Population density controls on microbial pollution across the Ganga catchment.

For millions of people worldwide, sewage-polluted surface waters threaten water security, food security and human health. Yet the extent of the problem and its causes are poorly understood. Given rapid widespread global urbanisation, the impact of urban versus rural populations is particularly important but unknown. Exploiting previously unpublished archival data for the Ganga (Ganges) catchment, we find a strong non-linear relationship between upstream population density and microbial pollution, and predict that these river systems would fail faecal coliform standards for irrigation waters available to 79% of the catchment's 500 million inhabitants. Overall, this work shows that microbial pollution is conditioned by the continental-scale network structure of rivers, compounded by the location of cities whose growing populations contribute c. 100 times more microbial pollutants per capita than their rural counterparts.

Secondary organic aerosol: a comparison between foggy and nonfoggy days.

Carbonaceous species, meteorological parameters, trace gases, and fogwater chemistry were measured during winter in the Indian city of Kanpur to study secondary organic aerosol (SOA) during foggy and clear (nonfoggy) days. Enhanced SOA production was observed during fog episodes. It is hypothesized that aqueous phase chemistry in fog drops is responsible for increasing SOA production. SOA concentrations on foggy days exceeded those on clear days at all times of day; peak foggy day SOA concentrations were observed in the evening vs peak clear day SOA concentrations which occurred in the afternoon. Changes in biomass burning emissions on foggy days were examined because of their potential to confound estimates of SOA production based on analysis of organic to elemental carbon (OC/EC) ratios. No evidence of biomass burning influence on SOA during foggy days was found. Enhanced oxidation of SO(2) to sulfate during foggy days was observed, possibly causing the regional aerosol to become more acidic. No evidence was found in this study, either, for effects of temperature or relative humidity on SOA production. In addition to SOA production, fogs can also play an important role in cleaning the atmosphere of carbonaceous aerosols. Preferential scavenging of water-soluble organic carbon (WSOC) by fog droplets was observed. OC was found to be enriched in smaller droplets, limiting the rate of OC deposition by droplet sedimentation. Lower EC concentrations were observed on foggy days, despite greater stagnation and lower mixing heights, suggesting fog scavenging and removal of EC was active as well.

Soluble microbial products formation and their effect on trace metal availability during anaerobic degradation of sulfate laden organics.

Anaerobic degradation of sulfate laden organics involves sulfide generation and release of soluble microbial products (SMP). Sulfide causes direct toxicity to microorganisms and precipitation of key metals. On the other hand, SMP helps in keeping higher soluble concentration of essential metals through complexation and alleviating sulfide toxicity. The role of SMP is well recognized in biological treatment of wastes but many issues are yet to be fully elucidated. The present paper discusses the effect of sulfide concentrations on SMP production and effect of complexation on soluble Fe, Ni, Zn and Co concentrations in laboratory scale uplflow anaerobic sludge blanket (UASB) reactor, anaerobic baffled reactor (ABR) and hybrid anaerobic baffled reactor (HABR) degrading synthetic sulfate laden organics at 35 degrees C for varying operating conditions. Results indicate increased SMP concentration with increasing sulfide concentration and significantly higher measured Fe, Ni, Zn and Co concentrations due to complexation in all three systems. Soluble Fe 0.43-0.66 mg/L; Ni 0.29-0.4 mg/L; Zn 0.15-0.19 mg/L; and Co 0.13-0.29 mg/L appears to be adequate for stable process operation and performance.

Enhancement of chemical-oxygen demand and color removal of distillery spent-wash by ozonation.

Distillery spent-wash has very high organic content (75,000 to 125,000 mg/L chemical-oxygen demand [COD]), color, and contains difficult-to-biodegrade organic compounds. For example, anaerobic treatment of the distillery spent-wash used in this study resulted in 60% COD reduction and low color removal. Subsequent aerobic treatment of the anaerobic effluent resulted in enhancement of COD removal to 66%. In this paper, the effect of ozonation on various properties of the anaerobically treated distillery effluent, including the effect on its subsequent aerobic biodegradation, was investigated. Ozonation of the anaerobically treated distillery effluent at various ozone doses resulted in the reduction of total-organic carbon (TOC), COD, COD/TOC ratio, absorbance, color, and increase in the biochemical-oxygen demand (BOD)/COD ratio of the effluent. Further, ozonation of the anaerobically treated distillery effluent at an ozone dose of 2.08 mg/mg initial TOC and subsequent aerobic biodegradation resulted in 87.4% COD removal, as compared to 66% removal when ozonation was not used.

Effects of some trace heavy metals on Poecilia reticulata (Peters).

Three trace heavy metals viz., nickel, copper and zinc were studied for their toxic action against Poecilia retriculata (Peters). Among these, copper was found to be most active followed by zinc and nickel. Accumulations of these metals as well as behavioural studies were carried out after exposing fish to sub-lethal concentration of LC20. It was found that the highest quantity of nickel was accumulated in the fish body followed by zinc and copper. After exposure to sub-lethal concentration of metals some behavioural changes in fish were observed due to stress, such as mucus like secretion over gills, excessive excretion, anoretic condition and increased distance between gills and operculum. In all the cases fin movement was observed. Role and use of such changes as biological indicators or as biological early warning system in water quality assessment has been discussed.

Three years experience with copper T-200.

PIP: The experience of 1077 women who accepted copper T-200 IUDs at the Family Planning Center of the Family Planning Association of India, Pune, was evaluated. Of the 1077, 494 IUDs were inserted after menses or during lactational amenorrhea and the remainder were inserted during abortion or menstrual regulation procedures as the last step of the procedure. Acceptors were asked to visit the Center 7 days after insertion and after their next menstrual period. Women who accepted the IUD as an interval method paid additional visits whenever they brought their children for immunization or for other health problems. After 3 months, the number of visits became less, and the women only attended if they had any complaints. The majority of the women were under age 30. 69.18% of the women had a high school or college education; only 6.96% were illiterate. 94.89% of the acceptors were Hindus. About 48.74% of the acceptors had incomes Rs 500 and above. Only 1.94% were in a low income group, i.e., below Rs. 100. 82.53% of the acceptors had 2 or fewer children; only 14.38% had 3 or more children. There were 6 pregnancies with IUDs in utero. The number of 1st and later expulsions were 15. About 40% of the expulsions occurred within the 1st 1-2 months and the remainder within the 1st 6 months. The incidence of reasons for removal was as follows: bleeding and pain, 50 cases; planned pregnancy, 40 cases; objection by relatives, 15 cases; and for acceptance of sterilization, 6 cases. A total of 111 women had the IUD removed for medical reasons. Most of the removals were due to bleeding and pain. The incidence of removal for personal reasons was significantly higher. This was because the acceptors were young, low parity women who desired more children. Most of the women had normal menstrual cycles. Only 1 woman had secondary amenorrhea. In sum, the copper T-200 is a safe and effective contraceptive device, highly acceptable to young women attending a public hospital.^ieng