生物质固体废物厌氧发酵过程中HS对产CH4作用研究进展

针对生物质固体废物量大面广,具有污染和资源利用双重特性,厌氧发酵能源化可促进其污染控制,且过程中部分有机成分在微生物作用下转化成腐殖质（HS）.通过分析厌氧发酵过程中HS转化规律、HS结构特征与氧化还原性能、腐殖质还原菌与产甲烷菌活性、产CH₄效率之间的响应关系和作用机制研究进展,总结凝练出生物质厌氧发酵系统内HS对CH₄的调控原理,为减少厌氧发酵系统内HS对产CH₄途径的抑制作用,提高发酵效率的技术研究提供理论支撑.     

Investigation on mechanism of phosphate removal on carbonized sludge adsorbent

For the removal of phosphate (PO₄^3 -) from water, an adsorbent was prepared via carbonization of sewage sludge from a wastewater treatment plant: carbonized sludge adsorbent (CSA). The mechanism of phosphate removal was determined after studying the structure and chemical properties of the CSA and its influence on phosphate removal. The results demonstrate that phosphate adsorption by the CSA can be fitted with the pseudo second-order kinetics and Langmuir isotherm models, indicating that the adsorption is single molecular layer adsorption dominated by chemical reaction. The active sites binding phosphate on the surface are composed of mineral particles containing Si/Ca/Al/Fe. The mineral containing Ca, calcite, is the main factor responsible for phosphate removal. The phosphate removal mechanism is a complex process including crystallization via the interaction between Ca^2 + and PO₄^3 -; formation of precipitates of Ca^2 +, Al^3 +, and PO₄^3 -; and adsorption of PO₄^3 - on some recalcitrant oxides composed of Si/Al/Fe.     

A comparison of chemical MSW compositional data between China and Denmark

Chemical waste compositions are important for municipal solid waste management, as they determine the pollution potentials from different waste strategies. A representative dataset for chemical characteristics of individual waste fractions is frequently required to assess chemical waste composition, but it is usually reported in developed countries and not in developing countries. In this study, a dataset for Chinese waste was established through careful data screening and assessment, named as CN dataset. Meanwhile, a dataset for Danish waste (DK dataset) was also summarized based on previous studies. In order to quantitatively evaluate the reliabilities of CN and DK datasets, the chemical waste compositions in four Chinese cities were estimated by utilizing both of them, respectively. It is indicated that the usage of CN datasets led to significantly lower discrepancies from the actual values based on laboratory analysis in most cases. Within the datasets, the moisture contents of food waste, paper, textiles, and plastics, the carbon content of food waste, as well as the oxygen content of plastics would induce significant divergences, which should be paid special attention when gathering the information. In addition, the fractional waste compositions in China showed similar features with other developing countries but differ significantly with developed countries. Thus the above-mentioned conclusions could also be true in other developing countries.     

活性污泥吸附预处理腈纶废水的机理研究

以活性污泥作为吸附材料,研究了其对腈纶废水COD的吸附特征。结果表明,活性污泥可吸附腈纶废水中的COD,吸附量可达135 mg/g。伪二级动力学方程能很好地描述活性污泥对腈纶废水中的COD的吸附过程,模型计算出的二级吸附速率常数(k2)为2.3×10-4g/(mg·min);Langmuir方程最适合描述该吸附过程,决定系数在0.96以上。从活性污泥吸附前后腈纶废水中的有机物相对分子质量分级结果可以看出,活性污泥对大分子(30 k Da)有机物有较好的去除,污泥的电镜照片也证明了该点。研究表明,活性污泥吸附可去除腈纶废水中的悬浮物和胶体物,是有效的腈纶废水预处理方法。     

贫营养条件下MBR与IAMBR脱氮效果分析

以膜生物反应器(Membrane Bio-Reactor,MBR)工艺和间歇曝气式膜生物反应器(Intermittent Aeration Membrane Bio-Reactor,IAMBR)工艺进行对比运行试验,探求贫营养条件下系统的运行和脱氮特性。定期测量各项氮指标及混合液污泥浓度等数据,结果表明:IAMBR系统整个周期内的氨氮去除率(平均值为81%)基本高于MBR(平均值为76%);IAMBR的总氮去除率虽然有限,但基本维持了理论上的出水总氮质量浓度小于进水总氮质量浓度,优于MBR的总氮去除率负值状态;试验末期,MBR的污泥质量浓度迅速下降至3 650 mg/L以下,而间歇曝气式IAMBR的污泥质量浓度仍旧保持在4 530 mg/L。因此,整体来看IAMBR系统比MBR更能经受贫营养环境的冲击。     

