Stormwater harvesting from landscaped areas: effect of herbicide application on water quality and usage

The suitability of stormwater harvested from pervious pavement system (PPS) structures for reuse purposes was investigated in conditions where glyphosate-containing herbicides (GCH) are applied as part of PPS maintenance procedure. The experiment was based on the four-layered design previously described as detailed in CIRIA C582. Results indicated that the highest sodium absorption ratio (SAR) of 1.6 recorded in this study, was less than that at which loss of permeability begins to occur as well as deterioration of matrix structure. Furthermore, the maximum electrical conductivity (ECw) of 2990 μS cm^?1, recorded for 7200 mg L^?1 concentration (GCH) was slightly below the unstable classification range at which salinity problems related to water quality occur such that salts accumulate in the root zone to the extent that crop yields are adversely affected. However, GCH concentration of 720 mg L^?1 was within ‘permissible’ range while that of 72 mg L^?1 was within ‘excellent’ range. Current study raises some environmental concerns owing to the overall impact that GCH at concentrations above 72 mg L^?1 exerts on the net performance of the organic decomposers, heavy metal and hydrocarbon release from the system and thus, should be further investigated. However, effluent from all the test models including those dosed with high GCH concentration of 7200 mg L^?1 do not pose any threat in terms of infiltration or deterioration associated with salinity although, there are indications that high dosage of the herbicide could lead to an elevated electrical conductivity of the recycled water.

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Graphical abstract Impact of herbicide on irrigation water quality

     

水平渗滤系统的污染物去除效果及动力学分析

基于人工快渗(CRIS)和水平潜流人工湿地(HSSFCWs)构建了水平流人工渗滤系统(HFCIS),研究了该系统对耗氧有机物(以COD计)、氨氮(NH₄⁺-N)的沿程去除情况和污染物在系统内的垂向分布情况,并进行了动力学分析。结果表明,在水力负荷为0.083 m·d⁻¹、进水耗氧有机物(以COD计)浓度为220~630 mg·L⁻¹、NH₄⁺-N质量浓度为13~47 mg·L⁻¹时,COD、NH₄⁺-N的去除率分别为88.6%和91.9%以上。在水力负荷为0.25 m·d⁻¹的条件下,进水耗氧有机物(以COD计)和NH₄⁺-N质量浓度分别为613~690 mg·L⁻¹和36~48 mg·L⁻¹时,总去除率分别为95.5%和78.2%以上。水平方向沿程污染物质量浓度呈现逐渐衰减的趋势,污染物降解符合一阶动力学模型,去除速率常数在CRIS和HSSFCWs的速率常数范围内并处于较高水平。该HFCI系统填料简单,复氧效果好,污染物去除性能优异,提高了土地利用率,建造位置选择较为灵活,在分散式污水处理中有独特的优势。     

一种基于脱氮和除磷分开的强化污染物去除组合工艺中试研究

针对北京等严重缺水地区提高污水综合排放标准,用于地表水和地下水补充水的需求,以强化COD、N和P去除为目的,研发了N和P不同单元处理的缺氧立体循环氧化沟单元/好氧立体循环氧化沟单元/除磷过滤器单元组合工艺,通过中试实验研究了该工艺的去除效果,并优化了该工艺水力停留时间(HRT)和溶解氧(DO)参数。结果表明,当缺氧和好氧立体循环氧化沟单元的HRT 和DO分别为12 h、DO 0.5 mg/L和6 h、2.0 mg/L,除磷过滤器滤速6~8 m/h时,该工艺的平均出水浓度COD 25 mg/L,TN 11 mg/L,NH4+-N 1.2 mg/L,TP 0.15 mg/L,平均去除率分别为88%、57%、94%和96%。其中缺氧立体循环氧化沟单元COD、NH4+-N和TN平均去除率为70%、80%和57%,好氧立体循环氧化沟单元进一步去除COD和NH4+-N(去除率为18%和14%);经缺氧、好氧氧化沟处理去除50%左右的TP,除磷单元吸附作用去除46%的TP。经过该组合工艺处理,COD、N和P都能达到北京市2013年出台的地方污水排放新标准一级B排放要求。     

