Analysis of pollution status of River Illo,Ota, Nigeria

An assessment of the pollution status of River Illo, located within River Owo catchments area in Ota, Ogun State, Nigeria, was carried out. The River’s response to deoxygenation due to BOD loading from an abattoir and its dissolved oxygen (DO) level was predicted using the modified Streeter-Phelps model. The average concentrations of measured parameters at the sampling stations include: 2.24 mg/l of DO, 312.85 mg/l of BOD, 782.86 mg/l of chemical oxygen demand, and 620.76 g/l of total solids. The DO model for River Illo showed a positive correlation between measured and calculated DO, while the dissolved oxygen curve gave a double spoon shape of two major segments with distinct zones of degradation, decomposition, and recovery. The self-purification factor (f) for both segments ranged between 0.8 and 1.1 depicting River Illo as a slow moving or sluggish river. The above results revealed slow reaeration of the water body while full recovery from pollution was difficult. The treatment of River Illo before usage is very essential to ensure public health safety of users from waterborne diseases.     

Co-utilization of two coal mine residues: Non-catalytic deoxygenation of coal mine methane over coal gangue

The deoxygenation of coal mine methane (CMM) is a necessary process for concentrating methane by pressure-swing adsorption technology. Removal of oxygen in CMM by the reaction between oxygen and carbon in coal gangue is a novel solution for simultaneously utilizing two kinds of byproducts of coal mine, CMM and coal gangue. Process conditions for the deoxygenation of CMM were investigated systematically by using a fixed-bed reactor. The results show that higher temperature and lower gas flow rate not only decreased the residual oxygen concentration in the outlet gas but also increased the methane loss, and that the particle size of gangue did not influence deoxygenation within the experimental conditions used. Under optimal conditions (650 °C and 250 mL/min), there was no residual oxygen in the outlet gas and the methane concentration decreased by less than 0.5 mol%. XRD results show that coal gangue was activated during deoxygenation, and that activated gangue was suitable for utilization as a main component in cementitious materials.     

综合调水前后苏州河下游水体耗氧特性比较

对综合调水前后的苏州河（北新泾下游）水体耗氧特性进行了定性与定量比较。结果表明，综合调水工程全面实施后，苏州河下游水体的还原性物质耗氧阶段消失，单位水体耗氧量大幅度下降，但难降解有机物阶段的耗氧量仍较高。耗氧动力学模拟计算表明，CBOD耗氧一级反应动力学速率常数（K）在综合调水前后变化不大，而硝化耗氧Logistic动力学速率常数（Kn-log)则明显提高。