In February 2011 a MW 6.3 earthquake in Christchurch, New Zealand inundated urban waterways with sediment from liquefaction and triggered sewage spills. The impacts of, and recovery from, this natural disaster on the stream biogeochemistry and biology were assessed over six months along a longitudinal impact gradient in an urban river. The impact of liquefaction was masked by earthquake triggered sewage spills (∼20,000 m3 day−1 entering the river for one month). Within 10 days of the earthquake dissolved oxygen in the lowest reaches was <1 mg l−1, in-stream denitrification accelerated (attenuating 40–80% of sewage nitrogen), microbial biofilm communities changed, and several benthic invertebrate taxa disappeared. Following sewage system repairs, the river recovered in a reverse cascade, and within six months there were no differences in water chemistry, nutrient cycling, or benthic communities between severely and minimally impacted reaches. This study highlights the importance of assessing environmental impact following urban natural disasters.

Sediments in lakes and coasts can release metals into water via static diffusion and especially resuspension. The resuspension under sediment liquefaction may severely affect the concentrations of metals in water. In this study, flume experiments were carried out twice to study the release of two metal combinations (Zn and Pb; Zn and Cu), respectively. Each experiment included three phases: consolidation; non-liquefaction and liquefaction. Results showed that total Zn concentration at liquefaction phase increased by a maximum rate of 26 compared with the consolidation phase. The concentration of particulate Zn at liquefaction phase increased by a maximum rate of 8.30 compared with the non-liquefaction phase. The average concentration of dissolved Zn at the liquefaction phase increased up to 0.24 times from the consolidation phase. Total Zn concentration at the non-liquefaction phase increased by several times compared with the consolidation phase. Metals were homogeneously distributed in the liquefaction layer through wave actions.

Activated coke was prepared by CO₂ activation using solid waste fine blue-coke as main raw material and coal direct liquefaction residue (DCLR) as binder. The activated coke was characterized by BET, XRD, and infrared analysis. The flue gas desulfurization experiment was carried out with a fixed bed reactor and activated coke as the adsorbent. The experimental results show that coal direct liquefaction residue pyrolysis process will produce a large number of cohesive colloids, further increasing the strength of the activated coke. BET analysis shows that there is abundant microporous structure in the activated coke, infrared analysis shows that the activated coke contains abundant surface functional groups, and XRD shows that the crystallization degree of the activated coke is high. At lower temperature, SO₂ and O₂ have competitive adsorption on the surface of activated coke, if the concentration of water vapor is too high, a water film will be formed on the surface of activated coke, which will hinder the adsorption of SO₂ by activated coke. The initial concentration of SO₂ is 700 ppm, the adsorption temperature is 80 °C, the oxygen concentration is 9%, and the concentration of water vapor is 8%. The removal of SO₂ by activated coke is better, and the desulfurization rate reaches 97%.

The total contents and chemical speciation analysis of Zn, Cu, Pb, Cr, Mn, Ni, Cd, and As in pig manure (PM), liquefaction residues (LRs), and bio-oils (BOs) derived from PM by liquefaction with ethanol as a solvent at 180–300 °C were thoroughly investigated in this study. The environment risk assessment, leachability, and bioavailability of heavy metals in PM and LRs were studied. The results showed that more than 75% of heavy metals remained in LRs. The total contents of heavy metals in LRs were markedly elevated, but those in BOs gradually decreased with the increase in liquefaction temperature. Moreover, the acid soluble/exchangeable fraction and reducible fraction (F1 + F2) of heavy metals in LRs and BOs was significantly reduced, while oxidizable fraction and stable fraction (F3 + F4) desirably increased after liquefaction. Furthermore, the potential risk of heavy metals in LRs was decreased in comparison to that in PM, but the risk of Pb, Mn, and As had not been obviously reduced; therefore, the LRs from the liquefaction of PM should be pretreated before recycling. Temperatures from 220 to 260 °C were the optimum conditions for disposing of PM by liquefaction with ethanol.

Strategic valorization of readily available sugarcane bagasse (SB) is very important for waste management and sustainable biorefinery. Conventional SB pretreatment methods are ineffective to meet the requirement for industrial adaptation. Several past studies have highlighted different pretreatment procedures which are lacking environmentally benign characteristics and effective SB bioconversion. This article provides an in-depth review of a variety of environmentally acceptable thermochemical and biological pretreatment techniques for SB. Advancements in the conversion processes such as pyrolysis, liquefaction, gasification, cogeneration, lignin conversion, and cellulose conversion via fermentation processes are critically reviewed for the formation of an extensive array of industrially relevant products such as biofuels, bioelectricity, bioplastics, bio adsorbents, and organic acids. This article would provide comprehensive insights into several crucial aspects of thermochemical and biological conversion processes, including systematic perceptions and scientific developments for value-added products from SB valorization. Moreover, it would lead to determining efficient pretreatment and/or conversion processes for sustainable development of industrial-scale sugarcane-based biorefinery.

Phosphogypsum (PG) is a solid waste product of the wet-process phosphoric acid industry that accumulates in large amounts on the ground, forming PG ponds. In recent years, the amount of PG produced and discharged into ponds has increased significantly with the increase in the market demand for phosphate fertilizers. To enrich the basic knowledge of PG properties and provide basic data for the stability analysis of PG dams, a series of laboratory geotechnical tests, including permeability tests, compressibility tests, triaxial shear tests, and dynamic triaxial tests, were conducted in this study. During the preparation of the test samples, solubility and high-temperature dehydration of PG were considered. The results indicated that PG exhibits medium compressibility and medium to weak permeability characteristics. The stress-strain curves of the triaxial shear tests were divided into three typical stages: initial deformation stage, strain hardening stage, and destruction stage. With increasing dry density and consolidation confining pressure, both the shear strength and deformation modulus significantly increased. The relationship between the deformation modulus and confining pressure gradually changed from linear to logarithmic with increasing density. The liquefaction resistance curves (CSR–NL curves) of PG were expressed by power functions. With increasing dry density, the curves shifted higher and became steeper. Compared with the Hardin–Drnevich model, the Davidenkov model was found to be more suitable for describing the relationship between the dynamic shear modulus ratio and damping ratio of PG and the dynamic shear strain. Furthermore, compared with those of tailings and natural soils, the engineering mechanical properties of PG were relatively poor, which may be related to its uniform particle distribution and neat particle stacking structure.

In this paper, a complete biomass composite processing system based on agricultural waste powders, recycled plastics, and waste oil is proposed. The wood-colored wallpaper, the green wallpaper, and the blue wallpaper are produced by this processing system. These wallpapers are new products with low cost, high added value, and environmental friendliness. These wallpapers have also been systematically tested. Based on the analysis of test results, a 3D model of material formation mechanism, liquefaction filling technology, and hybrid network model construction technology are obtained. The experiment found the reasonable RLDPE and RLLDPE ratio (1:0.26), the reasonable ratio of biomass to specialty solvents (1:1.5), the reasonable dose of the solid dye (3%), and the reasonable concentration of dye solutions. Wood-colored bio-composite wallpaper products have a smooth surface, wood color (ΔE = 36.7), natural aroma, and good comprehensive mechanical properties (tensile strength 9.255 MPa; elongation at break 20.998%; Young’s modulus 2229.475 MPa). The processing system and wallpaper products in this article not only promote the plastic recycling economy and sustainable agricultural development but also provide new channels for the development of waste oil reuse and new ideas for the development of high value-added biocomposite materials.