The objective of this study is to evaluate the possibility of recycling the liquid product obtained from sewage sludge by the hydrothermal treatment as a kind of organic fertilizer and its effect on the plant growth. A small scale hydrothermal treatment experiment was performed and proved that the liquid product contains high content of nitrogen and low content of micronutrients. Therefore, the liquid product has the potential to be used as a kind of liquid fertilizer. In a seed germination test, the liquid product indicated low phytotoxicity. Moreover, in a Komatsuna cultivation experiment, the liquid product showed accelerate effect to the crop yield which is not lower than the chemical fertilizer. Through the low-temperature hydrothermal treatment, the sewage sludge was converted into liquid organic material that could be used as a delayed-release nitrogen fertilizer for the growth of Komatsuna. These results indicated the possibility of establishing a comprehensive system for recycling sewage sludge into a kind of organic fertilizer.
In this research, desertification hazard has been analyzed by resilience range over eastern north of Iran. In this research was assumed that resilience of ecosystem refers to inherent properties of ecosystem. Soil erodibility, rainfall erosivity, topography and land cover- a reflection of land-use management- are assumed as representative factors of resilience range in this study. In order to calculate resilience range an integrated map was developed based on the combination of erodibility, erosivity and slope factors. Ultimately desertification vulnerability was estimated by multiplying resilience range and land cover into resultant maps. Results indicated that about 44% of study area is fragile ecosystems with high desertification vulnerability. Also the results showed that vegetation cover has main role to increase resilience potential of ecosystem to response perturbations.
Recent scientific attention has shown serious concern towards municipal solid wastes (MSW) as a source of greenhouse gases and concentrated leachate. We studied the leachate pollution index (LPI) and emission fluxes of two greenhouse gases (CH4 and CO2) at two municipal solid waste dumpsites situated along the Ganga River at Varanasi (India). The LPI is a quantitative tool by which the leachate pollution data of dumping sites can be reported uniformly. Concentration of nutrient ions (Ca2+, Mg2+, Na+, K+, NO3-, Cl-, PO43- ) and heavy metals (Cd2+, Fe2+, Cu2+, Pb2+, Ni2+, Zn2+, Co2+, Mn2+ ) in leachate varied with season with values being highest in rainy season. Total dissolved solids, conductivity and salinity in leachate showed a similar trend. Leachate pollution index was found to be 87.19 and 82.56 at KZP and BPS sites respectively. The LPI was much higher than the permissible limit at both the sites indicating high contamination potential for surface and ground water and risk to human health. Among all the study metals, Pb was found in abundance at Site 1. The emission flux of CH4 ranged from 10.73 to 96.74 mg m-2 h-1 and that of CO2 from 17.28 to 321.89 mg m-2 h-1. Emission flux of both the greenhouse gases increased with rising moisture and temperature. The rates were higher at young landfill site and between-site differences in the emission of CH4 and CO2 were significant. The study has relevance establishing landfill associated contamination to Ganga River and reducing uncertainties in greenhouse gas emission estimates in India.
Anuradhapura district is one of the largest agricultural crop production areas in Sri Lanka. But it is often affected by droughts and droughts caused severe damage for agricultural industry. Thus it is very important to identify the drought characteristics (drought duration and drought severity) and their joint probability distribution to minimize the adverse effects of droughts. Drought characteristics were defined using 3-month standard precipitation index (SPI). It is calculated using monthly rainfall data from 1951 to 2007 in Anuradhapura. Occurrences of 46 drought events were indentified using the calculated SPI. Since dependency nature of the drought variables, copula based joint distribution was used to calculate the joint distribution. The joint distribution could be obtained by combining the marginal distributions using copula. Five copulas were examined and compared to find the best fitted copula to represent the joint distribution. The best marginal distributions were identified as the gamma distributions for drought durations and drought severity using AIC, BIC and Kolmogorov-Smirnov test. Frank copula was identified as the best copula based on AIC, BIC and Cramer-Von Mises statistics. The joint distribution was derived combining the gamma distributions using the Frank copula. The univariate and joint returns periods of droughts were calculated. A drought event occurred in 1974 was identified as a major drought event. Drought duration and severity in 1974 were 9 months and 10.95 respectively. Using the indentified univariate and multivariate return periods, drought risks could be minimized by pre-planning and making decision against adverse effects.
Aims: In February and March 2014, more than 300,000 households were affected by water rationing in Kuala Lumpur, Malaysia and the surrounding State of Selangor. Further south, reservoir levels in Singapore were dropping, prompting the government to raise the water conservation rhetoric, but falling short of implementing water rationing schemes. The region experienced a dry spell that was unprecedented in the last 30 years. Preparedness for storms has been the "talk of the town" since the 2001, 2006 and 2007 extreme high precipitation events in the southern parts of the peninsula and in Singapore resulted in costly flood damage. While resilience has been a concept used frequently in climate change adaptation, it is derived from ecology, where it refers to the capacity of the system to respond to a disturbance and resist the impact or recover from the damage of the disturbance. This paper examines the case of Singapore as an urban area in responding to a similar extreme hydrologic phenomenon by examining the climate change resilience of the small city-state, with a view to recommending some considerations in designing climate change adaptation strategies. Place of Study: Singapore and peninsular Malaysia. Methodology: The paper reviews the rainfall extremes statistics covering the last 30 years for Singapore and then takes a hydrologic event-based case study approach to more closely examine the impact of record storms and the drought of March 2014 to discuss aspects of resilience that can serve as lessons for tropical cities in future adaptation to a climate-changing world. Results: Extreme rainfall events have become more frequent in Singapore over the past 30 years, while February, 2014 was the driest February since 1869. February, 2014 also had the lowest recorded daily relative humidity at 74.5%. Tropical cyclones are not expected to hit Singapore because of its location near the equator, yet Typhoon Vamei made history by delivering 210 mm of rain on 27 December, 2001. Between 19 and 20 December, 2007 Singapore received 366 mm of rain and within the same week another storm deposited 140 mm of rain in a 24 hour period. While there were some environmental and health impacts related to the February 2014 drought, including low dissolved oxygen levels in water and a localized fish kill, as well as reports of greater human respiratory problems, Singapore was able to weather the drought by requesting voluntary conservation measures, prudent reservoir management, and increasing the output of NEWater and desalinized water. Recent extreme rainfall events have produced localized flooding, but Singapore has progressively pursued a program of improved drainage, stream naturalization, and implementation of Low Impact Development (LID) technology to reduce flood-prone areas from 3,200 ha in the 1970’s to 36 ha today. Conclusion: We do not suggest that all countries need to have NEWater or desalinated water to solve drought problems. We do suggest that in managing rainfall related hazards, droughts and extremes have been treated rather independently. Based on the case study of extremes presented for Singapore we propose the importance of establishing a three-step preparedness program for extremes that includes Preparation (vulnerability and risk identification, adaptive capacity building, and monitoring), Response (information dissemination and relief action), and Recovery.