皮革厂固体废弃物的生物降解及沼气生产

Biodegradation and biogas production from solid waste of tanneries

制革生产过程中会产生大量的废弃物,给环境带来了严重负担,也成为制革行业经济发展的绊脚石。旨在估测该行业生产中所产生固体废弃物(蓝湿革革屑和污水处理厂的污泥(简称为WWTP))的可生物降解性,以取代将其作为垃圾进行填埋处理。生物降解过程中会产生沼气,则该处理方式也可以用作其他废弃物处理及可再生能源生产。该研究通过台式生物反应器在设定的条件下进行生物降解测试,对生物质和产生的气体(主要是甲烷和氧气)进行分析。结果表明:对25m L污泥和1g蓝湿革进行生物降解,产生甲烷的平均累积量约为250m L。生物降解测试证明该方法不仅能相对较快地产生沼气且气体中甲烷含量较高,而且生物反应器容易打开,同时易于生物质化,所以使用此方法来评估沼气的生产和生物质的收集是可行的。不过在消解过程中如果氧气进入,会使生物反应器的对位突然打开,但是当微生物组成联合体时,氧气的进入对厌氧微生物并不存在杀伤力。有人认为在纯的培养基里,氧气会对生物降解测试中的接种物产生重要的影响,而该接种物是用于提高沼气产生过程中甲烷的含量,但是在纯的培养基中并没有检测到这些微生物。

The economic importance of leather industry has as concern the environmental issues on waste generated in the process. In this context, this study aims to evaluate the biodegradation of the most problematic solid waste generated by this industry （wet-blue leather shaving and sludge from wastewater treatment plant （WWTP）） as an alternative to its landfill disposal. As there is biogas production in biodegradation, this treatment acts simultaneously on waste disposal and renewable energy production. Through biodegradation tests in bench bioreactors under controlled conditions, biomass and generated gas （mostly methane and oxygen） were analyzed. As a result, the average accumulated production of methane among assays was approximately 250mL for 25mL of sludge and lg of wet-blue leather biodegraded. Biodegradation tests proved to be viable for biogas generation evaluation and for biomass collection, because they had relatively quick results of biogas with high methane content generation and bioreactors presented easy opening and access to biomass. However, they presented the counterpoint of bioreactors opening interfere abruptly in digestion process due to oxygen entry. And although oxygen interference in reaction did not present lethality to anaerobic microorganisms when they are amidst a consortium of microorganisms, it is believed that in pure cultures oxygen has a major influence, as there was no detection of these microorganisms in pure cultures, for subsequent addition of inoculum in biodegradation tests for magnification of methane percentage in biogas.