A biological safety evaluation on reclaimed water reused as scenic water using a bioassay battery

An assessment method based on three toxicity tests (algae growth inhibition, daphnia immobilization and larval fish toxicity) was used to screen the biological safety of reclaimed water which was reused as sole replenishment for scenic water system in a park (SOF Park) in northern China. A total of 24 water samples were collected from six sites of water system in the SOF Park in four different seasons. The results indicated that: (1) the reclaimed water directly discharged from a reclamation treatment plant near the SOF Park as influent of park had relatively low biological safety (all samples were ranked as C or D); (2) the biological safety of reclaimed water was improved greatly with the ecological reclamation treatment processes composing of artificial wetland system and followed oxidation pond system; (3) the biological safety of reclaimed water in the main lake of SOF Park kept at a health status during different seasons (all samples were ranked as A); (4) there was some certain correlation (R² = 0.5737) between the sum of toxicity scores and dissolved organic carbon for the studied water samples. It was concluded that the assessment method was reliable to screen the safety of reclaimed water reused as scenic water, and the reclaimed water with further ecological purification processes such as artificial wetland and oxidation pond system can be safely reused as scenic water in park.     

稻田养鱼的生态防灾机制与效益分析—以湖南为例

以湖南为例从分散蓄水与扩容蓄水、即时蓄水与重复蓄水、分级截流与设阻截流等角度,分析了稻田养鱼的生态防灾机制,得出湖南宜鱼稻田87.0万hm^2,以蓄水30cm计算可蓄存107.9亿m^3。通过重复蓄水、设阻蓄水,接纳多次降雨洪水,调节水分时空分布,创造减灾避灾的人工生态防灾系统,形成多物种共生共存的农田湿地生态系统,提高农田生态经济效益。     

辽河水质中CODMn与TOC的相关关系探讨

高锰酸盐指数（CODMn）常被作为水体受有机物质污染程度的综合指标。总有机碳（TOC）是以碳的含量表示水体中有机物质总量的综合指标,也常被用来评价水体中有机物污染的程度。同样都是作为水体中有机物污染指标,TOC与CODMn具有一定的相关关系。但不同的水体有不同的相关关系,同一水体在不同时期,相关关系也不相同。     

高级氧化技术处理垃圾渗滤液的研究进展

垃圾渗滤液是一种成分复杂、有机物、氨氮浓度高的难处理废水,介绍了高级氧化技术在垃圾渗滤液处理中的研究与应用现状。主要介绍了臭氧氧化、光催化氧化、Fenton试剂、电氧化以及湿式氧化在处理垃圾渗滤液中的应用,分析了高级氧化技术处理垃圾渗滤液的原理,对国内外各种氧化技术在垃圾渗滤液处理中的应用进行了总结,并探讨了它们的优缺点。最后,提出了当前应用高级氧化技术处理垃圾渗滤液所存在的问题和发展方向。     

Screening and identification of cellulose degrading bacterium Bacillus siamensis BREC-11 with tolerance to furfural北大核心CSCD

Furfural is a toxic metabolic inhibitor that is created during the conversion of lignocellulose to produce fuel, which can retard fermentation and increase production costs. thus, it is important for lignocellulosic conversion that the ability of the strain to resist furfural stress be improved. A cellulose-degrading bacterium BREC-11 with tolerance to furfural was isolated from the intestinal tract of Omphisa fuscidentalis hampson larvae via the addition of furfural in the medium. Based on analyses of morphological observations, physiological and biochemical characterizations, and 16S rDNA sequences, strain BREC-11 was shown to represent a member of the genus Bacillus and was named B. siamensis BREC-11. to study the tolerance concentration of strain BREC-11, a wide range of furfural formaldehyde concentrations were tested and strain BREC-11 was shown to grow in the mineral medium containing furfural up to 3.5 g/L. Cellulase activity of strain BREC-11 was determined at the tolerable concentration of 3.5 g/L furfural after incubation at 30 ℃ and 150 r/min for 2 days. Results indicated that filter paper enzyme, CMC-Na enzyme, and β-glucosidase activity was 0.1 U/mL, 0.21 U/mL, and 0.07 U/mL, respectively. BREC-11 is a cellulose-degrading bacterium with resistance to furfural, which has potential application in future bio-refinery processes. © 2018 Science Press. All rights reserved.     

