Assessment of persistent organic pollutants in soil and sediments from an urbanized flood plain area

Polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and phenolic compounds (PCs) are persistent organic compounds. Contamination of these potentially toxic organic pollutants in soils and sediments is most studied environmental compartments. In recent past, studies were carried out on PAHs, OCPs and PCs in various soils and sediments in India. But, this is the first study on these pollutants in soils and sediments from an urbanized river flood plain area in Delhi, India. During 2018, a total of fifty-four samples including twenty-seven each of soil and sediment were collected and analyzed for thirteen priority PAHs, four OCPs and six PCs. The detected concentration of ∑PAHs, ∑OCPs and ∑PCs in soils ranged between 473 and 1132, 13 and 41, and 639 and 2112 µg/kg, respectively, while their concentrations in sediments ranged between 1685 and 4010, 4.2 and 47, and 553 and 20,983 µg/kg, respectively. PAHs with 4-aromatic rings were the dominant compounds, accounting for 51 and 76% of total PAHs in soils and sediments, respectively. The contribution of seven carcinogen PAHs (7CPAHs) in soils and sediments accounted for 43% and 61%, respectively, to ∑PAHs. Among OCPs, p, p’-DDT was the dominant compound in soils, while α-HCH was found to be dominated in sediments. The concentrations of ∑CPs (chlorophenols) were dominated over ∑NPs (nitrophenols) in both the matrices. Various diagnostic tools were applied for the identification of their possible sources in soil and sediments. The observed concentrations of PAHs, OCPs and PCs were more or less comparable with the recently reports from various locations around the world including India. Soil quality guidelines and consensus-based sediment quality guidelines were applied for the assessment of ecotoxicological health effect.

     

Coastal community resilience: analysis of resilient elements in 3 districts of Tamil Nadu State, India

India has a long coastline of about 7,517 km. with 20% occupying the coastal area. Due to increase in population; people have been exploring the possibility of developmental opportunities in the coastal areas. Tsunami in 2004 was another unexpected natural catastrophe which badly affected many South Indian coastal states especially the state of Tamil Nadu. Coastal communities here are increasingly at risk from many chronic and episodic coastal hazards which threaten the health and stability of coastal ecosystems and communities. The degradation of the coastal environment from chronic human-induced actions threaten food security, livelihoods, the overall economic development and well being of coastal communities. Disasters big or small affecting the coastal communities are reminders that, coastal communities are not resilient to normally recurring hazards. This fact has raised the question of developing community resilience since the most effective approach to reducing the long-term impact of coastal hazards would be to enhance capacities of coastal communities through initiatives which are aimed at ensuring a sustainable recovery in the aftermath of a disaster as well as reducing people’s vulnerability to these disasters. Eight elements of resilience i.e., Governance, Coastal Resource Management, Land Use and Structural Design, Society and Economy, Risk Knowledge, Warning and Evacuation, Emergency Response and Disaster Recovery have been identified which are considered essential to reduce risk from coastal hazards, accelerate recovery from disaster events, and adapt to changing conditions by the affected community. In this paper, all the eight resilience elements have been examined with respect to vulnerability and capacity assessment in selected Tsunami (2004) affected districts in the state of Tamil Nadu, India in order to identify the extent of resilience.     

Devicyprin induced gonadal impairment in a freshwater food fish, Channa punctatus (Bloch)

Synthetic pyrethroids are the recent major class of broad spectrum, photostable, organic insecticides used in agricultural, domestic and veterinary applications and now account for more than 30% of global insecticide use. Cypermethrin is metabolized and eliminated significantly more slowly by fish than by mammals or birds, which may explain this compound's high toxicity in fish compared to other organisms. The present communication deals with histoanatomical alterations in the gonads of a local fresh water food fish, Channa punctatus exposed to 0.033 ppm (96 hr LC50 X 1/10) concentration of a synthetic pyrethroid, devicyprin (cypermethrin 25%) in aquatic medium of aged tap water for 15, 30 and 45 days respectively. In testis, exposure dependent histological damage has been observed in terms of vacuolization, condensation of spermatogonic cells, distortion of tubular epithelium, shrinkage of interstitial cells and general inflammatory responses. Longest exposure of 45 days has resulted in peculiar starry-sky appearance of the testicular tissue. Gross histo-anatomy of ovarian tissue reveals epithelial lesions, inflammatory responses, stromal hemorrhage, increased interstitium and shrinkage of yolk vesicles towards periphery These findings are quite suggestive of reproductive impairments leading to delayed gonadal maturity and adversely affecting processes of sperm production and ovulation and thus, the fish production.     

