Effects Of Bamboo Charcoal And Bamboo Vinegar On Pollutant Control During Pig Manure Composting And Resource Utilization Of Compost

The loss of nitrogen and phosphorus has been the main contributor of water environment pollution with the development of pig breeding in China So it's important to develop the technology of pollution control and resource utilization for pig breeding waste, which can resolve the rural environment problem and ensure the continuable development of agriculture. Composting is the effective method to realize the disposal and resource utilization of pig manure (PM). In this thesis, lab scale experiments were carried out to study the effects of bamboo charcoal (BC) and bamboo vinegar (BV) adding on temperature rising, dehydrating, nitrogen conservation, phosphorus activing and heavy metal immobilizing during pig manure composting. The effects of BC and BV on compost fertilizer efficiency and quality were also studied through greenhouse pot experiment. The results can provid new technology approach for the temperature rising, dehydrating, nitrogen conservation, phosphorus activing and heavy metal immobilizing during pig manure composting and resource utilization of compost. The main results of this thesis are as following:(1) The effects of BC and BC+BV addition on temperature rising, dehydrating, germination index, and microbial diversity were mainly studied through PM composting experiment in lab scale. The results indicated that the addition of BC and BC+BV could accelerate temperature rising, prolong thermophilic phase, increase dehydration rate and germination index, and also enrich microbial diversity compared to the control. The addition of BC and BC+BV reduced by 24-72 h for temperature rising to thermophilic phase, prolonged thermophilic phase by 216-288 h, increased the last dehydration rate by 11.3%-21.4%, and increased the germination index by 13.32%-77.04%.(2) The effects of BC and BC+BV on nitrogen conservation and phosphorus activation during PM composting were studied. The results indicated that the addition of BC and BC+BV could obviously increase the content of ammonium nitogen, nitrate nitrogen, organic nitrogen, organic phosphorus, and available phosphorus in compost and decrease nitrogen loss during composting, compared to the control. The addition of 3% BC,6% BC,9% BC,3%BC+0.2%BV,3%BC+0.4%BV and 3%BC+0.6%BV could reduce nitrogen loss by 28%,61%,65%,66%,74% and 50%, respectively, compared to the control during composting. BC addition could reduce nitrogen loss and nitrogen loss decreased with increased BC addition during PM composting. These results suggested that the addition of BC+BV could be an effective method to reduce nitrogen loss during PM composting. The combined addition of BC and BV could be an effective method to reduce nitrogen loss during PM composting.(3) The effects of BC and BC+BV amendment on Cu, Zn immobilization and the acute toxicity of compost extract liquid aqueous on earthworms were studied. The results indicated that the addition of BC could obviously reduce the contents of DTPA extractable Cu and Zn and the bioavailability of Cu and Zn. The bioavailability of Cu and Zn reduced with increased BC addition, and the addition of BC+BV could futher reduce the bioavailability of Cu and Zn. The addition of 3% BC,6% BC,9% BC, 3%BC+0.2%BV,3%BC+0.4%BV and 3%BC+0.6%BV could reduce the extraction efficiency (content ratio of DTPA extractable Cu to total Cu) of DTPA extractable Cu by 6.2%,29.0%,35.1%,10.5%,13.7% and 11.2%, and reduced that of Zn by 18.6%, 30.9%,39.2%,28.6%,29.0% and 28.7%, respectively, compared to the control, during composting. Furthermore, the addition of BC and BC+BV could also reduce the acute toxicity of compost extract liquid aqueous on earthworm, and significantly reduce earthworm mortality at 48 h.(4) The greenhouse pot experiments were conducted to assess the effects of PM compost on plant growth and the physical and chemical properties of pot medium The results indicated that compost especially that with BC and BC+BV addition could increase soil fertility obviously. The growth of ryegrass was best with 15% PM compost application. The application of PM compost with 9% BC could even reduce the absorption of ryegrass for DTPA extractable Cu and Zn. Compared to the PM compost without BC, the substitute of part peat by compost with BC could obviously increase the content of ammonia nitrogen, nitrate nitrogen in potting medium, and also reduce that of Cu and Zn. The substitute of part peat by PM compost could also cultivate strong seedling of cucumber, the biggest seedling index of cucumber was obtained at the ratio of 25% peat substituted by PM compost. Compared to the PM compost without BC, the PM compost with BC could further increase the seedling index of cucumber.