Livestock excreta management through vermicomposting using an epigeic earthworm Eisenia foetida

In India, millions of tones of livestock excreta are produced. Our study explores the potential of an epigeic earthworm Eisenia foetida to compost different livestock excreta (cow, buffalo, horse, donkey, sheep, goat and camel) into value added product (vermicompost) at the laboratory scale. Vermicomposting resulted in lowering of pH, electrical conductivity, potassium and C:N ratio and increase in nitrogen and phosphorus contents. Total K was lower in the final cast than in the initial feed. C:N ratios of the vermicomposts ranged from 16.2 ± 2.17 to 75.4 ± 6.84. Microbial activity measured as dehydrogenase activity in buffalo, donkey and camel wastes increased with time up to day 90. But in sheep and goat wastes, maximum dehydrogenase activity was recorded on day 60 and decreased thereafter. The cocoons and hatchlings production by Eisenia foetida in different excreta were also investigated. The greatest number and biomass of hatchlings was recorded in horse excreta followed by cow, goat and sheep excreta. Thus, cow, horse, sheep and goat excreta show potential as good substrates in vermicomposting using Eisenia foetida, although further research is required to explore the feasibility of use of buffalo, donkey and camel excreta in combination with cow/sheep/goat excreta.     

Short-term leaching study of heavy metals from LD slag of important steel industries in Eastern India

Journal of Material Cycles and Waste Management - Considering Linz-Donawitz (LD) slag as a waste material for its bulk utilisation, there is a possibility that heavy metals will leach to...     

Biosynthesis and effects of copper nanoparticles on plants

Copper nanoparticles have improved properties compared to the bulk copper material. Copper nanoparticles indeed find applications in gas sensors, heat transfer fluids, catalysis, solar energy and batteries. Antibacterial and antifungal activities of copper nanoparticles find applications in the agriculture and healthcare sectors. Nonetheless, careless use of copper nanoparticles may cause environmental pollution and health effects. Here we review the biosynthesis of copper nanoparticles using plant materials, named phytosynthesis, and micro-organisms. We also discuss the effect of copper nanoparticles on crops and pathogenic micro-organisms. Copper nanoparticles varying in sizes from 5 to 295 nm have been synthesized using leaf extracts and latex from plants, and using bacteria and fungi. Biosynthesized copper nanoparticles show good antimicrobial activity inhibiting the growth of pathogenic bacteria and pathogenic fungi. Copper nanoparticles enhance the germination and growth of some plants at lower concentrations, whereas high concentrations result in retarded growth.     

Arsenic bioaccumulation in rice and edible plants and subsequent transmission through food chain in Bengal basin: a review of the perspectives for environmental health

Arsenic (As) is a metalloid that poses serious environmental threats due to its behemoth toxicity and wide abundance. The use of arsenic-contaminated groundwater for irrigation purpose in crop fields elevates arsenic concentration in surface soil and in the plants. In many arsenic-affected countries, including Bangladesh and India, rice is reported to be one of the major sources of arsenic contamination. Rice is much more efficient at accumulating arsenic into the grains than other staple cereal crops. Rice is generally grown in submerged flooded condition, where arsenic bioavailability is high in soil. As arsenic species are phytotoxic, they can also affect the overall production of rice, and can reduce the economic growth of a country. Once the foodstuffs are contaminated with arsenic, this local problem can gain further significance and may become a global problem, as many food products are exported to other countries. Large-scale use of rainwater in irrigation systems, bioremediation by arsenic-resistant organisms and hyperaccumulating plants, and the aerobic cultivation of rice are some possible ways to reduce the extent of bioaccumulation in rice. Investigation on a complete food chain is urgently needed in the arsenic-contaminated zones, which should be our priority in future researches.     

Explaining the status and scope of ecotourism development for livelihood security: Andaman and Nicobar Islands,India

In the past few decades, the tourism sector has emerged as a significant economic activity in island nations, particularly in tropical regions. However, most of the tropical islands face similar constraints, viz., threat to natural resources, chances of biopiracy, impact of climate change, population pressure and unsystematic tourist management. Ecotourism, as a concept, envisages promoting tourism with due regard to natural environment and ecological sanctity of the destination. Archipelago of Andaman and Nicobar (A&N) Islands is one of picturesque geographical creation in the Bay of Bengal, India, in tropical region and is an emerging tourist destination. It was observed that around 2.2 lakhs national and international tourists visit the A&N Islands annually. With tourism sector as an integral component, the service sector with share of 56% in gross state domestic product dominates the island economy. An analysis based on primary survey from various stakeholders associated with the sector revealed that factors such as economy in travel and boarding, availability of tourist facilities and comfort, safety, etc. were major factors that determined the choice of the tourists that visited the islands. The weights given by the tourists to the natural sites in A&N Islands revealed that the landscape topped list with 91.6% score by the visitors followed by beaches (91.3%), scenery (86.5%), reserved forests (84.6%), limestone caves (66.3%) and coral sights (65.8%). Coral sites were given weight of 65.8% of tourists, cultural and historical tourism products 85.4% for the natural history. Similarly, historical sites (83.7%), museums (78.6%) and heritage sites (72.8%) were also among top cites attraction. Recent initiatives by the Andaman administration gives due to care to sustainably develop the tourism infrastructure of the islands to harness the potential of eco-friendly tourism in this picturesque tourist haven.     

A review on occurrence,characteristics, toxicology and treatment of nanoplastic waste in the environment

Environmental Science and Pollution Research - Nanoplastics (NPs) have showed hotspot of discussion in recent years due to their impact in environment as a futuristic major pollutant in water, soil...     

Characterization and optimization of conditions for biodegradation of sella-rice mill effluent

The sella-rice mill effluent is a major environmental pollutant requiring proper treatment before disposal. The present study has been conducted to isolate and characterize micro-organisms capable of growing on sella-rice effluent and to optimize conditions for its rapid bioremediation. Using three different types of media (LB, YEPDA and PDA), a total of 139 isolates were isolated from effluent samples collected from three different locations. Out of these, 45 isolates were found to utilize starch on starch medium, eight isolates showing high efficiency. For the optimization of conditions for maximum utilization of starch by selected isolates, parameters such as effect of addition of carbon and nitrogen sources, effect of growth factors, temperature and pH were studied. Maximum growth (absorbance of 2.10) and starch-utilization (varying in the range of 2.33 to 3.62) was observed on starch medium supplemented with peptone and yeast extract at 30 degrees C with a pH of 6.0. These bacterial isolates also reduced the amount of starch (80.10%), BOD (64.24%) and COD (75.0%) of sella-rice mill effluent after 15 days of incubation. On the basis of morphological and biochemical characteristics, the selected isolates were found to belong to the genera Lactobacillus and Micrococcus.     

MicroRNAs and their role in environmental chemical carcinogenesis

Environmental Geochemistry and Health - MicroRNAs (miRNAs) are a class of small, noncoding RNA species that play crucial roles across many biological processes and in the pathogenesis of major...