Seasonal variations in species composition,abundance, biomass and production rate of tintinnids (Ciliata: Protozoa) along the Hooghly (Ganges) River Estuary,India: a multivariate approach

The study is the first documentation of seasonal variations in species composition, abundance and diversity of tintinnid (Ciliata: Protozoa), in relation to water quality parameters along the stretch of the Hooghly (Ganges) River Estuary (HRE), eastern coastal part of India. A total of 26 species (22 agglomerated and 4 non-agglomerated) belonging to 8 genera has been identified from 8 study sites where Tintinnopsis (17 species) represented the most dominant genera, contributing up to 65 % of total tintinnid community followed by Tintinnidium (2 species), Leprotintinnus (2 species) and Dadayiella, Favella, Metacylis, Eutintinnus and Helicostomella (each with solitary species). The maximum (1,666 ind.?l^?1) and minimum (62 ind.?l^?1) abundance of tintinnids was recorded during post-monsoon and monsoon, respectively. A distinct seasonal dynamics in terms of biomass (0.005–2.465 μg C l^?1) and daily production rate (0.04–3.13 μg C l^?1 day^?1) was also noticed, accounting highest value during pre-monsoon. Chlorophyll a and nitrate were found to be potential causative factors for the seasonal variations of tintinnids as revealed by a stepwise multiple regression model. The result of ANOVA showed a significant variation between species abundance and months (F?=?2.36, P?≤?0.05). k-dominance curves were plotted to determine the comparison of tintinnid dominance between the investigated stations. Based on a principal component analysis (PCA), three main groups were delineated with tintinnid ciliates and environmental parameters. The changes in lorica morphology in terms of temperature and salinity, recorded for three dominant species, provided information on the ecological characteristics of the species assemblage in this estuarine system.     

Risk assessment and pathway study of arsenic in industrially contaminated sites of Hyderabad: a case study

Different areas in the industrial region of Patancheru near Hyderabad, Andhra Pradesh (A.P), India are contaminated with high concentration of arsenic, which is attributed to industrial source like veterinary chemicals, pharmaceuticals, pesticide industries, etc. Fourteen villages of this area of Patancheru were assessed for arsenic contamination by collecting samples of water (surface and ground), soil, fodder, milk, and vegetables. The total arsenic content in the whole blood, urine, hair, and nails of the residents showing arsenical skin lesions and other clinical manifestations were also studied. To understand the bioavailability of arsenic in this environment and its possible entry into human food chain, speciation studies of arsenic was carried out and the results are presented in this paper.     

A comparison of sediment quality guidelines for toxicity assessment in the Sunderban wetlands (Bay of Bengal, India)

The aim of this paper was to obtain the first screening ecotoxicological risk evaluation in the Sunderban wetlands, the largest prograding delta in the estuarine phase of the River Ganges. The characterization of exposure was conducted by means of an extensive survey of several persistent organic pollutants (PAHs, PCBs, DDTs, PBDEs, HCHs, HCB) measured in seven core sediments from the Sunderban wetlands, obtaining a dataset with more than 2200 analyses. The pollutant effects were assessed by the use of three different sediment quality guidelines (SQGs) previously developed in the literature to evaluate toxicity induced in sediment-dwelling organisms. The three different approaches chosen for risk assessment of the Sunderban were the consensus SQGs obtained by TEC (threshold effect concentration), PEC (probable effect concentration) and EEC (extreme effect concentration), the threshold/probable effect level (TEL/PEL) approach and, finally, the ERL-ERM guidelines, including the m-ERM-Q (mean ERM quotient). The evaluation of the toxicity induced by a mixture of the target pollutants indicated the importance of gamma-HCH contamination in the Sunderban sediments despite the very low concentrations measured in core sediments. A different sensitivity for toxicity assessment due to quality guidelines was obtained, as the consensus SQGs based on TEC were less conservative and protective than the TEL and ERL approaches, while the use of m-ERM-Q seems to be the most powerful tool to predict the toxicity related to a contaminant mixture.     

An assessment of trace element contamination in intertidal sediment cores of Sunderban mangrove wetland, India for evaluating sediment quality guidelines

This paper presents a comprehensive account regarding concentration, distribution and possible sources of trace elements (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in 20-30 cm sediment cores (<63 microm particle size) collected at the confluence of the Ganges River and Bay of Bengal (Sunderban wetland, India). This work aims to evaluate the fluvio-marine and geochemical processes influencing the metal distribution. The most interesting features are the downward increase of concentrations of majority of the elements reaching overall maximum values at a depth of 10-15 cm observed in station Lot No.8 located along the main stream of the Ganges estuary as well as an overall elevated concentration of all the elements in the lower littoral zone. The interelemental relationship revealed the identical behaviour of elements during its transport in the estuarine environment. The overall variation in concentration can be attributed to differential discharge of effluents originating from industrial and agricultural as well as from domestic sewage. Arsenic exceeded effects range - low (ER - L) concentrations, implying occasional or frequent adverse biological effects. For Cu, Ni and Cr a smaller proportion of samples had exceeded the ER - L values indicating that the dataset would be suitable for future use in evaluating predictive abilities of SQGs.     

