Variation of the percentage of metals in different fractions.

<p>Species distribution of Cu, Pb, Cd and Zn extracted with Tessier scheme before and after the column tests.</p

Total amounts of the metals leached from the soil columns in mg of metal per kg of soil.

<p>Note: The values are means ± standard deviation. Different lower case letters show significant differences in the same treatment (ANOVA/LSD, <i>P</i><0.05).</p

Leaching experimental design.

<p>(A) Schematic diagram of soil column. (B) Schematic analytical setup for the measurement of metal concentrations in the leaching experiment.</p

Two-way ANOVA of pH levels and metal species effects for total amounts of the metals leached from the soil columns.

<p>Note: **significant at 99% probability level, *significant at 95% probability level.</p

Metal concentrations in leachates as functions of addition of SAR.

<p>The concentrations of Cu and Zn in the leachates as functions of addition of SAR at different pHs. (A) Copper. (B) Zinc.</p

Synergistic Effects of Initial Moisture Content and Particle Size on Drying Rate and Heat Production during Bio-Drying of Sludge after Electro-Dewatering

Electro-dewatered sludge (EDS) can be bio-dried alone, instead of adding bulking agents. The initial moisture content (IMC) and particle size of the electro-dewatered sludge affect the efficiency and energy consumption during the bio-drying process. This study aimed to investigate the synergistic effects of sludge IMC and particle size on the drying rate and heat production of bio-drying with EDS. Experiments were conducted with two different IMC sludge and two different sludge particle sizes. Results showed that the highest moisture removal rate was 43.18% in treatment T4, which had materials with a smaller particle size (<3 mm) and lower IMC (38.69%). And bio-drying of T4 had the highest biological heat production (7413.14 kJ, i.e., 741.31 kJ/kg sludge), and the lowest bio-drying index (the ratio of water loss to volatile solid loss) was 7.10 among the four treatments. Five thin-layer drying kinetic models and a nonlinear regression method were analyzed to estimate the bio-drying kinetic parameters. The Midilli et al. model had a better fitting result, and the highest R2 value was 0.9929 during bio-drying of EDS. The new coefficients k (0.1465) and n (1.0898) were obtained. Through the heat balance, the heat used for evaporation was 40–57% of the total energy consumption (5873–9140 kJ). According to the PCA, the particle size had a great influence on the bio-drying process. Also, the particle size positively correlated with temperature, moisture ratio, and drying rate

DataSheet1_Full-Scale of a Compost Process Using Swine Manure, Human Feces, and Rice Straw as Feedstock.docx

Regarding the composting of rural waste, numerous studies either addressed the composting of a single waste component or were conducted at a laboratory/pilot scale. However, far less is known about the mixed composting effect of multi-component rural waste on a large scale. Here, we examined nutrient transformation, maturity degree of decomposition, and succession of microbial communities in large-scale (1,000 kg mixed waste) compost of multi-component wastes previously optimized by response models. The results showed that multi-component compost can achieve the requirement of maturity and exhibit a higher nutritional value in actual compost. It is worth noting that the mixed compost effectively removed pathogenic fungi, in which almost no pathogenic fungi were detected, and only two pathogenic bacteria regrown in the cooling and maturation stages. Structural equation models revealed that the maturity (germination index and the ratio of ammonium to nitrate) of the product was directly influenced by compost properties (electrical conductivity, pH, total organic carbon, moisture, temperature, and total nitrogen) compared with enzymes (cellulase, urease, and polyphenol oxidase) and microbial communities. Moreover, higher contents of total phosphorus, nitrate-nitrogen, and total potassium were conducive to improving compost maturity, whereas relatively lower values of moisture and pH were more advantageous. In addition, compost properties manifested a remarkable indirect effect on maturity by affecting the fungal community (Penicillium and Mycothermus). Collectively, this evidence implies that mixed compost of multi-component rural waste is feasible, and its efficacy can be applied in practical applications. This study provides a solution for the comprehensive treatment and utilization of rural waste.</p