Prashant R. Thawale

Bioaccumulation and phyto-translocation of arsenic, chromium and zinc by Jatropha curcas L.: Impact of dairy sludge and biofertilizer

The present study was planned to remediate the metalloid and metal contaminated soil by using non-edible and economic plant species Jatropha curcas L. The experiment was conducted on pots to improve the survival rate, metal tolerance and growth response of the plant on soil; having different concentrations of arsenic, chromium and zinc. The soil was amended with dairy sludge and bacterial inoculum (Azotobacter chroococcum) as biofertilizer. The results of the study showed that the bioaccumulation potential was increased with increase in metalloid and metal concentration in soil system. Application of dairy sludge significantly reduces the DTPA-extractable As, Cr and Zn concentration in soil. The application of organic amendment stabilizes the As, Cr and Zn and reduced their uptake in plant tissues.

Biochemical changes in plant leaves as a biomarker of pollution due to anthropogenic activity.

The air pollution due to anthropogenic activities seriously affected human life, vegetation, and heritage as well. The vegetation cover in and around the city mitigates the air pollution by acting as a sink for pollution. An attempt was made to evaluate biochemical changes occurred in four selected plant species, namely Azadirachta indica, Mangifera indica, Delonix regia, and Cassia fistula of residential, commercial, and industrial areas of Nagpur city in India. It was observed that the correlated values of air pollutants and plant leaves characteristics alter foliar biochemical features (i.e., chlorophyll and ascorbic acid content, pH and relative water content) of plants due to air pollution. The changes in air pollution tolerance index of plants was also estimated which revealed that these plants can be used as a biomarker of air pollution.

The role of sand, marble chips and Typha latifolia in domestic wastewater treatment – a column study on constructed wetlands

ABSTRACT The relative importance of sand, marble chips and wetland plant Typha latifolia is evaluated in constructed wetlands (CWs) for the treatment of domestic wastewater intended for reuse in agriculture. The prototype CWs for the experiments are realized in polyvinyl chloride columns, which are grouped into four treatments, viz. sand (<2 mm) + Typha latifolia (cattail), sand, marble chips (5–20 mm) + cattail and marble chips. The removal percentage of organic and nutritional pollutants from the wastewater is measured at varying hydraulic retention time in the columns. The statistical analysis suggests that the main effects of sand and cattail are found to be significant (p < .05) for the removal of biological oxygen demand and chemical oxygen demand from the wastewater. The presence of cattail significantly (p < .01) contributes to the conversion of total nitrogen in wastewater into by fostering the growth of favorable microbes for the nitrification. The removal of and turbidity from the wastewater is significantly (p < .01) influenced by sand than the presence of cattail. The maximum adsorption capacity of the sand is estimated to be 2.5 mg/g. Marble chips have significantly (p < .01) influenced the removal of and its maximum removal capacity is estimated to be 9.3 mg/g. The negative correlation between the filter media biofilm and column hydraulic conductivity is also reported for all the treatments. Thus, the findings of this study elucidate the role of low-cost and easily available filter media and it will guide the environmental practitioners in designing cost-effective CWs for wastewater treatment.

Phytoremediation technology for wastewater treatment: high rate transpiration system

High Rate Transpiration System (HRTS) is a well-designed land treatment system composed of ridges and furrows and well-controlled hydraulic loading of wastewater. The present case study describes long-term operating experience of zero discharge of pulp and paper mill wastewater, which is characterised by high BOD, COD, TDS and colour that poses disposal problems into water bodies and on land. The result of field trials showed that there was no appreciable build-up of salt concentration in the furrows, at wastewater application rate of 250 m 3 /ha/day. The quality of groundwater was monitored within and outside the HRTS through well water sampling and it was satisfactory with respect to salt, metal concentrations and colour. The findings showed that HRTS is environmentally acceptable solution to manage the problem of coloured wastewater and also minimise the impact on groundwater quality.

Natural vs. reclaimed forests – a case study of successional change, reclamation technique and phytodiversity

The present study accounts for the successional changes that took place in vegetation structure and composition over a time span of 25 years at reclaimed manganese mine site. Adjoining natural forest site was also studied for comparison of floral composition. The results corroborate the fact that as the age of succession increases, the reclaimed area gets invaded by higher successional species leading to an ecologically sound self-sustaining restructured system. This is an indication of the efficacy of the restoration programme. Plant species diversity of reclaimed site was 3.34, 2.81 and 2.12 for herbs, shrubs and trees, respectively, whereas in the adjoining natural forest site (Pench national park, reserved forest), it was 2.74, 1.88 and 2.13 for herbs, shrubs and trees, respectively. Phytodiversity assessments at both sites led to the conclusion that higher values of importance value index (IVI) were obtained for shrubs and herbs at the reclaimed site when compared to the adjoining natural forest site. However, higher values of tree diversity and IVI were associated with the natural forest site than the 25-year-old reclaimed site. This paper compares the composition of flora, species diversity and rapid succession of phytodiversity of a 25-year-old reclaimed site with nearby natural reserved forest site. Plant species richness of reclaimed site was 141, 38 and 18 for herbs, shrubs and trees, respectively, as compared to reserved forest site values of 55, 11 and 20 for herbs, shrubs and trees, respectively. Also, this paper evaluates the total and available nutrient, and microbial diversity in both the newly formed ecosystem and the adjacent natural forest site.