Nickel recovery from spent nickel catalyst.

A process for nickel recovery from a spent catalyst of definite composition has been developed using the hydro-metallurgical route. The processing steps includes direct sulphuric acid leaching followed by separation of iron as well as silica and other impurities. For a 152 microm particle size catalyst, extraction of about 98% nickel was achieved at 363 K in 2 h using a sulphuric acid concentration (v/v) of 8% and a pulp density of 10%. The dissolution of nickel followed diffusion-controlled leaching kinetics. Increase in temperature and sulphuric acid concentration resulted in increase in the nickel recovery. The activation energy for nickel dissolution was calculated to be 62.8 kJ mol(-1). Finally, nickel was recovered as value-added products such as sulphide and oxalate with overall recovery of 90 and 88% of nickel, respectively.     

Environmental Attitudes and Behavior of Primary and Secondary Students in Asian Cities: An Overview Strategy for Implementing an Eco-schools Programme

Environmental education is essential to the success of Agenda 21. Yet currently it is without focus and effectively side-lined. This paper presents the results of preliminary investigations on the environmental attitudes and knowledge of Indian and Filipino primary and secondary school students, and their readiness to engage in pro-environmental behavior that could involve some change in their personal lifestyle. For the most part, environmental education efforts are embedded mainly into various science subjects. The relationship between environmental education and environmental awareness is analyzed to examine whether schools' environmental education could contribute to the shaping of environmental attitudes. A strategy and accompanying methodology for establishing environmental education is supplied.     

Heavy metals concentration in edible fishes from coastal region of Kalpakkam, southeastern part of India

Concentrations of Cu, Mn, Zn, Fe, Cr, and Pb were estimated using ICP-MS in nine commercially important and locally consumed fish species (Sarda orientalis, Scomberomorus commerson, Rastrelliger kanagurta, Sardinella longiceps, Paraplagusia bilineata, Cynoglossus lida, Cynoglossus macrostomus, Lepturacanthus savala, and Siganus javus) collected from coastal waters of Kalpakkam, eastern part of India. Their concentration (μg g(-1)) in the examined fish species ranged as follows: Cu (0.8-6.5), Zn (14.3-27.9), Mn (0.5-8.8), Fe (17.6-117.0), Cr (0.24-1.78), and Pb (0.18-2.29). Concentrations of most of the metals in the fish species studied were found to be safe for human consumption barring Mn.     

An overview on the production of pigment grade titania from titania-rich slag.

To recover pigment grade TiO2, operating plants all over the world use chemical processes. Slag-based technology is considered to be attractive because of low waste generation and low chemical cost due to high titanium content and is poised to replace the conventional technology. This paper provides a review of the slag-based technology with the specific aim to produce leachable slag and achieving high titania yield from recovered wastes. Leachable oxides of the lower oxidation state, such as TiO and Ti2O3, facilitate the leaching process. However, during smelting these oxides increase the viscosity of the slag. Formation of titanium carbide or carbonitride is also not desirable as it leads to resistance to the leaching of titanium. This report highlights the problems and their possible solutions to obtain leachable slag.     

Potential of Hemidesmus indicus for phytoextraction of lead from industrially contaminated soils

Many sites in the industrial region of Kattedan near Hyderabad, Andhra Pradesh (AP), India are contaminated with high concentrations of lead. The use of plants to remove toxic metals from soils (phytoremediation) is emerging as a potential strategy for cost-effective and environmentally sound remediation of contaminated soils. We studied remediation of soils contaminated with lead using a lead hyperaccumulating plant, Hemidesmus indicus. The ability of this plant to accumulate lead in shoots and roots was studied with pot experiments. The results showed that accumulation was maximum in roots for the first 1-3 weeks and later for a contact period of three months, the accumulation rate was maximum in shoots. In addition we used various chelating agents such as EDTA, HEDTA, DTPA and CDTA to determine the best chemical modifier for efficient lead removal from contaminated soils. The effect on lead accumulation of plant in the presence of various metal co-ions was also studied. An attempt was made for the decontamination of lead from five different "Real-life" soils of Kattedan using H. indicus.     

Comprehensive review on naringenin and naringin polyphenols as a potent anticancer agent

Environmental Science and Pollution Research - Though the incidence of several cancers in Western societies is regulated wisely, some cancers such as breast, lung, and colorectal cancer are...