Socioeconomics and sources of livelihood security in Central Himalaya,India: a case study

ABSTRACT

This case study was conducted in Himalayan watershed to understand traditional farming and socio-economic status of the people in Kumaon Himalaya, Uttarakhand, India. In spite of high literacy rate in this area, their livelihood security is reliant on traditional farming practices that include agroforestry beside forest produce. More than 85% farming is rainfed and managed in a traditional way. Land holding size owned by farmers in the area extended from 0.57 to 2.57 ha but majority of farmers (51–80%) had farms of size less than 0.50 ha. The study revealed that forests provided 73–79% of required energy from fuelwood and more than 81% fodder. Agroforestry, livestock (dairy and poultry/goat rearing) and labour employment are the major sources of income to the people in the watershed. The income of people was positively correlated with livestock rearing and traditional farming.     

Green Synthesis of Silver Nanoparticle Capped with <Emphasis Type="Italic">Allium cepa</Emphasis> and Their Catalytic Reduction of Textile Dyes: An Ecofriendly Approach

Today, environment pollution control is a matter of concern, everybody is willing to make a product that should be ecofriendly. Nowadays, water resources are full of untreated waste materials, discharge of hazardous and toxic dyes coming from textile and other chemical industries. These environmental hazards are difficult to remove by commercial water treatment plans, thus we need something that would present an efficient means for removal of these hazards. In this research paper, we have synthesize silver nanoparticle in a green way by using aqueous extract of Allium cepa (onion), and further these silver nanoparticle were tested for the catalytic degradation of various dyes by UV/Visible spectroscopy and silver nanoparticle showed reduction in dyes intensity after a particular period of incubation time. SEM and TEM, Particle size and Zeta potential analysis was done to analyze the surface morphology, particle size range and stability of the silver nanoparticle. Greenly synthesized silver nanoparticle was found to be spherical in shape, having particle size value ranged from 50 to 100 nm with a zeta potential value of ?29 mV. An EDX spectroscopy method was used to confirm the presence of silver nanoparticle in the synthesized material. An X-ray crystallography was done to ensure the crystallinity of the silver nanoparticle. Further an ATR-FTIR was performed to confirm the capping of the silver nanoparticle with the phenolic group of the onion. All these study emphasized that silver nanoparticle capped with onion (AgNPs@Ac) is the excellent catalyst for the reduction of hazardous and toxic dyes as well as they serve best purpose of the eco-friendly approach.     

Evaluation of the strength characteristics of cement-stabilized clay–crumb rubber mixtures for its sustainable use in geotechnical applications

The proper disposal of discarded waste tires is becoming a serious matter of concern worldwide as huge proportion of this waste is being generated which makes the proper disposal virtually infeasible. About 1000 million of waste tires are discarded every year, and by the year 2030, it will turn up to 1200 million per year. If this enormous quantum of waste remains unattended, it would led to serious health and environmental problems. The investigation aims at appraising the compaction and strength characteristics of clayey soil incorporated with waste crumb rubber and cement for its sustainable use in geotechnical application. A series of unconfined compression strength and split tensile strength tests were carried out on clayey soil incorporated with two percentages of cement (3 and 6%) by weight and four percentages of crumb rubber (2.5, 5.0, 7.5, and 10.0%) by weight. Moreover, scanning electron microscope analysis was also carried out to get better intuition about the behaviour of the composite. Test results suggested that crumb rubber (up to 5%) could be mixed with uncemented/cemented clay soil with the congruent impression. The inclusion of discarded waste tires in cemented clay would be one of the congenial methods for the disposal of this waste as it substantially reduces the deleterious influence of waste tire disposal on human health and ecology.     

