AMD持续污染岩溶区旱地土壤的环境及生物效应

发布时间：2018-04-27 02:12

本文选题：酸性矿山废水 + 岩溶环境　；参考：《贵州大学》2015年硕士论文

【摘要】：贵州是中国西南地区典型的喀斯特岩溶区,通常认为,喀斯特生态系统非常的脆弱,具有明显较低的环境容量。贵州是煤炭大省,其在大规模开采与利用时给贵州的经济发展带来了巨大的效益,但是也造成了严重的生态破坏及环境污染等问题。由于喀斯特地区土层薄、生物量低、群落结构简单,一旦遭到破坏或污染,将对岩溶生态系统造成严重的威胁。因此,研究岩溶区煤矿在挖掘后产生的酸性煤矿废水(AMD)对周边旱地土壤持续污染的环境及生物效应就显得尤为重要。本文以贵州典型煤矿周边的石灰性旱地土壤为对象,通过添加不同比例的AMD模拟AMD持续污染对土壤pH、Eh、EC及CEC等综合特性的影响;对土壤中的氮磷钾、钙镁等矿质养分的影响;对土壤特征污染指标和微生物学特征的影响研究。其结果表明:(1)岩溶区石灰性旱地土壤对AMD的持续污染具有较为优越的缓冲性能,在固液比为1:10的AMD污染下,岩溶区石灰性旱地土壤pH仍然能维持在6.65以上;随着AMD污染程度的增大,土壤氧化还原电位和电导率呈极显著的升高趋势(p0.01);在较低AMD(固液比1:0.1-1:1)污染程度时,土壤阳离子交换量显著的降低,而在较高AMD(固液比1:5-1:10)污染程度下则又明显的升高。(2)与未污染土壤相比,不同固液比AMD污染对土壤全磷总体影响不明显,土壤全氮、全钾、全钙、全镁呈明显降低的趋势;土壤中的速效氮、速效钾、缓效钾等有效态矿物养分均随废水污染程度加大呈极显著降低趋势(p0.01);低浓度AMD(固液比1:0.1-1:1)污染在一定程度上增加土壤有效磷、有机质含量,而在高AMD污染程度下又急剧促进土壤有效磷释放、有机质的分解,且均达到了极显著性差异(p0.01)。(3)不同固液比AMD污染对岩溶地区石灰性旱地土壤的特征污染指标有显著影响,且随着污染程度的加大影响也增大。随着AMD污染浓度的增大,土壤中的铁、铜、砷含量呈显著或极显著的增加(p0.05);土壤中硫酸根的含量在较低AMD污染程度下变化趋势较为不明显,在较高AMD(固液比1:2.5-1:10)污染程度下极显著的增加,总体上也达到了极显著水平(p0.01);在较低AMD(1:01-1:7.5)污染时,土壤锰和锌有明显的上升趋势,而在较高AMD污染程度(特别是固液比为1:10)时,土壤锰和锌含量均表现出降低的趋势且均低于对照土壤,总体上,不同固液比AMD污染对土壤锰未表现出明显差异性,而对土壤锌则表现出极显著性差异(p0.01);随着AMD污染程度的加大,土壤中二氧化碳的释放量呈极显著升高的趋势(p0.01)。(4)AMD污染对岩溶区石灰性旱地土壤的生物学指标也有较为明显的影响。AMD污染在一定程度上增强了脲酶活性;不同固液比AMD污染均可降低土壤微生物量,且在较高AMD(固液比1:2.5-1:10)污染程度下达到极显著水平,整体上随不同固液比AMD污染呈现极显著性差异(p0.01);综上表明,岩溶区土壤对AMD有一定的酸缓冲性,但会促使土壤中的Ca2+、Mg2+离子的大量淋失,这将对已适应的岩溶生态系统可能造成致命的影响,长期适应性进化形成的石灰性土壤的喜钙植物,对其适应的喀斯特生境有非常强的依赖性,一旦植物的这种生境遭到破坏,将对植物的生长造成严重的影响。其次,AMD污染将导致土壤中的N、K,尤其是有效性大量的淋失,由此将会影响到植物的生长发育状况、生理生化过程及作物产量,从而威胁到整个农业生态系统。再次,在较高AMD污染程度时,土壤中的特征污染物急剧的累计,土壤中的微生物总量显著的减少,土壤酶活性明显的降低,这将严重影响土壤的质量。此外,AMD污染将导致大量二氧化碳产生,从而对大气温室效应的贡献也是不容忽视的。
[Abstract]:Guizhou is a typical Karst karst area in Southwest China. It is generally believed that the Karst ecosystem is very fragile and has obvious lower environmental capacity. Guizhou is a big coal province, which has brought great benefits to the economic development of Guizhou in large-scale exploitation and utilization, but it also causes serious ecological damage and environmental pollution. Because of the thin soil layer, low biomass and simple community structure in Karst area, once destroyed or polluted, it will cause serious threat to the karst ecosystem. Therefore, it is particularly important to study the environmental and biological effects of acid coal mine waste water (AMD) on the continuous pollution of the soil surrounding the Dryland in the karst area. In this paper, the effects of AMD simulation on the comprehensive characteristics of soil pH, Eh, EC and CEC, and the effects of nitrogen, phosphorus, potassium, calcium and magnesium and other mineral nutrients in soil, and the effects on soil characteristics and microbiological characteristics were studied by adding different proportions of AMD to simulate the effects of AMD continuous pollution on the soil, such as pH, Eh, EC and CEC. (1) (1) the calcareous Dryland Soil in karst area has superior cushioning performance for continuous pollution of the soil. Under the AMD pollution of the solid to liquid ratio at 1:10, the soil pH of calcareous Dryland in karst area can remain above 6.65. With the increase of the degree of AMD pollution, the redox potential and electrical conductivity of soil are significantly higher (P0.01), and lower at lower levels (P0.01). When AMD (solid-liquid ratio 1:0.1-1:1) pollution degree, the soil cation exchange volume decreased significantly, while the higher AMD (solid-liquid ratio 1:5-1:10) pollution level increased obviously. (2) compared with the unpolluted soil, the total nitrogen, total potassium, total calcium and