Selection of tropical trees and shrubs for urban greening in coal mine complex: a case study of Singrauli, Madhya Pradesh.

An experimental investigation was conducted to determine the effectiveness of roadside trees for removing dust and the effects of dust load on the physiology and micromorphology of the foliage. The present study was conducted near an open coal mining complex situated in Singrauli, Madhya Pradesh, India, to assess the air pollution tolerance index (APTI), anticipated performance index (API), dust capturing capacity (DCC), and leaf morphology of trees and shrubs growing around the coal fields. Results showed that Azadirachta indica, Mangifera indica, Ficus religiosa, Ailanthus excelsa, and Ficus benghalensis were the most tolerant species towards air pollution (high APTI scores), while plants like Calotropis gigantea, Lantana camara, and Tectona grandis were proven to be bio-indicator species. Butea monosperma, Ficus benghalensis, Alstonia scholaris, and Terminalia arjuna were plant species with the highest DCC. Two-way ANOVA showed significant differences site-wise and season-wise in the biochemical parameters of APTI and a considerable difference site-wise with respect to dust capturing capacity. Correlation and regression analyses revealed a very high positive correlation between APTI and ascorbic acid value. The study recommends suitable plant species to manage rising air pollution in the coal mine and nearby areas apart from suggesting the development of a green belt.

Garbage to Gains: The role of biochar in sustainable soil quality improvement, arsenic remediation, and crop yield enhancement.

Threats of soil quality deterioration and metal pollution have inflicted several parts of the world, apart from the need for surplus crop production. The investigation used biochar prepared from waste biomasses such as wheat and rice straw, kitchen waste, leaf litter, Lantana camara, orange peel, and walnut shell to improve soil quality, reduce As pollution, and enhance plant growth. Biochars were amended at doses of 0%, 2.5%, 5%, and 7.5% and conditioned for 3 months. At a 7.5% dose, the maximum improvements in cation exchange capacity (a 62% increase), anion exchange capacity (a two-fold increase), bulk density (a 31% decrease), porosity (a 32% increase), water holding capacity (an 86% increase), soil respiration (a 32% increase), total carbon (a two-and-a-half-fold increase), total nitrogen (an eleven-fold increase), total phosphorus (3 times rise), total potassium (a two-and-a-half-fold increase), mobile As (a 38% decrease), leachable As (a 53% decrease), and bio-available As (a 56% decrease) were observed. Further, pot experiments revealed augmented biomass growth (61% and 177%), increased length (71% and 209%), and decreased As accumulation (56% and 55%) in the above-ground parts of Bengal gram and coriander plants, respectively. Therefore, the application of biochar was found to enhance the physico-chemical properties of soil, reduce As contamination levels, and improve crop growth. The study recommends using waste biomasses to prepare eco-friendly biochars, which could contribute to advancing sustainable agriculture and the circular economy.

Assessment of heavy metal contamination in street dust: concentrations, bioaccessibility, and human health risks in coal mine and thermal power plant complex.

Coal mining has also been associated with adverse environmental and health impacts including cancer and respiratory disorders, with the presence of thermal power plants exacerbating the problem of heavy metal pollution. Minimal studies have been conducted on the environmental impacts, health risks, and bioaccessibility of heavy metals in coal mine areas. Consequently, samples of street dust were collected from different locations in the Singrauli mine complex and analysed. Heavy metals (Cu, Ni, Zn, Cr, Co, As, and Mo) were found to be higher than the background concentration, with the maximum concentration was found in areas close to the Thermal Power Plants, like Near Vindyachal TPP, Near Shakti Nagar TPP, and Anpara. The highest geo-accumulation index value was found for Co, Mo, Zn, and As, indicating moderate to strong pollution levels. Health risk assessment (for both adults and children) revealed that Cr and Fe posed significantly higher Hazard Quotient and Hazard Index (HI) values, indicating significant non-carcinogenic threats. Moreover, Carcinogenic Risk (CR) values for Cd, Cr, and Ni indicated a risk of carcinogenicity to the public exposed to road dust. The study also examined the bioaccessibility of the metals, which showed that the gastric phase accumulated a higher percentage of Ni (42.52%), Pb (34.79%), Co (22.22%), As (20%) and Cu (15%) than the intestinal phase. Strong positive correlation was observed between metal concentration (Cu, Pb, Cr, Fe, Zn, and Mn), HI, and CR of adult and child, while bioaccessibility of intestinal phase was positively correlated with gastric phase of metals (Cu, Ni, Co, As, and Mn).

