Improvements to the performance of trickling filters by inclusion of alternative surface-active media

Water pollution has become a global issue with impacts in all countries but particularly those undergoing rapid urbanisation such as China. The review for this thesis established that in 2015 China had 3,910 urban treatment plants with daily treatment capacity of 167million cubic metres. This treatment capacity was able to serve more than 90% of the population in urban regions. Compared to the previous 20 years, these treatment facilities represented a major improvement. However, the thesis uses recent annual environmental reports to show that this level of treatment is still not enough to avoid serious water pollution, more than 30% of Chinese rivers were classified as polluted. The main reason for this it is suggested is that most of treatment infrastructure is for urban areas and the rural areas still lack even basic treatment and rural communities represents about half the total Chinese population. The statistics reported in Chapter 2.1 indicates only 25.3% of towns and 11% of villages are connected to treatment facilities. It was concluded that this lower treatment rate was the major factor impacting on the water environment. Therefore, it is important to improve treatment infrastructure in China remote areas. The literature suggested that trickling filter (TF) technology had advantages as wastewater treatment in this type of situation namely Chinese rural areas. This thesis therefore reports on research to upgrade the TF basic processes to remove newly prioritized nutrient pollutants using novel, sustainable and easily available local media, these were; zeolite, maifan stone, recycled concrete aggregate (RCA), brick, blast furnace slag and dolomite. The media were screened using simple absorption tests first focussing on P removal and then a short-listed group tested under dynamic pilot scale. Further static experiments were carried out on this group to understand the mechanisms involved. The pilot tests used the selected concrete and brick. The best performers against traditional media controls and the results showed pollutant removal (COD, TSS, Turbidity, TOC and N) in line with previous models. The media, except concrete, however released phosphorus. This was further confirmed by batch tests with different operating conditions which found the media released P when the initial P concentration was below 10mg/l or above 15mg/l. Concrete was not affected and continued to adsorb P under all conditions (Chapter 4). It was recommended that tests using crushed concrete for tertiary treatment be carried out. Concrete was further studies by isotherm models the best fit was the Langmuir equation with a maximum adsorption of 6.88mg/g. The mechanism of adsorption was ionic attraction determined by kinetic study and thermodynamic models. The adsorption capacity was compared with other literature, and the results from this study suggested a larger size of crushed concrete (2-5mm) could be used for P removal as effectively as smaller sizes. In order to determine the phase of the P adsorbed, sequential extractions were carried out. The results confirmed labile or easily removed P (LBP) dominated (44%) followed by refractory or occluded P (O-P), Ca-P, Mg-P and Al-P. The literature, suggested LBP would be easily available to plants and the RCA could be reused for plant nutrient supply. Different grades of RCA in terms of their original water to cement ratio (W/C) were also tested for P removal. The study showed high W/C ratio removed more P due to the greater porosity and larger pore sizes than the lower W/C ratio

Effect of alkaline microwaving pretreatment on anaerobic digestion and biogas production of swine manure

Microwave assisted with alkaline (MW-A) condition was applied in the pretreatment of swine manure, and the effect of the pretreatment on anaerobic treatment and biogas production was evaluated in this study. The two main microwaving (MW) parameters, microwaving power and reaction time, were optimized for the pretreatment. Response surface methodology (RSM) was used to investigate the effect of alkaline microwaving process for manure pretreatment at various values of pH and energy input. Results showed that the manure disintegration degree was maximized of 63.91% at energy input of 54 J/g and pH of 12.0, and variance analysis indicated that pH value played a more important role in the pretreatment than in energy input. Anaerobic digestion results demonstrated that MW-A pretreatment not only significantly increased cumulative biogas production, but also shortened the duration for a stable biogas production rate. Therefore, the alkaline microwaving pretreatment could become an alternative process for effective treatment of swine manure