total magnesium showed a significant decrease in total soil total phosphorus (total n), total potassium, total calcium and total magnesium. The available mineral nutrients such as available nitrogen, available potassium and slow acting potassium in the soil decreased significantly with the pollution degree of wastewater (P0.01). Low concentration of AMD (solid-liquid ratio 1:0.1-1:1) increased soil available phosphorus and organic matter content to a certain extent, and promoted the release of effective phosphorus in soil and organic matter at high AMD pollution degree. The difference was very significant (P0.01). (3) different solid-liquid ratio AMD pollution had significant influence on the characteristic pollution index of calcareous Dryland Soil in karst area, and increased with the increase of pollution degree. With the increase of AMD pollution concentration, the content of iron, copper and arsenic in the soil increased significantly or significantly (P0.05); The change trend of the content of sulphuric acid root at low AMD pollution level is not obvious, which is greatly increased under the high AMD (solid-liquid ratio 1:2.5-1:10) pollution degree, and it also reaches a very significant level (P0.01) on the whole. In the lower AMD (1:01-1:7.5) pollution, the soil manganese and zinc have a obvious upward trend, but in the higher AMD pollution degree (especially the degree of AMD pollution) When the solid-liquid ratio was 1:10), the content of manganese and zinc in soil decreased and was lower than that of the control soil. On the whole, the different solid-liquid ratio AMD pollution showed no significant difference to the soil manganese, but the soil zinc showed significant difference (P0.01). With the increase of AMD pollution range, the release of carbon dioxide in the soil was very significant. The rising trend (P0.01). (4) AMD pollution has a significant effect on the biological indexes of the soil in calcareous Dryland in karst area..AMD pollution has enhanced urease activity to a certain extent; the soil microbial biomass can be reduced by different solid-liquid ratio AMD pollution, and the overall level of soil microbial biomass is extremely significant at the degree of high AMD (solid-liquid ratio 1:2.5-1:10). There is a significant difference (P0.01) with different solid-liquid ratio AMD pollution, which shows that the soil in karst area has a certain acid buffer to AMD, but it will cause a large amount of leaching of Ca2+ and Mg2+ ions in the soil, which may cause a fatal impact on the adapted karst ecosystem and the calcareous soil of calcareous soil formed by long-term adaptive evolution. Plants are strongly dependent on their adapted Karst habitats. Once this habitat is destroyed, it will have a serious impact on the growth of plants. Secondly, AMD pollution will lead to N, K, and especially a large amount of leaching in the soil, which will affect the growth and development of plants, physiological and biochemical processes and production. As a result, the whole agricultural ecosystem is threatened. Again, when high AMD pollution, the characteristic pollutants in the soil are accumulated sharply, the total amount of microbes in the soil is significantly reduced and the soil enzyme activity is obviously reduced. This will seriously affect the quality of the soil. In addition, the AMD pollution will lead to a large amount of carbon dioxide production, thus to the high temperature. The contribution of the room effect can not be ignored.

【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53;X752

【参考文献】