Evaluating Water Conservation and Reuse Policies Using a Dynamic Water Balance Model

A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley’s water demands through 2035.     

Relative salinity tolerance of warm season turfgrass species

Fresh water, coupled with soil salinization in many areas has resulted in an increased need forscreening of salt tolerant turf grasses. Relative salinity tolerance of eightwarm season turfgrass species were examined in this study in sand culture. Grasses were grown in a glasshouse, irrigated with either distilled water or saline sea water adjusted to 24, 48 or 72 dSm-1. Salt tolerances of the grasses were assessed on the basis of their shoot and root growth, leaf firing and turf quality. Regression analysis indicated that Zoysiajaponica (Japanese lawn grass) (JG), Stenotaphrum secundatum (St. Augustine) (SA), Cynodon dactylon (satiri) (BS), Zoysia teneuifolia (Korean grass) (KG), Digitaria didactyla (Serangoon grass) (SG), Cynodon dactylon (Tifdwarf) (TD), Paspalum notatum (Bahia grass) (BG) and Axonopus compressus(Pearl blue) (PB) suffered a 50% shoot growth reduction at 36.0, 31.8, 30.9, 28.4, 26.4, 25.7, 20.0 and 18.6 dSm1 of salinity, respectively and a root growth reduction at44.9, 43.7, 33.4, 31.0, 29.5 27.5, 21.5 and 21.4 dSm- of salinity, respectively. Leaf firing and turf quality of the selected species, as a whole, were also found to be affected harmoniously with the change in root and shoot growth. On the basis of the experimental results the selected species were ranked for salinity tolerance as JG>SA>BS>KG>SG >TD>BG>PB.     

Parameters and mechanism of membrane-oriented processes for the facilitated extraction and recovery of norfloxacin active compound

Environmental Science and Pollution Research - In the present work, a polymer inclusion membrane (PIM) using an amphiphilic molecule Tween 20 (TW20) as the carrier was developed and characterized...     

Studies on Rhizospheric Mycoflora of Tea (Camellia sinensis):In vitro Antagonism with Dominant Bacteria

The rhizospheres of established tea bushes have some specificcharacteristics which are associated with the long lived nature of teaplants,viz.,negative rhizospheric effect,lowering of soil pH,antagonistic activities among microbial communities and dominan…     

Effect of different design aspects of pipe for earth air tunnel heat exchanger system: A state of art

Earth air tunnel heat exchanger (EATHE) is a promising passive technique to provide thermal comfort condition in buildings. EATHE system uses undisturbed temperature of the ground for heating/cooling of air. Despite the several advantages, this technique has not become much popular owing to its high capital cost (mainly pipe cost and trench excavation cost) and large land area requirements. The primary objective of this study is to present a comprehensive review of different EATHE pipe layouts, pipe properties and positioning of the pipe with their advantages and limitations. It is observed that the ring pipe layout is the most cost-effective pipe-layout for small size EATHE system because it saves excavation cost by using a trench of the existing foundation of the building. However, Grid pipe-layout is an ideal layout for a large size EATHE system. Multi-layer pipe layouts should be used to reduce the land area requirement significantly. Moreover, EATHE system can be installed beneath the building (under building foot-print) to eliminate extra land area requirement for the installation of EATHE system. This review article shows that the Initial capital cost and land area requirement for the EATHE system can be substantially reduced by using appropriate pipe layout. It can be concluded that if EATHE system is installed with proper design strategies, it will be a clean and cost-effective method for building heating/cooling with significant power savings.     