Carbon Sequestration in Terrestrial Ecosystems

Global climate change has already had observable effects on the environment. For instance glaciers have shrunk, ice on rivers and lakes is breaking up earlier, lands are deteriorating, plant and animal ranges have shifted and trees are flowering sooner. Carbon emission is considered as the strongest factor for global warming. Removing atmospheric carbon and storing it in the terrestrial biosphere is one of the cost-effective options, to compensate greenhouse gas emissions. Millions of acres of abandoned mine land throughout the world, if restored and converted into vegetative land, would solve global warming and would remediate degraded wastelands. Reclamation of mining wastelands using an integrated biotechnological approach (IBA) has resulted in the improvement in the physico-chemical properties of the soil. The findings presented in this chapter may help the industries to achieve clean development mechanism status through afforestation of degraded lands as per the guidelines of United Nations Framework Convention on Climate Change.

Biotechnological approach for ecosystem restoration of mine spoil dump in India

Mine-degraded land (mine spoil dumps) has been restored through plantation in India by eco-friendly and cost-effective approach. This technology involves selection of suitable native plant species, isolation and inoculation of site-specific nitrogen-fixing microbial strains and nutrient mobilising vesicular arbuscular mycorrhizal species in combination with organic amendments to control the limiting factors associated with mine degraded land and to build up functional ecosystem. Exhaustive lab-scale experiments to screen the plant species, microbial cultures and proper organic amendment through pot culture experiments has been carried out. The best treatment screened under pot culture experiment was successfully implemented at a field level. The approach improved the survival rate of the plants over 83-99% and attained the level of restoration to that in a productive soil. Results also indicated that the biodiversity of degraded land could be achieved within a short period of time through amendment and microbial intervention.

Comparative study on removal of enteric pathogens from domestic wastewater using Typha latifolia and Cyperus rotundus along with different substrates

ABSTRACT A comparative study was carried out to evaluate the efficiency of different substrate materials along with macrophytes Typha latifolia and Cyperus rotundus in treating domestic wastewater intended for reuse in agriculture. The study was conducted over a period of 6 months with different retention times, and observations were taken twice per month. One-way analysis of variance and Tukeys Honest Significant Difference (HSD) tests were used to determine statistical significant differences between experimental columns. Treatment with T. latifolia planted in sand and mix substrate with 4-day retention time remarkably reduced the concentration of all bacterial pathogens. Log reductions observed were approximately 5.01 and 4.82 for total coliform (TC), 4.46 and 3.93 for Escherichia coli, and 5.52 and 5.48 for Shigella, respectively. Moreover, these treatments were also efficient in completely removing fecal coliform (FC) and Salmonella.Maximum parasites were removed by the treatment having sand alone as a substrate containing C. rotundus, but the difference was not significant from those planted with T. latifolia in the same substrate. The results suggest that T. latifolia aids in bacterial pathogens removal, while C. rotundus aids in parasites removal. Thus, wastewater treatment through constructed wetland having mix plantation of these species along with sand can eliminate some of the major enteric pathogens.

Land Capability Classification for Agro-economic Evaluation of Mahadayi Dam, Karnataka, India

This paper examines the socio-economic impact of proposed dam on cropland productivity of Mahadayi project, Karnataka, India. Systematic appraisal of dam and their designing by categories of classes on the basis of physical and chemical characteristics of soil has been done in favour of development of agronomic conditions for the study of proposed dam sites in Karnataka. The study is aimed at the effective utilization of land according to their classes. Documentation on the land capability classification is a versatile component in formulation effective land use planning before the construction of dam. Thus an attempt was made to evaluate dominantly occurring soils on four class’s viz. soil depth, soil texture, soil drainage and soil erosion. The study was focused on the evaluation of economics of crop production based on agro climatic condition of the study area and existing cropping pattern. This study is important as it explores how an input of water and nutrient would respond under variable climatic conditions. In addition, interactions of water supplies with fertilizer rates at optimizing these resources need have been investigated. This paper identifies key challenges and solutions for carrying out project-level economic analysis of adaptation to climate change, both stand-alone and integrated into broader development projects. Very few projects addressing adaptation thus far have been subject to in-depth and rigorous economic analysis for a variety of reasons, including a lack of guidance on how to deal with assessments of the impacts of climate change, as well as with estimating costs and benefits of adaptation under uncertainty. Our focus is on the agricultural sector, where the impacts of climate change have the potential to disrupt the livelihoods of rural populations in many regions and where adaptation must be given urgent consideration. Nevertheless, some of the approaches discussed are suitable to projects in other sectors. Key wordsSocio-Economic; Dam; Agronomic Condition; Land Capability Classification; Catchment Area; Crop Productivity; Land Suitability Maps