Analysis Of Colliery Wastewater From Kaili Area And Microbial Treatment Experiments

As an important part of energy resource, coal has enormous negative effects on the ecological environment, although it offers energy. In the course of coal production, acid mine drainage brought by mines, coal washing process, tailing dump and abandoned mine pits etc., has endangered the peripheral ecosystem of mining area particularly seriously. During two years, the author carried on the field work and the study about the analysis of acid mine drainage pollution and biological treatment examination in the area from Yudong village to Jiangkou stockaded village of Kaili in Guizhou province.By using a series of assessment methods and pollution evaluation criteria, such as soil enrichment factor, individual pollution index, N.C.Nemerow integrated pollution index, HQ (hazard quotient to human health) and so on, this paper describes the heavy metal pollution characteristics of Fe, Pb, Zn and Hg in the river-soil-vegetation system in the coal mining region of Kaili. The research shows that the upper reaches of the Chongan River have been polluted seriously by colliery wastewater. A number of water quality indices, such as pH, SS, chromaticity color, content of heavy metal, etc., have already overrun the second Chinese discharge standard. The potential acidity of soil in the mining district is relatively large, and the soil has been slightly polluted by Zn and seriously polluted by Hg. On the whole, the soil has been deeply polluted by heavy metals. Moreover, plant samples such as Pteris vittata, rice seedling and vegetables have all been affected by colliery wastewater. Among them, the vegetables closely related to human beings are most seriously polluted. Lead contents of kidney bean, tomato and eggplant have overrun the regulated contents by 53.00, 30.35 and 15.20 times of the Chinese Food Hygiene Standards, respectively. Mercury contents of capsicum, cucumber, kidney bean, tomato and eggplant have also preponderated over the regulated contents by 49.00, 33.50, 61.70, 88.30 and 60.70 times, respectively. On the basis of the analysis about the hazard to the circumjacent ecological environment,which was caused by the colliery wastewater of this area. Treat the river polluted by the coal mine's wastewater using silicate bacterium BM03 with the result that it has better treatment effect that the microbial flocculant treats coal mine's wastewater by means of microbial adsorption. It was shown that the maximum flocculation ratio was 97.94% ,the maximum SS removal ratio was 99.43%, and the maximum removal ratios was 91.94%, 90.93 %, and 90% for the total Fe, Zn²⁺, and Ti⁴⁺.Further more, the process of microbial adsorption is optimized by Plackett-Burman method, the most steep hill climling and the central composite design. The factor effect for the total iron removing ratio is that: static handing time> dosage of bacteria solution>dynamic handling time>the rotation rate of shaking table>dynamic handling temperature≈static handing temperature. In these factors, there are only two factors about static handing time and dosage of bacteria solution with their interaction whose influence are distinct. Others effect are not marked. Using the testing result it can obtain the twain order fitting equation. After differentiate, it can be known that when the dosage of bacteria solution is 42.35mL and the static handing time is 9.13h, the maximum total iron removal ratio is 92.88%.Combined with the research on the analysis of acid mine drainage pollution and biological treatment examination, this article designs the doable biological rehabilitation scheme about land farming, bioaugmentation, phytoremediating and so on, which can gradually get ecological environment better.Guizhou Province possesses abundant coal resources, and all kinds of coal mines are distributed in all parts of the whole province. Pollution is serious in majority of them, which needs governing. Thus, it has the wide application foreground in studying and exploiting microbe method for governing the colliery wastewater. Enhancing the comprehensive treatment of the coal mine area is not only in favour of the melioration of environment status, but also the necessary selection for the salubrious development of coal industry.