电极间距对自生电场MBR去除污染物的影响

膜生物反应器(MBR)已在污水处理领域得到广泛的应用,然而氮、磷难以达到排放要求。为了强化污染物去除效果,可将MBR与其他新型污水处理技术耦合,进一步降低出水污染物浓度。使用折流板将反应器分隔为厌氧池和好氧池,以石墨毡为阳极材料,以自制铜纳米线(Cu-NWs)导电微滤膜为阴极材料,构建自生电场膜生物反应器(SEF-MBR),用来处理模拟废水,研究了不同电极间距下自生电场强度的变化及污染物去除效果对自生电场强度变化的响应规律。结果表明：当电极间距从4 cm减小到2 cm时,自生电场强度提高了41.7%,出水化学需氧量(chemical oxygen demand, COD)、总氮(total nitrogen, TN)和总磷(total phosphorus, TP)的浓度分别降低了31.3%、24.2%和37.5%;电极间距对SEF-MRBs污泥的活性影响不大,但均高于对对照-MBR的影响;随电极间距减小,好氧池H₂O₂浓度提高了80.9%,从而促进了COD和${{\rm{NH}}_4^ +}$-N的降解,提高了微生物对正磷的吸收,从而降低了TP的含量。三维激发发射矩阵(EEM)结果显示,污水中类色氨酸的特征峰荧光强度降低了5.3%。而膜过滤作用去除有机物的贡献随自生电场强度的提高而降低。自生电场作用与膜过滤互补协同,可为优化出水水质提供双重保障。该技术可降低MBR运行成本,丰富MBR技术的理论成果,为城镇生活污水的回用提供参考。     

Enhancing mixed toluene and formaldehyde pollutant removal by Zamioculcas zamiifolia combined with Sansevieria trifasciata and its CO2 emission

Indoor air pollutants comprise both polar and non-polar volatile organic compounds (VOCs). Indoor potted plants are well known for their innate ability to improve indoor air quality (IAQ) by detoxification of indoor air pollutants. In this study, a combination of two different plant species comprising a C3 plant (Zamioculcas zamiifolia) and a crassulacean acid metabolism (CAM) plant (Sansevieria trifasciata) was used to remove polar and non-polar VOCs and minimize CO₂ emission from the chamber. Z. zamiifolia and S. trifasciata, when combined, were able to remove more than 95% of pollutants within 48 h and could do so for six consecutive pollutant’s exposure cycles. The CO₂ concentration was reduced from 410 down to 160 ppm inside the chamber. Our results showed that using plant growth medium rather than soil had a positive effect on decreasing CO₂. We also re-affirmed the role of formaldehyde dehydrogenase in the detoxification and metabolism of formaldehyde and that exposure of plants to pollutants enhances the activity of this enzyme in the shoots of both Z. zamiifolia and S. trifasciata. Overall, a mixed plant of Z. zamiifolia and S. trifasciata was more efficient at removing mixed pollutants and reducing CO₂ than individual plants.

     

电极面积对无质子交换膜微生物燃料电池协同去污能力的影响

以间距是180μm的不锈钢网为电极,构建了单室型无质子交换膜微生物燃料电池(MFC)污水处理系统。分别驯化、培养厌氧消化菌和反硝化菌,厌氧消化菌在阳极附着成膜组成生物阳极氧化去除有机污染物,反硝化菌在阴极附着成膜组成生物阴极反硝化去除含氮污染物,研究了电极面积对污染物协同去除能力的影响。当电极面积为45 mm×100mm和45 mm×50 mm时,两系统的开路电压最大值分别为(182.8±6.2)mV和(161.8±5.4)mV,COD、NH4+-N和NO3--N最大去除率分别为96.5%、99.7%、99.7%和85.4%、92.2%、97.9%;出水中NO2--N的含量分别低于(0.072±0.006)mg/L和(0.084±0.008)mg/L。这表明电极面积大的系统具有较好的有机污染物和含氮污染物协同去除能力。     

多孔陶瓷滤料的亲油改性及其除油性能

研究了铝酸酯偶联剂对多孔陶瓷滤料的亲油改性及改性滤料的除油性能。用正交实验优化改性工艺,并对改性前后滤料用FTIR、SEM、密度、孔隙率及接触角等手段进行表征。结果表明:最佳改性工艺参数为铝酸酯偶联剂5%(改性液质量分数)、改性温度90℃、改性时间20 min和涂层次数1次。改性滤料FTIR图在2 920.95 cm-1和2 851.63cm-1处出现了CH3、CH2等特征吸收峰,其密度和孔隙率减小,而对水的接触角明显增大,表明多孔陶瓷滤料亲油改性成功。用改性滤料处理模拟油田采出水,控制滤速15 m/h,20 min后采样测出水中油的浓度,其去油率由预处理65.18%增加到96.46%;穿透曲线的研究表明,原始、预处理及改性滤料运行时间分别为48、85和149 min,可见改性滤料的运行时间更长,其较原始与预处理滤料分别延长了101 min和64 min,且其去油率能持续45 min维持在90%以上。可见经亲油改性的多孔陶瓷滤料是一种良好的聚结除油材料。     

