碱渣吸收硫酸尾气工艺设计与研究

探讨碱渣代替纯碱吸收硫酸尾气,其内容包括产品质量状况、产品方案、消耗成本、工艺控制条件、产品市场调研小结等;为有关厂家试验尝试提供了可行性研究和技术指导;也为关注尾气吸收和亚硫酸氢钠产品的厂家和商家提供了有参考价值的信息。     

The Effect of Starch Composition on Structure of Foams Prepared by Microwave Treatment

A microwave technique was used to prepare foams from different potato starches in granular form, with varying amounts of amylose content, and water. In addition to native potato starch (PN), high amylose potato starch (HAP) and potato amylopectin (PAP) were used, as well as mixtures thereof. In all cases the native crystallinity of starch granules was lost upon microwave treatment and an amorphous material was created. An increased concentration of starch in the initial water dispersion resulted in a less dense foam structure. The potato amylopectin formed open cell foams, whereas increased amylose content, as in native potato starch, yielded a more compact structure with irregular pore shapes. The high amylose potato starch yielded a structure with hardly any porosity. Foaming experiments were done to compare pre-gelatinized and granular starches dispersed in water. The pre-gelatinisation did not affect the pore formation process. These experiments indicated that the molecular architecture of starch polymers is more important for foam formation than starch polymer organization in the granules. Studies of temperature profile and dry matter content during microwave treatment showed that water evaporates more rapidly from a high amylose starch solution than native potato starch and potato amylopectin solutions. Rheological measurements showed that the amylose solution had much lower viscosity than starch and amylopectin. This confirms that polymer – water interaction, such as in amylopectin solution, favours stabilization of bubbles formed upon boiling and evaporation of water, which yields high porosity materials.     

固定食用菌加工废弃物对废水中重金属Cu2+的吸附性能

用聚乙烯醇-海藻酸钠(PVA-SA)将金针菇(Flammulina velutipes)、毛木耳(Auricularia polytricha)、杏鲍菇(Pleurotus eryngii)和平菇(Pleurotus ostreatus)加工废弃物固定制成吸附小球,研究初始p H值、反应时间对Cu~(2+)吸附的影响及吸附特性,并应用到实际废水的处理中。结果表明:固定金针菇、毛木耳、杏鲍菇和平菇废弃物吸附小球的最大吸附率分别为81.3%、60.8%、42.8%和50.0%;伪二级动力学模型比颗粒内扩散模型能更好地描述固定食用菌加工废弃物吸附小球对Cu~(2+)的吸附过程;固定金针菇、毛木耳和平菇废弃物吸附小球的等温吸附过程与Langmuir等温模型拟合度高,吸附过程主要是单层吸附,固定杏鲍菇废弃物小球的等温吸附过程则更符合Freundlich等温模型;扫描电镜(SEM)分析显示,固定金针菇废弃物吸附小球吸附Cu~(2+)后,细胞壁增厚,细胞壁上形成了明显的Cu~(2+)无机沉淀或晶体,表现为物理性吸附。研究表明,固定金针菇废弃物吸附小球对自然废水中Cu~(2+)的去除率为73.11%,具有一定的实际应用价值。     

Crop residue removal and fertilizer N: Effects on soil organic carbon in a long-term crop rotation experiment on a Udic Boroll

Biofuels can be produced by converting cellulose in crop residues to ethanol. This has recently been viewed as a potential supplement to non-renewable energy sources, especially in the Americas. A 50-yr field experiment was analyzed to determine the influence of (i) removing approximately 22% of the above-ground wheat (Triticum aestivum L.) residue each crop year, and (ii) N and P fertilization on soil carbon (C) in the top 15 cm depth of a fallow–wheat–wheat (F–W–W) rotation. The study was conducted from 1958 to 2007 on a clay soil, at Indian Head in sub-humid southeast Saskatchewan, Canada. Soil C concentrations and bulk densities were measured in the 0–7.5 and 7.5–15 cm depths in 1987, 1996 and 2007 and soil C changes were related to C inputs estimated from straw and root yields calculated from regressions relating these to grain yields. Two soil organic matter models [the Campbell model and the Introductory Carbon Balance Model (ICBM)] were also used to simulate and predict the effects of the treatments on soil C change over time, and to estimate likely soil C change if 50% or 95% of above-ground residues were harvested each crop year. Crop residue removal reduced cumulative C inputs from straw and roots over the 50-yr experiment by only 13%, and this did not significantly (P > 0.05) reduce soil C throughout the experiment duration. However, after 50 yr of applying N fertilizer at recommended rates, soil C increased significantly by about 3 Mg ha⁻¹ compared to the non-fertilized treatment. The simulated effect of removing 50% and 95% of the above-ground residues suggested that removing 50% of the straw would likely have a detectable effect on the soil C, while removing 95% of the straw certainly would. Measurements and model simulations suggest that adoption of no-tillage without proper fertilization will not increase soil C. Although it appears that a modest amount of residue may be safely removed from these Udic Borolls (Black Chernozems) without a measurable effect on soil C, this would only be feasible if accompanied by appropriate fertility management.     

