Photo-/Bio-degradability of Agro Waste and Ethylene–Propylene Copolymers Composites Under Abiotic and Biotic Environments

Composites were prepared by two methods, (i) graft copolymerization (GFC) of isotactic polypropylene (PP) with maliec anhydride, (MAH) followed by esterification with coir fiber and (ii) by direct reactive mixing (DFC) of polypropylene (PP) and ethylene–propylene (EP) copolymers with MAH and peroxide with coir fiber. These composites, after molding in films (5×5 cm, m thickness) were examined for susceptibility to biological attack by measuring the percentage weight loss in compost upto 6 months, periodically, and fungal colonization on surface of the samples, when kept as sole carbon source for the growth of Aspergillus niger in culture medium upto 40 days. Photodegradation was evaluated by monitoring the variations in FT-IR spectrum and crack formation after successive treatment with UV light (≥290 nm) for 0, 20, 50 and 100 h at 60°C in the presence of air. Specimens of virgin PP were taken as a reference during all period of photo and biodegradation studies. Significant changes were observed depending on the preparation methods during photodegradation and biodisintegration of composites. DFCs samples were disintegrated faster than GFCs during the composting whereas, in culture, GFCs were covered highly in well uniform way by fungi. It was observed that photo-oxidative ageing directly enhanced the biodegradability of composites as the increase in fungal growth rate and decrease in weight during composting were found. It was concluded that extent of compatibilization had a profound effect on photo-oxidation and biodisintegration of composite material; consequently ester bonds were main units during fungal consumption. Composition of monomers in copolymers was also showing significant effect on the degradability which decreased with increasing content of ethylene in ethylene–propylene (EP) copolymers.     

SPEEK涂层纳滤膜处理草甘膦废水

以聚醚砜(PES)超滤膜为基膜,采用涂层法制备磺化聚醚醚酮(SPEEK)中空纤维复合纳滤膜,研究其对草甘膦的浓缩和去除。考察了该膜在浓缩草甘膦模拟废水中的操作条件,如跨膜压力、进料浓度、进料pH和离子强度等对通量和截留率的影响。结果表明,随跨膜压力的增加,草甘膦的截留率和水通量均增加,当跨膜压力由0.3 MPa增加到0.8 MPa时,水通量由34.0 L/(m2.h)增加至98.0 L/(m2·h),截留率高于98%;增加进料浓度和离子强度,截留率和通量均减小,当进料浓度由100 mg/L增至1 000 mg/L,水通量降低12.4%,截留率降低8.4%;而pH由3.0升至11.0时,截留率增加,但通量几乎不变。当把该膜材料用于浓缩含高浓度NaCl的草甘膦母液时,发现在0.5 MPa压力和pH=11.0下,复合纳滤膜对NaCl的截留率低于20%,对草甘膦的截留率可达90%。这说明该复合纳滤膜可以把草甘膦与NaCl有效分离开来,为草甘膦的回收利用提供了基础。     

硅烷化改性MCM-41负载戊二酸锌催化CO2与环氧丙烷共聚制备可降解材料

以三甲基氯硅烷(TMCS)为硅烷化试剂,对MCM-41分子筛进行表面改性处理,并以此为载体制备负载型戊二酸锌催化剂(ZnGA/TMCS-MCM-41);采用红外光谱、氮气吸附-脱附和X射线衍射等分析手段对催化剂进行表征,结果表明:三甲基氯硅烷基团被成功接枝到MCM-41分子筛表面,形成比表面积略低的硅烷化MCM-41载体,但其骨架未被破坏,负载活性物质过程中,戊二酸锌能以更小的粒径均匀分散到载体的表面;聚合反应实验表明,与单纯戊二锌催化剂相比,ZnGA/TMCS-MCM-41催化剂对CO2与环氧丙烷(PO)的共聚反应显示出更高的催化效率和更快的反应速度,在反应34 h后催化效率达到86.3 g聚合物/g ZnGA;红外光谱和核磁分析表明所得共聚产物中碳酸酯结构含量大于95.8%。     

过量生石灰对污泥含水率和有机物含量的影响

为了研究生石灰(氧化钙,CaO)处理活性污泥对污泥含水率和有机物含量的影响,通过向南京某城市污水处理厂出厂污泥投加过量CaO进行脱水实验,测定投加CaO后污泥的含水率;烘干后的脱水污泥进行热重实验,研究CaO投加量对污泥中有机组分含量的影响.脱水实验表明:随着CaO与污泥质量比的增大,污泥含水率迅速减小,当质量比达到1.5时,污泥达到完全脱水;投加过量CaO的脱水污泥呈干燥的粉末状,粒度均匀,可作为水泥生产的辅料。热重实验表明:投加CaO后单位干泥失重百分比随CaO与污泥质量比增大而逐渐减小,向污泥中投加CaO有利于污泥中有机组分的释放和去除,实现污泥的稳定化。     

