Disinfection of wastewater: comparative evaluation of chlorination and DHS-biotower

The present study reports the onsite evaluation of two pilot scale disinfection units. One of the pilot plants is based on chlorination, and other is based on fixed film aerobic process (biotower). Evaluation study consisted of onsite monitoring of COD, BOD5 and TSS and fecal coliform over a period of three months. Samples were collected from the inlet and outlet of the pilot plants. These pilot plants were evaluated so as to have an appropriate disinfection technology for the treatment of the effluents from upflow anaerobic sludge blanket reactor (UASBR) based sewage treatment plants which could meet the biological quality standards. All the influents samples collected from both the pilot plants contained fecal coliform ranging from 105 to 10(6) MPN/100 ml. The results show that the fecal coliform removal is up to 98.2% and 100% forbiotower and chlorination, respectively. Both, the chlorination and down hanging sponge-biotower (DHS-biotower) improved the quality of effluent from the UASBRin terms of COD, BOD5 and TSS. Though chlorination performed better compared to the DHS-biotower, however, it has additional risk associated with the formation of trihalomethanes (THMs).     

A note on the thyroid function of the pregnant females in the USA: data from NHANES 1999–2002 and 2007–2012

Thyroid dysfunction during pregnancy has been shown to be associated with adverse pregnancy outcomes. Consequently, this study was undertaken to assess the thyroid health of the pregnant females in the United States. Publically available data from National Health and Nutrition Examination Survey for the cycles 1999–2002 and 2007–2012 were analyzed for this purpose. Over 22% (SE: 5.7%) of the pregnant females based on the unweighted data in their first trimester had higher than the recommended levels of thyroid-stimulating hormone (TSH) or 2.5 mIU/L. Free triiodothyronine (FT3) and free thyroxine (FT4) levels decreased over pregnancy trimesters. Based on unweighted data, about 6% (SE: 2.6%) pregnant females were positive for thyroglobulin antibodies and 34.9% (SE: 5.2%) pregnant females were positive for thyroid peroxidase antibodies. Over 55% (SE: 3.5%) pregnant females based on the unweighted data were iodine deficient. As many as 41% (SE: 3%) first trimester pregnant females having TSH > 2.5 mIU/L is of concern. Future research should concentrate on developing educational and other materials that can advise pregnant females during their prenatal care and other appointments about the adverse effects of high TSH levels and what they can do to keep their TSH levels within the recommended levels.     

Heavy Metal Transport in the Hindon River Basin, India

Total mass transfers of heavy metal in dissolved and particulate form has been determined in the downstream section of river Hindon, an important tributary of river Yamuna (India). The contribution of different point sources to the river Hindon has also been assessed. The river Kali has the largest contribution to the river Hindon. The highest metal loads were related to the highest flow of the river and thereby increased both by surface runoff and sediment resuspension. The contribution of monsoon months to the total transported load was also calculated and it was observed that monsoon months contributes more than 40% of total loading annually for all the metals. The metal fluxes from the river Hindon were compared with other rivers of Indian sub-continent.     

Dynamics and determinants of land change in India: integrating satellite data with village socioeconomics

We examine the dynamics and spatial determinants of land change in India by integrating decadal land cover maps (1985–1995–2005) from a wall-to-wall analysis of Landsat images with spatiotemporal socioeconomic database for ~630,000 villages in India. We reinforce our results through collective evidence from synthesis of 102 case studies that incorporate field knowledge of the causes of land change in India. We focus on cropland–fallow land conversions, and forest area changes (excludes non-forest tree categories including commercial plantations). We show that cropland to fallow conversions are prominently associated with lack of irrigation and capital, male agricultural labor shortage, and fragmentation of land holdings. We find gross forest loss is substantial and increased from ~23,810 km² (1985–1995) to ~25,770 km² (1995–2005). The gross forest gain also increased from ~6000 km² (1985–1995) to ~7440 km² (1995–2005). Overall, India experienced a net decline in forest by ~18,000 km² (gross loss–gross gain) consistently during both decades. We show that the major source of forest loss was cropland expansion in areas of low cropland productivity (due to soil degradation and lack of irrigation), followed by industrial development and mining/quarrying activities, and excessive economic dependence of villages on forest resources.

     

Establishing influence of morphological aspects on microclimatic conditions through GIS-assisted mathematical modeling and field observations

Environment, Development and Sustainability - Local climate in an area is significantly affected by the extent of urbanization. The microclimatic parameters such as wind speed (W), relative...     

