Study On The Impacts Of Simulated Acid Rain On Distribution Of Zinc Pollution In Pakchoi

As the growth of the world’s population and level of economic development afterthe industrial revolution, the demand of human activities on the fossil fuel resourceshave been improved, which generally caused the increasing of environmentalproblems with burning fossil fuels and other human activities. Then the phenomenonof acid rain caused worldwide attention. After North America and Europe, China hasbecome the world’s third largest area of acid rain because of a big deal of coal using.The space distribution of acid rain has obvious trend in our country with the YangtzeRiver as the dividing line, and the south of the Yangtze River regions are widelyaffected by the strong acidic precipitation. According to the data of nationwide acidrain monitoring system in recent decades, the distribution of acid rain had a tendencyto expand. In addition to the southern regions, the pollution scopes of acid rain onnorthern area also incline to expanding trend. The northeast area has been sufferedfrom strong acid rain pollution. The precipitation regularity of time and space onnortheast has serious effects on agriculture.Heavy metals pollution gradually becomes a global environmental issue ofcommon concern due to its migrating and transforming and biological accumulatingproperties in every layer of the environment. The main causes of the pollution stemfrom excessive waste emissions in the process of mining, smelting and using inindustrial and mining development.“Itai-itai disease” and “minamata disease” once inJapan are forceful evidences for heavy metal pollution on bioaccumulation andamplification causing serious harm to human body, which is a wake-up call tohumanity. Metal pollution from mining industries in China has its outward andpotential threats on surface water, soil and the biosphere. And as the old industrialbase in China, northeast area was inevitably affected by the heavy metal pollution,including the soil metal pollution with directly impacts on crop planting and hiddendangers to human health. Pakchoi is a common crop in vegetable farm, withsensitivity to acid rain and a certain degree of bio-concentration of metals, so that it ischosen as the research object in this paper. There are a large number of researches about acid rain and heavy metalspollution on harm and loss of vegetables growth at home and abroad, but less researchhas done about heavy metal accumulation in the root, stem and leaf of vegetablesunder the condition of acid concentration gradient. So this article choose pakchoi asthe research object, and analyzed the changing tendency and generation mechanismsof zinc distribution in pakchoi and the growth situation as well as physiological andnutritional quality indexes of pakchoi under different acid rain concentration. Theresearch significance is to laid a foundation for relevant researches on stressmechanism of migration and conversion of metals to vegetable quality causing byacid precipitation and soil acidification, as well as a certain reference value toagricultural production development.The results of research on distribution of zinc pollution in pakchoi under thecondition of simulated acid rain showed that accumulated zinc content in roots, stemsand leaves were increased because of the increase of the intensity of simulated acidrain. The reason is that the absorption of effective zinc in soil by roots increased. Andthe higher acidity caused the greater accumulation. It is proofed that accumulated zincconcentration in every part of pakchoi is significantly affected by the pH value of acidrain.The research on changing trend of growth indicators on pakchoi under thecondition of simulated acid rain showed that every growth index had a tendency toreduce with increasing intensity of simulated acid rain. And the stronger acidicprecipitation caused more obvious reduction of the growth indexes. Under the impactof pH value of2.5the leaves were significantly apparent damage. Meanwhile,because of the stimulating effect of the weak acid precipitation on vegetable growthand development, the growth indicators of the pakchoi under the pH value of5.6werehigher than other research objects under the other intensity of acid rain.The research on tendency of physiological index of pakchoi under differentsimulated acid rain showed that the chlorophyll content was on the rise with thehigher pH value of acidic precipitation. There is a positive correlation and significantdifference between them. At the same time, the weak acid precipitation had a effect on the growth of its chlorophyll content, so that the sample data is higher than theobjects under the other pH value of simulated acid rain.The nutritional quality indexes of pakchoi under simulated acid rain had similarchanging trend in research results. It showed that the simulated environmentalcondition of acid rain inhibited the synthesis of soluble sugar and vitamin C in thebody of pakchoi, so that the nutritional quality indicators appeared the decliningtendency. The stronger the acid, the more obvious inhibitory effect is. But with theweak acid precipitation, every nutritional index level was higher than the pakchoiunder the other pH value of acidic precipitation.