Sustainable design of sanitation system based on material and value flow analysis for urban slum in Indonesia

Material flow analysis (MFA) and value flow analysis (VFA) were applied to the sanitation system in an urban slum in Indonesia. Based on the results of the MFA and VFA, garbage and excreta disposal costs were evaluated to be 0.7% and 1.1%, respectively, of per capita income. Such value flows seem reasonable in light of the recognized affordability to pay (ATP) standard. However, current excreta disposal methods create negative impacts on downstream populations. Because such disadvantages do not go back to disposers, but passed to downstream, the current value flow structure does not motivate individual toilet users to install treatment facility. Based on current material and value flow structures, a resource recycling sanitation system scenario was examined. Based on VFA, an affordable initial cost for such a system was calculated; this was found to be comparable in price to a cheaper composting toilet that is currently available in the market.     

初始温度对可燃气体爆炸下限影响的研究

研究初始温度对可燃气体爆炸下限的影响规律,运用阿累尼乌斯定律,可得出温度与化学反应速度之间的关系式,从而得出简化的温度和爆炸极限影响的模型。利用该模型对5种烷烃在不同温度下的爆炸下限实验值进行拟合相关度比较,所得爆炸下限模型平均拟合相关系数达到0.995 5。结果表明,该简化模型具有较强的可靠性。     

基于基尼系数法的区域水污染物分配研究

将经济领域用于评价收入公平性指标——基尼系数法用于区域水污染物总量分配。以湖北省17市州为分配对象,以各地基准年排放量为初步分配方案,分别绘制人口、水资源量和地区生产总值各指标下洛伦兹曲线图,计算各基尼系数值并评估公平性。以省年度环保规划为削减依据,在完成减排目标的前提下,研究确定重点削减区域,达到使各指标基尼系数趋于合理的目的。结果表明,该方法既能衡量不公平程度,明确重点调整指标,在兼顾各指标影响差异的同时,改善分配方案,是一种较适宜的评估分配方法。     

薄壁圆柱壳初始爆破强度的可靠度分析

充分考虑固体火箭发动机壳体的结构特点,建立用中径公式预测其初始爆破强度的方法,对固体火箭发动机壳体爆破强度的可靠度进行了探索。研究表明:①固体火箭发动机壳体实际初始爆破强度与中径公式的名义值之比是符合正态分布的随机变量;②借助于钢制薄壁内压容器的爆破试验数据,在置信度为99%时,得到了该随机变量的分布参数;③应用强度-载荷干涉模型,推导得到了固体火箭发动机壳体爆破强度的可靠度指标计算公式;④固体火箭发动机壳体的可靠度在一定范围内变动。     

初始损伤对不同钢组织延性起裂韧性的影响

对两种钢热处理后得到的3种材料组织的缺口试样,在常温下进行了不同预加载荷的4点弯曲正反弯实验.在缺口前引入不同的微孔洞损伤量,而后通过高温回火处理消除残余应力和加工硬化.随后在室温下进行4点弯曲加载和不同载荷下的卸载实验,通过力学参数测量和微观观察就初始损伤对不同钢组织缺口试样延性起裂韧性的影响进行了实验研究.结果表明:当预加载荷比Po/Pgy小于0.86时,材料A的延性起裂韧性Pi/Pgy随Po/Pgy的增加缓慢下降,材料B和C的Pi/Pgy基本不变;当Po/Pgy大于0.86后,随着Po/Pgy的增加,3种材料的延性起裂韧性Pi/Pgy很快下降.延性起裂韧性的降低是由于材料在预加载中产生的初始损伤所引起的.初始损伤的量越大,延性起裂韧性降低的程度越大.细晶粒材料A的延性起裂韧性Pi/Pgy低于粗晶粒材料C.夹杂物含量较高,尺寸较大的材料C的延性起裂韧性Pi/Pgy低于夹杂物量少,尺寸小的材料B.对产生这些结果的原因进行了分析.     

长江口溯河鳗苗开发率估算

利用长江口南支上段东风西沙调查站位(121°15′45′′E;31°40′18′′N)2015年度鳗苗捕捞数据,通过CPUE波动趋势分析,确定当年日本鳗鲡鳗苗溯河汛期特征;进而采用Leslie和Delury两种方法估算东风西沙站位鳗苗资源指标。结果显示,2015年度东风西沙站位出现6个明显的鳗苗补充汛期,两种方法估算的汛期波动规律一致。各汛期捕捞持续时间5~27 d,平均为10.17 d。Leslie法估算的各汛期捕捞开发率43.38%~96.30%,平均77.14%;Delury法估算结果为43.36%~105.37%,平均81.43%;均为较高水平。高开发率表明东风西沙水域樯张网作业方式致使溯河迁移鳗苗处于高度开发状态,减少溯河鳗苗数量,影响长江流域成鳗资源。Leslie法估算日捕捞死亡系数和日捕捞死亡率平均值分别为0.23和20.02%,均分别低于De Lury法估算平均值0.27和22.79%;捕捞死亡系数将为采用年渔获量估算鳗苗资源量提供基础数据。     