Chemical characteristics and source apportionment of PM<Subscript>2.5</Subscript> using PCA/APCS,UNMIX, and PMF at an urban site of Delhi,India

The present study investigated the comprehensive chemical composition [organic carbon (OC), elemental carbon (EC), water-soluble inorganic ionic components (WSICs), and major & trace elements] of particulate matter (PM_2.5) and scrutinized their emission sources for urban region of Delhi. The 135 PM_2.5 samples were collected from January 2013 to December 2014 and analyzed for chemical constituents for source apportionment study. The average concentration of PM_2.5 was recorded as 121.9 ± 93.2 μg m^?3 (range 25.1–429.8 μg m^?3), whereas the total concentration of trace elements (Na, Ca, Mg, Al, S, Cl, K, Cr, Si, Ti, As, Br, Pb, Fe, Zn, and Mn) was accounted for ～17% of PM_2.5. Strong seasonal variation was observed in PM_2.5 mass concentration and its chemical composition with maxima during winter and minima during monsoon seasons. The chemical composition of the PM_2.5 was reconstructed using IMPROVE equation, which was observed to be in good agreement with the gravimetric mass. Source apportionment of PM_2.5 was carried out using the following three different receptor models: principal component analysis with absolute principal component scores (PCA/APCS), which identified five major sources; UNMIX which identified four major sources; and positive matrix factorization (PMF), which explored seven major sources. The applied models were able to identify the major sources contributing to the PM_2.5 and re-confirmed that secondary aerosols (SAs), soil/road dust (SD), vehicular emissions (VEs), biomass burning (BB), fossil fuel combustion (FFC), and industrial emission (IE) were dominant contributors to PM_2.5 in Delhi. The influences of local and regional sources were also explored using 5-day backward air mass trajectory analysis, cluster analysis, and potential source contribution function (PSCF). Cluster and PSCF results indicated that local as well as long-transported PM_2.5 from the north-west India and Pakistan were mostly pertinent.     

Coal Combustion Product: Nonhazardous Material for Mine Fill

As is the case in many other countries around the world, India's main source of electricity is coal‐fired power plants. In addition to providing energy, the burning of coal also results in large amounts of coal combustion products (CCP), the incombustible material, such as fly ash, left after the coal is burned. These materials are produced in large volume, and if they are not managed or utilized properly, they can pose a danger to the environment. This article discusses the uses of CCP, with a special emphasis on fly ash, and the role that it is currently playing and can continue to play as a mine filler for India's depleted opencast and underground coal mines.     

Multivariate statistical analysis of heavy metals in soils of a Pb–Zn mining area, India

Surface soil samples collected from a Pb and Zn mining area in India were subjected to multi-elemental analysis by using inductively coupled plasma-atomic emission spectrometry. Multivariate statistical methods such as principal component analysis and cluster analysis, coupled with correlation coefficient analysis, were used to analyze the data and to apportion the possible sources of elements in soils of a metal mining area. Soils in this area have elevated heavy metal concentrations especially Pb, Zn, Mn, Cu, As, and Tl. Using principal component (PC) analysis, six components were extracted, out of which two PCs explaining 50.12% of total variance are more important. The first principal component with a high contribution of Ag, As, Be, Cd, Co, Cu, Mg, Mn, Ni, Pb, and Zn was deemed to be technogenic/anthropogenic component, and the second principal component, with high loadings for the five discerning variables (Al, Be, Cr, K, Li), was considered as lithogenic component. The third component having strong loadings of Ba, Ca, K, and Na is supposed to have a mixed origin (lithogenic as well as technogenic). Electrical conductivity and total organic matter were not correlated with any element and also have a strong loading in the fifth component which is probably the biomass and ions present in these soils. The findings of the principal component analysis were also substantiated by the cluster analysis. The present study would not only enhance our knowledge regarding the soil pollution status in the study area but would also provide us information to manage the sources of these elements in the study area.     

Water quality improvement after shifting of idol immersion site: A case study of Upper Lake,Bhopal, India

Most of freshwater bodies all over the world are becoming polluted, thus decreasing the portability of the water. In India religious practices have deep relationship with water bodies. They also patronized religious practices and constructed numerous relatively small water bodies along with temples throughout the country. Today, with the rapid pace of urban development, most of these water bodies have become sinks for waste discharge, resulting in deterioration of their water quality. Upper Lake of Bhopal, constructed in the eleventh century, is typical example of urban water bodies and a major source of potable water for the people of Bhopal. Till the middle of the last century, the water of Upper Lake did not require any treatment before supply for drinking purposes. Idol worship is common in India. Idols are usually made up of wood, bamboo, straw, jute ropes, clay, and plaster of Paris and are painted with bright synthetic colors, which often contain heavy metals. Other materials, such as straw, jute ropes, flowers, leaves and germinated grains cause short-term deterioration of water quality on their decay, while heavy metals in the paints pose health hazards in the long-run. Religious issues are extremely sensitive and hence it was felt necessary to use the regard that the citizens had for the lake to build a consensus in support of change. The Bhoj Wetland Project was implemented with the aid of Japanese Bank of International Cooperation (JBIC) to take action for preserving the Upper Lake of Bhopal (called Bhoj Wetlands). Our study is highlighted to water quality parameters like turbidity, total hardness, DO (Dissolved oxygen), BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand) and heavy metals in the year 1999 and 2005 i.e. before implementation of project and completion of project.     

Sub-hourly changes in biogeochemical properties in surface waters of Zuari estuary, Goa

Processes in natural waters are highly variable in time and space. Although changes are expected in short-time scales, how short one could get to measure reliably is subjective to sampling strategies and methodologies. Here, we show that sub-hourly changes in surface waters dissolved oxygen, nutrients, and pigments are measurable and significant in an estuarine system. Tidal circulation has been found to strongly influence the observed changes and has implications to material fluxes in and out of estuaries.