青岛市完善循环经济产业链——解决历史遗留“五大废渣”难题

困扰青岛市的环境污染难题“五大渣”——铬渣、白泥、钢渣、粉煤灰、电石泥,通过发展循环经济,不但成功解决了污染问题,并且在钢厂、碱厂、化工厂、发电厂和建材厂之间,建立了以废物为纽带的具有青岛特色的跨行业、区域性的循环经济发展模式,为老工业基地的经济结构调整,落实青岛市战略发展规划打下了很好的基础。     

硫酸渣制备高纯度硫酸亚铁

以高铁硫酸渣为原料,采用酸浸-还原-除杂-结晶一重结晶-干燥工艺,合成高纯度硫酸亚铁。通过反应温度、反应时间对硫酸渣中铁的浸出率的影响,以及结晶温度、干燥温度、干燥时间对硫酸亚铁产品纯度的影响做分析实验,得出最佳酸浸条件：硫酸渣与硫酸的固液比为1：3,硫酸质量分数为20％～25％,反应温度为80℃,反应时间为6h,搅拌强度为200r／min;最佳结晶精制条件：结晶溶液pH值为1-3,温度为60℃;除杂最佳条件：pH值约为4．5;冷却结晶温度控制在20℃,结晶干燥过程为30℃,干燥6h。     

钡渣石灰协同作用处理含磷废水的研究

以钡渣为水处理剂,研究钡渣与氢氧化钙协同作用对水中磷去除率的影响。试验表明,钡渣与氢氧化钙协同作用去除水中磷时,去除率高于钡渣或氢氧化钙单独作用的处理效果。投加比例为钡渣1g+氢氧化钙1.5g/1mg磷,时,对水中磷的去除率达到90.42%出水含磷量已经降低到1mg/L以下,可以达到国家排放标准。去除率随着pH提高而增加。     

贵阳市餐厨废弃物资源化体系构建

贵阳市餐厨废弃物资源化、无害化活动刚刚起步,面临着餐厨废弃物回收难等一系列问题。从行政管理、技术两个方面简要介绍了贵阳市餐厨废弃物资源化体系建设的现状,针对其中存在的问题,从政府机构、有资质的餐厨废弃物处理机构、餐饮企业、公众4个层次入手分析,初步构建了贵阳市餐厨废弃物资源化体系,从而促进餐厨废弃物的资源化。     

利用污泥残渣制备生物絮凝剂及其絮凝机理的探讨

考察了由污泥残渣制备生物絮凝剂的条件,同时对其絮凝机理进行了初步的探讨。结果表明,絮凝剂的最佳制备条件为:污泥残渣浓度100 g/L,处理方式为水洗,水洗次数为3次。该絮凝剂具有良好的热稳定性和pH稳定性,储存100 d内,絮凝剂的絮凝活性均保持在94%以上;对其成分分析的测定结果表明该絮凝剂的主要成分为多糖类物质;絮凝剂与高岭土颗粒之间通过离子键结合;利用扫描电镜观察絮体形态,发现其结构密实,有利于絮体沉降。推测其絮凝机理为絮凝剂和高岭土之间首先以离子键结合,然后通过吸附架桥作用絮凝沉淀。     

糠醛渣对苯酚吸附性能研究

文章研究了糠醛渣对苯酚的吸附性能。采用低温N2吸附-脱附和傅里叶红外光谱对糠醛渣进行了表征,测得糠醛渣的平均孔径为14.5 nm,孔容为0.016 cm3/g,BET比表面积为5.3 cm2/g,并且官能团丰富。室温下,考察了吸附时间、溶液pH值、苯酚的初始浓度、糠醛渣的粒度对吸附苯酚的影响。结果表明,当糠醛渣粒度为20目、加入量为2.0 g,吸附时间25 min,pH值为3,苯酚的初始浓度为0.1 g/L时,对溶液中苯酚的吸附率为95.2%。糠醛渣丰富的孔结构和较大的比表面积使其作为吸附剂,实现了以废治废的目的。