多孔硅酸钙滤料吸附床除磷试验研究

以多孔硅酸钙滤料为吸附载体处理含磷的二沉池出水.通过静态吸附试验和动态吸附试验,研究了滤料粒径及投加量、初始pH、反应时间、温度以及滤料填充高度对除磷效果的影响.在静态吸附试验中,取初始磷质量浓度为4.98 mg/L的含磷废水100 mL,当多孔硅酸钙滤料粒径为4～14目,投加量为1.0g,吸附时间为2.5h,温度为25℃,溶液初始pH为7.0～9.0时,磷的去除率可达95％以上,出水磷满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准(≤0.5 mg/L).动态吸附试验表明,在长期运行条件下,多孔硅酸钙滤料吸附床能持续有效地去除污水中的磷,综合考虑吸附率和运行费用,选择水力停留时间为30 min,滤料填充高度为60 cm为宜.     

曝气时长对中试曝气塘-浮萍塘联合系统中污染物去除的影响

浮萍塘污水处理技术具有管理简便、运行成本低、可资源化回收氮磷污染物等优势。然而,因水体溶解氧(DO)不足造成的污染物去除率低的问题限制了该技术的推广应用。为此,本研究在浮萍塘前端引入曝气塘,构建中试曝气塘-浮萍塘联合系统,借此增加浮萍塘DO含量,并进一步考察了曝气时长(0、0.5、1、2和4 h)对污染物去除效果及浮萍生长的影响,以此探寻低耗高效的最佳曝气时长。结果表明,曝气塘可有效降低水体的浊度,但对氮磷去除的贡献较小,氮磷的去除以浮萍塘为主。曝气处理可显著提高曝气塘及浮萍塘水体DO含量和氧化还原电位(Eh),且DO和Eh随曝气时长的增加而上升。此外,曝气处理还能显著促进浮萍生长及其污染物的去除,但促进效果并未简单地随曝气时长的增加而提高。其中,TN、氨氮和浊度的去除率在曝气时长1 h时已基本达到峰值(去除率分别为58.42%、61.89%和89.90%),TP去除率虽在曝气时长4 h时最大(81.44%),但与曝气时长0.5 h(73.05%)相比并无显著差异;浮萍虽在曝气时长2 h时干基生长速率最高(8.00 g·(m²·d)⁻¹),但与曝气时长0.5 h和1 h(7.35 g·(m²·d)⁻¹左右)相比也无显著差异,而曝气成本却成倍增加。因此,综合考虑污染物去除、浮萍生长及曝气成本,建议曝气时长不宜高于1 h,推荐0.5~1 h为佳。以上结果可为曝气塘-浮萍塘联合系统的应用及曝气时长的选择提供参考。     

Pesticide residue removal in classic domestic processing of tomato and its effects on product quality

This study was undertaken to evaluate the effectiveness of several household practices (washing with water or acidic, alkaline, and oxidizing solutions, and peeling) in minimizing pesticide residue contamination of tomatoes, as well as the impact on the quality of the treated fruit. Tests were performed using two systemic fungicides (azoxystrobin and difenoconazole) and one contact fungicide (chlorothalonil). Solid-liquid extraction with low temperature partition (SLE/LTP) and liquid-liquid extraction with low temperature partition (LLE/LTP) were used to prepare the samples for pesticides determination by gas chromatography. Washing the tomatoes with water removed approximately 44% of chlorothalonil, 26% of difenoconazole, and 17% of azoxystrobin. Sodium bicarbonate (5%) and acetic acid (5%) solutions were more efficient, removing between 32 and 83% of the residues, while peeling removed from 68 to 88% of the pesticides. The washing solutions altered some fruit quality parameters, including acidity and chroma, and also caused weight loss. Acetic acid (0.15 and 5%) and hypochlorite (1%) solutions had the greatest effect on these parameters.     

