| China is the world's largest producer of MSG produces in the process, the production of high concentration organic wastewater directly discharged into the rivers, a considerable part of severe environmental pollution not only, but also discards the precious resources as waste. Meanwhile the input of high concentrations organic waste into water would cause the lower of water dissolved oxygen, water degradation, the deterioration of urban water environment, which also brings a series of consequences such as damage to health, water shortage, and the serious restriction of the economic and urban sustainable development. Due to the high COD, high ammonia nitrogen, high Cl - and strong acidity, it is greatly difficult to treat the waste water of MSG. In recent years, MSG manufacturers all switch to adopt isoelectric point of sulfuric acid for reducing the cost of production, which adds high concentration sulfate into the waste water, and consequently brings new difficulties into comparative mature anaerobic process. Therefore, MSG wastewater treatment technology and engineering research appears extremely important and urgent. How to choose an appropriate MSG wastewater treatment technology to combine a set of technical, economic and effective treatment scheme is the concern of MSG factory and the whole society.This issue originated from one sewage disposal reconstruction project in one MSG factory of Henan, is based on high concentration organic waste water and reclamation of high ammonia nitrogen into slurry-spraying granulation system fertilizer, utilizing new technology to solve the environmental protection in producing MSG, and transforming the tail gas treatment system for supporting standard drainage. This paper is designed to meet energy saving, consumption reduction, pollution abatement for eliminating the negative effects of MSG production to human beings and ecological environment, by means of technology management. Thus it aims to be sort of guidance for MSG industry to prevent pollution, improve economical and social benefits.This paper has conducted flocculation condition experiments on comprehensive utilization of glutamate in the pretreatment stage. Firstly, to choose the existing common flocculant through properties, and then after comparing and contrasting to choose PAM as the flocculant of this experiment, to study the flocculant concentration, flocculant substitutability, pH value, impacts of factors such as temperature in high concentration organic wastewater flocculation effect, and to determine the pretreatment optimum conditions: temperature for 40℃, pH = 3.0, addition of PAM of 10ml with the concentration of 4‰into per 100ml MSD waste water. In these conditions, COD is declined from 36000mg/L to 19000mg/L, and COD removal would be listed between 41-45% after many trials.In this paper the pretreatment flocculation mechanism and flow physical chemistry factors related discussion. The experiment chooses the flocculant polyacrylamide (PAM) and divided into non-ionic, weak anion type and weak cation type three kinds, because the weak anion type PAM precipitation flocculation superior performance, in industry widely application. Its main function mechanism is "bridging" mechanism adsorption, be in namely flocculation process, polymer concentration, adsorption in the lower on the surface of polymer particle long chain may also adsorption in another particles on the surface of the bridge , through the "bridging" means two or more particles together, resulting in particles together flocculent; When applied to the mud water, shear force between particles produced velocity gradient, improved particle collisions in the process. In addition, mechanical agitation and centrifugal shear flow field of the secondary flow influence of particle collisions. In flocculation stage, because of a body of flocculant generated flocculant body and big experience micro flocculant body the two stages, which required hydraulic conditions is different, so, fluid of shearing force requirements imposed, on one hand, be helpful for the appropriate secondary flow produce, make the particles and mainstream secondary flow of collision form micro particles between particles flocculant body, shorten the reaction time, improve efficiency; On the other hand, to avoid the big flocculent body formed, in order to accelerate flocculent body damage settlement.This paper selects compound fertilizer technology utilizing liquid enrichment - slurry-spraying granulation to manage high concentration organic wastewater and high ammonia nitrogen. The production process parameters have been determined through the experiments, and currently the first phase of compound fertilizer transformation process has already completed and been put into operation. The various index of compound fertilizer have reached national standards with a high fertilizer efficiency and substantial economic profits, therefore it is convincible to prove that the compound fertilizer technology utilizing slurry-spraying granulation is effective and feasible for realizing the sustainable developmentThis paper aims to do innovation about optimizing process design and to select the most appropriate equipments for producing compound fertilizer. To compare slurry-spraying granulation which is the core of the whole process in technology, to adopt internal returns dryer with internal grading slurry-spraying granulation drying process, compact in structure, simple in process, low in energy consumption, large amount in output, and closed in powder cycle, to lower production cost and dispose large amounts of high concentration organic wastewater and sewage sludge, and simultaneously according to actual production conditions to devise and calculates correlative equipment parameters, and to analyze the problems and working conditions that should be paid attention to in operation.The design also makes technological innovation about tail gas and dust processing system in fertilizer plants. Through technological comparison, exhaust and ion purifier is selected as the device of tail gas treatment, the operating parameters of this equipment are calculated, and simultaneously the productive experiments are carried on to determine the main factors affecting equipment operation and to determine the best working condition. Judging from the actual tail gas treatment effect, dust removal rate reaches up to 90%, and discharging gas reaches the standard, which proves that the gas of tail gas treatment process renovation is completely reasonable.Through feasibility analysis and environmental assessment of compound fertilizer's economic and social benefits, and economic and technical accounting of finished products, it is concluded that this recycling scheme's profits are considerable. Detected by authorities, each index of the compound fertilizer has reached national standard for land utilization, which also reflects the policy of by waste, turning waste into wealth. |
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