论对危险废物及副产品的界定和管理

通过厘清固体废物、危险废物、副产物等的概念,分析上述物质及副产品的特性,阐述危险废物和副产品间的转换关系,从适用标准、企业实例两方面入手分析危险废物和副产品该如何界定,着重分析副产品在生产管理过程中的关注点,以期为生产企业及行政管理部门的固废管理工作提供参考.     

餐厨垃圾堆肥理化特性变化规律研究

餐厨垃圾主要包括厨余和泔脚,二者的化学组成、物料结构以及初始微生物量均存在差异. 对厨余和泔脚分别与相同质量比的木屑混合堆制的一次好氧堆肥过程进行了比较研究. 结果表明,在相同好氧堆肥条件下,二者的特性变化不同:与厨余堆肥系统相比,泔脚堆肥系统初始水溶性w(C)/w(N)高,堆肥pH较低,高温持续时间长,CO₂释放率高,NH₃挥发少,氮素损失低,堆制后堆肥含氮量升高; 但泔脚一次堆肥所需时间偏长,应采取有效方法加速其堆肥进程. 厨余堆肥系统升温快,堆肥周期短, 但生物可利用碳的短缺造成系统氮素损失量大,可采用在厨余堆肥中添加适当碳源等措施来减少氮素损失.      

宁东能源化工基地固体废物中汞含量分布及对环境影响

通过分析宁东能源化工基地各大燃煤电厂以及煤化工厂固体废物样品,研究了固体废物中的汞分布规律及环境影响。结果表明:汞易在脱硫石膏、粉煤灰和气化粗渣中富集,汞浓度分别为0.16、0.24、0.15 mg/kg,而炉渣和气化细渣中的汞含量则相对较低,分别为0.05、0.03 mg/kg。通过化学组成及汞含量数据分析发现,出现这种情况的原因与汞本身易挥发的性质和固体废物的物化性质有关。此外,通过固体废物浸出毒性实验发现,脱硫石膏、粉煤灰、气化粗渣的浸出汞浓度小于浓度限值(0.1 mg/L),而气化细渣因锅炉回用,不参与填埋,汞又不易在炉渣中富集,故总体上宁东能源化工基地的固体废物无汞环境污染倾向。     

气封壁高浓度有机污染物超临界水氧化处理系统

利用干燥空气替换亚临界水作为蒸发壁流体,对传统蒸发壁超临界水氧化反应器进行了改进,即将干燥空气用作污染物超临界水氧化反应氧化剂的同时,又作为该超临界水氧化反应体系的密封介质,避免其与反应器内壁的直接接触,以改善超临界水氧化反应器的耐腐蚀性能。通过对采用城市活性污泥和异丙醇配制的高浓度难降解污染物悬浮液进行超临界水氧化处理后,发现反应器内衬陶瓷管在实验前后无论是外观形貌,还是结构组成均未发生明显变化;处理后液体COD降至80 mg/L以下,去除率达到99.6%以上,固体残渣量约为污染物总量的1%,且体系运行过程中压力和温度控制准确,可操作性强。进一步验证了将干燥空气作为超临界水氧化体系的密封介质具有可行性,同时表明,该气封壁超临界水氧化反应系统可用于高浓度难降解有机污染物的环境处理。     

城市生物质废物中温单级厌氧消化中试研究

建立了城市生物质废物中温单级厌氧消化中试反应器,对城市生物质废物厌氧消化过程系统稳定性、产甲烷性能及有机物的去除效果进行解析.反应器稳定运行410 d,共经历2.4、3.6、4.8、6.0 kg VS/(m3·d)4个负荷,反应器pH稳定在7.2 ～7.6之间,有机酸浓度＜500 mg/L.在负荷6.0 kg VS/(m3·d)时反应器平均容积产气率4.25m3/(m3·d),有机物去除率为63.2％;另外,实验结果表明,厌氧消化过程对蛋白质、脂肪、纤维素及多糖类物质的去除效果有明显差异,其中脂肪类物质去除率为98.2％,产沼气贡献率为38.8％.实现了针对我国城市生物质废物的高负荷高效厌氧消化,为我国城市生物质废物厌氧消化规模化处理提供了基础数据.     

社会资本对农民环保投资意愿的影响分析——来自湖北农村农业废弃物资源化的实证研究

我国尚处于转轨经济时期,市场体系建设不完善,尤其是在广大农村地区,正式制度的建设和发展相对滞后,社会资本在农村社会经济中的作用更加突出。鉴于此,本文基于Putnam的社会资本理论,以农村农业废弃物资源化为例,基于其"集体行动"与"利他主义"属性,应用Tobit模型系统分析了3个层面的社会资本的核心要素(信任、互惠规范、公民参与网络)对农民环境保护投资意愿的影响冲击。研究结果表明:1农业废弃物资源化得到了多数农民的认同,68.3%的受访农民对农业废弃物资源化具有投资意愿,且意愿投资水平为8.46-12.39元/月;2社会资本变量中对农民环保投资意愿的贡献度大小排序依次是制度信任公民参与网络人际信任互惠规范;3人力资本中的文化程度、物质资本中的家庭纯收入、控制变量中的是否兼业、是否为村干部对农民环保投资意愿均表现出积极的作用;4要缩小私人投资与社会最优投资之间的差距,实现农业废弃物资源化利用在经济效益、环境效益上的统一,需要政府或宏观经济管理者在制度安排上向其倾斜:通过强化政策支持或舆论引导提升农村的社会资本水平,增进农民对"信任互助"、"团队合作"的认知;完善环境保护相关法律法规,做到有法可依、执法必严、违法必究,改变民众对法规持有的"法不责众"态度;大力发展农村地区的基础教育,提高农村地区人们的文化教育水平。     