能源物质和接种物的投量对生物沥浸改善城市污泥脱水性能的影响

选用硫粉(S0)和黄铁矿粉(Fe S2)作为复合能源物质,以生物沥浸处理城市污泥脱水。通过正交试验分析了不同能源物质和接种物配比下的污泥脱水、沉降性能。结果表明:能源物质和接种物的合理配比为S0投量2 g/L、Fe S2投量6 g/L、接种物投量20%,在该投量下进行生物沥浸试验,污泥比阻由初始的3.35×1012m/kg降至3.90×1011m/kg,降幅达88.36%,污泥沉降率由68%升至78%;沥浸过程中污泥比阻、沉降率与p H值、ORP、Fe2+、Fe3+、总Fe和SO2-4质量浓度的变化同步,表明污泥脱水和沉降性能的改善是酸化、氧化和絮凝的协同作用所致;同时,细菌总数、总大肠菌群和粪大肠菌群的灭活率均在99%以上,表明生物沥浸还可高效杀灭病原微生物。     

溶菌酶和硫酸铝联用优化污泥脱水性能的研究

以污泥沉降体积、污泥比阻和污泥泥饼含水率为指标,考察了溶菌酶和硫酸铝联用时加药方式和加药剂量对活性污泥沉降性能及脱水性能的影响。结果表明,先投加溶菌酶后投加硫酸铝时污泥的脱水性能更佳,硫酸铝和溶菌酶的最佳投加量均为0.10 g/g TS(总固体),此时,污泥泥饼含水率和污泥比阻分别可达71.84%和0.68×1012m/kg,相比于硫酸铝单独调理分别降低了约5%和0.23×1012m/kg。污泥胞外聚合物(EPS)含量分析表明,溶菌酶和硫酸铝联用时显著降低了污泥中LB-EPS(松散附着性EPS)含量,在最佳投量下可将原污泥的LB-EPS中的蛋白质和多糖依次从(13.44±2.11)mg/L和(23.97±3.44)mg/L降至(1.72±0.32)mg/L和(8.69±0.15)mg/L,表明联合处理使得EPS中的水分得到释放,提高了脱水性能。     

有机垃圾组分种群增长及修正一级产气动力学研究

以米饭、鸡蛋清、生菜、肥肉馅为原料,分别代表淀粉、蛋白质、纤维素、脂肪进行厌氧消化产沼气实验,并用种群增长模型和修正一级产气模型进行拟合.结果表明:脂肪的厌氧消化过程用修正Gompertz方程拟合效果较好,其余物料用Logistic方程拟合效果较好;脂肪的延滞期最长,为13 d,其次是蛋白质、纤维素,其值分别为8.72 d、6.24 d,淀粉的延滞期接近零.同时,建立了修正一级产气模型,并在延滞期之后用其模拟4种有机物厌氧消化产气过程,发现淀粉水解过程更趋向于遵循圆柱形颗粒模型,蛋白质、纤维素和脂肪水解过程更趋向于片状颗粒模型,淀粉和蛋白质的水解产气速度较快,脂肪稍慢,纤维素最慢;在延滞期内蛋白质和纤维素累积沼气产率都遵循零级水解动力学,脂肪的累积沼气产率遵循三次函数模型.在综合分析的基础上,得到了整个实验周期的产气动力学模型.     

UASB反应器反硝化处理工业废水

采用絮状污泥成功启动升流式厌氧污泥床(UASB)反应器处理含甲酸、苯胺、环已酮、NO3-等的工业废水。UASB反应器以低负荷启动,10天后逐渐提高进水COD,出水COD保持在710~770 mg/L,COD去除率为40%~60%;出水TOC保持在115~314 mg/L,TOC去除率由60.3%逐渐升高至87.2%,最终维持在81%左右;出水中ρ(NO3-)维持在134~176 mg/L,NO3-去除率为90%左右,系统稳定后NO3-去除率几乎为100%。在进水COD容积负荷不超过5.00 kg/(m3·d)的条件下,实际COD容积负荷稳定在2.00 kg/(m3·d)左右,实际TOC容积负荷稳定在1.00 kg/(m3·d)以上。当进水COD容积负荷不大于4.48 kg/(m3·d)时,COD去除率为55%~74%,TOC去除率为63%~87%,NO3-去除率大于95%。     

喷淋工艺处理PVC塑料生产废气

采用喷淋工艺处理PVC塑料生产废气,将专利的吸收液与改型的喷淋塔相结合,在中试成功的基础上进行了实际工业化应用。应用结果表明:采用该工艺处理某PVC塑料生产企业的生产废气,吸收液在喷淋塔循环液中所占体积分数为15%时,废气中各污染物指标的去除率达85%以上,对于难处理的苯系物也能较好地去除;处理后废气中各污染物指标的含量满足GB 14554—1993《恶臭污染物排放标准》和DB 44/27—2001《大气污染物排放限值》的要求;该工艺装置运行费用较低,仅为电费和少量药剂费用,吸收液可循环使用,设备保养及维护简单,可满足市场需求。