A state-of-the-art review on cadmium uptake, toxicity, and tolerance in rice: From physiological response to remediation process.

Cadmium (Cd), a major contaminant of concern, has been extensively reviewed and debated for its anthropogenic global shifts. Cadmium levels in rice grains raise wide food safety concerns. The aim of this review is therefore to capture the dynamics of Cd in paddy soil, translocation pathways of Cd from soil to consumption rice, and assess its bio-accessibility in human consumption. In crop plants, Cd reduces absorption of nutrients and water, triggers oxidative stress, and inhibits plant metabolism. Understanding the mechanisms and behaviour of Cd in paddy soil and rice allows to explain, predict and intervene in Cd transferability from soil to grains and human exposure. Factors affecting Cd movement in soil, and further to rice grain, are elucidated. Recently, physiological and molecular understanding of Cd transport in rice plants have been advanced. Morphological-biochemical characteristics and Cd transporters of plants in such a movement were also highlighted. Ecologically viable remediation approaches, including low input cost agronomic methods, phytoremediation and microbial bioremediation methods, are emerging.

Removal of toxic dye from dye-laden wastewater using a new nanocomposite material: Isotherm, kinetics and adsorption mechanism.

In this study, (hemi)cellulosic biochar-based environment-friendly non-toxic nanocomposite (nAg-AC) was fabricated for an inordinate overlook of toxic dye-laden wastewater depollution. This hybrid nanocomposite grafted with silver nanoparticles, numerous hydroxyl and π-bond containing functional groups exhibited outstanding physicochemical properties. FESEM images indicated the heterogeneous porous structure of nAg-AC, while BET analysis revealed mesoporous property with a significant increment of overall surface area (132%). Imbedding of silver nanoparticles and the presence of multiple hydroxyl groups was evident from the XRD and XPS spectrum. Further, the TGA result indicated excellent thermal stability, and FTIR analysis suggested the involvement of surface functional groups like -OH, =C = O, =NH, =C = C = , and -CH in Rhodamine B (RhB) adsorption. The adsorbent matrix provided the overall mechanical strength and facilitated recycling, while the functional matrix (biochar) provided the adsorptive locus for augmented RhB adsorption efficiency (92.77%). Experiments pertaining to adsorption isotherms and kinetics modeling suggested that RhB was removed through multilayer chemisorption on the heterogeneous nAg-AC surface. The main RhB adsorption mechanism included cumulative efforts of H-bindings, π-π stacking interaction, pore-filling, and electrostatic interactions. The nAg-AC maintained mechanical robustness with significant RhB adsorption even after three consecutive regeneration cycles signifying facile recycling. The nAg-AC displayed an outstanding efficacy for the real industrial wastewater depollution, indicating high effectiveness for practical environmental applications. Finally, the cost analysis (incorporating economic, environmental, and social dimensions) suggested a significant role of the nAg-AC in promoting and establishing sustainable development with the circular economy.

Valorization of fruit waste-based biochar for arsenic removal in soils.

