A simple chemical free arsenic removal method for community water supply - A case study from West Bengal, India

This report describes a simple chemical free method that was successfully used by a team of European and Indian scientists (www.qub.ac.uk/tipot) to remove arsenic (As) from groundwater in a village in West Bengal, India. Six such plants are now in operation and are being used to supply water to the local population (www.insituarsenic.org). The study was conducted in Kasimpore, a village in North 24 Parganas District, approximately 25 km from Kolkata. In all cases, total As in treated water was less than the WHO guideline value of 10 μg L⁻¹. The plant produces no sludge and the operation cost is 1.0 US$ per day for producing 2000 L of potable water.     

Antibiotic uptake by plants from soil fertilized with animal manure

Antibiotics are commonly added to animal feed as supplements to promote growth of food animals. However, absorption of antibiotics in the animal gut is not complete and as a result substantial amounts of antibiotics are excreted in urine and feces that end up in manure. Manure is used worldwide not only as a source of plant nutrients but also as a source of organic matter to improve soil quality especially in organic and sustainable agriculture. Greenhouse studies were conducted to determine whether or not plants grown in manure-applied soil absorb antibiotics present in manure. The test crops were corn (Zea mays L.), green onion (Allium cepa L.), and cabbage (Brassica oleracea L. Capitata group). All three crops absorbed chlortetracycline but not tylosin. The concentrations of chlortetracycline in plant tissues were small (2-17 ng g(-1) fresh weight), but these concentrations increased with increasing amount of antibiotics present in the manure. This study points out the potential human health risks associated with consumption of fresh vegetables grown in soil amended with antibiotic laden manures. The risks may be higher for people who are allergic to antibiotics and there is also the possibility of enhanced antimicrobial resistance as a result of human consumption of these vegetables.     

Atmospheric dry deposition to leaf surfaces at a rural site of India

Dry deposition flux of major ions (Na+, K+, Ca2+, Mg2+, NH4+, F-, Cl-, NO3- and SO4(2-) to natural surfaces [guava (Psidium guyava) and peepal (Ficus religiosa) leaves] are determined at Rampur, a rural site of semi-arid region of India. Dry deposition flux is the highest for Ca2+ on guava leaves and for NH4+ on peepal leaves. Overall dry deposition flux is higher on guava leaves than of peepal leaves. The variation in deposition flux may be due to surface characteristics (surface roughness) and arrangement of leaves. Peepal leaves are arranged along the axis of the stem, whereas guava leaves are at right angles to the stem. The deposition flux of cations contributes 66% and 76% of dry deposition of all major ions on guava and peepal leaves, respectively as soil is major contributor towards dry deposition flux in tropical regions. ANOVA revealed no significant seasonal difference in deposition, although there is a trend for higher in winter. Deposition velocities of NH4+, NO3- and SO4(2-) are greater on guava leaves than peepal leaves, which can be attributed to the rougher surface of the guava leaf.     

Effects of coal-smoke pollutants from different sources on the growth, chlorophyll content, stem anatomy and cuticular traits of Euphorbia hirta L

Variations occurred in the growth, assimilate partitioning, chlorophyll content, stem anatomy and leaf cuticular traits of Euphorbia hirta L. on long-term exposure to coal-smoke pollutants prevailing at two sites, one situated close to a railway loco shed (site B) and another in the vicinity of a thermal power plant (site C). The Botanical Garden of Aligarh Muslim University, Aligarh, was considered as a control site (A). Site C possessed a greater load of coal-smoke pollutants than site B. The present study had shown that coal-smoke pollutants have led to a decrease in plant height, jeopardised the production of leaves and enhanced their fall, and caused a reduction in leaf area, leading to decreases of the total photosynthetic area of the plants, with increasing pollution load. The losses incurred in chlorophyll a were relatively more than chlorophyll b and, as a result, the total chlorophyll contents of leaves were decreased in polluted plants. The dry weights of stems, roots and leaves were decreased to different degrees, whereas the shoot/root dry weight ratio was found to increase in the polluted environment. The growth of stem cortex and pith were slightly affected on site B, but showed significant decreases on site C, due to a greater load of pollutants. Decreased area of xylem tissue was found to couple with an increasing number of vessels of reduced sizes. The stomatal density, pore size and index showed decreases, while the epidermal cells were larger and trichomes longer, on both surfaces of polluted leaves.     

Assessing drivers of post-harvest losses: tangible and intangible resources’ perspective

Environment, Development and Sustainability - Many stakeholders in agro-food industry are concerned about sustainability, especially in addressing post-harvest loss (PHL). However, resources...     

Matrix method for evaluation of existing solid waste management system in Himachal Pradesh,India

Journal of Material Cycles and Waste Management - Effective management of Municipal Solid Waste (MSW) is an essential function of the city municipal corporation. The present study reports on the...     

Bacterial tolerance strategies against lead toxicity and their relevance in bioremediation application

Among heavy metals, lead (Pb) is a non-essential metal having a higher toxicity and without any crucial known biological functions. Being widespread, non-biodegradable and persistent in every sphere of soil, air and water, Pb is responsible for severe health and environmental issues, which need appropriate remediation measures. However, microbes inhabiting Pb-contaminated area are found to have evolved distinctive mechanisms to successfully thrive in the Pb-contaminated environment without exhibiting any negative effects on their growth and metabolism. The defensive strategies used by bacteria to ameliorate the toxic effects of lead comprise biosorption, efflux, production of metal chelators like siderophores and metallothioneins and synthesis of exopolysaccharides, extracellular sequestration and intracellular bioaccumulation. Lead remediation technologies by employing microbes may appear as potential advantageous alternatives to the conventional physical and chemical means due to specificity, suitability for applying in situ condition and feasibility to upgrade by genetic engineering. Developing strategies by designing transgenic bacterial strain having specific metal binding properties and metal chelating proteins or higher metal adsorption ability and using bacterial activity such as incorporating plant growth-promoting rhizobacteria for improved Pb resistance, exopolysaccharide and siderophores and metallothionein-mediated immobilization may prove highly effective for formulating bioremediation vis-a-vis phytoremediation strategies.

     

Climate-proof planning for flood-prone areas: assessing the adaptive capacity of planning institutions in the Netherlands

It is generally acknowledged that adapting low-lying, flood-prone deltas to the projected impacts of climate change is of great importance. Deltas are densely populated and often subject to high risk. Climate-proof planning is, however, not only a new but also a highly complex task that poses problems for existing institutional and administrative structures, which are the product of times in which climate issues were of little importance. This paper assesses the capacity of the historically grown Dutch planning institutions to promote climate-proof planning for flood-prone areas. The Adaptive Capacity Wheel provides the methodological framework. The analysis focuses on two planning projects in the west of the Netherlands: the Zuidplas Polder project at the regional level and the Westergouwe project at the local level. It is shown that the planning institutions involved in these projects enable climate-proof planning, but to a limited extent. They face five institutional weaknesses that may cause risks on the long term. To climate-proof urban developments in flood-prone areas, it is necessary to break through the strong path–dependent development of planning institutions and to build in more flexibility in existing rules and procedures.