城市生活垃圾智能分类技术研究与应用进展

城市生活垃圾清运量逐年增加,由此带来的环境问题日益严峻.不同垃圾组分有其各自适宜的处理与利用方式,因此,有效的垃圾分类技术具有重要意义.我国现有的以人工为主的垃圾分类方式存在效率低、成本高、准确性差等弊端,而垃圾智能分类技术是解决相关瓶颈的重要手段.本文简述了中国代表性城市生活垃圾分布和近年变化趋势,从密度、电、磁、声...     

Control factors of partial nitritation for landfill leachate treatment

Anaerobic ammonium oxidation (ANAMMOX) technology has potential technical superiority and economical efficiency for the nitrogen removal from landfill leachate, which contains high-strength ammonium nitrogen (NH4 -N) and refractory organics. To complete the ANAMMOX process, a preceding partial nitritation step to produce the appropriate ratio of nitrite/ammonium is a key stage. The objective of this study was to determine the optimal conditions to acquire constant partial nitritation for landfill leachate treatment, and a bench scale fixed bed bio-film reactor was used in this study to investigate the effects of the running factors on the partial nitritation. The results showed that both the dissolved oxygen (DO) concentration and the ammonium volumetric loading rate (Nv) had effects on the partial nitritation. In the controlling conditions with a temperature of 30±1℃, Nv of 0.2-1.0 kg NH4 -N/(m3d), and DO concentration of 0.8-2.3 mg/L, the steady partial nitritation was achieved as follows: more than 94% partial nitritation efficiency (nitrite as the main product), 60%-74% NH4 -N removal efficiency, and NO2--N/NH4 -N ratio (concentration ratio) of 1.0-1.4 in the effluent. The impact of temperature was related to iVv at certain DO concentration, and the temperature range of 25-30癈 was suitable for treating high strength ammonium leachate. Ammonium-oxidizing bacteria could be acclimated to higher FA (free ammonium) in the range of 122-224 mg/L. According to the denaturing gradient gel electrophoresis analysis result of the bio-film in the reactor, there were 25 kinds of 16S rRNA gene fragments, which indicated that abundant microbial communities existed in the bio-film, although high concentrations of ammonium and FA may inhibit the growth of the nitrite-oxidizing bacteria and other microorganisms in the reactor.     

Nitrogen interception in floodwater of rice field in Taihu region of China

A field experiment located in Taihu Lake Basin of China was conducted,by application of urea or a mixture of urea with manure, to elucidate the interception of nitrogen(N)export in a typical rice field through"zero-drainage water management"combined with sound irrigation,rainfall forecasting and field drying,N concentrations in floodwater rapidly declined before the first event of field drying after three split fertilizations,and subsequently tended to retum to the background level.Before the first field drying,total particulate nitrogen(TPN)was the predominant N form in floodwater of plots with no N input,dissolved inorganic nitrogen(DIN)on plots that received urea only,and dissolved organic nitrogen(DON)on plots treated with the mixture of urea and manure.Thereafter TPN became the major form.No N export was found from the rice field,but total nitrogen(TN)of 15.8 kg/hm~2 was remained,mainly due to soil N sorption.The results recommended the zero-drainage water management for full-scale areas for minimizing N export.     

pH对吉林西部湖泊底泥中不同形态氟迁移转化影响的实验研究

针对吉林西部花敖泡、道字泡、大布苏泡等湖泊水体及底泥中氟污染严重情况,利用土壤的连续分级浸提法,分别在天然状态下及不同pH下将吉林西部湖泊底泥中的氟逐级提取,依次为水溶态氟、可交换态氟、铁锰结合态氟、有机束缚态氟及残余态氟.研究吉林西部湖泊底泥中氟赋存形态及主要影响因素,并基于pH对底泥中不同形态氟分布的影响来研究底泥...     

金属盐改性活性氧化镁对饮用水中氟离子的去除性能

饮用水中氟含量超标会损害人体的健康,本研究研制了一种改性吸附剂用于去除饮用水中过量的氟离子。本研究采用浸渍,焙烧的方法将金属盐负载到活性氧化镁上,制备改性活性氧化镁,考察了其除氟效果和吸附除氟的主要影响因素。结果表明,经过钙盐,铁盐改性后的活性氧化镁最大吸附容量显著增加,在复杂水体环境中仍有突出的除氟效果;改性吸附剂适宜pH为3~10;金属盐改性活性氧化镁处理水样不会有Mg²⁺和浸渍盐离子溶出,是一种安全可靠的吸附除氟材料。     

悬浮填料生物膜反应器细菌群落季相更替对处理效果的稳定作用

针对生物实验室污水处理难度高及其秋冬季节达标率低的问题,采用改进工艺的悬浮填料生物膜反应器(moving bed biofilm reactor, MBBR)进行连续处理,观察秋冬季节MBBR水质处理效果,利用高通量测序技术研究环境因子水温(Tw)、溶解氧(DO)、pH对生物膜细菌群落更替的影响以及主要微生物种群变化。结果表明,Tw由26 ℃下降到10 ℃期间,反应器COD、${{\rm{NH}}_4^ + }$-N去除率仍然分别保持在75%、80%左右,MBBR出水稳定在一级A标准。变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和浮霉菌门(Planctomycetes)是生物膜主要优势菌门,Tw的下降引起拟杆菌门的相对丰度显著升高。假单胞菌属(Pseudomonas)和黄杆菌属(Flavobacterium)在低Tw下成为优势菌属,动胶菌属(Zoogloea)相对丰度保持稳定。通过冗余分析(RDA)发现,DO与短波单胞菌属(Brevundimonas)、pH与脱氯单胞菌(Dechloromonas)、固氮弧菌属(Azoarcus)具有显著正相关性,Tw与假单胞菌属、黄杆菌属具有显著负相关性。MBBR结果揭示,细菌群落动态更替是MBBR出水水质仍然保持稳定的重要原因。     