Fruit waste disposal is a serious global problem with only 20% of such waste being routinely treated prior to discharge. Two of the most polluting fruit wastes are orange peel and walnut shell and new methods are urgently required to valorize such waste. In the present study, they where valorized via conversion into biochars at 500 °C (OPB500 for orange peel-based biochar produced at 500 °C and WaSB500 for walnut shell-based biochar produced at 500 °C), and evaluated for arsenic adsorption. A pore-rich surface morphology was observed with a low H/C ratio indicating high stability. Spectroscopic studies revealed the presence of minerals and surface functional groups (amide, carbonyl, carboxyl, and hydroxyl) suggesting high potential for arsenic immobilization. Adsorption studies revealed an arsenic removal efficiency of 88.8 ± 0.04% for WaSB500 exposed to initial arsenic concentration of 8 ppm for 5% biochar dose at 25 °C and 30 min contact time. In comparison, OPB500 showed slightly lower removal efficiency of 80.7 ± 0.1% (10 ppm initial concentration, 5% dose, 25 °C, 90 min contact time). Peak shifts in XRD and FTIR spectra together with isotherm, kinetic, and thermodynamic studies suggested arsenic sequestration was achieved via a combination of chemisorption, physisorption, ion exchange, and diffusion. The present investigation suggests valorization of fruit waste into thermo-stable biochars for sustainable arsenic remediation in dynamic soil/water systems and establishes biochar's importance for waste biomass minimization and metal (loid) removal from fertile soils.

Lead time of early warning by wastewater surveillance for COVID-19: Geographical variations and impacting factors.

The global data on the temporal tracking of the COVID-19 through wastewater surveillance needs to be comparatively evaluated to generate a proper and precise understanding of the robustness, advantages, and sensitivity of the wastewater-based epidemiological (WBE) approach. We reviewed the current state of knowledge based on several scientific articles pertaining to temporal variations in COVID-19 cases captured via viral RNA predictions in wastewater. This paper primarily focuses on analyzing the WBE-based temporal variation reported globally to check if the reported early warning lead-time generated through environmental surveillance is pragmatic or latent. We have compiled the geographical variations reported as lead time in various WBE reports to strike a precise correlation between COVID-19 cases and genome copies detected through wastewater surveillance, with respect to the sampling dates, separately for WASH and non-WASH countries. We highlighted sampling methods, climatic and weather conditions that significantly affected the concentration of viral SARS-CoV-2 RNA detected in wastewater, and thus the lead time reported from the various climatic zones with diverse WASH situations were different. Our major findings are: i) WBE reports around the world are not comparable, especially in terms of gene copies detected, lag-time gained between monitored RNA peak and outbreak/peak of reported case, as well as per capita RNA concentrations; ii) Varying sanitation facility and climatic conditions that impact virus degradation rate are two major interfering features limiting the comparability of WBE results, and iii) WBE is better applicable to WASH countries having well-connected sewerage system.

Ecological and human health risks from pseudo-total and bio-accessible metals in street dusts.

Street dust samples were collected from industrial and commercial cities (Jamshedpur and Ranchi during monsoon and post-monsoon seasons) for detecting the levels of Cr, Cd, Cu, Ni, Pb, Zn, As, Co, Al, and Mn. The industrial city recorded higher metal concentrations compared to commercial. Similar trend of pseudo-total metal concentrations was observed in both the seasons at industrial city (Al > Mn > Zn > Cr > Pb > Cu > Ni > Cd) and only monsoon season at commercial city (Al > Mn > Zn > Cu > Cr > Pb > Ni > Cd). Zn > Cd was the most bioaccessible metal throughout the cities (monsoon and post-monsoon). The geochemical parameters (Igeo, EF, CF) were highest for Cd and lowest for Ni (both cities for the two seasons). Pollution Load Indices (PLI zone) were highest during the post-monsoon season in the industrial city. The highest carcinogenic risk was posed by Cr ranging from 1.87E-05 to 4.80E-05, in both the cities through ingestion and inhalation pathways. Children were found at higher risks, while the bioaccessible fractions posed neither carcinogenic nor non-carcinogenic threats to the population. Principal component analysis and correlation analysis indicated the influence of vehicular and industrial emissions, especially steel industry and coal-based thermal power plants as the major source of metals in street-dust. The outcomes of this work will be useful in providing baseline information of pollution along with their consequent environmental and human health risks of Jharkhand state.

Removal of Arsenic by Wheat Straw Biochar from Soil.

