Potential energy production from organic waste and its environmental and economic impacts at a tertiary institution in Palestine

Municipal solid waste (MSW) is one of the most well-known biomass resources that can be utilized to produce renewable energy. Numerous countries are plagued by the proliferation of waste, particularly organic waste that can be utilized for energy recovery. Palestine suffers from inefficient solid waste management, and only recently have a few projects focused on bioenergy production been implemented. Throughout the years, the city of Tulkarm experiences power outages which cause a challenge to the Palestine Technical University-Kadoorie campus in Tulkarm. Thus, the possibility of energy recovery from the organic portion in Palestine Technical University-Kadoorie was evaluated. The analysis of an economic impact included discussions of a number of economic aspects, including Levelized cost of energy, internal rate of return, present worth, annual worth, and payback period. On the other hand, a carbon dioxide savings analysis and gas emission were evaluated. The outcomes of the energy optimization demonstrated that the suggested system could supply the institution with an average of roughly 7 MWh of electrical energy. According to the economic study, this project offers 0.25 million dollars in present value, 0.144 million dollars in annual value, a 13 percent internal rate of return, a payback period of 6 years, and a levelized cost of energy of 0.11 dollars for each kWh generated. Additionally, the environmental assessment revealed that this system might reduce CO₂ emissions by around 8,343,778 tons. For effective waste management, energy recovery, and emission reduction, it is advised to implement anaerobic digestion technology.     

Biohythane production from pineapple peel using Methanosarcina mazei enhanced with palm oil mill effluent (POME) sludge in single-stage anaerobic digestion

Biohythane production via single-stage anaerobic digestion (AD) is an effective way for sustainable energy recovery from lignocellulosic biomass. In this paper, biohythane was produced through the AD process from pineapple peel waste substrate using purely cultured Methanosarcina mazei with the enhancement of palm oil mill effluent (POME) sludge as the inoculum. This study focuses on the effects of the lignocellulosic pre-treatment method, the addition of POME sludge into M. mazei culture medium as inoculum, and various operational conditions (food to microorganisms (F/M) ratios, temperature, pH) on gas production performances. The experimental results indicate that these parameters influenced the efficiency of biohythane production by producing the peak maximum biohythane production rate values (HPR_max) and (MPR_max), H₂:CH₄ = 1.93:0.67 L/L-d, and biohythane yield (HY) and (MY), H₂:CH₄ = 1.18:0.55 mL/L-substrate. This study demonstrates that biohythane gas (H₂ + CH₄ + CO₂) production from pineapple waste can be accelerated by M. mazei only with the enhancement of POME sludge through single-stage AD system under mesophilic batch process conditions.     

SMBBR-AF-SMBBR组合工艺处理高氨氮农药废水

采用特异性移动床生物膜反应器(SMBBR)和厌氧生物滤池(AF)组合工艺处理高氨氮农药废水。考察了HRT、pH和DO等工艺条件对SMBBR-AF-SMBBR组合工艺运行稳定期COD和氨氮去除率的影响。试验结果表明,在进水COD为2 408~7 440 mg/L、ρ(NH_4~+-N)为160.21~433.84 mg/L、TN为208.27~537.65 mg/L、HRT为8d、pH为8.0、DO为4 mg/L的条件下,处理后出水平均COD为342 mg/L,COD去除率达92.3%;ρ(NH_4~+-N)小于4.0mg/L,氨氮平均去除率为89.2%;TN小于50 mg/L,平均TN去除达83.0%。出水各指标均优于原A2O工艺出水。     

Aerobic treatment of swine manure to enhance anaerobic digestion and microalgal cultivation

Aerobic treatment of swine manure was coupled with anaerobic digestion and microalgal cultivation. A 14-day aerobic treatment reduced the total solid content of swine manure by >15%. Ammonia and carbon dioxide were stripped by the air supplied, and this off-gas was further used to aerate the culture of Chlorella vulgaris. The microalgal growth rates in Bristol medium and the wastewater with the off-gas increased from 0.08 to 0.22 g/L/d and from 0.15 to 0.24 g/L/d, respectively. Meanwhile, the aerobically treated swine manure showed a higher methane yield during anaerobic digestion. The experimental results were used to establish a demonstration unit consisting of a 100 L composter, a 200 L anaerobic digester, a 60 L tubular photobioreactor, and a 300 L micro-open raceway pond.     

厌氧水解酸化处理含高浓度聚丙烯酰胺污水

运用厌氧瓶和厌氧折流板反应器(ABR)对含部分水解聚丙烯酰胺(HPAM)的污水进行厌氧水解酸化生物处理.选取PAM-F1和PM-2两株厌氧菌为HPAM降解菌,并优化了单株菌和混合菌的降解条件.结果发现,最佳降解条件为降解9 d,连续活化3次,温度35~40℃,初始pH=7.5.此时,混合菌对500 mg·L-1HPAM污水的降解效果最好,降解率可达到40.69%.通过生理生化特征和16S rDNA分析,确定PAM-F1为红球菌(Rhodococcus sp.).混合菌降解前后的HPAM傅里叶-红外光谱图分析表明,细菌能够降解并利用HPAM的部分胺基和碳作为生长所需的氮源和碳源,并推断出HPAM的降解过程发生在厌氧水解酸化阶段.扫描电镜(SEM)图片显示,ABR中形成了能有效促进HPAM生物降解的颗粒污泥.而经过ABR处理的HPAM污水,CODCr去除率和HPAM降解率可分别达到89.96%和75.48%.研究表明,厌氧水解酸化法是一项能够有效处理含高浓度HPAM污水的技术.     