降解聚丁二酸丁二醇酯菌株的诱变选育及降解性能

诱变选育是基因资源开发的重要手段之一,为了对降解聚丁二酸丁二醇酯(PBS)菌株的降解性能进行改良,选择具有一定降解PBS能力的尖孢镰刀菌(Fusarium oxysporum)DSCF-8为出发菌株,分别研究了其在5种诱变途径下的突变效应及最佳诱变条件,测定了突变菌株D8B14在不同条件下的降解性能。结果表明,复合诱变途径的高效降解菌株获得率大于单因子诱变途径,分别达到了4.55%和1.30%,但突变株的降解特性遗传不稳定;硫酸二乙酯单因子诱变效应大于紫外线诱变和微波诱变,且得到的突变株较复合诱变得到的菌株具有更强的遗传稳定性,最佳诱变条件为5%的浓度处理40 min。硫酸二乙酯诱变得到的突变株D8B14传代稳定且降解性能优异,其对PBS薄膜的降解率较出发菌株提高了34.49%,粗酶液酶活性提高率为23.86%。该突变株在35℃条件下仍表现出较高的降解能力,对不同的初始pH条件亦具有更强的耐受能力,尤其在pH 4.0或pH 9.0的酸性和碱性条件下,降解率分别提高了13.26%和27.04%。     

聚合硫酸铝铁预处理垃圾渗滤液

采用聚合硫酸铝铁（PAFS）预处理垃圾渗滤液中的高浓度有机物,为后续的吸附环节及生物处理阶段创造良好的水质条件。试验结果表明,在低投加量的条件下,PAFS投加量在200mg／L、pH为8．0、沉淀时间为40min时,混凝效果最佳,CODcr的去除率可达37．5％。     

钙质煤渣吸附剂脱除烟气中二氧化硫的实验研究

利用锅炉本身排出的煤渣作脱硫剂的基本核粒,配人少量的石灰,加水搅拌均匀,使石灰裹覆在煤渣颗粒表面,制成具有较大比表面积的钙质煤渣脱硫剂,用于烟气脱硫实验研究.实验结果表明,钙制煤渣脱硫剂比未经处理的煤渣脱硫率高,在一定的石灰添加范围内(10%～20%),脱硫率随石灰添加量的增加而增加,并存在一最佳用量.     

石灰湿式洗涤法脱硫的应用研究

本文介绍了石灰湿式洗涤法脱硫的改进思路 ,通过采用三级串联喷淋、低液气比和投加防垢剂等办法 ,成功解决了设备管道结垢问题。实践表明 ,该法具有工艺简单、投资省、操作简便、运行费用低、脱硫率高等特点。     

石灰湿法脱硫传质－反应过程机理

对以族流板塔作吸收器的石灰湿法烟气脱硫技术进行了试验研究,分析了石灰浆液吸收ＳＯ２的传质－反应过程,并提出了Ｃａ（ＯＨ）２浆液吸收ＳＯ２的传质－反应过程机理。本机理认为,总反应速度由气相中ＳＯ２的扩散（气相阻力）和液相中Ｃａ（ＯＨ）２固体的溶解（包括在液相阻力之内）及扩散控制;同时认为,反应过程可分为气相阻力控制、气液相阻力共同控制、液相阻力控制３个阶段。此外,本机理得到了实验的验证。以上结果将有助于改进石灰湿法烟气脱硫工业装置的设计和操作。     

PBS降解过程对植物发芽和生理特性的影响研究

采用青菜（Green vegetables）和生菜（Romaine lettuce）的种子发芽和室外盆栽实验,通过考察植物的种子发芽、生物量以及叶绿素质量浓度等指标,研究了可生物降解材料聚丁二酸丁二醇酯（PBS）对青菜和生菜发芽和生长过程中生理特性（植株地上鲜、干质量,地下鲜、干质量,株高,根长,叶片数,叶绿素质量浓度）的影响。研究结果表明：（1）土壤中加入PBS有利于青菜种子的发芽,较大幅度的提高了其发芽率、苗长、根长等,并且随着PBS质量分数的增加这种促进作用越发明显,PBS×100处理组的苗长和根长较空白对照组分别增长了12.9%和26.1%;（2）低质量分数的PBS对青菜和生菜的发芽、生长以及叶绿素的合成具有一定的促进作用,但是高质量分数的PBS则会产生轻微的抑制作用。