Biochar prepared from wheat straw (Triticum aestivum) at different pyrolysis temperatures was screened, followed by its application to soil for arsenic removal in the present study. Characterization of biochar by Field emission scanning electron microscope studies and Fourier thermal Infrared imaging showed smooth and porous biochar surface and abundance of surface functional groups. A low value of H/C was obtained by CHNS analyzer, indicating high stability of biochar. The surface area was 15.86 m2/g on an average. Batch sorption experiments were carried out to optimize conditions for arsenic sorption. Maximum arsenic removal of 83.7% was obtained when applied at a 7.5% dose for a contact time of 60 min at 25 °C. Isotherm, kinetic and thermodynamic studies revealed the feasibility of sorption and removal of arsenic through physisorption, chemisorption, ion exchange, and diffusion.

Biochar-based nanocomposite from waste tea leaf for toxic dye removal: From facile fabrication to functional fitness.

The present study utilized discarded tea leaf waste to produce 'Tea leaf biochar' (TLB) as the functional matrix for the fabrication of hybrid nanocomposite (nAg-TC), with colloidal deposition of silver nanoparticles (nAg) via modified chemical co-precipitation, for treatment of dye-laden wastewater. The chemical composition, physicochemical properties, and morphology of nAg-TC, and active surface functional groups involved in adsorption were identified using BET, FESEM-EDX, FTIR, TGA, XPS, and XRD. The nAg-TC matrix was found to be heterogeneous, mesoporous, thermostable, with rich in active surface functional groups (-OH, =NH, =CH, CC, CO, CN, and CC), and nAg as a dopant material. The dye adsorption results indicated the maximum removal efficiency (RhB = 95.89%, CR = 94.10%) at 300 K for rhodamine B (RhB) and Congo red (CR) concentrations of 25 mg L-1 and 22.5 mg L-1, respectively. The present investigation agreed with Freundlich isotherm (R2CR:0.991; R2RhB:0.993) and pseudo-second order kinetic (R2CR:0.999; R2RhB:0.999) model, indicating overall adsorption of RhB and CR through spontaneous and exothermic chemisorption on the heterogeneous surface of nAg-TC. The mechanism of RhB and CR adsorption was complex where nAg-TC, possessing the synergistic effects of TLB and nAg, showed surface complexation, electrostatic attraction, and H-bonding, leading to chemisorption. Study showed excellent reusability of spent nAg-TC, and commendable treatment efficiency for dye-laden real industrial effluents. The study exhibits substantial techno-economic feasibility of adsorbent and translates the principles of circular economy into synthesis of value-added products through sustainable management of biowaste and bioresource.

Performance evaluation of crop residue and kitchen waste-derived biochar for eco-efficient removal of arsenic from soils of the Indo-Gangetic plain: A step towards sustainable pollution management.

Biochar was produced from wheat straw (Triticum aestivum), rice straw (Oryza sativa), and kitchen waste at varying pyrolysis temperatures (300°C-700 °C). The biochars were screened depending on their production and physicochemical properties for the adsorptive removal of arsenic (As). The morphological analysis by Field emission scanning electron microscope revealed a porous biochar surface. Spectroscopic characterization of biochars indicated the co-existence of minerals, carboxyl, carbonyl, amide, and hydroxyl groups, which implies the suitability of biochar to immobilize metal (loid)s from soils. Changes in peaks were observed in Fourier-transform infrared and X-ray diffraction images after As sorption indicating the involvement of chemisorption. The thermogravimetric analysis and a low H/C value derived from the CHNS analyzer confirmed the high stability of biochar. The BET analysis was used to estimate the surface areas of wheat straw (15.8 m2 g-1), rice straw (12.5 m2 g-1), and kitchen waste (2.57 m2 g-1) -derived biochars. Batch sorption studies were performed to optimize experimental parameters for maximum removal of As. Maximum removal of As was observed for wheat straw-derived biochar (pyrolyzed at 500 °C) at 8 mg L-1 initial concentration (IC), 7.5 % dose, 25 °C temperature, and 60 min contact time (83.7 ± 0.06 %); in rice straw-derived biochar (pyrolyzed at 500 °C) at 8 mg L-1 IC, 7.5 % dose, 25 °C temperature, 90 min contact time (83.6 ± 0.37 %); and in kitchen waste-derived biochar (pyrolyzed at 500 °C) at 8 mg L-1 IC, 5 % dose, 25 °C temperature, 60 min contact time (76.7 ± 0.16 %). The sorption model parameters suggested the possibility of chemisorption, physisorption, diffusion, and ion exchange for the removal of As. Therefore, it could be recommended to farmers that instead of disposing or burning straws and waste openly, they could adopt the process of charring to generate livelihood security and mitigation of geogenic contaminants from the soil/water dynamic systems.

