-
截至2021年底,我国城镇生活垃圾年清运量为2.487×108 t,其中生活垃圾无害化处理量达2.484×108 t,占比接近100%[1]。在垃圾无害化处理过程中,恶臭气体释放是亟待解决的难题之一。它不仅会污染空气,还会对周边居民的身体健康造成危害[2-5]。目前,应用于治理恶臭气体的方法主要包括物理、化学和生物法3种方法 [6-8]。常用的除臭技术如垃圾覆盖技术和除臭剂技术等,都是将上述多种方法综合应用,从而达到较好的除臭效果。其中常用于处理垃圾填埋场的恶臭气体的覆盖技术,以物理法阻隔为主,化学法联合除臭为辅。该技术具有使用规模较大、持续时间长的优点,但存在操作、运输不便的缺点。除臭剂技术可利用多种具有不同去除原理的除臭剂进行恶臭气体的去除,如物理吸附除臭剂、化学法除臭剂、植物除臭剂、微生物除臭剂等。除臭剂具有便于运输储存的优点,但存在效果不稳定、持续时间较短的缺点。尤其是在垃圾中途转运过程中,因路途颠簸的等特点特性,单独使用上述2种除臭技术很难实现恶臭气体的有效阻隔。高分子喷涂薄膜技术,能够方便快捷地形成兼具物理覆盖以及化学、生物法联合的恶臭去除的薄膜,从而实现恶臭气体的有效去除[9-11]。
普鲁兰多糖是一种天然线性高分子[12],由于其具有良好的成膜性[13],且无毒无害,有较好的生物可降解性能,已在医疗、食品、石油、化工、轻工业等领域广泛应用。非离子型表面活性剂吐温80由于其无毒、无害,常应用于医药配方、食品薄膜等领域[14],能够增加所制备薄膜的粘附性,使其更紧密地黏附在垃圾表面。除此之外,在成膜材料中添加功能纳米材料,能够增强薄膜对于恶臭气体的吸附。其中,纳米零价铁 (nanoscale zero-valent iron, nZVI) 具有典型的核壳结构,内核为零价铁,外层为氧化铁[15],能够作为填充物填充到有机高分子链的孔隙中,使其形成的薄膜更加致密,提高薄膜的物理阻气能力;另因nZVI表面的氧化层与硫化物发生反应,可达到固定、去除有毒有害硫化物的效果[16]。
本研究选取普鲁兰多糖作为成膜基质材料,对恶臭气体的主要成分硫化氢 (H2S) 和氨气 (NH3) 进行阻隔实验。首先,拟测试普鲁兰多糖喷涂薄膜对H2S和NH3的阻隔能力,并探究在普鲁兰多糖喷膜溶液中添加表面活性剂吐温80、无机纳米材料nZVI,对成膜性能及气体阻隔性能的影响等,以为存余垃圾开挖及中途转运过程中垃圾恶臭气体的有效阻隔提供参考。开发高分子成膜配方并应用于垃圾短途转运过程中恶臭气体的阻隔具有实际使用价值。
普鲁兰多糖基恶臭气体阻隔喷膜的制备及性能
Preparation and performance of polymer pullulan-based film spraying agent for garbage odor barrier
-
摘要: 针对存余垃圾在开挖、运输过程中释放的恶臭气体,研发一种具有阻隔功能的环保型喷膜配方。选取水溶性的高分子普鲁兰多糖作为成膜基质材料制备成喷膜溶液后,通过改变成膜基质的质量分数,添加表面活性剂、纳米功能性材料等途径进行成膜配方优化,使其在应用中快速成膜发挥阻隔作用。结果表明,质量分数为1%普鲁兰多糖、0.1%吐温80所制成的喷膜溶液,最短可在5 min内形成致密的薄膜,并且对质量浓度70 mg∙m−3的硫化氢 (H2S) 和氨气 (NH3) 的气体截留率分别达到84.73%和86.43%。在此基础上添加质量浓度0.2 mg∙L−1的纳米零价铁 (nanoscale zero-valent iron, nZVI) ,喷膜溶液对相同质量浓度的H2S气体截留率提高至91.74 %,NH3气体截留率提高至99.08%。以上研究结果可为存余垃圾资源化利用,尤其是中途转运过程中的恶臭气体阻隔提供参考。Abstract: Aiming at the actual application scenarios of odorous gas emission during the transfer of stock rubbish, polymer spraying film was developed to effectively block the short-distance transportation of odorous gas. Polymer pullulan was selected as a film-forming matrix material, and the film spraying agent was optimized by changing the content of the film-forming matrix and adding surfactants or functional nanomaterials to obtain a spraying film with excellent odor barrier property. Results showed that the formula made by 1% pullulan and 0.1% tween 80 had excellent gas barrier effect. The removal efficiency on H2S and NH3 could reach 84.73% and 86.43% when the concentration of H2S and NH3 were 70 mg∙m−3. After adding 0.2 mg∙L−1 nZVI, the removal efficiency of H2S and NH3 were promoted to 91.74% and 99.08%. This study can provide a reference for the resource utilization of stock rubbish, especially for the odor gas barrier in the process of midway transportation.