Mechanisms of Phosphorus Removal by Recycled Crushed Concrete

Due to urbanisation, there are large amounts of waste concrete, particularly in rapidly industrialising countries. Currently, demolished concrete is mainly recycled as aggregate for reconstruction. This study has shown that larger sizes (2–5 mm) of recycled concrete aggregate (RCA) removed more than 90% of P from effluent when at pH 5. Analysis of the data, using equilibrium models, indicated a best fit with the Langmuir which predicated an adsorption capacity of 6.88 mg/g. Kinetic analysis indicated the equilibrium adsorption time was 12 h, with pseudo second-order as the best fit. The thermal dynamic tests showed that the adsorption was spontaneous and, together with the evidence from the sequential extraction and desorption experiments, indicated the initial mechanism was physical attraction to the surface followed by chemical reactions which prevented re-release. These results suggested that RCA could be used for both wastewater treatment and P recovery

Immune Response of A Novel ATR-AP205-001 Conjugate Anti-hypertensive Vaccine

Abstract We developed a virus-like particle (VLP)-based therapeutic vaccine against angiotensin II receptor type 1, ATR-AP205-001, which could significantly reduce the blood pressure and protect target organs of hypertensive animals. In this study, we focused on the immunological effect and safety of the VLP-based vaccine. By comparing to the depolymerized dimeric vaccine ATR-Dimer-001, we found that ATR-AP205-001 reached subcapsular sinus of lymph node shortly after administration, followed by accumulation on follicle dendritic cells via follicle B cell transportation, while ATR-Dimer-001 vaccine showed no association with FDCs. ATR-AP205-001 vaccine strongly activated dendritic cells, which promoted T cells differentiation to follicular helper T cells. ATR-AP205-001 vaccine induced powerful germinal center reaction, which was translated to a boost of specific antibody production and long-lasting B cell memory, far superior to ATR-Dimer-001 vaccine. Moreover, neither cytotoxic T cells, nor Th1/Th17 cell-mediated inflammation was observed in ATR-AP205-001 vaccine, similar to ATR-Dimer-001 vaccine. We concluded that ATR-AP205-001 vaccine quickly induced potent humoral immunity through collaboration of B cells, follicular dendritic cells and follicular helper T cells, providing an effective and safe intervention for hypertension in the future clinical application

Long noncoding RNA SNHG12 integrates a DNA-PK-mediated DNA damage response and vascular senescence

Long noncoding RNAs (lncRNAs) are emerging regulators of biological processes in the vessel wall; however, their role in atherosclerosis remains poorly defined. We used RNA sequencing to profile lncRNAs derived specifically from the aortic intima of Ldlr(-/-) mice on a high-cholesterol diet during lesion progression and regression phases. We found that the evolutionarily conserved lncRNA small nucleolar host gene-12 (SNHG12) is highly expressed in the vascular endothelium and decreases during lesion progression. SNHG12 knockdown accelerated atherosclerotic lesion formation by 2.4-fold in Ldlr(-/-) mice by increased DNA damage and senescence in the vascular endothelium, independent of effects on lipid profile or vessel wall inflammation. Conversely, intravenous delivery of SNHG12 protected the tunica intima from DNA damage and atherosclerosis. LncRNA pulldown in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that SNHG12 interacted with DNA-dependent protein kinase (DNA-PK), an important regulator of the DNA damage response. The absence of SNHG12 reduced the DNA-PK interaction with its binding partners Ku70 and Ku80, abrogating DNA damage repair. Moreover, the anti-DNA damage agent nicotinamide riboside (NR), a clinical-grade small-molecule activator of NAD(+), fully rescued the increases in lesional DNA damage, senescence, and atherosclerosis mediated by SNHG12 knockdown. SNHG12 expression was also reduced in pig and human atherosclerotic specimens and correlated inversely with DNA damage and senescent markers. These findings reveal a role for this lncRNA in regulating DNA damage repair in the vessel wall and may have implications for chronic vascular disease states and aging