Issue 1

Severe energy crisis and vilest economic conditions in Pakistan demand the country’s energy portfolio to be revised with increased reliance on indigenous energy resources. The perspective of utilization of abundantly available biomass waste fractions as a fuel alone and their co-combustion with two different indigenous coal varieties has been emphasized in this study. Coal samples were blended with the organic fraction of municipal solid waste, rice husk and sugarcane bagasse waste fractions in varying ratios of 20%, 40%, 60% and 80% and the resulting variation in their fuel characteristics and co-combustion efficiency was determined. The execution is a basis to assess the assumption that co-combusion in appropriate proportions can arrange a solution for the massive amounts of produced organic waste and cut dependency on imported energy sources. The tanner diagram visualization for the assessment of proposed blends suggest that the blending samples exhibit an increase in moisture and combustible content while some decrease in ash content and calorific values with increased biomass ratios. Within the assortment of conducted trials, khaushab coal and rice husk in various proportions evidenced to be the best arrangement for fuel consumption based on energetic optimization. The overall results of studies inferred that both coal and biomass fuels alone and their co-firing can sustain self-combustion and subsequently arrange for finding area based solutions related to various energy operations.

Kalamata’s decentralized waste management and composting scheme is a successful demonstration of the capacity of a municipality to manage its Municipal Solid Wastes (MSW) by adopting methodologies that can be supported by small scale mobile equipment. According to the revised legislation, Join Ministerial Decision (JMD) 51373/4684/2015, each municipality in Greece should organize a regional decentralized waste management plan to comply with the National and EU Legislation. In Kalamata, a mobile Mechanical Biological Treatment (MBT) unit is in operation which consists of a sorting facility in which recyclable materials are recovered from mixed wastes and a composting facility where the Organic Fraction of Municipal Solid Wastes (OFMSW) is treated into closed aerated windrows. This paper attempts to analyze the characteristics of the applied methodology as well as to set a framework for the optimal treatment of the OFMSW in small decentralised units. Several trials have been performed to optimise the effectiveness of different composting practices for OFMSW. Desirable temperature values for degradation (over 50°C), were achieved during the composting process, while oxygen content was kept between 15-20%. Heavy metals were presented in all the samples analyzed, with concentration levels below the limits set by National Legislation. The values of the physicochemical parameters monitored in this study did not exceed the maximum permissible as well.

To find out the relationship between industrial agglomeration and environmental pollution, this paper carried out empirical research on the panel data collected from 271 prefecture-level cities in China from 2004 to 2017 through a spatial panel econometric model. It reviewed the influence of agglomeration externality on environmental pollution. The results detected an inverted "U"-shaped relationship between manufacturing industry agglomeration and environmental pollution nation-wide. The manufacturing industry agglomeration level at the inflection point was 0.652, suggesting that prefecture-level cities suffered severe environmental pollution problems. At the regional level, the manufacturing industry agglomeration in eastern and western China had a significant adverse effect on environmental pollution. In the central China, the relationship between manufacturing industry agglomeration and pollution was "N" -shaped. The manufacturing industry agglomeration levels in most prefecture-level cities were between the two inflection points. The environmental pollution aggravated as the manufacturing industry agglomeration level rose in the range. As for cities in the northeastern region, manufacturing industry agglomeration has no direct causal relationship with environmental pollution.

The reductive gas composition produced by the reburning of sludge can reduce NOx in flue gases to N2, which provides a new idea for the study of gas denitration, and at the same time makes denitration by sludge reburning become an important part of gas denitration research. However, due to the complexity of the sludge structure, the existence of reductive groups in the sludge is still unclear. This study aims at exploring these highlighted problems. First, the thermal decomposition of sludge was analyzed at five gradient temperatures. Then, the products of the thermal decomposition at the various temperatures were analyzed by nuclear magnetic resonance (NMR). Finally, the forms in which the reductive groups in exist sludge were deduced using the inversion method, backward from higher to lower temperatures. The results of the experiment indicate that the reductive groups in the sludge exist in the form of organic functional groups or hydrocarbon such as CH3N=, RCH2–S–, RCH2–N=, RCH2–O–, R2CH–N=, R2CH–S–, and cycloalkynes. The NMR inversion method employed contributed to the prevention of the superposition of NMR peaks caused by the complex structure of sludge and improved the accuracy of the analysis.