分类前后苏州市生活垃圾管理的环境效益比较

为系统认识生活垃圾分类对城市环境效益的提升,基于2017~2021年苏州市推行分类前后生活垃圾的处置数据,核算整个收运-处置过程的环境影响潜值,预测苏州市到2035年生活垃圾全过程管理的环境效益. 苏州市自2019年底全面实施生活垃圾分类后,单位质量生活垃圾的环境影响潜值（以PET₂₀₀₀计,下同）由2017年的2.34×10^-13 t^-1降至2021年的1.91×10^-13 t^-1,降幅18.38%,分类可改善生活垃圾全过程管理的环境效益. 以苏州市2021年生活垃圾清运情况为基准,设定不同前端分类效果-后端分质处置规模情景测算,发现生活垃圾前端分类效果梯度提升且末端分质处置能力相应配套后环境效益进一步提升,厨余垃圾分出率和纯度分别提高至40%和95%且实现“垃圾零填埋”的规划处置能力情景下,单位质量垃圾环境影响潜值和碳排放总量较2021年实际情况分别减少23.96%和30.73%. 建立基于苏州市人口规模及经济发展水平的线性模型,预计到2035年苏州市的生活垃圾清运量达696.50万t. 在苏州市生活垃圾前端分类不断改善及环境卫生持续优化的背景下,基于苏州市末端处置能力现状,至2035年分类效果提高后单位质量生活垃圾环境影响潜值为1.54×10^-13 t^-1,总环境影响潜值1.05×10^-6,碳排放总量达到380.17万t;在垃圾末端分质处置规模扩大、原生生活垃圾“零填埋”、厨余垃圾充分资源化的理想情景下,2035年单位质量生活垃圾环境影响潜值为1.28×10^-13t^-1,总环境影响潜值和碳排放总量分别为8.69×10^-7和322.57万t,分别较2021年实际情况减少约5.65%和1.23%. 统筹推进分类收运和分质处置的协同,能更好地控制生活垃圾管理过程的潜在环境影响和碳排放.     

大气颗粒物酸缓冲能力来源解析技术与应用

建立了大气颗粒物酸缓冲能力的表征方法,测定了天津市区不同源类的酸缓冲能力;建立了基于二重源解析技术(NCMB)的TSP酸缓冲能力来源识别技术,阐述了其技术原理,并在天津城区加以应用.结果表明,大气中颗粒物浓度和降雨量是影响天津城区降雨pH值的关键因素;颗粒物的酸缓冲能力主要来源于城市扬尘、建筑水泥尘和土壤风沙尘等开放源.开放源污染是现阶段决定天津城区酸雨发展的关键因素之一.     

动力波洗涤器脱硫试验研究

采用动力波洗涤器冷模试验装置,在不加脱硫剂的情况下,考察各操作参数(液气比、pH值)及液柱喷射方式(逆喷、顺喷)对脱硫效率的影响,并对不同水质的清水(自来水、去离子水)的脱硫效率进行对比分析。结果表明:自来水的脱硫效率随液气比的增加而增大;逆喷时的脱硫效率明显高于顺喷;液气比>7时,逆喷的脱硫效率在75%以上;自来水的脱硫效率较去离子水要高;撞击流有强化吸收的特性。     

ARTIFICIAL NEURAL NETWORKS FOR SUBSURFACE DRAINAGE AND SUBIRRIGATION SYSTEMS IN ONTARIO,CANADA1

ABSTRACT: Artificial neural network (ANN) models were developed to simulate fluctuations in midspan water table depths (WTD) given rainfall, potential evapotranspiration, and irrigation inputs on a Brookston clay loam in Woodslee, Ontario, having a dual‐purpose subsurface drainage/subirrigation setup. Water table depths and meteorologic data collected at this site from 1992 to 1994 and from 1996 to 1997 were used to train the ANNs. The ANNs were then used for real‐time control and time series simulations. The lowest root mean squared errors (RMSE) for the various ANNs were 60.6 mm for real‐time control simulation, and 88.4 mm for time‐series simulation of water table depths. It was possible to simulate WTD for the different modes of water table management in one network by incorporating an indicator for switching from one to the other. The ANN simulations were quite good even though the training data sets had irregular measurement intervals. With fewer input parameters and small network structures, ANNs still provided accurate results and required little time for training and execution. ANNs are therefore easier and faster to develop and run than conventional models and can contribute to the proper management of subsurface drainage and subirrigation systems.     

包气带中造纸废水COD天然生物降解作用

通过野外试验和土柱实验,研究了造纸废水渠底部包气带中,天然形成的生化层分布特征及其对ＣＯＤ降解能力和机制．结果表明,包气带中生化层由生物氧化带和生物还原带组成,生化层的发育厚度受包气带厚度控制,当包气带厚度大于１０ｍ 时,生化层发育良好,对ＣＯＤ的降解率达到９７％ 以上．