ranged between 5.5 and 8.0. Average EC was found to be less than 100 μS/cm, for most of the study region. The pre monsoon minimum and maximum TDS were found as 25.6 and 227.84 mg/L respectively, where as post monsoon values ranged between 16 and 162.56 mg/L. The relatively low EC and TDS values found both during the seasons in the lateritic terrain of the river basin signifies the lower residence time of ground water with the country rock. This makes the groundwater quality of this river basin as good. Pre monsoon season samples showed high total iron content than that during the post monsoon period. During the study period values of the fluoride contents were found to be within the permissible limits.     

Rainfall and Spring Discharge Patterns in Two Small Drainage Catchments in the Western Himalayan Mountains, India

Relationship between rainfall and spring discharge study is important to understand hydrological behaviour of springs and water resources management. In the Himalayan mountains springs are the freshwater sources for household consumption. We studied six springs of different recharge area characteristics in two micro-watersheds in western Himalayan mountains in India. Based on the recharge area geology these springs were divided into fracture/joint (FR/JT) and fracture/joint/colluvium (FR/JT/COLL). We found a strong positive relationship between rainfall and spring discharge. Peak spring discharge coincided with peak rainfall in two FR/JT/COLL springs, which was delayed by about one month in FR/JT springs. Mean annual discharge was about two times greater for FR/JT/COLL springs than the FR/JT springs (6.47 vs. 3.94 liter per minute). But spring discharge per 1000 L of rainfall in spring recharge area for FR/JT springs was about 2.3 times greater than the FR/JT/COLL springs (49 vs. 21 liter per minute). In the FR/JT springs, rainfall in spring recharge area and spring discharge were weakly related (r=0.174), while they were strongly related in FR/JT/COLL springs (r=0.595). In the former category of springs decline in discharge was gradual, while it was rapid in the latter category of springs. Therefore, with regard to sustained supply of water for household consumption FR/JT springs can be considered more suitable. Land use and land cover such as moderately grazed pasture, abandoned agricultural terraces and few trees but dense growth of bushes and oak forest in the spring recharge area were found conducive for spring discharge and may be promoted for long-term water resource conservation in this region.     

Was Mauritius really successful in banning plastic carry bags,after promulgation of the regulation prohibiting plastic bags usage?

Environment, Development and Sustainability - Plastic carry bags are increasingly seen as environmental hazards that threaten human and animal welfare, rather than being modern conveniences....