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Phosphorus is an indispensable element, while the existing phosphate rock resources are not enough to maintain the long-term demand of modern agricultural development. To ensure the sustainability of economic and social, it is necessary and urgent to seek the alternative phosphorus source of phosphate rock. In this study, calcined clam shell powder (CSP) was firstly used as a modifier and mixed with sewage sludge (SS) for co-pyrolysis to obtain sludge-derived pyrochars containing a large amount of bioavailable phosphorus. The effect of different temperatures (500, 600, 700, 800 °C) and dosages (0%, 10%, 20%, 30%) on the change in the form of phosphorus during the pyrolysis process were investigated. With the increase of temperature and the addition of CSP, the orthophosphate (Ortho-P) increased from 63.69% in the original SS to nearly 100%. Furthermore, the main phase of inorganic phosphorus (IP) changed, mainly in the form of apatite phosphorus (hydroxyapatite increased from 8.88% to 35.97%), and the concentration of easy-to-lose phosphorus reduced to 0.11 mg/g. After co-pyrolysis of SS with CSP, the passivation situation of heavy metals (HMs), such as Zn, Mn, Cr, Cu, Cd and Pb was significantly improved, thus reducing the potential environmental risk. The planting experiment proved that the sludge-derived pyrochars obtained by adding 20% CSP at 800 °C promoted the germination of seeds and the growth of seedlings. Consequently, the product of SS co-pyrolysis with CSP could be used as an excellently bioavailable and environmentally friendly phosphate fertilizer for agricultural production.

Malignant soft tissue tumors (STTs) are often mistaken for benign tumors, leading to inappropriate treatment including unplanned resection. Elastography, as a non-invasive measurement of tissue mechanical properties, makes use of the different soft tissue elasticity in diverse pathologies to generate information that can be used for diagnostic purposes. Elastography for STTs carries important information that is helpful in differentiating malignant and benign masses. The present study was undertaken to systematically review existing trials on the reliability of elastography in assessment of malignant STTs. A comprehensive literature exploration of the PubMed, EMbase and China National Knowledge Infrastructure databases was conducted for published articles involving the application of elastography in distinguishing malignant STTs. The diagnostic performance of elastography was evaluated with pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the summary receiver operating characteristic curve. Publication bias was also evaluated. This meta-analysis enrolled 18 eligible studies with a total of 1420 patients. The overall number of reported STTs was 1569, of which 478 were classified as positive and 1091 as negative at elastography. The pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of elastography were 0.82 (95% confidence interval: 0.74-0.87), 0.80 (0.71-0.86), 3.99 (2.65-6.01) and 0.23 (0.15-0.34), respectively. The diagnostic odds ratio and area under the curve were 17.36 (8.28-36.38) and 0.88 (0.84-0.90), respectively (Glas et al. 2003). The results of meta-regression analysis revealed that the total number of patients and prevalence of malignant STTs were significant factors in sensitivity, and the year of publication, total number of patients and index test were significant factors affecting study heterogeneity for specificity (p0.05). No significant publication bias was observed. This meta-analysis indicates that ultrasound elastography achieves relatively good performance in discriminating between malignant and benign STTs. Nevertheless, further research is needed to verify this finding.

As a promising phosphorus source, phosphorus recovery from sewage sludge ash is necessary to ensure sustainable phosphorus cycle and management. To achieve these targets, a novel strategy including phosphorus capture by acid-resistant adsorbent from acid-extract of sewage sludge ash and repeated enrichment in eluent was first proposed in this study. Over 93% of phosphorus was extracted by H2SO4 acidification at pH of 2.0, and a tailored acid-resistant adsorbent recovered almost all the extracted phosphorus in acid-extract of sewage sludge ash. The fitting results of multiple models showed that the rate-limiting step for phosphorus recovery was chemical reaction, and the maximum recovery capacity of acid-resistant adsorbent was 41.7–44.0 mg/g. Characterization results of X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and Zeta potential suggested that the recovery mechanism of acid-resistant adsorbent for phosphorus included ligand exchange, inner-sphere complexation and electrostatic attraction. After 8 cycles of recovery-repeated enrichment, the phosphorus in eluent was enriched about 6.7 times. Over 99% of phosphorus in eluent was recovered as struvite by adding external magnesium and ammonium at pH of 8.5. The content of heavy metals in recovered struvite were far below the utilization standard of plant fertilizer, indicating that the phosphorus in sewage sludge ash could be recovered in the form of high-quality phosphorus fertilizer.