Detection of a Toxic Product Released by a Polyurethane-Containing Film Using a Composting Test Method Based on a Mineral Bed

The degradation of a film containing a 4,4diphenyl methane diisocyanate (MDI) poly(€-caprolactone)-based polyurethane was followed in a test system based on a mineral solid bed designed to facilitate analysis of break-down products released under composting conditions. The use of a mineral solid bed can help extraction and analytical procedures which could be hindered by the heterogeneous nature of compost. The fermentation conditions are typical of the composting environment and generate a powerfully degradative environment. The film fully disintegrated within 30 days of treatment. Analysis on the mineral bed extracts showed that: (i) about 40% of the initial polyurethane was still present in the bed extracts; (ii) this residue was strongly degraded in the poly(€-caprolactone) part, while the urethane part was almost completely recovered (from 80 to 95%, according to the measurement method); (iii) 4,4 diamino diphenyl methane (MDA), a very dangerous product of MDI, was released during biodegradation. The results indicate that a mineral bed can be employed to study degradation and metabolites formation in solid phase fermentation and that the MDI-based polyurethanes are not susceptible of a full degradation during composting and maintain the potential of a slow release of MDA into the environment after soil application.     

Effect of bio-surfactant on municipal solid waste composting process

Bio-surfactant is a new type of surfactant that is produced in microbial metabolism. Adding bio-surfactant during composting process, especially to those contain some toxic substances, has been proved to be a promising way. In this study, Strains Ⅲ(2), a bacterial with high activity to produce bio-surfactant, were isolated firstly. Following comparison experiments with and without adding Strains Ⅲ(2), namely Run 1 and Run R, were conducted, respectively. The experimental results showed that, by adding Strains Ⅲ (2),the surface tension could reduce from 46.5 mN/m to 39.8 mN/m and the corresponding time to maintain the surface tension under 50 mN/m could prolong from 60 h to 90 h. The oxygen uptake rate and total accumulated oxygen consumption with Stains Ⅲ (2) were both higher than those without Strains Ⅲ (2), while the accumulation of H2S in outlet gas was reduced to around 50% of Run R. Moreover, two additional experiments were also carried out to examine the effects of strains coming from different systems. One is adding Strains Ⅲ (2)with a dose of 0.4% (Run 2), and the other is seedling commercial Strains at the same conditions, the composting experiments showed that: Run 2 was more effective than Run 3, because the commercial Strains can be suppressed significantly in a complex composting system with different pH, high temperature and some of metals. The bio-surfactant was also added into the solid waste, which contained some toxic substances, the corresponding results showed that the remove rate of Hg and sodium pentachlorophenolate(PCP-Na) could be improved highly. Thus, the microenvironment, reactionrate and composting quality could be enhanced effectively by adding bio-surfactant to the composting process.     

催化湿式氧化处理碱渣废水的研究

以催化湿式氧化 (CWO)技术对碱渣废水进行治理 ,考察了各种反应条件对废水处理效果的影响。结果表明 ,在 2 30℃ ,6 6MPa ,空速 8h-1的反应条件下 ,CODCr的去除率 78% ,硫的去除率达到 99% ,BOD5/CODCr超过 0 8,并对CWO处理后的尾气进行了分析 ,表明除空气和CO2 以外没有其它有害气体。     

Optimal turning method of composting regarding hygienic safety

The new tuming method was proposed and verified its effectiveness to pathogens by laboratory scale experiments. Considering the results obtained from the previous studies, it could be said that tuming of a composting pile was essential in terms of hygienic aspects but the number of tuming should be minimized. Effectiveness of inactivation was estimated for each composting run. From this estimation,tuming by layers, which is different from conventional tuming that mixes compost pile entirely, was proposed and investigated its performance by experiments. Composting operations with static pile method, complete mix(conventional) tuming method, and proposed tuming( layer tuming) method were done and their effectiveness on inactivation of indicator microorganism was evaluated and compared.As results, the conventional tuming method was not a proper method in terms of pathogen inactivation, whereas, the proposed tuming method showed an excellent performance and should be employed in a composting operation.     

