Facultative-anaerobic microbial digestion of coal preparation waste and use of effluent solids to enhance plant growth in a sandy soil

Abstract

Coal preparation solid waste, which is a major environmental issue for coal-producing areas in China, may be microbiologically digested and transformed into a product suitable as a soil amendment to increase soil organic matter content and prevent and enhance plant/crop growth. Coal preparation waste collected from a coal sorting plant in Inner Mongolia, China was digested in bioreactors inoculated with microbial enrichments prepared from activated sludge and cow manure. The effluent solids from the coal preparation waste bioreactors were analyzed for their suitability as organic soil amendments, which complied with China standards. Plant growth tests were conducted in sandy soil from a semi-arid region in Colorado, which was amended with the effluent solids. Kentucky bluegrass (Poa pratensis L.) and chives (Allium schoenoprasum) were used as the representative plants for the growth tests, where results indicated substantially higher yields of Kentucky bluegrass and chives for the sandy soils amended with the effluent solids when compared to a commercial organic fertilizer. The number and average length of Kentucky bluegrass shoots were 10 and 5.1 times higher, respectively, in soils amended with the effluent solids. Similarly, the number and average length of chives shoots were 10 and 1.7 times higher, respectively, in soils amended with the effluent solids. Overall, the microbial digestion of coal preparation waste for application as an organic soil amendment is a viable alternative and beneficial use of coal preparation solid waste.

Prediction of Water-Blocking Capability of Water-Seepage-Resistance Strata Based on AHP-Fuzzy Comprehensive Evaluation Method—A Case Study

“…(3) When using the fluid-solid coupling module of FLAC 3D , our predecessors generally only studied the variation in the pore water pressure of the aquifer. They argue that the amplitude of pressure fluctuation can indirectly reflect the impact of coal extraction on the aquifer [78][79][80]. The authors hold the view that the water level fluctuation induced by coal extraction is responsible for the pore water pressure variation of the Quaternary Salawusu formation aquifer.…”

Waste valorization in winery and distillery industry by producing biofertilizers and organic amendments

“…Esta notable diferencia se atribuye a la alta capacidad de los consorcios microbianos (BAL y Bacillus) para degradar compuestos insolubles como los presentes en los sustratos orgánicos utilizados y a los procesos de espesamiento y deshidratación antes de ser tamizado; explicándose con ello el buen contenido de materia orgánica presente en el sólido (27.22%) similar a un compost cumpliendo con los rangos establecidos por la NTP (≥ 20%), la NOCh (25-45%) y la FAO que exige valores mayores a 20% [50,51,52]. En efecto, el Biosol presentó un importante contenido de nutrientes (1,93% N, 5,65% P2O5, 0,95 K 2 O, 13,66% CaO, 9,4% MgO) confiriéndole propiedades de biofertilizante [53] y como abono orgánico NPK de origen animal y vegetal. De acuerdo a la normativa española, los digestatos también deben someterse a un adecuado control y tratamiento antes de su uso como biofertilizante (para eliminar la toxicidad y patogenicidad), estando regulado al igual que el compost, por el Real Decreto 999/2017 [54].…”

Environmental risk assessment of industrial byproduct gypsum utilized for filling abandoned mines

“…With the increasing promotion of coal mine filling and mining technology, the demand for solid waste for use in mine backfilling has also increased greatly. For example, coal gangue and fly ash are often used in mine backfilling, but the annual gangue discharges only account for 10%-20% of coal production, and an insufficient supply of filling materials that is caused by long-term filling has inevitably become a problem (Wang et al 2019a;Fallgren et al 2021).…”