Insight into performance of nitrogen removal enhanced by adding lactic acid-rich food waste fermentation liquid as carbon source in municipal wastewater treatment.

Lactic acid-rich fermentation liquid (LAFL) of food waste is found to act as a promising alternative carbon source for nitrogen removal in wastewater treatment. Here, LAFL was employed to investigate its impacts on nitrogen removal during raw municipal wastewater treatment with a comparison to sodium acetate (NaAc). Results indicated that nitrogen removals were comparable when incorporated with LAFL and NaAc (92.89 % v.s. 91.23 %). Unlike the utilization of NaAc, using LAFL could avoid suppressing the relative abundance of the nitrification genes and thus pose a negative risk to nitrogen removal during prolonged operation. The introduction of LAFL increased the stability and robustness of the functional microbial community and effectively reduced excess activated sludge (AS) generation by 109 % compared to NaAc addition, consequently enhancing nitrogen removal but diminishing the treatment cost. In general, LAFL exhibits prospective engineering application potentials and economic advantages in improving nitrogen removal by AS process.

Aeration pre-treatment role in improving the performance of bio-conditioning dewatering of food waste anaerobic digestate.

Bio-conditioning dewatering followed by activated sludge process (BDAS) is a promising technology for purifying food waste anaerobic digestate (FWAD). However, the bio-conditioning dewatering efficiency is often affected by FWAD properties and ambient temperature. Here, we firstly reported that aeration pre-treatment of FWAD played an important role in improving the bio-conditioning dewatering performance of FWAD. The study found that the accumulated carbonate (CO32-) in FWAD severely affected the flocculation of Fe-containing flocculant formed in microbial fermentation liquor due to the competitive consumption of the flocculant by CO32-. The capillary suction time (CST) and specific resistance to filtration (SRF) of the bio-conditioned FWAD increased from initial 77.8 s and 2.0 × 1012 m/kg to 122.7 s and 3.4 × 1012 m/kg, respectively, within 1 day of aeration. Prolonged aeration pre-treatment of FWAD could reduce its CO32- concentration and total alkalinity. Additionally, the aeration pre-treatment simultaneously decreased the proportion of macromolecular organic matter that hindered dewatering and the content of total solids (TS) and hydrophilic protein-like substances in FWAD. After 20 days of aeration followed by bio-conditioning, the CST and SRF reduced to final 36.5 s and 2.3 × 1011 m/kg, respectively, indicating a substantial improvement in dewatering performance. Successive forced aeration combined with the addition of CaCl2 to eliminate adverse factors mainly CO32- was a feasible and cost-effective strategy to realize bio-conditioning dewatering of FWAD in less than 2 days and a lower reagents dose of bio-conditioning, which was helpful in the engineering application of the novel BDAS process for FWAD purification.

A novel approach for purifying food waste anaerobic digestate through bio-conditioning dewatering followed by activated sludge process: A case study.

Although anaerobic digestion is the mainstream technology for treating food waste (FW), the high pollutant concentration in the resultant food waste anaerobic digestate (FWAD) often poses challenges for the subsequent biochemical treatment such as activated sludge process. In this study, taking a typical FW treatment plant as an example, we analyzed the reasons behind the difficulties in treating FWAD and tested a novel process called as bio-conditioning dewatering followed by activated sludge process (BDAS) to purify FWAD. Results showed that high concentrations of suspended solids (SS) (16439 ± 475 mg/L), chemical oxygen demand (COD) (24642 ± 1301 mg/L), and ammonium nitrogen (NH4+-N) (2641 ± 52 mg/L) were main factors affecting the purification efficiency of FWAD by the conventional activated sludge process. By implementing bio-conditioning dewatering for solid-liquid separation, near 100% of SS and total phosphorus (TP), 90% of COD, 38% of total nitrogen (TN), and 37% of NH4+-N in the digestate could be effectively removed or recovered, consequently generating the transparent filtrate with relatively low pollution load and dry sludge cake (<60% of moisture content). Furthermore, after ammonia stripping and biochemical treatment, the effluent met the relevant discharge standards regulated by China, with the concentrations of COD, TN, NH4+-N, and TP ranging from 151 to 405, 10-56, 0.9-31, and 0.4-0.8 mg/L, respectively. This proposed BDAS approach exhibited stable performance and low operating costs, offering a promising solution to purify FWAD in practical engineering and simultaneously realize resource recovery.

