Rice straw is one of the organic materials and natural residue of rice crop or paddy material and is the third-largest residue from agriculture after sugarcane bagasse and maize straw. Southeast Asian countries produce approximately 80% of rice production in the world. It leads to a large quantity of rice straw as a by-product every year. Surplus rice straw is a focal issue associated with storage of rice straw, removal of entire straw from the field, and very little time between the cultivation of the crop. Stubble burning is a quick, cheap, and efficient way to prepare the soil bed for wheat, the next crop. Rice straw has both nutrient and calorific values. Straw is the only organic material available in significant quantities to most rice farmers. About 40 percent of the nitrogen (N), 30 to 35 percent of the phosphorus (P), 80 to 85 percent of the potassium (K), and 40 to 50 percent of the sulfur (S) taken up by rice remains in vegetative plant parts at crop maturity. Straw is either removed from the field, burned in situ, piled or spread in the field, or incorporated in the soil. Open burning of the crop residue kills useful microflora of soil, leads to soil degradation, and contributes to harmful greenhouse gases such as SO2, NO2, CH4, N2O, carbon monoxide in the atmosphere including the hydrocarbon and particulate matter. Therefore, rice straw burning is a serious creator of environmental pollution. The study investigated environment-friendly options of rice straw such as bedding material for cattle, mushroom cultivation, nutrition in the soil, power generation, combustion material, pellet making, bio-gas, bio-ethanol, bio-char, acoustic material, 3D objects, cardboard and composite board, packaging materials, production of bio-composite, cement bricks, and handmade paper. The key purpose of this paper is to provide environmentally friendly alternatives to rice straw instead of open field burning.

Municipal solid waste deposition in metropolitan areas has become a major concern that, if not addressed, can lead to environmental degradation and possibly endanger human health. It is important to adopt a smart waste management system in place to cope with a range of waste materials. This research aims to develop a smart modelling method that could accurately predict and forecast the production of municipal solid waste. An integrated convolution neural network and air-jet system-based framework developed for pre-processing and data integration were developed. The results showed that machine learning algorithms could be used to detect different types of waste with high accuracy. The best performers were obtained from neural network models, which captured 72% of the information variation. The method proposed in this study demonstrates the feasibility of developing tools to assist urban waste through the supply, pre-processing, integration, and modelling of data accessible to the public from a variety of sources.

The characteristic stages of metamorphic transformations of mines are established according to the increase in the elemental content of carbon and changes in other components of organic matter. Stages of metamorphism transformations with an average carbon content of more than 93.6% can significantly differ in properties due to the unpredictability of the ratio between the components of organic matter. At these stages, even a minimal difference between the components can be the reason for the emergence of new properties of the coal seams. As the influence of the processes of metamorphism increases, the boundaries of the stages, determined by the percentage of carbon, narrow. The established stages of the transformation of reservoirs in terms of the individual proportion of the components in carbonization practically do not differ from the boundaries of the stages determined by the elemental composition of organic matter. It is noted that the average carbon content at the stages of seam metamorphism, determined by the yield of coke, in most cases does not coincide with the ranges of changes in the average carbon content, established by the individual content of the components or their share in carbonization. The inconsistency of the boundaries in the stages of seam metamorphism makes it unacceptable to use the coke yield as the main criterion for assessing the conversion of coal and even more so the manifestation of hazardous properties of coal seams.

Remote Sensing (RS) technology using SENTINEL-2 Multispectral Instrument (MSI) imagery was used in the estimation of residual biomass’ available energy potential. The estimation was done in Panglao Island, within the province of Bohol, Philippines. Estimation of biomass availability was processed using Geographical Information System (GIS) software incorporating the calculation of Normalized Difference Vegetation Index (NDVI) to extract information on land resources and its spatial distribution. It was found that the majority of vegetation cover on the island is in the form of perennial woody plants and coconut trees. Coconut production on the island of Panglao contributed 1.26% of the total cultivation area for the province based on processed captures of Sentinel-2 imagery. The residue concentration amounted to 2,865 tons of coconut residues based on the RPR method. This amount of residues can be translated to 52.92 TJ of theoretical energy potential. The result of this study may serve as a baseline for the locality to consider the utilization of agricultural residues such as coming from coconut trees to support the use of indigenous resources for energy generation.

River water quality is an important indicator for identifying river changes and analyzing river health, and has an important impact on the ecological environment of the river basin. In this paper, the matter-element analysis method based on the coupling weight method is used to evaluate the water environment of the water quality measured data of Wenyu River in 2019, which provides a reference for water quality management and protection. Through the establishment of the object element to be evaluated, the classical domain, the section domain, the normalization of the evaluation standard, and the measured data, three representative indicators such as DO, NH3-N, and CODcr are selected as the object element to be evaluated. The standard value corresponding to the water quality standards of Grade I to V is the classic domain. The weight of river indicators is determined by the coupling of the ordinary objective weighting method and the multiple super-scale weighting method. After the weight is determined, the correlation degree is calculated and the matter-element analysis model for water quality evaluation is established. The results showed that the water quality of the Wenyu River in May 2019 was still mainly Grade V water, which was in line with the actual water quality situation. It shows that the method meets the feasibility and practicability in water quality evaluation and is relatively reliable.