膜生物反应器中的基质降解动力学研究

通过动力学推导,得到了膜生物反应器降解有机物和氨氮的的动力学模型,并采用膜生物反应器处理人工配制的生活污水,确定了相关的动力学参数KS=264.04mgCOD/L,νmax=2.01d-1,K=0.0076L/d·mgCOD,y=0.44mgMLSS/mgCOD,Kd=0.021d-1,KN=0.061d-1,并得到了动力学方程,实验表明该动力学方程能较好地预测MBR的出水水质状况,可以为膜生物反应器处理污水的工艺设计提供参考。     

油污土壤堆制处理实验研究

堆制处理工艺是处理油污土壤的一种强化的生物处理工艺 .通过实验室实验 ,结果表明 :原油降解菌剂投加量 6× 10 12个 (CFU) kg(土壤 )、营养物投加量为使土壤中C∶N∶P =10 0∶2 5∶0 2 5、土壤含水量为饱和含水量的 30 %— 70 %、通风量 14 0mL s为适宜处理条件 ,此时 ,处理 2个月 ,油去除率在 5 0 %以上 .在油污土壤中添加的降解菌和营养物种类、数量完全相同时 ,堆制处理效率明显高于生物耕翻处理效率 ;在相同处理时间内 ,堆制处理时油去除率可比生物耕翻处理时提高 10 %以上 .在处理过程中 ,原油中大部分饱和烃和芳香烃组份被降解     

3种偶氮染料厌氧生物降解性能的试验研究

酸性媒介黄GG ,酸性媒介黑T ,派拉丁兰RRN在厌氧条件下通过还原脱氮发生生物降解 .本文研究在葡萄糖作为共代谢基质时酸性媒介黄GG ,酸性媒介黑T ,派拉丁兰RRN的降解情况 .试验结果表明 :在厌氧微生物的作用下酸性媒介黄GG ,酸性媒介黑T ,派拉丁兰RRN还原氮氮双键效果较好 ,酸性媒介黄GG厌氧降解动力学方程符合一级动力学方程 .酸性媒介黑T ,派拉丁兰RRN的厌氧降解都符合零级动力学方程 .其反应速率常数K分别为 0 0 4 99h-1,0 2 6 5 2mg·(h·L) -1和0 2 2 38mg·(h·L) -1;半衰期分别为 13 8h ,35h和 34h ,在同样条件下酸性媒介黄GG降解最快 ,酸性媒介黑T次之 ,派拉丁兰RRN较慢     

Lix54-100从印刷电路板蚀刻废液中回收铜

本文对Lix5 4 10 0萃取剂萃取铜氨料液中铜的性能做了研究 ,发现其具有动力学速率快、饱和容量高、分离效果好、反萃容易及不萃氨等特点。并把其应用于印刷电路板蚀刻废液中铜的回收 ,在铜初始浓度为 15 6.96g/L ,相比为 2∶1条件下 ,用 80 %Lix5 4 10 0 -煤油经过三级错流萃取 ,铜的浓度可下降到 2 6.88g/L。三级总萃取率达 82 .87%。由此设计推荐了无废排放工艺流程 ,实现了经济效益和环境效益的统一     

石墨炉原子吸收分光光度法测定生活垃圾堆肥中镉

通过试验研究,建立了硝酸-氢氟酸-高氯酸消解、石墨炉原子吸收分光光度法测定生活垃圾堆肥产品中的镉。该方法的检出限为0.01mg/kg(按称取0.5g试样消解定容至50mL计算),用于不同地域堆肥样品中镉的测定,其相对标准偏差(RSD)在5.78%～11.9%之间,加标回收率介于88.0%～106.0%之间,可作为一种较理想的检验堆肥产品质量的方法。     

人工湿地不同基质和粒径对污水净化效果的比较

为研究人工湿地基质类型和粒径对水质净化效率的影响,选择了1~2、2~4、4~8 mm的沸石,2~4、4~8、8~16mm的砾石和2~4、3~5、6~8 mm的无烟煤基质,在无植物人工实验柱中开展单一基质的水质净化实验.结果表明,相同类型不同粒径的基质对COD、TN、TP的去除效果不同.4~8 mm沸石和砾石、6~8 mm无烟煤对COD的去除率最高,分别为53.74%、60.76%、62.93%;人工实验柱中氮素的去除以反硝化作用为主,粒径对TN去除效果的影响表现为小粒径更优;砾石和无烟煤的TP去除率也表现为小粒径更高,但沸石的TP去除率随着粒径的增大而增大.基质类型对COD、TP、TN的去除效果也存在差异.无烟煤对COD、TP、TN均有较好的去除效果,平均去除率在60%以上;沸石对TN的去除效果最好,TP去除率不高;砾石对COD有较高的去除率,对TP的去除效果一般.