Ammonia nitrogen removal from coking wastewater and high quality gypsum recovery by struvite recycling by using calcium hydroxide as decomposer.

This study deals with the highly significant and cost-effective pretreatment of the high concentration of the Total Ammonia Nitrogen (TAN) in coking wastewater to improve the biodegradability. Struvite crystallization is a promising process for TAN removal, but the high operating cost hinders its application. To solve this problem, a novel struvite recycling process was proposed for pre-treating TAN present in the coking wastewater, within which struvite was decomposed in the solid-liquid system using Ca(OH)2 as the decomposer. The results indicates that 91% of ammonium in struvite could be stripped out from the decomposition solution, with Ca(OH)2:NH4+ in the molar ratio of 2:1, temperature at 35 °C and a gas to liquid volume ratio of 3500. The resulting solution, post the escape of the ammonia, was dissolved by sulfuric acid. Approximately 100% of the phosphate and magnesium were observed to be released from the insoluble phosphate compounds, resulting in the formation of high-purity gypsum. A TAN removal efficiency of 89% could be achieved by reusing the supernatant after the dissolution of the decomposition product, at pH 9.5 and the Mg:TAN:PO4-P molar ratio of 1.2:1:1. The pilot-scale test demonstrated that approximately 86% TAN was removed from the coking wastewater and the purity of recovered could reach over 99%. Further economic analysis proves that the operation cost of the proposed process is 0.55$ per m3 of coking wastewater, showing a 73% cost reduction when compared to struvite crystallization without recycling.

MicroRNA-610 is downregulated in glioma cells, and inhibits proliferation and motility by directly targeting MDM2.

The expression of microRNA (miR)-610 has previously been reported to be downregulated in gastric cancer and hepatocellular carcinoma. However, miR-610 has yet to be investigated in human glioma. In the present study, miR-610 expression was analyzed by reverse transcription-quantitative polymerase chain reaction. Post­transfection with miR­610 mimics and inhibitors, MTT assay, cell migration and invasion assays, western blot analysis and a luciferase assay were performed in glioma cell lines. The results demonstrated that miR­610 was downregulated in glioma tissues compared with their normal adjacent tissues and normal brain tissues (P<0.05). The reduced expression levels of miR­610 were associated with World Health Organization grade and the Karnofsky performance status of patients with glioma. Furthermore, the present study revealed that miR­610 inhibited cell growth, migration and invasion in glioma cells. To the best of our knowledge, the present study is the first to provide evidence suggesting that miR­610 directly targets MDM2 proto-oncogene E3 ubiquitin protein ligase to function as a tumor suppressor in glioma. These results indicate that miR­610 may be investigated as a target for therapeutic drugs designed to treat glioma.