Assessment of temporal variation in water quality of some important rivers in middle Gangetic plains, India

The study explains water quality of three important tributaries of the Ganga River in the middle Gangetic plains in India. Seasonal changes in the water quality of the studied rivers: Gandak, Ghaghra, and Sone were observed. During monsoon, several water quality parameters show considerable changes due to increased runoff from the catchments and other seasonal factors. Multivariate discriminant analysis delineated a few parameters responsible for temporal variation in water quality. Seasonal variation in water quality of the Gandak River was rendered by seven parameters??turbidity, sulfate, pH, phosphate, water temperature, total alkalinity, and sodium, while total alkalinity and water temperature were responsible for seasonal discrimination in water quality of Ghaghra River. Water temperature, turbidity, total dissolved solids, total suspended solids, calcium, and phosphate were important for seasonal discrimination in water quality of Sone River. The seasonal changes in water quality of the rivers were due to seasonal effects and catchment characteristics. The discriminant functions classified most of the cases correctly.     

Removal of substituted phenols onto iron‐treated Nostoc sp. biomass

This study explored the possibility of removing 4‐nitrophenol (4‐NP) and 2,4‐dichlorophenol (2,4‐DCP) from water by using a dead blue‐green algae, Nostoc sp., dried and untreated and dried and treated with iron (Fe‐treated with 0.1 M ferric chloride solution for 1 day). The Nostoc sp. untreated and Fe‐treated biomass were used to study the sorption and desorption of 4‐NP and 2,4‐DCP. The effects of solute concentration, ionic strength, and temperature on sorption and desorption in the presence of untreated and treated Nostoc sp. biomass were investigated. The Fe‐treated Nostoc sp. biomass sorbed higher amounts of both 4‐NP and 2,4‐DCP than the untreated biomass. The percent cumulative desorption decreased from 6.41% to 0.28% and 1.84% to 0.19%, respectively, for 4‐NP and 2,4‐DCP for the Fe‐treated biomass. Biosorption of 4‐NP and 2,4‐DCP onto untreated and Fe‐treated Nostoc sp. biomass conformed to Freundlich isotherms. Iron treatment of Nostoc sp. biomass increased the value of ln K from 8.07 to 8.59 for 4‐NP and from 8.04 to 8.51 for 2,4‐DCP but decreased their desorption. An increase in ionic strength (0.003–0.03) increased the biosorption of both substituted phenols and decreased their percent desorption. An increase in temperature in the range of 15–35°C decreased the sorption of 4‐NP and 2,4‐DCP onto both untreated and Fe‐treated Nostoc sp. biomass and increased their desorption, indicating that the biosorption of both substituted phenols onto untreated and Fe‐treated Nostoc sp. biomass was principally a physical process. The results of this study suggest that Fe‐treated dried Nostoc sp. biomass could be explored as an inexpensive and eco‐friendly material for the effective removal of these phenols and, potentially, other chemicals from industrial wastewater and contaminated groundwater.     

Assessment of micronuclei and chromosomal anomalies of five biocompatible materials in mice

In vivo genetic toxicology tests measure direct DNA damage or the formation of gene or chromosomal mutations, and are used to predict mutagenic and carcinogenic potential of compounds for regulatory purposes. These adverse genotoxic effects may be manifested in the form of gene mutations, structural chromosomal aberrations (CA), recombination, and numerical changes. The present investigation was carried to assess genotoxic effects of five different implantable biomaterials developed in different laborataries of Sree Chitra Tirunal Institute of Medical Sciences and Technology. All biomaterials were developed for clinical applications. CA and micronuclei (MN) studies are biomarkers of genotoxicity testing. Leachants from the extract of biomaterials are capable of inducing structural and numerical chromosomal changes. The studies were conducted in Swiss albino mice with the physiological saline extract of materials together with cyclophosphamide and physiological saline as positive and negative controls. Animals were administered intraperitoneally (ip) with a single injection of test, positive (cyclophosphamide), and negative (physiological saline) control and sacrificed after 24 or 48?h. Bone marrow cells were collected for CA and MN assays. Data showed that all five biomaterials did not significantly exert genotoxic effects. Hence, the study indicates that these biomaterials do not induce any chromosomal anomalies.     

