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h i g h l i g h t sNatural degradation of RDX is very slow and its release into the environment is a concern. Molasses enhances biodegradation of RDX and complete degradation occurred within few weeks. Low molasses dose of 1:40 (molasses to water ratio) was as effective as the higher dose (1:20). The combination of Guinea Grass (Panicum maximum) and molasses did not improve RDX degradation. Addition of molasses to soil in army training ranges can prevent migration of RDX to groundwater and off-site. a r t i c l e i n f o The energetics in the soil were royal demolition explosive (RDX) and high-melting explosive (HMX). Among the 6 treatments employed in this study, enhanced removal of RDX was observed from treatments that received molasses and went to completion. The RDX degradation rates in treatments with molasses diluted 1:20 and 1:40 were comparable suggesting that the lower dose worked as well as the higher dose. Treatments without molasses degraded RDX slowly and residuals remained after 15 weeks. The bacterial densities in molasses-treated units were much greater than those without molasses. Phytoremediation alone seems to have little effect on RDX disappearance. For HMX, neither bioremediation nor phytoremediation was found to be useful in reducing the concentration within the experimental period. The concentrations of nitrogen and phosphorous in the soil did not change significantly during the experiment, however, a slight increase in soil pH was observed in all treatments. The study showed that irrigating with diluted molasses is effective at enhancing RDX degradation mainly in the root zone and just below it. The long term sustainability of active training ranges can be enhanced by bioremediation using molasses treatments to prevent RDX deposited by on-going operations from migrating through the soil to groundwater and off-site.

Rapid population growth and urbanization are exerting excessive pressure on soil and water resources. To address these problems this paper proposes a cheap and sustainable alternative sanitation system, which accelerates nutrient recycling ("closing the loop"): ecological sanitation (ecosan) is a potential alternative to conventional sanitation systems that replenishes the organic matter and nutrients of the soil that are taken off as the crop harvest. A comparison is made of the environmental and the operation and maintenance costs between a modern wastewater treatment plant and on-site sanitation. An elevated double box urine diverting toilet ("ecotoilet") is proposed and its advantages and disadvantages over a system with a centrally controlled modern WWTP are discussed. Bagmati Area Sewerage Project in Kathmandu is taken as an example of modern WWTP and ecosan being practiced in a village in Nepal is taken as an example of ecotoilet for the comparison.

Elevated concentrations of estrogens in natural waters pose a significant threat to public health and aquatic ecosystems. Both natural (estrone, 17β-estradiol and estriol) and synthetic (17α ethynylestradiol) estrogens, ubiquitous in wastewater effluents and receiving waters, have been shown to affect the endocrine system of human and aquatic life. The effects vary from cancer to sex reversals at levels as low as parts per trillion in sensitive organisms. Separation of urine, which constitutes only about 1% of domestic sewage and contains nearly all of the excreted estrogens, potentially offers an energy-efficient way to contain and then treat these chemicals. With a capital expense of $2100 and operation and maintenance costs of $69 per year for a urine diverting toilet system, a family in the USA can realize estimated savings of $101 per year in energy, water, and nutrients and a decrease of 100 kg in greenhouse gas emissions. To remove 99% of estrogenicity in discharged waters would require approximately 12 kW h per year using continuous electrodialysis followed by ozonation (O(3)) of source separated urine. To achieve the same results by adding O(3) treatment after activated sludge at existing municipal wastewater treatment plants would require 23 kW h per year. From an energy standpoint it makes sense to practice source separation and treatment of urine to limit estrogen discharges into the environment.

A nine-month in situ bioremediation study was conducted in Makua Military Reservation (MMR) in Oahu, Hawaii (USA) to evaluate the potential of molasses to enhance biodegradation of royal demolition explosive (RDX) and high-melting explosive (HMX) contaminated soil below the root zone. MMR has been in operation since the 1940's resulting in subsurface contamination that in some locations exceeds USEPA preliminary remediation goals for these chemicals. A molasses-water mixture (1 : 40 dilution) was applied to a treatment plot and clean water was applied to a control plot via seven flood irrigation events. Pore water samples were collected from 12 lysimeters installed at different depths in 3 boreholes in each test plot. The difference in mean concentrations of RDX in pore water samples from the two test plots was very highly significant (p < 0.001). The concentrations differences with depth were also very highly significant (p < 0.001) and degradation was greatly enhanced at depths from 5 to 13.5 ft. biodegradation was modeled as first order and the rate constant was 0.063 per day at 5 ft and decreased to 0.023 per day at 11 ft to 13.5 ft depth. Enhanced biodegradation of HMX was also observed in molasses treated plot samples but only at a depth of 5 ft. The difference in mean TOC concentration (surrogate for molasses) was highly significant with depth (p = 0.003) and very highly significant with treatment (p < 0.001). Mean total nitrogen concentrations also differed significantly with treatment (p < 0.001) and depth (p = 0.059). The molasses water mixture had a similar infiltration rate to that of plain water (average 4.12 ft per day) and reached the deepest sensor (31 ft) within 5 days of application. Most of the molasses was consumed by soil microorganisms by about 13.5 feet below ground surface and treatment of deeper depths may require greater molasses concentrations and/or more frequent flood irrigation. Use of the bioremediation method described herein could allow the sustainable use of live fire training ranges by enhancing biodegradation of explosives in situ and preventing them from migrating to through the vadose zone to underlying ground water and off-site.