Potential and safe utilization of Fly ash as fertilizer for Pisum sativum L. Grown in phytoremediated and non-phytoremediated amendments.

The present study focuses on the possibility of applying fly ash to agricultural fields for enhancing the production of agricultural crops. In this study, Pisum sativum L. was grown from germination stage to maturation stage in phytoremediated and non-phytoremediated or raw fly ash-amended soil. All the morphological (height, biomass, number of leaf, and leaf size) and physiological parameters like, protein content, chlorophyll content, nitrate reductase activity, and peroxidase activity were monitored to understand the effects of fly ash or its usefulness for using it as a fertilizer for facilitating micronutrients. Major finding of this study is that 40% (w/w) of non-phytoremediated fly ash amendment could be used for field application. Percentage increase of toxic metals in below ground organs was 6% for Cd, 6% for Cr, 5% for Cu, 15% for Mn, and 7% for Pb when compared with the control. In the non-phytoremediated fly ash-amended set, heavy metals and metalloids were present in the grains only at higher amendments T3 (60%) and T4 (80%). However, except Cd, all the metals were below the permissible limits suggested by the WHO. Phytoremediated fly ash could be used as a fertilizer up to 100% for the cultivation of pea plant as metals concentrations were found either below detection limit or below the WHO permissible limit.

Air pollution tolerance, metal accumulation and dust capturing capacity of common tropical trees in commercial and industrial sites.

Total nine tree species of common tropical trees were assessed for their air pollution tolerance, dust capturing capacity and possibility to act as metal bio-monitors in commercial, industrial and control sites. Two seasons sampling was done respectively in monsoon and post-monsoon, to study their seasonal variations. According to Air Pollution Tolerance Index (APTI) values Mangifera indica, Azadirachta indica and Ficus religiosa were the most tolerant species while Ficus bengalensis and Alstonia scholaris were intermediately tolerant towards air pollution. Single factor ANOVA of biochemical parameters between the sampling sites, revealed that APTI of plants did not vary significantly in both the seasons. Site-wise variation was significant both at commercial and industrial sites. The same trend of result was also found in Anticipated Performance Index (API) which also includes other social benefits. So, these species can be recommended for the green belt development in urban commercial and industrial areas. Ficus bengalensis, Ficus religiosa and Mangifera indica were also having the best dust capturing capacity as Scanning Electron Microscope image revealed that they have rough and large surface area of leaf with short petiole and large canopy structure. According to the Geoaccumulation index (Igeo) and Enrichment Factor (EF) of soil in the sampling sites were found to be contaminated with copper and cadmium. Psidium guajava, Mangifera indica, Alstonia scholaris and Ficus religiosa were found to be good phytoextractors of copper. They did not accumulate cadmium. So, these plants can be recommended as copper bioindicators. However, the metals accumulation efficiencies were high for Mangifera indica and Ficus religiosa.

Effect of two biodegradable chelates on metals uptake, translocation and biochemical changes of Lantana Camara growing in fly ash amended soil.

