Effect of initial material bulk density and easily-degraded organic matter content on temperature changes during composting of cucumber stalk.

To inactivate the potentially pathogenic microorganisms and safely utilize vegetable waste compost, ultra-high temperatures (>70°C) should be maintained during the composting without having an inhibitory effect on maturity. This study investigated the influence of bulk density (part 1) and easily-degraded organic matter content (EDOMC, part 2) on temperature evolution during vegetable waste composting: Part 1: corn straw with different particle sizes was used to achieve different bulk densities in the composting material (BD1-BD3); Part 2: partial or total substitution of the corn straw by corn starch was carried out to obtain different EDOMC (ED1-ED4). The composting experiments were conducted in a lab-scale reactor (1.

The Solidification of Lead-Zinc Smelting Slag through Bentonite Supported Alkali-Activated Slag Cementitious Material.

The proper disposal of Lead-Zinc Smelting Slag (LZSS) having toxic metals is a great challenge for a sustainable environment. In the present study, this challenge was overcome by its solidification/stabilization through alkali-activated cementitious material i.e.

Interactive influences of intercropping by nitrogen on flavonoid exudation and nodulation in faba bean.

In order to address the question of how flavonoids affected root nodulation of faba bean in a wheat and faba bean intercropping system, we set up soil and hydroponic experiments comprising two cropping pattern treatments (intercropped and monocropped) and three nitrogen (N) supply treatments at the deficient (50% N), adequate (100% N), and excessive (150% N) levels with three replicates in a randomized complete block design. Across the three N treatments and two experiments, it was frequently observed that intercropping increased but N fertilization decreased the nodule number and nodule dry weight of faba bean. Six types of flavonoids were detected in the faba bean root secretion, but only genistein, hesperetin, and naringenin often had significant correlations with the nodule number and nodule dry weight.

Impact of phosphate additive on organic carbon component degradation during pig manure composting.

Phosphate, as an additive to composting, could significantly reduce ammonia emission and nitrogen loss but may also cause adverse effects on the degradation of organic matter. However, there is little information about the influence of pH change, salt content, and phosphate on different organic fraction degradation during composting with the addition of phosphate at a higher level. In this study, the equimolar phosphoric acid (HPO), sulfuric acid (HSO), and dipotassium phosphate (KHPO) were added into pig manure composting with 0.

A secret of high-rate mass transfer in anammox granular sludge: "Lung-like breathing".

The granulation of anaerobic ammonium oxidation (Anammox) biomass can play a key role in developing stable and high-rate working of anammox process. It is important to know the working mechanism of anammox granular sludge (AnGS) for the optimization of reactor performance. In this study, a "lung-like breathing" determinator was invented to investigate the working behavior of AnGS in the bioreactor.

Effects and mechanisms on the reduction of lead accumulation in rice grains through lime amendment.

The influence of lime amendment on the absorption and accumulation of lead (Pb) in the grains of three rice cultivars ((Dong Lian 5 (DL-5, Indica), TeYou 009 (TY-009, Hybrid Indica), and YiYou 673 (YY-673, Hybrid Indica)) was investigated and the associated mechanisms were explored. Pot experiment was conducted in heavily Pb-polluted paddy soil. The transformation of Pb species in soil and roots under different levels of lime application was studied by Pb L3-edge X-ray absorption spectroscopy (Pb L3-XAS) and BCR sequential extraction.

Electrodes Donate Electrons for Nitrate Reduction in a Soil Matrix via DNRA and Denitrification.

Microbial strains and indigenous microbiota in soil slurries have been reported to use electrons from electrodes for nitrate (NO) reduction. However, few studies have confirmed this in a soil matrix hitherto. This study investigated if, and how, an electric potential affected NO reduction in a soil matrix.

Genotype and rhizobium inoculation modulate the assembly of soybean rhizobacterial communities.

Rhizosphere bacterial communities are vital for plants, yet the composition of rhizobacterial communities and the complex interactions between roots and microbiota, or between microbiota, are largely unknown. In this study, we investigated the structure and composition of rhizobacterial communities in two soybean cultivars and their recombinant inbred lines contrasting in nodulation through 16S rRNA amplicon sequencing in two years of field trials. Our results demonstrate that soybean plants are able to select microbes from bulk soils at the taxonomic and functional level.

Effects of yam/leguminous crops intercropping on soil chemical and biological properties of yam field.