初始温度对人粪便好氧堆肥过程的影响

温度是好氧堆肥过程中需要控制的一个重要因素。不同的初始温度直接影响了堆肥过程中微生物活性及有机物的降解。为了研究初始温度对粪便好氧堆肥过程的影响,采用序批式好氧堆肥反应器,以新鲜锯末为载体,控制含水率在55%~60%的范围左右并强制通风的好氧条件下,进行了初始温度分别为25、35、45和55℃,20 d为一个周期好氧堆肥实验,研究了不同初始温度条件下堆肥过程有机物降解、氮的迁移转化及种子发芽指数的变化。结果表明,初始的高温度会抑制堆肥反应的进行,但初始温度越高,水解效果越显著;初始的高温有利于COD的去除,最终COD的去除率分别为88.2%、89.3%、92.0%和89.9%。初始高温对种子发芽率有抑制作用,同时延迟了堆肥的腐熟期。     

基于奖优罚劣的省区初始水权优化配置

针对我国最严格水资源管理制度要求,研究省区初始水权优化配置模型。首先,基于流域经济效益、省区排污权协调性等建立目标函数,根据流域排污总量构建约束条件,建立多目标省区初始排污权免费分配模型;其次,将排污权嵌入初始水量权配置中,根据奖优罚劣机制构建省区初始水权配置模型;最后,以太湖流域为研究背景进行实证研究。结果表明:太湖流域规划年2030年在75%来水频率下,基于流域可分配初始水权总量为363.3亿m~3和排污量为54.46亿m~3的限制,江苏、浙江和上海初始水权配置量分别为135.19亿m~3,129.21亿m~3和98.89亿m~3。本文的模型通过奖优罚劣函数,把超标或未超标排污的外部性内化到水量分配上,实现了水量权与排污权分配的统一,可为其它流域开展同类研究提供借鉴。     

Degradation of MTBE and TBA by a new isolate from MTBE-contaminated soil

Methyl ten-butyl ether （MTBE）, a gasoline additive, possesses serious problems to the environmental health. In the present study, a bacterial culture named A-3 which could effectively degrade MTBE was isolated from the MTBE contaminated soil. The isolate was identified as Chryseobacterium sp., a new species capable of degrading MTBE. In order to enhance its degradation ability, selected environment factors were investigated. The results showed that the optimal temperature was in the range of 25-30℃, the pH was 7.0, the inoculum size was 2 × 10^8 CFU/ml and the optimal concentration of MTBE was from 50 to 100 mg/L. The maximum MTBE utilization rate （Vmax） was 102 nmol MTBE/（mg cell protein.h）. Furthermore, it was found that the isolate could also degrade tert-butyl alcohol （TBA）. The degradation rates of TBA were much faster than those of MTBE. The additional TBA would lead to the decrease of the initial MTBE degradation rate and the inhibitory effect of TBA increased with the increase of TBA concentration. Similar protein profiles at least seven peptides were demonstrated after SDS-PAGE analysis of crude extracts obtained from the cells growing in MTBE and TBA culture.     

Treatment of tannery wastewater by electrocoagulation

Treatment of tannery wastewater by electrocoagulation with low cell current(≤1A)and soluble electrodes(mild steel electrodes and aluminum electrodes)was studied.Compared with aluminum electrodes,mild steel electrodes were more effective for the removal of sulfide,with a removal efficiency of over 90%.But during the treatment process,black color precipitate typical to iron(Ⅱ)sulfides was produced.While aluminum electrodes were effective to eliminate the colority of the effluent,the removal efficiency of sulfide was lower than 12%.The mechanisms of the removal of chemical oxygen demand,ammonia,total organic carbon,sulfide and colority with the two soluble electrodes(mild steel and aluminum electrodes)were discussed in detail.In order to exert the predominance of diffenent types of electrodes,the tannery wastewater was treated using mild steel electrodes first followed by the filter and finally by the aluminum electrodes,the elimination rates of chemical oxygen demand,ammonia,total organic carbon,sulfide and colority were 68.0%,43.1%,55.1%,96.7% and 84.3%,respectively,with the initial concentrations 2413.1 mg/L,223.4 mg/L,1000.4 mg/L,112.3 mg/L and 256 dilution times,respectively.The absorbance spectra and energy consumption during electrocoagulation process were also discussed.