The present work had two purposes firstly to evaluate the potential of Lantana Camara for phytoextraction of heavy metals from fly ash amended soil and to assess the suitability of a proper biodegradable chelating agent for chelate assisted phytoextraction. Plants were grown in manure mixed soil amended with various concentration of fly ash. Two biodegradable chelating agents were added (EDDS and MGDA) in the same dose separately before maturation stage. Sampling was done at different growing stages. The plant took up metal in different plant parts in the following order: for Cu, and Zn leaf >root >stem, for Cr and Mn leaf>stem >root, for Ni root >leaf>stem and for Pb root≈leaf>stem respectively. For Cu, Zn, Cr and Mn Lantana camara acted as phytoextractor. Translocation factor and bioaccumulation coefficient was>1 signifying enrichment and translocation of metals in the plant. Morphological studies showed no toxicity symptom in the plant. Among biochemical parameters protein and nitrate reductase activity decreased, whereas, chlorophyll and peroxidise activity increased with the growth stages. Finally, it was evident from the results that Lantana Camara can be used as efficient phytoextractor of metals, with proper harvesting cycle and both chelate were proved as effective chelators for phytoextraction of metals.

Assessment of soil characteristics in the vicinity of open cast coal mine and its suitability for vegetative reclamation in Charhi and Kuju of Jharkhand, India.

Coal mining is inevitable for economic growth of a country, but at the same time deteriorates the quality of the environment. Open cast mine, especially affects the top soil most negatively. In the present study, soil samples from three representative areas of mining viz proposed, operational and abandoned sites from Charhi and Kuju of Jharkhand were collected and analysed for physicochemical parameters and metals with an objective to determine their suitability for vegetative reclamation. Soil samples appeared to be slightly acidic (5.97 ± 0.66) with low EC values (101 ± 76 µScm(-1)), total organic carbon (0.71 ± 0.35 %), organic matter (1.34 ± 0.66%) and overall nutrient, especially nitrogen (167 ± 64 kg ha(-1)) contents than required for reclamation by revegetation. However, bulk density was found conducive for reclamation. Total Cr (317 ± 287 to 417 ± 393 mg kg(-1)), Cu (121 ± 72 to 344 ± 143 mg kg(-1)), Ni (171 ± 46 to 373 ± 134 mg kg(-1)) and Pb (114 ± 115 to 182 ± 145 mg kg(-1)) content were found to be higher in soil. Sitewise variation was also significant for Cu and Ni. Pearson's correlation suggested significant (p ≤ 0.05) positive inter elemental correlation between Cr-Fe, Cr-Mn, Cu-Ni, Fe-Mn and Mn-Ni. Positive geoaccumulation index (Igeo) values for all the metals except Fe, overall contamination degree of 31.10 and significant enrichment factor indicated considerable contamination. This baseline data could be utilized for vegetative reclamation planning of the study area in future.

Metal phytoremediation potential of naturally growing plants on fly ash dumpsite of Patratu thermal power station, Jharkhand, India.

Three naturally growing plants Ipomoea carnea, Lantana camara, and Solanum surattense were found in fly ash dumpsite of Patratu thermal power station, Jharkhand, India. They were assessed for their metal uptake potential. The fly ash was slightly alkaline with very less nitrogen and organic carbon but enriched with phosphorus and heavy metals. Lantana camara and Ipomoea carnea showed good translocation from root to shoot for most of the metals except Mn and Pb. The order of metal accumulation in stem of both the plants were Fe(205mg/kg)>Mn(65mg/kg)>Cu(22.35mg/kg)>Pb(6.6mg/kg)>Cr(3.05mg/kg)>Ni(1 mg/kg)>Cd(0.5 mg/kg) and Fe(741 mg/kg)>Mn(154.05 mg/kg)>Cu(20.75 mg/kg)>Pb(6.75 mg/kg)>Ni(4.0 mg/kg)>Cr(3.3mg/kg)>Cd(0.05mg/kg), respectively. But Solanum surattense accumulated most of the metals in roots. The order was in the following order, Mn (382.2mg/kg) >Fe (264.1mg/kg) > Cu (25.35mg/kg) >Pb (5.95 mg/kg) > Ni (1.9 mg/kg) > Cr (1.8mg/kg) > Cd (0.55 mg/kg). The order of Bioconcentration factor (BCF) in root and shoot followed almost the same order as, Mn>Fe>Ni>Pb>Cu>Cr≈ Cd in all the three species. ANOVA showed significant variation in metal accumulation by root and stem between the species. Finally, it can be concluded that Solanum surattense can be used as phytostabilizer and other two species as phytoextractor of metal for fly ash dumpsite reclamation.