Polybrominated diphenyl ethers occurrence in major inflowing rivers of Lake Chaohu (China): Characteristics,potential sources and inputs to lake

Eight commonly occurring polybrominated diphenyl ethers (PBDEs), including BDE 28, 47, 99, 100, 153, 154, 183, 207, and 209, were investigated in water samples from seven major inflowing rivers of Lake Chaohu to determine the distribution characteristics, potential sources and inputs to the lake. The sum of 8 BDE congeners (Σ₈PBDEs) had a concentration varied from 0.31 to 84 ng L⁻¹, with those of BDE 209, BDE 47, BDE 99, and BDE 153 being 0.31–83, <0.012–0.36, <0.012–1.3, and <0.012–0.77 ng L⁻¹, respectively. These levels were in the high range of the global PBDEs concentrations in the water environments. The highest concentrations of Σ₈PBDEs were detected in the western rivers, of which the main pollution sources were strongly related to human activities in urban centers, such as automobile-derived wastes. A sewage treatment plant was likely an important source of the lower brominated BDEs input to one western river. The correlation analyses (all p < 0.05) between PBDEs and DOC, TN, TP, and EC, suggested that the distributions and sources of PBDEs in rivers might also be related with the soil erosion by heave floods. Σ₈PBDEs input to Lake Chaohu from the rivers outlets was estimated at 344 kg yr⁻¹ during the flood season. BDE 209 was the dominant contributor with an input of 340 kg yr⁻¹, followed by BDE 99 (1.3 kg yr⁻¹), BDE 47 (0.83 kg yr⁻¹) and BDE 153 (0.60 kg yr⁻¹).     

微波联合酸预处理对厨余垃圾酶水解糖化的影响

酶水解糖化是厨余垃圾制造燃料乙醇的关键步骤,对厨余垃圾进行预处理以促进糖化过程,具有重要意义.以学生食堂厨余垃圾为原料,以常规、微波为加热手段,比较不同预处理方式对厨余垃圾酶水解的影响.结果表明,微波加热结合酸性溶剂的预处理方式最有利于厨余垃圾酶水解糖化.考察微波联合酸预处理的影响因素,得到最佳的预处理条件为:溶剂为H2SO4、溶剂浓度3％、微波功率80 W,预处理时间40 min,固液比1∶8,该条件预处理后,与未经预处理的厨余垃圾酶水解糖产量相比,提高46.1％.     

耐酸厌氧消化污泥处理餐厨垃圾

采用耐酸驯化的厌氧消化污泥处理餐厨垃圾,在酸性条件下（pH=4．5）,对实验装置容积负荷从1．0kgVS／（m3·d）分9次逐级增加到5．0kgVS／（m3·d）的过程进行了跟踪监测,并较深入地研究了驯化污泥代谢活性和处理效果。实验结果表明,pH4．5的耐酸厌氧消化污泥,最佳投加负荷约为4．5kgVS／（m3·d）,此负荷下容积产气率,CH4含量平均值均达最大,分别为1．68m3／（m3·d）,75．0％。耐酸厌氧消化装置持续增料运行46d,产甲烷菌仍能保持较高的活性,其COD去除率范围为40．4％-75．0％,仍能保持pH7．2时处理效果的65．0％-91．8％,表明在低pH、低碱度下实现稳定的产甲烷过程是可行的。     

Hydrothermal treatment of MSWI fly ash for simultaneous dioxins decomposition and heavy metal stabilization

Researches on the hydrothermal treatment of municipal solid waste incineration (MSWI) fly ash were conducted to eliminate dioxins and stabilize heavy metals. In order to enhance decomposing polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) during hydrothermal process, a strong reductant carbohydrazide (CHZ) is introduced. A hydrothermal reactor was set up by mixing raw MSWI fly ash or the pre-treated fly ash with water and then heated to a pre-set temperature; CHZ was spiked into solution according to specially defined dosage. Experimental results showed that under the temperatures of 518 K and 533 K, the decomposition rates of PCDDs/PCDFs were over 80% and 90%, respectively, by total concentration. However, their toxic equivalent (TEQ) decreased only slightly or even increased due to the rising in concentration of congeners 2, 3, 7, 8-TCDD/TCDF, which might be resulted from the highly chlorinated congeners losing their chlorine atoms and being degraded during the hydrothermal process. Better results of TEQ reduction were also obtained under the higher tested temperature of 533 K and reactor with addition of 0.1%wt CHZ was corresponded to the best results. Good stabilization of heavy metals was also obtained in the same hydrothermal process especially when ferrous sulphate was added as auxiliary agent.