Vermicomposting And Odor Control Of Aquatic Products Processing Factory Sludge

The sludge would cause atmosphere, groundwater and soil pollution evenendanger human health if it was not disposed reasonably. Vermicomposting is aneconomically feasible sludge disposal method. In this paper, Eisenia foetida wasused to treat the mixture of aquatic products processing plant sludge and corn stalks.Organic fertilizer suitable for agriculture was obtained and the environmentalpollution caused by corn stalks burning was reduced through vermicomposting. Theresearch included: the pre-composting effects of different C to N ratio (C/N) anddifferent EM(Effective Microorganisms) solution adding amount of substrates,appropriate pre-composting period, the vermicomposting effects of differentpre-composting materials, appropriate vermicomposting period. In addition, odorcontrol experiment which used wormcast as filler in the biosorption column was doneto deal with the odor produced in the composting. The intake odor flow in the besttreatment would be obtained through three comparative tests of different intake odorflow. The main research results could be concluded as follows:(1) In the pre-composting experiments, the decline of the total orgnic carbon (TOC)which EM solution adding amount was0.8%was the biggest in case of the same C/N.The TOC dropped faster in the piles of C/N equal to26.40than in the piles of C/Nequal to35.91in case of the same EM solution adding amount. At the end ofpre-composting experiments, the pH and ammonia nitrogen concentration in eachpiles were in the range of suitable earthworms survival. The increase extent of thetotal phosphorus (TP) of the pile which had high initial C/N was higher than the pilewhich had low initial C/N in case of adding EM solution. The increase extent of theavailable phosphorus was reduced by the reduction of piles’ C/N under the sameconditions. The increase extent of the available phosphorus was decreased by theincrease of EM solution in the case of adding EM solution and the same piles’ C/N,but the content of available phosphorus were higher than the control pile without EMsolution. The appropriate pre-composting period was about35days.(2) In the vermicomposting experiment, the content of TOC in each pile showed adownward trend overall. The trend of C/N was similar to the TOC, the C/Nremained stable basically at last. The content of TP in each pile was not changed obviously, and the content of available phosphorus showed a downward trend in thevermicomposting process. The C/N and ammonia nitrogen could be used as thepreferred indicator of compost maturity in this vermicomposting experiment, and seedgermination index could be selected as a general indicator, while urease activity couldnot be used as indicators. The daily weight of the earthworms gain multiple changeswhich was same to earthworms’ daily breeding multiple changes first increased andthen decreased and finally increased. The piles which C/N was between25and35were suitable for vermicomposting, and the approriate vemicomposting period wasabout two weeks.(3) In the odor control experiment which dealed with odor by biosorption column,the ammonia gas removal effect was the best when the intake odor flow rate was20L/h. The pH and ammonia nitrogen concentration in each pile increased and thendecreased, but the total nitrogen (TN) decreased and then increased. What’s more,the TOC showed a downward trend overall. The result showed that the moisturecontent, TOC and TN of the filler in each biosorption column was lower than beforein contrast to pH. The ammonia nitrogen concentration of upper filler in thebiosorption column in each biosorption was lower than the initial value, but the underfiller was converse, moreover, the under ammonia nitrogen content increased on therise of intake air flow.(4) The genaral results could be obtained from three experiments as follows: the NO.2pile which the C/N was35.91and EM solution adding amount was0.8%was the bestin composting effect, and the appropriate pre-composting period was about35days.It was suitable for vermicoposting if the C/N of the pile was between25to35in thestart of pre-composting, and the appropriate vermicomposting period was about twoweeks. In addition, wormcast was used as filler in the biosorption column in odorcontrol experiment was considered as an economic and effective method for odorcontrol with the20L/h of intake odor flow rate.