We investigated the effects of yam/leguminous crops intercropping on soil chemical and biological properties as well as soil comprehensive fertility in a field experiment. Results showed that compared with the monoculture, both yam/alfalfa and yam/clover intercropping increased the concentrations of nitrate nitrogen (N), available phosphorus (P) and available potassium (K) in the 0-20 cm and 20-40 cm soil layers, while reduced soil pH and electrical conductivity (EC) in early growth period and rhizome rapid expansion period of yam. Intercropping with leguminous crops enhanced the activities of urease, alkaline phosphatase and catalase, and also enhanced soil basal respiration in the 0-20 cm and 20-40 cm soil layers during the whole growth period of yam.

Co-disposal of MSWI fly ash and electrolytic manganese residue based on geopolymeric system.

MSWI fly ash (MSWI FA) and electrolytic manganese residue (EMR) were successfully co-disposed by use of a geopolymeric system. Alkaline products of MSWI FA and NaOH were used to elicit chemical reactions to promote solidification. The best performing formulation of EMR-based geopolymer for immobilization of heavy metals was composed of 75 wt% MSWI FA and 25 wt% EMR with NaOH solution (7.

Climatic and topographic variables control soil nitrogen, phosphorus, and nitrogen: Phosphorus ratios in a Picea schrenkiana forest of the Tianshan Mountains.

Knowledge about soil nitrogen (N) and phosphorus (P) concentrations, stocks, and stoichiometric ratios is crucial for understanding the biogeochemical cycles and ecosystem function in arid mountainous forests. However, the corresponding information is scarce, particularly in arid mountainous forests. To fill this gap, we investigated the depth and elevational patterns of the soil N and P concentrations and the N: P ratios in a Picea schrenkiana forest using data from soil profiles collected during 2012-2017.

Comparing the effects of three in situ methods on nitrogen loss control, temperature dynamics and maturity during composting of agricultural wastes with a stage of temperatures over 70 °C.

The study investigated the effects of three in situ methods for controlling nitrogen loss and maturity with different mechanisms: struvite-based addition (KHPO and MgO, MP), woody peat addition (WP) and intermittent aeration (IA), during composting of vegetable waste (cucumber vine) with temperature over 70 °C to inactivate potential viral pathogens. The experiment was conducted in a 200 L pilot-scale composting system, with which temperature and ammonia emission were recorded in real time, and solid samples were collected and analyzed during the process. The results indicated that the methods of MP and IA reduced the total nitrogen loss by 27.

Probing active microbes involved in Bt-containing rice straw decomposition.

Transgenic Bacillus thuringiensis (Bt) rice extends significant protection against insect pests and meets the increasing demands for food and energy. Many studies have been conducted investigating the impacts of Bt rice to the agricultural ecosystem, but much less attention has been given to efforts attempting to determine how the presence of Bt rice influences and shapes the microbial community, especially the active microbes. Stable isotope probing and high-throughput sequencing were employed to explore the active microbes involved in Bt-containing straw decomposition.

Developmental stage has a greater effect than Cry1Ac expression in transgenic cotton on the phyllosphere mycobiome.

Transgenic Bt cotton is widely cultivated, yet its impact on the phyllosphere mycobiome is poorly understood. Hence, the objective of this study was to investigate the effects resulting from the planting of Bt cotton on fungal diversity composition. The α diversity for the Bt cotton line SGK321 was lower than that of control plants at the budding stage and the blossoming and boll-forming stage, while an obvious increase in diversity for Bt cotton XP188 was observed at the same stage.

Waste solidification/stabilization of lead-zinc slag by utilizing fly ash based geopolymers.

Solidification/stabilization (S/S) is recognized as an effective technology for solid waste treatment. In S/S, the application of geopolymers synthesized by industrial waste (rich in active silicon and aluminum) to immobilize hazardous waste is a research focus. In this article, a fly ash based geopolymer was used to immobilize lead-zinc slag containing Pb, Ni, Zn and Mn.

Distribution and transformation of lead in rice plants grown in contaminated soil amended with biochar and lime.

This study aimed to investigate the effects of rice straw biochar and lime (RBL) on the remediation of lead (Pb)-contaminated soil and mitigation of Pb translocation in rice plants by using pot experiments. Lead-contaminated soil collected from a farmland near a Pb-zinc (Zn) mine, biochar, limestone powder, and indica rice (Oryza sativa L.) were used in the present study.

Benefits of integrated nutrient management on NO and NO mitigations in water-saving ground cover rice production systems.

To cope with challenges of food security and water scarcity in rice production, water-saving ground cover rice production systems (GCRPSs) are increasingly adopted in China and globally. Reduced soil moisture as well as increased soil aeration and temperature under GCRPSs may promote soil N transformations, and in turn give rise to environmental challenges. These include emissions of the potent greenhouse gas nitrous oxide (NO) and atmospheric pollutant nitric oxide (NO).