Catalytic hydrothermal treatment of pulping effluent using a mixture of Cu and Mn metals supported on activated carbon as catalyst

The present study was performed to investigate the performance of activated carbon-supported copper and manganese base catalyst for catalytic wet oxidation (CWO) of pulping effluent. CWO reaction was performed in a high pressure reactor (capacity?=?0.7 l) at temperatures ranging from 120 to 190 °C and oxygen partial pressures of 0.5 to 0.9 MPa with the catalyst concentration of 3 g/l for 3 h duration. With Cu/Mn/AC catalyst at 190 °C temperature and 0.9 MPa oxygen partial pressures, the maximum chemical oxygen demand (COD), total organic carbon (TOC), lignin, and color removals of 73, 71, 86, and 85 %, respectively, were achieved compared to only 52, 51, 53, and 54 % removals during the non-catalytic process. Biodegradability (in terms of 5-day biochemical oxygen demand (BOD₅) to COD ratio) of the pulping effluent was improved to 0.38 from an initial value of 0.16 after the catalytic reaction. The adsorbed carbonaceous fraction on the used catalyst was also determined which contributed meager TOC reduction of 3–4 %. The leaching test showed dissolution of the metals (i.e., Cu and Mn) from the catalysts in the wastewater during CWO reaction at 190 °C temperature and 0.9 MPa oxygen partial pressures. In the future, the investigations should focus on the catalyst reusability.     

Effect of biosludge and biofertilizer amendment on growth of Jatropha curcas in heavy metal contaminated soils

The pot experiments were conducted to evaluate the effect of different concentrations of arsenic, chromium and zinc contaminated soils, amended with biosludge and biofertilizer on the growth of Jatropha curcas which is a biodiesel crop. The results further showed that biosludge alone and in combination with biofertilizer significantly improved the survival rates and enhanced the growth of the plant. With the amendments, the plant was able to grow and survive upto 500, 250 and 4,000 mg kg(-1) of As, Cr and Zn contaminated soils, respectively. The results also showed that zinc enhanced the growth of J. curcas more as compared to other metals contaminated soils. The heavy metal accumulation in plant increased with increasing concentrations of heavy metals in soil, where as a significant reduction in the metal uptake in plant was observed, when amended with biosludge and biofertilizer and biosludge alone. It seems that the organic matter present in the biosludge acted as metal chelator thereby reducing the toxicity of metals to the plant. Findings suggest that plantation of J. curcas may be promoted in metal contaminated soils, degraded soils or wasteland suitably after amending with organic waste.     

Factors and sources influencing ionic composition of atmospheric condensate during winter season in lower troposphere over Delhi, India

Atmospheric condensate (AC) and rainwater samples were collected during 2010–2011 winter season from Delhi and characterized for major cations and anions. The observed order of abundance of cations and anions in AC samples was NH ₄ ⁺ ?>?Ca²⁺?>?Na⁺?>?K⁺?>?Mg²⁺ and HCO ₃ ^? ?>?SO ₄ ^2? ?>?Cl^??>?NO ₂ ^? ?>?NO ₃ ^? ?>?F^?, respectively. All samples were alkaline in nature and Σ _cation/Σ _anion ratio was found to be close to one. NH ₄ ⁺ emissions followed by Ca²⁺ and Mg²⁺ were largely responsible for neutralization of acidity caused by high NO _x and SO₂ emissions from vehicles and thermal power plants in the region. Interestingly, AC samples show low nitrate content compared with its precursor nitrite, which is commonly reversed in case of rainwater. It could be due to (1) slow light-mediated oxidation of HONO; (2) larger emission of NO₂ and temperature inversion conditions entrapping them; and (3) formation and dissociation of ammonium nitrite, which seems to be possible as both carry close correlation in our data set. Principal component analysis indicated three factors (marine mixed with biomass burning, anthropogenic and terrestrial, and carbonates) for all ionic species. Significantly higher sulfate/nitrate ratio indicates greater anthropogenic contributions in AC samples compared with rainwater. Compared with rainwater, AC samples show higher abundance of all ionic species except SO₄, NO₃, and Ca suggesting inclusion of these ions by wash out process during rain events. Ionic composition and related variations in AC and rainwater samples indicate that two represent different processes in time and space coordinates. AC represents the near-surface interaction whereas rainwater chemistry is indicative of regional patterns. AC could be a suitable way to understand atmospheric water interactions with gas and solid particle species in the lower atmosphere.