The development of a movement-density relationship for people going on four in evacuation

Occupant movement in evacuation models has been simulated and predicted based on a number of variables, including crowd density. This study investigates the relationship between crowd density and occupant crawling movement, as a physical response to environmental conditions in fire. It is an attempt to generate the fundamental speed-density relationship that has been developed for walking movement. This is conducted by examining the impact of population size and exit access width on crowd walking and crawling speeds on a flat surface. The findings of the study suggest that exit access width has a significant impact, whereas occupant configuration (population size) plays less of a factor. The results further demonstrate that there is a significant difference in the crawling speed given the exit access width available, due to the secondary effect of crowd density. The relationship between crowd crawling speed and density is best represented by a quadratic regression model. The study concludes with the need to continuously develop new predictive movement methods, or enhance existing ones in order to cope with the level of detail required to ensure occupant safety and model complexity.     

Trihalomethane Formation Potential and Concentration Changes During Water Treatment at Mumbai (India)

The treated water at the outlet oftreatment plants and representative servicereservoirs of Mumbai city have been evaluatedfor trihalomethane formation potential in1995–1996. Chloroform, dichlorobromomethane,chlorodibromomethane and bromoform have beenmonitored during monsoon, winter and summer.The levels of chloroform are found above theregulated WHO guideline value of 200 g L^-1 in final water during postmonsoon atGhatkopar (226 g L^-1), Malbar (210.3 g L^-1) and Tulsi (231.26 g L^-1).     

Analysis of uranium and its correlation with some physico-chemical properties of drinking water samples from Amritsar, Punjab

Fission track technique has been used for uranium estimation in drinking water samples collected from some areas of Amritsar District, Punjab, India. The uranium concentration in water samples is found to vary from 3.19 to 45.59 microg l(-1). Some of the physico-chemical properties such as pH, conductance and hardness and the content of calcium, magnesium, total dissolved solids (TDS), sodium, potassium, chloride, nitrate and heavy metals viz. zinc, cadmium, lead and copper have been determined in water samples. An attempt has been made to correlate uranium concentration with these water quality parameters. A positive correlation of conductance, nitrate, chloride, sodium, potassium, magnesium, TDS, calcium and hardness with uranium concentration has been observed. However, no correlation has been observed between the concentration of uranium and the heavy metals analysed.     

Dietary exposure assessment of cadmium,arsenic, and lead in market rice from Sri Lanka

Environmental Science and Pollution Research - Rice is frequently reported to be contaminated with heavy metals (HMs); thus, the human health risks from its consumption have received increasing...     

Hydrogen Peroxide and Ultraviolet Irradiations in Water Treatment

Trihalomethanes (THMs) the by-products of chlorination in water treatment are recognised as a threat to public health due to their carcinogenicity. The photodegradation of THMs using hydrogen peroxide has been found to give increased removal efficiency and the outcome of the study may find, its application in designing a unit process for water treatment. Batch experiments were carried out using UV lamp of 83 W and 40% w/w Hydrogen peroxide (H₂O₂) in test waters between 2.5–10 pH range of chloroform, bromodichloromethane, dibromochloromethane and bromoform at 50–200 μg L⁻¹ initial concentration. 92–100% removal of chloroform, bromodichloromethane, dibromochloromethane and bromoform were found with 0.1% of H₂O₂ and 90 min of UV exposure.     

Coal Combustion Product: Nonhazardous Material for Mine Fill

As is the case in many other countries around the world, India's main source of electricity is coal‐fired power plants. In addition to providing energy, the burning of coal also results in large amounts of coal combustion products (CCP), the incombustible material, such as fly ash, left after the coal is burned. These materials are produced in large volume, and if they are not managed or utilized properly, they can pose a danger to the environment. This article discusses the uses of CCP, with a special emphasis on fly ash, and the role that it is currently playing and can continue to play as a mine filler for India's depleted opencast and underground coal mines.