城市污泥资源化利用对土壤及植物的影响研究

发布时间：2018-05-21 19:34

本文选题：污泥 + 石灰干化　；参考：《西北农林科技大学》2015年硕士论文

【摘要】：我国作为世界上最大的发展中国家,社会经济逐年增长,工业化进程也正快速推进,我国城市化水平也伴随着正逐年提高。由此引发的城市污水处理厂污泥的处理处置问题成为人们关注的焦点。城市污泥中含有丰富的氮、磷、有机质等养分,但同时其中的污染物质也有可能对环境和人体造成危害。因此,如何将污泥“变废为宝”,保证城市污泥产品土地综合利用效率的同时,将作物中污染物质含量控制到安全范围以内,一直是研究的一个热点。本论文以北京市小红门石灰干化厂提供的污泥石灰干化产品和清河热干化厂提供的污泥热干化产品为例,分别研究了污泥干化产品中养分和重金属含量,分析其农用潜力和安全性影响;将污泥干化产品与表层土壤(0~20cm)混配,设置施用量为0kg/m2、1kg/m2、2kg/m2、3kg/m2四种处理,利用盆栽试验得出施用后对土壤环境的影响以及污泥干化产品土地利用对蔬菜生长状况和重金属积累的规律,对土壤和蔬菜中重金属含量安全性进行了分析评价,提出污泥土地利用的适宜参数。研究结果表明如下:(1)热干化污泥产品中总养分(N+P2O5+K2O)和有机质含量较高,远超国家有机肥料标准,农用价值较大,对土壤养分的改善作用较强,石灰干化污泥产品中有机质含量较低,总养分含量仅能满足污泥农用标准;热干化污泥产品中重金属含量高于石灰干化污泥产品,其中热干化产品中Pb、Cd、Hg、As和Ni的含量约为石灰干化产品中的2倍,Cu和Zn含量则是石灰干化产品的好几倍。可见污泥热干化产品对表层土壤的威胁更大,两种污泥干化产品中重金属含量均远低于国家标准限值。(2)施用污泥石灰干化产品、污泥热干化产品均能使表层土壤中全N、全P以及有机质的含量呈显著增加趋势(P0.01),全K含量显著减少。施用污泥热干化产品比施用石灰干化产品后土壤中全N和有机质的含量增幅要大得多,说明热干化产品更能保留污泥中的有机质和养分,具有较高的土地利用价值。(3)施用两种污泥干化产品后土壤中各重金属含量均有显著增加(P0.05),但不同重金属元素增加的幅度有所不同。本试验施用这两类污泥干化产品时各处理表层土壤中重金属元素的含量均未超过(GB 15618—2008二级)的限值要求。说明本试验中的污泥干化产品用量均在安全限值以内,但在农用过程中仍应该重视土壤中重金属含量的动态变化。(4)在污泥石灰干化试验组中,污泥石灰干化产品对小白菜产量的增长起的作用并不显著,只有在3kg/m2处理时三茬小白菜总产量比对照组有一定增长。污泥热干化产品对小白菜的增产效果更显著。污泥热干化试验组中施用2kg/m2、3kg/m2污泥热干化产品时,小白菜的产量比对照增加了73.20%和77.20%。两种污泥干化产品对小白菜生长均能表现出一定的抑制作用,但当施用量达到一定量后能够使小白菜产量增加。(5)施用污泥石灰干化产品后Pb、Cd、Cr、As、Cu、Zn的含量相比对照均呈现显著增长趋势,3kg/m2处理时增长率均在100%以上,其中As的含量增长最多,增长了408.33%,其中小白菜Cd、Cr的含量超出(NY 5003-2008)标准限值要求。在施用污泥热干化产品时各重金属元素的含量均有不同程度的增加,但各重金属含量并未超过(GB 18406.1—2001)中的标准限值。
[Abstract]:As the largest developing country in the world, the social economy is increasing year by year, the process of industrialization is also advancing rapidly. The level of urbanization in our country is also increasing year by year. The treatment and disposal of sewage sludge in urban sewage treatment plant has become the focus of attention. The municipal sludge contains rich nitrogen, phosphorus, organic matter and so on. But at the same time, the pollutants may also be harmful to the environment and the human body. Therefore, how to make the sludge "waste into treasure", to ensure the comprehensive utilization efficiency of the urban sludge products, and to control the content of the pollutants in the crops to within the safety range has always been a hot spot of research. This paper is a small red gate stone in Beijing. The sludge drying products provided by the ash drying plant and the sludge heat drying products provided by the Qinghe heat drying plant are taken as an example. The contents of nutrients and heavy metals in the sludge dry products are studied respectively, and the agricultural potential and safety effects are analyzed. The application of the sludge dry product and the surface soil (0~20cm) is set to 0kg/m2,1kg/m2,2kg/m2,3kg/m 2 four treatments, by pot experiment, the effect of application on soil environment and the regulation of the growth of vegetables and heavy metal accumulation in the land use of sludge dry products were obtained. The safety of heavy metal content in soil and vegetables was analyzed and evaluated, and the suitable parameters of sludge land use were put forward. The results showed as follows: (1) hot dry The content of total nutrient (N+P2O5+K2O) and organic matter in the