电解液循环对废手机线路板碱性矿浆电解回收的影响

针对废手机线路板碱性矿浆电解资源化过程中电解液带来的污染问题,采用氨-氯化铵碱性矿浆电解液循环回收废手机线路板中金属,以降低能耗、减少污染。研究了氨-氯化铵碱性矿浆电解体系从废手机板制备阴极铜的过程中,电解液循环对Cu的回收率、电流效率、Cu纯度以及Cu和Ni、Zn、Pb等金属迁移转化的影响。经过7次电解液循环实验,结果表明,电解液循环对Ni、Zn、Pb等金属分布及电流效率的影响十分显著,但Cu的分布、纯度及回收率基本不受影响。Cu主要分布在电解液和沉积物中,其他金属则主要在电解液与阳极渣中;8组实验获得的沉积物中Cu的纯度和回收率分别高于99.9%和90%。基于碱性矿浆电解回收废手机板中金属工艺中,完全可以实现电解液的循环利用。本研究可为碱性矿浆电解废线路板提供参考。     

水体中27种有机磷阻燃剂(OPFRs)的检测及风险评价

有机磷阻燃剂(organophosphorus flame retardants,OPFRs)具有致畸、致癌、致突变风险以及神经毒性作用。为了更好地研究其存在水平和健康风险,建立了固相萃取与高效液相色谱-串联质谱仪和气相色谱-质谱联用仪检测水体中27种OPFRs的分析方法,并对OPFRs进行了健康风险评价。20种OPFRs采用MCX固相萃取柱预处理和LC-MS/MS进行检测,以甲醇和含10 mmol·L⁻¹的甲酸水溶液作为流动相进行梯度洗脱,7种OPFRs采用HLB串联Envi-18固相萃取柱进行预处理并利用GC-MS进行检测。检测结果表明,27种OPFRs的检出限为0.02~2.53 ng·L⁻¹;定量限为0.06~8.43 ng·L⁻¹;回收率为65.82%~108.48%。2021年4月份,采集北京市潮白河地表水和地下水8个水样并检测其OPFRs。实测结果表明：除磷酸三(2-异丙基苯)酯、磷酸异癸基二苯酯、磷酸叔丁基苯二苯酯、磷酸二苄酯外,其余23种OPFRs均有不同程度检出,质量浓度为0~973.17 ng·L⁻¹;磷酸三(2-乙基己基)酯、磷酸三乙酯、磷酸三丙酯、磷酸三异丙酯含量相对较高,分别高达973.17、459.90、315.47、298.41 ng·L⁻¹。采用USEPA模型对水样中的OPFRs进行了健康风险评价, 13种OPFRs的非致癌风险值为0~6.17×10⁻⁴,4种OPFRs致癌风险值为1.37×10⁻⁹~1.07×10⁻⁷;在高暴露条件下,OPFRs的非致癌风险值为1.61×10⁻⁵~6.17×10⁻⁴,致癌风险值为1.00×10⁻⁸~1.07×10⁻⁷,均低于风险阈值。上述结果说明,水体中OPFRs产生的健康风险处于较低水平。此次采集的潮白河地表水和地下水水中OPFRs的致癌风险和非致癌风险均处于较低水平。本研究结果可为地表水和地下水水体中OPFRs的检测及风险评价提供参考。     

城镇污水AAOA高标准除磷脱氮技术开发与应用

针对城镇污水在高标准除磷脱氮过程中碳源不足的问题,提出了基于多路径协同的AAOA除磷脱氮技术,探究了AAOA系统实现高标准除磷脱氮对进水C/N的要求,并对实际城镇污水处理进行了实验研究。结果表明：当进水C/N分别为6、7.5、9时,系统TN去除率分别为74.12%、84.90%、90.05%,TP去除率分别为48.29%、97.68%、98.50%;当进水C/N≥7.5时,系统可以实现高标准脱氮除磷。16S rRNA高通量测序结果表明：系统中脱氮除磷功能菌属主要有Aeromonas、Nitrospira、Aeromonas、Comamonadaceae_unclassified、Uliginosibacterium、Saccharibacteria_norank、Candidatus_Accumulibacter、Aeromonas、Pseudomonas、Dechloromonas,系统通过自养硝化、异养硝化、异养反硝化、反硝化聚磷、好氧反硝化等多条路径协同作用实现了高标准除磷脱氮。同时,采用AAOA系统处理城镇污水,当城镇污水进水C/N为7.5时,系统出水${\rm{NH}}_4^{+} $-N、TN和PO43--P平均质量浓度分别为0.40、3.57、0.21 mg·L−1,平均去除率分别达到98.76%、89.03%和95.55%,即无需外加碳源可实现城镇污水的高标准除磷脱氮。