Food waste hydrolysate as a carbon source to improve nitrogen removal performance of high ammonium and high salt wastewater in a sequencing batch reactor.

The high ammonium and high salt (HAHS) wastewater generated from the anaerobic digestate of food waste is usually difficult to be treated by biological process because of its low C/N ratio. Herein, food waste hydrolysate (FWH) is rich in readily biodegradable organic matter, was utilized as carbon source to enhance the nitrogen removal of HAHS in the activated-sludge system. Results showed that compared with the control average total nitrogen removal efficiency increased from 73.4% to 94.9% and effluent declined from 281.4 mg/L to 53.9 mg/L by adding FWH at the C/N ratio of 6, satisfying the sewage discharge standard regulated by China. Besides, FWH utilization led to higher selectivity of the species responsible for nitrogen removal in related to glucose-adding group, which were dominated by Flavobacteriaceae, Melioribacteraceae, PHOS-HE36, and Rhodobacteraceae after a long-term operation. In general, FWH is an alternative carbon source to enhance nitrogen removal in HAHS wastewater treatment.

Long non-coding RNA LINC00173 enhances cisplatin resistance in hepatocellular carcinoma via the microRNA-641/RAB14 axis.

A growing body of evidence indicates that long non-coding RNAs (lncRNAs) play crucial roles in the chemoresistance of human cancers. However, the molecular mechanisms underlying the functions of certain lncRNAs in the chemotherapeutic resistance of hepatocellular carcinoma (HCC) remain unclear. The aim of the present study was to investigate the function and potential mechanism of action of lncRNA LINC00173 in HCC cisplatin (DDP) resistance. Reverse transcription-quantitative PCR analysis indicated that LINC00173 was highly expressed in DDP-resistant HCC tissues and cell lines, and high expression levels of LINC00173 were found to be associated with poor prognosis in patients with HCC. Moreover, LINC00173-knockdown improved the DDP sensitivity of DDP-resistant HCC cells. A luciferase reporter assay also demonstrated that microRNA (miR)-641 was a direct target of LINC00173. miR-641 inhibition restored the promoting effect of LINC00173 knockdown on DDP sensitivity in HCC cells. Furthermore, RAB14 was identified as a target of miR-641, and RAB14 overexpression restrained the inducing effect of LINC00173 knockdown on HCC cell DDP sensitivity. The findings of the present study demonstrated that LINC00173 increased DDP resistance in HCC via the miR-641/RAB14 axis, which may represent a promising therapeutic strategy for HCC.

COL5A2 as a potential clinical biomarker for gastric cancer and renal metastasis.

BACKGROUND: Gastric cancer, characterized by insidious onset and multiple metastasis, is almost incurable and has poor prognosis, and also one of the leading causes of treatment failure and death in patients with gastric cancer (GC). However, the prognosis of collagen type V alpha2 chain (COL5A2) in GC and renal metastasis is unknown. METHODS: Recruited 148 patients who underwent GC. The diagnosis of GC was confirmed by ultrasound imaging and pathological examination. Immunohistochemistry and RT-qPCR were performed to exam the expression level of COL5A2. The statistical methods included Pearson chi-square test, Spearman-rho correlation test, univariate and multivariate cox regression analysis. Finally, this research constructed receiver operating characteristic (ROC) curves and applied the area under the curve (AUC). RESULTS: Based on Pearson's chi-square test, Spearman-rho test, and univariate/multivariate cox regression, pathologic grade (P < .001), renal metastasis (P < .001) and staging (P < .001) were significantly related to COL5A2. And COL5A2 expression (hazard ratio [HR]: 18.834, P < .001) is an independent risk factor of GC. The AUC was used as the degree of confidence in judging each factor: COL5A2 (AUC = 0.878, P < .001), COL1A1 (AUC = 0.636, P = .006), COL1A2 (AUC = 0.545, P = .368), and COL3A1 (AUC = 0.617, P = .019). Through the ROC result, COL5A2 had more advantage as a biomarker for GC than other collagens. CONCLUSIONS: COL5A2 gene expression level might be a risk factor for GC. COL5A2 has a strong correlation with the prognosis of the disease.