-
Key words:
- stock rubbish /
- odor barrier /
- hydrogen sulfide /
- ammonia /
- spraying film materials
-
表 1 普鲁兰多糖喷膜配方
Table 1. Formulas of pullulan film spraying agent
样品编号 普鲁兰多糖质量分数/% 吐温80质量分数/% 1 1 0.1 2 1 0.3 3 1 0.5 4 3 0.1 5 3 0.3 6 3 0.5 7 5 0.1 8 5 0.3 9 5 0.5 表 2 不同天气条件下喷膜剂的成膜时间
Table 2. Film forming time of spray agent under different weather conditions
温度/ ℃ 湿度/% 光照 成膜时间/min 26 90 无 35.42 26 83 无 22.07 27 71 有 11.67 29 77 有 9.23 32 37 有 4.28 32 59 有 5.90 32 70 无 13.52 32 73 无 19.10 36 60 有 5.70 36 54 无 7.82 -
[1] 中华人民共和国住房和城乡建设部. 2021年城乡建设统计年鉴[EB/OL]. [2022-10-12]. https://www.mohurd.gov.cn/gongkai/fdzdgknr/sjfb/tjxx/jstjnj/index.html, 2022 [2] 张杰. 生活垃圾末端处置过程二次污染控制技术研究[M]. 同济大学, 2016. [3] 崔玉雪, 郭广寨, 黄皇, 等. 垃圾填埋场苍蝇和恶臭污染控制技术研究进展[J]. 环境污染与防治, 2016, 38(1): 69-75,110. doi: 10.15985/j.cnki.1001-3865.2016.01.013 [4] 李海青, 刘欣艳, 孙宇, 等. 垃圾焚烧厂恶臭污染物分布特征及健康风险评价[J]. 环境污染与防治, 2020, 42(9): 1158-1162. [5] 孙翔, 肖芸, 阚慧, 等. 基于生命周期分析的餐厨垃圾肥料化利用环境风险评价研究[J]. 环境污染与防治, 2013, 35(8): 33-38. doi: 10.3969/j.issn.1001-3865.2013.08.008 [6] 朱登磊, 赵修华. 有机垃圾处理机排放臭气的生物脱臭研究[J]. 环境科学与技术, 2007, 30(9): 89-91. doi: 10.3969/j.issn.1003-6504.2007.09.031 [7] DAI Z N, ZENG F S, LIU J, et al. Application of deodorant in odor control of municipal solid waste//IOP Conference Series: Earth and Environmental Science[J]. IOP Publishing, 2018, 192(1): 012063. [8] 杨凯雄, 李琳, 刘俊新. 挥发性有机污染物及恶臭生物处理技术综述[J]. 环境工程, 2016, 34(3): 107-111,179. doi: 10.13205/j.hjgc.201603022 [9] YOU J, OH B, YUN Y S, et al. Improvement in barrier properties using a large lateral size of exfoliated graphene oxide[J]. Macromolecular Research, 2020, 28(8): 709-713. doi: 10.1007/s13233-020-8089-x [10] TRAN T T D, TRAN P H L. Controlled release film forming systems in drug delivery: the potential for efficient drug delivery[J]. Pharmaceutics, 2019, 11(6): 290. doi: 10.3390/pharmaceutics11060290 [11] ATES O. Systems biology of microbial exopolysaccharides production[J]. Frontiers in Bioengineering and Biotechnology, 2015, 3: 200. [12] 孙华, 张彦昊, 张翔, 等. 