Carbon emission is further intensified as urbanization and industrialization continue to accelerate. China has maintained its rapid economic development and urbanization in the last 2 decades. The development of the construction industry has not only consumed a large number of energy sources but also resulted in significant carbon emissions, causing some environmental damage. Recognizing the major influencing factors of carbon emissions in the construction industry has become a research hotspot to alleviate environmental pollution caused by the construction industry and meet industrial demands for energy saving and emission reduction. In this study, the factors that influence annual carbon emissions of different building types in China from 2011 to 2018 were decomposed by Logarithmic Mean Divisia Index (LMDI) through a case study in Henan Province. The major influencing factors of carbon emissions have been identified. Results demonstrate that the per capita carbon emission in the construction industry in Henan Province remains high from 2011 to 2018, but it decreases year by year. Carbon emissions from the construction industry in Henan Province increase due to economic development and energy structure. Energy efficiency can inhibit carbon emissions from the construction industry in Henan Province. The obtained conclusions have a positive effect on analyzing annual variations in carbon emissions from the construction industry in a region, identifying influencing factors, and proposing specific countermeasures of energy saving and emission reduction.

Pollutants generally exist as mixtures in the environment. Their cumulative toxicity and toxicity interactions are potential risks. Therefore, this study aimed to examine the variation of joint toxicity of a multi-component mixture system, which consisted of six common quaternary ammonium salt surfactants in the environment, on Vibrio qinghaiensis sp.-Q67 (Q67). Vibrio qinghaiensis sp. -Q67 (Vqin-Q67) is a freshwater luminescent bacterium that continuously emits blue-green light (485 nm). The bacterium has been widely used for detecting toxic contaminants. In the mixture system, the luminescent toxicity of each component of the mixture to Q67 was determined by the microplate toxicity analysis method, and the toxicity interaction of the mixture was determined by the toxicity unit method (TU). The combined toxicity of the mixture system was investigated from four aspects, including the number of components, key components, concentration (toxicity) ratio, and exposure time. The results showed that the combined toxic effect of the same mixture system tends to be an additive effect with the increase of the number of components. The combined toxicity of the mixture system was close to that of the key components. Antagonism was presented in the equal toxicity mixture, while synergism was presented in the non-equal toxicity mixture. The combined toxic effect of the multi-component mixture system was not only related to the concentration of the pollutant but also related to the exposure time of the pollutant.

The physical and mechanical properties of the ecological slope protection substrate will be affected by long-term variation of the meteorological condition, resulting in the stability of the substrate being reduced. So an artificial substrate of vegetation cement-soil was selected as the research object to prepare specimens with the different initial moisture content of 13%, 19%, 25%, 31%, 37%, and 43%. And a series of tests are conducted to investigate the evolution of the physical and mechanical properties under drying-wetting cycling conditions. Typical results of the vegetation cement-soil evolution can be divided into three stages: cement hydration stage, shrinkage stage, and stabilization stage. In terms of different initial moisture content, the shrinkage cracks number, cracks length, crack width, and cracks surface area are increased first and then stabilize with the increase of the number of drying-wetting cycles. In contrast, the cohesion and internal friction angle of the vegetation cement-soil is reduced with the increase of the number of cycles. Comprehensive analysis shows that the initial moisture content of vegetation cement soil ranges from 25% to 31% is the optimal choice to ensure substrate stability in production practice.

The thesis is aimed to provide a reference for the sustainable utilization of farmland soils along the Wuma River, an upstream tributary of the Chishui River in Guizhou Province. Geo accumulation index method, Nemero comprehensive pollution index method, and potential ecological hazard index method were used based on the experimental data for analyzing and evaluating the heavy metal pollution status of farmland soil along Wuma River. The results showed that: (1) The contents of heavy metals Ni, Cu, Zn, Pb and Hg in farmland soil exceeded the soil background values of 9.82%, 47.80%, 13.72% and 76.06% in Guizhou Province, respectively, but did not exceed the standard limit class II based on the environmental quality. (2). The pollutants of Pb and Zn in the research area mainly come from mineral exploitation, waste residue accumulation, and transportation. The enrichment of Cr and Cu may originate from the domestic garbage dumping and incinerated waste by residents along the coast and irrational agricultural activities. The main contents of Cd, As and Hg come from soil geochemistry. (3) The ranking of accumulations of eight heavy metals was IPb>IHg>ICu>INi>IZn>ICr>IAs>ICd, among which Pb was non-moderately polluted and the remaining heavy metals were at the clean level; Nemero comprehensive pollution index showed that As, Cr, Zn, and Ni were mildly polluted, while Pb, Hg, and Cu were moderately polluted. The ranking of potential ecological risk levels for the eight heavy metals was Hg, Pb, Cu, Ni, As, Cd, Cr, Zn. The overall ecological risk level is mild.

This research was conducted to quantitatively evaluate the application effect of the frost-resistant ecological substrate in the rock slope of the hydropower station. Field sampling and laboratory tests were conducted to determine the erosion resistance and fertility of frost-resistant ecological substrate, and the test results were compared with those of natural soils with similar site conditions. The research conclusions were as follows. Compared with the natural soil, the content of > 0.25 mm mechanical-stable aggregates, > 0.25 mm water-stable aggregates, average weight diameter, geometric average diameter, organic matter, available nitrogen, available phosphorus, and available potassium of frost-resistant ecological substrate, significantly increased. On the contrary, erodibility factor, percentage aggregate disruption, aggregate degree, and dispersion rate decreased evidently. These results showed that erosion resistance and fertility of the frost-resistant ecological substrate have a better prospect in the engineering application of alpine regions. In addition, the principal component analysis showed that the principal component value of frost-resistant ecological substrate increased by 1.9 times that of natural soil. According to the correlation study, the increase in the amount of > 0.25 mm macro-aggregates and organic matter is the primary reason that ecological substrate has greater stability and fertility than natural soil. In conclusion, the frost-resistant ecological substrate was a suitable soil to create a suitable vegetation growth environment on the surface of rock slope in the alpine region.