Screening pesticides for their ability to damage bacterial DNA

Abstract

Twenty‐six pesticides and pesticide degradation products were screened (125 μg ‐ 2000 μg) for their ability to induce unrepairable damage to bacterial DNA. Three repair test systems were utilized in this study, the Salmonella typhimurium (TA1538/TA1978), the E. coli K‐12 (Pol A₁ ⁺/Pol^‐ ₁) and the E. coli WP₂ (WP₂, WP₂ uvrA, WP67, CM611 and CM571). Aldicarb (1000 μg), benomyl (250 μg), 2‐aminobenzimidazole (2000 μg), captan (125 μg), fenazalor (500 μg), 5,6‐dichloro‐2‐trifluoromethylbenzimida‐zole (NC‐2983) (250 μg), isothymol (250 μg), maleic hydrazide(1000 μg), pentachloronitrobenzene (1000 μg) were DNA‐damaglng to one or more bacterial test systems. Isothymol and NC‐2983 affected all three test systems. Chlorinated hydrocarbon insec ticides, some being recognized as carcinogens, did not: produce a zone of inhibition in any of the tester strains possibly due to their poor solubility and diffusion in the agar overlay. It was concluded that these tests can be performed along with bacterial reversion tests to complement each other as short‐term screening tests for potential carcinogens and mutagens.     

Investigation of impact of environmental changes on precipitation pattern of Pakistan

In this paper, variability in precipitation pattern of Pakistan due to environmental and climatic changes has been studied. Maps have been generated to depict global precipitation variation. Precipitation data of 25 stations of Pakistan have been used. These data were taken from Meteorological Department, Islamabad, Pakistan. The results of two global climate models, namely Australia’s Commonwealth Scientific and Industrial Research’s third generation general circulation model and National Center for Atmospheric Research’s first generation precipitation circulation model for A2 scenario have been applied to investigate the changes. It is observed that precipitation pattern will change significantly in the future. The occurrence of precipitation in all seasons for Pakistan is expected to increase with almost uniform distribution across a season. Average annual precipitation of the country will undergo an increase in the range of +57 to +71 % as compared to average of the base period.     

Sri Lankan livelihoods after the tsunami: searching for entrepreneurs,unveiling relations of power

This paper analyses the performance of aid‐funded livelihoods recovery efforts in Sri Lanka following the Indian Ocean tsunami of 26 December 2004, with special attention paid to the effects on the rural poor. It argues that successful livelihoods recovery was hampered by an excessive focus by aid agencies on entrepreneurs and entrepreneurship, and by the lack of a politically informed understanding of the economy. Based on ethnographic and survey‐based research, the study demonstrates that the category of ‘entrepreneur’ is misleading for large parts of the economy. Indeed, the desire to build an entrepreneurial economy actually hampered successful livelihoods recovery in Sri Lanka and, in some cases, reinforced inequitable relations of power. The paper concludes that for livelihoods recovery programmes to be effective, they must be founded on an understanding of the relations of power that constitute the economy; these relations operate across scales, and are historically and geographically specific.     

Human health risk from organ-specific accumulation of toxic metals and response of antioxidants in edible fish species from Chenab River,Pakistan

In the current study, the bioaccumulation of essential and nonessential metals and related antioxidant activity were analyzed in three organs (muscle, gills, and liver) of herbivorous (HF) and carnivorous (CF) edible fish of Chenab River. The comparative analysis revealed a more heterogeneous accumulation of metals in the muscles of HF fish than that of CF fish [chromium (Cr, 3.4 μg g^?1), cobalt (Co, 1.7 μg g^?1), copper (Cu, 3 μg g^?1), and iron (Fe, 45 μg g^?1) versus Cr (1.3 μg g^?1), Co (0.1 μg g^?1), Cu (1.1 μg g^?1), and Fe (33 μg g^?1), respectively, P?<?0.001]. These results implied an organ-specific accumulation of metals at different trophic levels. According to logistic regression analysis, the bioaccumulation of metals had marked differences in HF and CF. The antioxidant activity was significantly related to the tissue type and the metals to which the organs are exposed to. The liver of CF fish had a higher activity of antioxidant superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and lipid peroxidase (LPO) than that of HF (P?<?0.05). LPO and guaiacol peroxidase (POD) in both groups were associated with a number of metals, but in HF, cadmium (Cd), Cr, Pb, and Zn were more related with the LPO and SOD activities. Moreover, Cd, Co, Fe, Pb, Ni, Cu, and Zn were above the permissible limits set by various agencies. In numerous cases, our results were even higher than those previously reported in the literature. The results provide an insight into the pollution pattern of Chenab River. These results may be helpful in the future to identify biomarkers of exposure in aquatic organisms.