普鲁兰多糖在食品保鲜和生物医学中的应用综述[J]. 江苏农业科学, 2019, 47(20): 48-52. doi: 10.15889/j.issn.1002-1302.2019.20.011 [13] 于雪梅. 新型普鲁兰多糖抗菌食品包装膜制备及性能研究[D]. 黑龙江: 哈尔滨工业大学, 2018. [14] OH S, CHO S, LEE J. Preparation and characterization of hydrophilic PLGA/Tween 80 films and porous scaffolds[J]. Molecular Crystals and Liquid Crystals, 2004, 418(1): 229-241. doi: 10.1080/15421400490479352 [15] YAN W, LIEN H L, KOEL B E, et al. Iron nanoparticles for environmental clean-up: recent developments and future outlook[J]. Environmental Science:Processes & Impacts, 2013, 15(1): 63-77. [16] SU L, ZHEN G, ZHANG L, et al. The use of the core–shell structure of zero-valent iron nanoparticles for long-term removal of sulphide in sludge during anaerobic digestion[J]. Environmental Science:Processes & Impacts, 2015, 17(12): 2013-2021. [17] LI L, HAN Y, YAN X, et al. H2S removal and bacterial structure along a full-scale biofilter bed packed with polyurethane foam in a landfill site[J]. Bioresource Technology, 2013, 147: 52-58. doi: 10.1016/j.biortech.2013.07.143 [18] 刘建伟, 高柳堂. 生物滤池高径比对其去除恶臭物质和微生物气溶胶特性的影响[J]. 环境污染与防治, 2018, 40(1): 15-18. doi: 10.15985/j.cnki.1001-3865.2018.01.004 [19] RYBARCZYK P, SZULCZYŃSKI B, GĘBICKI J, et al. Treatment of malodorous air in biotrickling filters: A review[J]. Biochemical Engineering Journal, 2019, 141: 146-162. doi: 10.1016/j.bej.2018.10.014 [20] SU L, LIU C, LIANG K, et al. Performance evaluation of zero-valent iron nanoparticles for high-concentration H2S removal from biogas at different temperatures[J]. RSC Advances, 2018, 8(25): 13798-13805. doi: 10.1039/C7RA12125C [21] LI X, ZHAN Y, SU L, et al. Sequestration of sulphide from biogas by thermal-treated iron nanoparticles synthesized using tea polyphenols[J]. Environmental Technology, 2020, 41(6): 741-750. doi: 10.1080/09593330.2018.1509891 [22] SHINGEL K I. Determination of structural peculiarities of dexran, pullulan and γ-irradiated pullulan by Fourier-transform IR spectroscopy[J]. Carbohydrate Research, 2002, 337(16): 1445-1451. doi: 10.1016/S0008-6215(02)00209-4 [23] SAKATA Y, OTSUKA M. Evaluation of relationship between molecular behavior and mechanical strength of pullulan films[J]. International Journal of Pharmaceutics, 2009, 374(1/2): 33-38. doi: 10.1016/j.ijpharm.2009.02.019