chemical sludge products is high, far exceeding the national organic fertilizer standard, the agricultural value is larger, the soil nutrient is better, the content of organic matter in the lime dry sludge product is low, the total nutrient content can only meet the sludge agricultural standard, and the heavy metal content in the hot dry sludge product is higher than the lime. In the dry sludge products, the content of Pb, Cd, Hg, As and Ni in the hot drying products is about 2 times of the lime dry products, and the content of Cu and Zn is several times more than that of the lime dry products. It can be seen that the sludge hot drying products have a greater threat to the surface soil, and the heavy metal content in the two kinds of sludge dry products is far below the national standard limit. (2) application of sludge The content of all N, all P and organic matter in the surface soil increased significantly (P0.01), and the content of all K decreased significantly. The content of all N and organic matter in the soil of the application of sludge hot drying products was much larger than that of the N and the organic matter in the soil, which indicated that the hot drying products could retain the sludge more. The organic matter and nutrient in the soil have high land use value. (3) the content of heavy metals in the soil increased significantly after the application of two kinds of sludge dry products (P0.05), but the increase in different heavy metals was different. The contents of heavy metals in the surface soil of the two kinds of sludge dry products were not the same. Exceeding the limit requirement of (GB 15618 - 2008, two). It shows that the amount of dry sludge in this experiment is within the limit of safety, but the dynamic change of heavy metal content in the soil should still be paid attention to in the agricultural process. (4) the effect of sludges on the increase of the yield of Chinese cabbage in the dry lime drying test group It is significant that the total yield of the three cropping of Chinese cabbage is higher than that of the control group at the time of 3kg/m2 treatment. The effect of the sludge hot drying product on the production of Chinese cabbage is more significant. When the 2kg/m2,3kg/m2 sludge heat drying product is used in the sludge hot drying test group, the yield of Chinese cabbage is increased by 73.20% and 77.20%., and two kinds of sludge dry products are white. The growth of vegetable can all show a certain inhibitory effect, but when the dosage reached a certain amount, it can increase the yield of Chinese cabbage. (5) the content of Pb, Cd, Cr, As, Cu, Zn, after the application of sludge lime drying products, showed a significant increasing trend compared with the control, and the growth rate of 3kg/m2 treatment was above 100%, and the content of As increased by 408.33%. Among them, the content of Cd and Cr is beyond the standard limit of (NY 5003-2008). The contents of heavy metals in the application of the sludge are increased in varying degrees, but the content of each heavy metal does not exceed the standard limit of (GB 18406.1 - 2001).
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

【参考文献】