不同有机废水厌氧产酸过程的研究

主要研究了不同类废弃有机物厌氧产酸过程中产生的挥发性脂肪酸的产量和组成比例。研究发现,废糖蜜溶液、蛋白废液和淀粉废液在达到最高产酸量时,超过50%的VFAs是乙酸,其次是丙酸,还含有少量的丁酸和戊酸。废甘油溶液在达到最高产酸量时,产生的VFAs的主要成分是丙酸。4种有机废液中,相同初始COD浓度条件下,淀粉废液产生的VFAs产量最多,初始COD为5000mg/L时最高产量为2.321g/L,其次是废甘油溶液,最高产量是2.244g/L。     

“污泥+生物质”混合厌氧消化分类管理研究

污泥单独厌氧消化困难,产气量低,能量回收价值低.但“污泥+生物质”混合厌氧消化能够改善物料间的营养平衡,运行更平稳,既有效处理污泥,又能够提高甲烷产气量,更适合生产实际,符合行业发展趋势.分析了安阳市四家污水处理厂脱水污泥的重金属含量,依据土地利用限值标准,结合生产实际,把安阳市四个污水处理厂脱水污泥分类,分类混合厌氧消化处理后分类土地利用,既提高了污泥的土地利用,更强化了污泥土地利用的重金属管理.     

初始pH对厌氧环境下污泥中抗生素抗性基因行为特征的影响

污水处理厂产生大量的剩余污泥中含有丰富的抗性基因,给环境带来了潜在风险。以城市污水处理厂的剩余污泥为研究对象,在不同初始p H(对照组、初始p H=3、5、7、9、11)下观察厌氧条件下,8种抗生素浓度以及四环素类抗性基因(tet A、tet G、tet L、tet M、tet O、tet Q、tet W、tet X)、磺胺类抗性基因(sul I、sul II)和Ⅰ类整合子(int I 1)的行为特征。研究结果显示,初始p H对抗生素的降解影响较小,污泥中总抗生素的平均去除率为42%。对照组及初始p H为3、5、7、9、11下的总四环素类抗性基因分别削减0.65 log、0.96 log、0.75 log、0.62 log、0.86 log和0.98 log。不同四环素类抗性基因表现相似,在初始p H=3和初始p H=11下部分抗性基因削减较多,特别是tet A、tet G、tet L、tet O和tet X。2种磺胺类抗性基因均无削减,浓度平均上升0.18log。相关性分析显示,总抗性基因与TN、NH3-N、TP、SCOD(溶解性COD)均存在显著相关性(P0.05)。上述研究结果为污泥厌氧消化中抗生素抗性基因减量条件提供参考依据。     

四环素类抗生素和铜复合污染对猪粪厌氧消化的影响

兽用抗生素和矿物元素添加剂可起到预防动物疾病、促进动物生长、提高饲料转化率等作用,因此被广泛应用于畜禽养殖业。本研究以猪粪中温厌氧消化为研究目标,采用全自动甲烷潜势测试系统,考察了一定浓度的四环素(TC:30 mg·kg~(-1)dry weight,DW)、土霉素(OTC:50 mg·kg~(-1)DW)和金霉素(CTC:15 mg·kg~(-1)DW)对厌氧累积产甲烷量和日产甲烷速率的影响。结果表明,TC、OTC和CTC对猪粪中温厌氧消化累积产甲烷量和日产甲烷速率均有促进作用(累积产甲烷总量提高比例分别为7.9%、0.4%和5.4%)。另外,采用超高效液相色谱-四极杆串联质谱对猪粪厌氧消化前后样品中四环素类抗生素及其代谢产物进行了分析。结果表明,液相中的四环素类抗生素在猪粪厌氧消化过程中得到了明显的去除,去除率达到90%~100%;而固相中只有金霉素和差向异构金霉素有明显的去除效果,去除率分别为41.69%和41.58%。采用Tessier连续提取法对猪粪厌氧消化前后样品中5种形态的铜包括可交换态、碳酸盐结合态、铁锰氧化结合态、有机物结合态、残渣态进行了分析,结果表明,猪粪厌氧消化后,可交换态、碳酸盐结合态和铁锰结合态的铜浓度比厌氧消化前分别降低了1%~9%、0.1%~3%、12%~19%,而有机态和残渣态的铜浓度却在厌氧消化后分别增加了15%~35%、1%~2%。厌氧消化后,70%~80%的铜都是以有机铜的形态存在。铜逐渐从不稳定态转化为相对稳定的有机态和残渣态铜,因此,厌氧消化过程使铜从可生物利用态转变为不可生物利用态,趋于稳定化。     

秸秆厌氧发酵产沼气技术现状进展

秸秆是世界上数量最大的可再生资源,但是秸秆内木质纤维素的复杂结构和难降解性限制了秸秆的应用,因此秸秆预处理成为秸秆发酵产气的重要一环。本文介绍了木质纤维素预处理物理技术、化学技术、生物技术、联合处理技术和秸秆厌氧发酵研究进展,并对秸秆预处理技术前景进行展望。