An experimental study of deformation and fracture characteristics of shale with pore-water pressure and under triaxial cyclic loading.

The deformation and fracture characteristics of shale in the Changning-Xingwen region were experimentally studied under triaxial cyclic loading with a controlled pore-water pressure. An RLW-2000M microcomputer-controlled coal-rock rheometer was used in the State key Laboratory of coal mine disaster dynamics and control in Chongqing University. These experimental results have indicated the following.

Reactor performance and economic evaluation of anaerobic co-digestion of dairy manure with corn stover and tomato residues under liquid, hemi-solid, and solid state conditions.

Anaerobic co-digestion of tomato residues, dairy manure, and corn stover at ratios of 20:48:32, 40:36:24, and 60:24:16 (volatile solid basis) were compared for liquid anaerobic digestion (L-AD), hemi-solid state AD (HSS-AD), and solid state AD (SS-AD) systems. The highest methane yield (353.5 L/kg-VS) and volumetric methane productivity (24.

[Effects of Different Substrates and Particle Sizes on Wastewater Purification].

Choosing suitable substrate is key to improving the efficiency of wetland decontamination. However, little is known about the effect of particle size. In order to study the effect of substrate type and size on COD, TN, and TP removal from sewage, 1-2, 2-4, and 4-8 mm zeolite, 2-4, 4-8, and 8-16 mm gravel, and 2-4, 3-5, and 6-8 mm anthracite were selected for establishment of the constructed system of experimental media with three replications.

Effect of different components of single superphosphate on organic matter degradation and maturity during pig manure composting.

Single superphosphate (SSP) as an additive could improve phosphorus availability and reduce nitrogen loss for composts, but few studies have explored the influence of SSP on the transformation of carbon fractions in composting. The aim of this work was to assess the effect of different components of SSP, including calcium dihydrogen phosphate (CDP), calcium sulfate (CS) and free acid (FA) on organic matter degradation and maturity during pig manure composting. The results showed that CDP had significantly negative effects on the duration of thermophilic phase and organic matter degradation, but lengthened the curing phase for the transformation of organic matter.

High oxygen reduction reaction performance nitrogen-doped biochar cathode: A strategy for comprehensive utilizing nitrogen and carbon in water hyacinth.

In this study, a novel nitrogen-doped biochar oxygen reduction reaction cathode-water hyacinth carbon, was prepared by ZnCl molten salt carbonization without additional nitrogen source, which displayed a high performance in electro-Fenton (E-Fenton) process. The BET result shows that water hyacinth carbon achieved a much larger specific surface area (829 m·g) than non-melt salt carbonized one (323 m·g) and graphite powder (28 m·g). Furthermore, characterization by XPS and EIS shows that both pyridinic-N (43.

[Review of CO and CH Emissions from Rivers].

Streams and rivers play a major biogeochemical role in the global carbon cycle and act as hot spots for carbon dioxide (CO) and methane (CH) emissions to the atmosphere, excepting their roles of transporting the water and carbon from the terrestrial environment to the ocean. While carbon gases have been of great global concern, systematic reviews are still scarce. Given recent recognition of the pervasiveness of CO and CH in streams and rivers, this study synthesized existing research and discoveries to identify patterns and controls for riverine CO and CH, knowledge gaps, and research opportunities.

A versatile and injectable poly(methyl methacrylate) cement functionalized with quaternized chitosan-glycerophosphate/nanosized hydroxyapatite hydrogels.

Injectable polymethylmethacrylate (PMMA) bone cement is alluring because it allows a minimally invasive surgical approach, reducing both the cost of treatment and patient discomfort. However, several documented drawbacks have necessitated the design of a more versatile version with adorable properties for future application. In this study, to amend the bulk behavior of PMMA cement, we synthesized a modified version by combining PMMA with quaternized chitosan (N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride, HTCC)-based hydrogels loaded with nanosized hydroxyapatite (Nano-HA).

Ca-containing amendments to reduce the absorption and translocation of Pb in rice plants.

The influence of three Ca-containing amendments (dolomite, slaked lime, and limestone) on soil water soluble Pb (Pb-w) levels, Pb accumulation by two rice plants (TJ-8, japonica and II-3301, indica), and the factors affecting Pb-w were investigated. Pot experiment was performed under waterlogged conditions using Pb-contaminated soil collected from an agricultural field near a mine. It was found that the soil amendments significantly reduced Pb content in the rice plants in the order dolomite > slaked lime > limestone, irrespective of rice cultivar.