Anaerobic digestion of biowaste in Indian municipalities: Effects on energy, fertilizers, water and the local environment

Anaerobic digestion (AD) of biowaste seems promising to provide renewable energy (biogas) and organic fertilizers (digestate) and mitigate environmental pollution in India. Intersectoral analyses of biowaste management in municipalities are needed to reveal benefits and trade-offs of AD at the implementation-level. Therefore, we applied material flow analyses (MFAs) to quantify effects of potential AD treatment of biowaste on energy and fertilizer supply, water consumption and environmental pollution in two villages, two towns and two cities in Maharashtra. Results show that in villages AD of available manure and crop residues can cover over half of the energy consumption for cooking (EC) and reduce firewood dependency. In towns and cities, AD of municipal biowaste is more relevant for organic fertilizer supply and pollution control because digestate can provide up to several times the nutrient requirements for crop production, but can harm ecosystems when discharged to the environment. Hence, in addition to energy from municipal biowaste - which can supply 4-6% of EC - digestate valorisation seems vital but requires appropriate post-treatment, quality control and trust building with farmers. To minimize trade-offs, water-saving options should be considered because 2-20% of current groundwater abstraction in municipalities is required to treat all available biowaste with ’wet’ AD systems compared to <3% with ’dry’ AD systems. We conclude that biowaste management with AD requires contextualized solutions in the setting of energy, fertilizers and water at the implementation-level to conceive valorization strategies for all AD products, reduce environmental pollution and minimize trade-offs with water resources

Environmental potential analysis of co-processing waste in cement kilns

Технологiя спiльного спалення вiдходiв у цементних печах зарекомендувала себе надiйним, ефективним та зручним методом утилiзацiї вiдходiв (побутових та промислових). Проте країни по всьому свiту зiштовхуються з наступними ключовими бар'єрами на шляху до впровадження технологiї сумiсної переробки вiдходiв у цементних печах: нечiтке законодавство, вiдсутнiсть фiнансової пiдтримки, сприйняття громадськiстю, тощо. Цi бар'єри можуть бути частково усунутi за допомогою заходiв, запропонованих у цьому дослiдженнi.The technology of waste co-processing in cement kilns has proven to be a reliable, efficient and convenient method of waste disposal (domestic and industrial). However, countries around the world face the following key barriers to the implementation of the technology of waste co-processing in cement kilns: fuzzy legislation, lack of financial support, public acceptance, etc. These barriers can be partially eliminated by the measures proposed in this study. In addition, waste sorting and processing are often not carried out systematically. National and international cement companies operate modern cement kilns which could substitute a part of their fossil fuel and raw material with suitable waste streams to be co-processed. Co-processing non-recyclable waste is often a valid option to close loops towards circular economy. This technology is widely used in different European countries, but with different environmental impacts. Therefore, it is important to investigate the environmental potential of this technology, which is variable for different waste morphology conditions

Experimental fire behaviour of precast CFRP pretensioned HPSCC slabs

Optimized concrete elements have been developed using high-performance, self-consolidating, fibre-reinforced concrete (HPSCC) reinforced with high-strength, lightweight, non-corroding pre-stressed carbon fibre reinforced plastic tendons. This new type of thin-walled precast carbon FRP (CFRP) pretensioned HPSCC slab has been used in building façades and is under consideration for a range of other applications in buildings. However, it is well known that the bond strength between both steel and FRP reinforcements and concrete deteriorates at elevated temperature, and that HPSCC has a comparatively high risk of heat-induced concrete spalling. Reductions in bond strength, the occurrence of heat-induced concrete spalling, and their impacts on the load-bearing capacity of precast CFRP pretensioned HPSCC slabs during fire are not well understood. This paper gives insights into the fire behaviour of precast CFRP pretensioned HPSCC slabs by evaluating the influence of concrete mixture, slab thickness and the presence of local reinforcement (CFRP grids) in the prestress transfer zones. Selected results and analysis of a large scale fire resistance test on five HPSCC slabs are presented in this paper. It is shown that the occurrence of heat-induced concrete spalling resulted in sudden failure of the specimens, and that in cases where no spalling occurred failure was due to loss of bond strength

Tensor Polarized Deuteron Capture by the Hydrogen Isotopes

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Tensor Polarized Deuteron Capture by the Hydrogen Isotopes

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Sub- and above barrier fusion of loosely bound 6^6Li with 28^{28}Si

Fusion excitation functions are measured for the system $^6$Li+$^{28}$Si using the characteristic $\gamma$-ray method, encompassing both the sub-barrier and above barrier regions, viz., $E_{lab}$= 7-24 MeV. Two separate experiments were performed, one for the above barrier region ($E_{lab}$= 11-24 MeV) and another for the below barrier region ($E_{lab}$= 7-10 MeV). The results were compared with our previously measured fusion cross section for the $^7$Li+$^{28}$Si system. We observed enhancement of fusion cross section at sub-barrier regions for both $^6$Li and $^7$Li, but yield was substantially larger for $^6$Li. However, for well above barrier regions, similar type of suppression was identified for both the systems.Comment: 8 pages, 6 figures, as accepted for publication in Eur.Phys.J.

New apparatus for DTA at 2000 bar: thermodynamic studies on Au, Ag, Al and HTSC oxides

A new DTA (Differential Thermal Analysis) device was designed and installed in a Hot Isostatic Pressure (HIP) furnace in order to perform high-pressure thermodynamic investigations up to 2 kbar and 1200C. Thermal analysis can be carried out in inert or oxidising atmosphere up to p(O2) = 400 bar. The calibration of the DTA apparatus under pressure was successfully performed using the melting temperature (Tm) of pure metals (Au, Ag and Al) as standard calibration references. The thermal properties of these metals have been studied under pressure. The values of DV (volume variation between liquid and solid at Tm), ROsm (density of the solid at Tm) and ALPHAm (linear thermal expansion coefficient at Tm) have been extracted. A very good agreement was found with the existing literature and new data were added. This HP-DTA apparatus is very useful for studying the thermodynamics of those systems where one or more volatile elements are present, such as high TC superconducting oxides. DTA measurements have been performed on Bi,Pb(2223) tapes up to 2 kbar under reduced oxygen partial pressure (p(O2) = 0.07 bar). The reaction leading to the formation of the 2223 phase was found to occur at higher temperatures when applying pressure: the reaction DTA peak shifted by 49C at 2 kbar compared to the reaction at 1 bar. This temperature shift is due to the higher stability of the Pb-rich precursor phases under pressure, as the high isostatic pressure prevents Pb from evaporating.Comment: 6 figures, 3 tables, Thermodynamics, Thermal property, Bi-2223, fundamental valu

Tensor Polarized Deuteron Capture by the Hydrogen Isotopes

This research was sponsored by the National Science Foundatoin Grant NSF PHY 87-1440