Benthic macroalgae as biological indicators of heavy metal pollution in the marine environments: a biomonitoring approach for pollution assessment.

Metal pollution in the marine coastline environment is an important topical issue in the context of ecological disturbance and climate change. Heavy metal contaminations (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in seawater and surficial sediments, as well as macroalgal diversity, were determined in six different locations along the coast of the Gulf of Kutch in India. The marine coastline environment was found to be enriched with Cd and Zn in comparison to other metals. Significant (p ≤ 0.05) inter-elemental positive-correlations were observed between Fe-Mn, Fe-Cu, Fe-Cr, Fe-Zn, Cr-Cu, Cu-Mn, and Cd-Zn, as well as negative-correlations between Cd-Pb, Ni-Pb, and Zn-Pb. Though genus specific macroalgal responses to heavy metal accumulation were significant, species specific response was insignificant (p ≤ 0.05). The relative abundance of metals in macroalgae followed the order of Fe>Zn>Mn>Cu>Cd>Cr>Ni>Pb. The high uptake of metals in green algae (Ulva lactuca and Enteromorpha intestinalis) and brown algae (Padina gymnospora and Dictyota bartayresiana) suggested that these algae may be used as potential biomonitors for heavy metal pollution. Three pollution indicators, Contamination Factor (CF), Enrichment Factor (EF) and Geochemical Index (Igeo) were calculated to determine the degree of metal pollution in the marine coastline and the contribution of anthropogenic influence.

Heavy metal uptake and its effect on macronutrients, chlorophyll, protein, and peroxidase activity of Paspalum distichum grown on sludge-dosed soils. Heavy metal uptake and its effect on P. distichum.

This study assessed the heavy metal (Cr, Mn, Ni, Cu, Zn, and Pb) uptake and its effect on biochemical parameters in Paspalum distichum, a wetland plant. Sludge collected from Bhalswa waste dump, New Delhi, was used as heavy metal source and dosed in different proportions viz. 20%, 40%, 60%, and 80% to the garden soil. The plants accumulated metals mostly in belowground organs. The metal accumulation followed the order: Cr>Mn>Cu>Zn>Ni>Pb. The range of heavy metal concentration in tissue of belowground organs after 180 days of growth was 1,778.65-4,288.01 ppm Cr, 828.11-1,360 ppm Mn, 236.52-330.07 ppm Ni, 155.79-282.35 ppm Cu, 27.05-91.16 ppm Zn, and 27.09-50.87 ppm Pb. The biochemical parameters viz. chlorophyll and protein contents and peroxidase (POD) activity exhibited no considerable adverse effect indicating the plants' tolerance towards heavy metals. The high POD activity and synthesis of new protein bands at high sludge-dosed plants were also in support of this fact.

Heavy metal uptake by Scirpus Littoralis Schrad. from fly ash dosed and metal spiked soils.

Scirpus littoralis is a wetland plant commonly found in Yamuna flood plains of Delhi, India. The ability of Scirpus littoralis to take up and translocate five metals- Mn, Ni, Cu, Zn and Pb from fly ash dosed and metal spiked soils were studied under waterlogged and field conditions for 90 days. Scirpus littoralis accumulated Mn, Ni, Cu, Zn and Pb upto a maximum of 494.92, 56.37, 144.98, 207.95 and 93.08 ppm dry wt., respectively in below ground organs (BO) in 90 days time. The metal content ratios BO/soil (B/S) were higher than shoot/soil ratios (T/S) for all the metals, the highest being for Ni. Metal ratios BO/water (B/W) were also higher than shoot/water (T/W) ratios but the B/W ratio was maximum for Zn. The changes in nutrient status (N, P) in soil water and plants were also studied at interval of 30 days. The Pearson's correlation between metal uptake and N, P uptake were calculated. All the metals except Ni showed negative correlation with nitrogen but they were all non-significant. However, P uptake showed positive correlations with all the metals and all were significant at 1% confidence limit.