一株异养脱氮菌的脱氮性能及其影响因素研究

研究异养硝化过程中分离得到一株具有异养脱氮性能的菌株,经16S rRNA鉴定后为Providencia rettgeri菌属,命名为Providencia rettgeri strain YL。在实验室条件下,初步探讨了不同碳氮源、温度、pH值、摇床转速和微量元素对Providencia rettgeri strain YL菌株脱氮作用的影响,研究结果显示,Providencia rettgeri strain YL菌株在葡萄糖和氯化铵为碳氮源的培养基中生长最好,温度为30℃、pH值为7、摇床转速为120 r/min时具有最佳的脱氮效果,微量元素Mg²⁺最有利于Providencia rettgeri strain YL菌株的生长和脱氮。     

Seasonal variations in roadside conditions and the performance of a gall-forming insect and its food plant

A transplant experiment using potted plants was performed over two years in a field located along a heavily used highway to test for the effects of seasonal variations in roadside conditions on the performance of a gall-forming insect, Eurosta solidaginis Fitch, and its perennial host plant, Solidago altissima L. The experiment was designed to separate temporally the two major classes of road pollutants (air pollutants versus de-icing salt). The population density and survivorship of E. solidaginis were not affected by road-stressed goldenrods. However, gall-forming larvae had a greater biomass when they were grown on plants exposed to road air pollutants, although these effects were tempered by a simultaneous exposure to de-icing salt. The shoot growth of S. altissima was severely affected by road stress during each growing season but after two years the biomass of roots and rhizomes combined did not differ between the treatments. This experiment showed that the effects of air pollutants and de-icing salt on a gall-forming insect via stressed host plants are less than additive.     

Assessment of air quality benefits from national air pollution control policies in China. Part II: Evaluation of air quality predictions and air quality benefits assessment

Following the meteorological evaluation in Part I, this Part II paper presents the statistical evaluation of air quality predictions by the U.S. Environmental Protection Agency (U.S. EPA)’s Community Multi-Scale Air Quality (Models-3/CMAQ) model for the four simulated months in the base year 2005. The surface predictions were evaluated using the Air Pollution Index (API) data published by the China Ministry of Environmental Protection (MEP) for 31 capital cities and daily fine particulate matter (PM_2.5, particles with aerodiameter less than or equal to 2.5 μm) observations of an individual site in Tsinghua University (THU). To overcome the shortage in surface observations, satellite data are used to assess the column predictions including tropospheric nitrogen dioxide (NO₂) column abundance and aerosol optical depth (AOD). The result shows that CMAQ gives reasonably good predictions for the air quality.The air quality improvement that would result from the targeted sulfur dioxide (SO₂) and nitrogen oxides (NO_x) emission controls in China were assessed for the objective year 2010. The results show that the emission controls can lead to significant air quality benefits. SO₂ concentrations in highly polluted areas of East China in 2010 are estimated to be decreased by 30–60% compared to the levels in the 2010 Business-As-Usual (BAU) case. The annual PM_2.5 can also decline by 3–15 μg m^?3 (4–25%) due to the lower SO₂ and sulfate concentrations. If similar controls are implemented for NO_x emissions, NO_x concentrations are estimated to decrease by 30–60% as compared with the 2010 BAU scenario. The annual mean PM_2.5 concentrations will also decline by 2–14 μg m^?3 (3–12%). In addition, the number of ozone (O₃) non-attainment areas in the northern China is projected to be much lower, with the maximum 1-h average O₃ concentrations in the summer reduced by 8–30 ppb.     

Recent insights into greywater treatment: a comprehensive review on characteristics,treatment technologies,and pollutant removal mechanisms

Environmental Science and Pollution Research - With the rapid socio-economic and industrial development, the problem of water shortage is becoming increasingly serious. Seeking alternative water...     

改性HDPE填料的制备及对MBBR脱氮除磷效果的强化

为解决传统填料亲水性差、挂膜速度慢等问题,对高密度聚乙烯(HDPE)填料进行亲水改性并改善填料的挂膜性能及在移动床生物膜反应器(MBBR)中的应用效果,用浸涂的方式将纳米SiO₂、聚乙烯醇(PVA)、聚多巴胺(PDA)等材料涂覆在HDPE填料表面,对改性后填料进行接触角、SEM、FT-IR和XPS表征以及MBBR挂膜启动实验,研究化学需氧量(COD)、氨氮(NH₃-N)、总氮(TN)、总磷(TP)的去除效果以及对填料挂膜时间、生物膜量、蛋白质和多糖含量的影响。结果表明：改性后,填料接触角由94.82°降至 60.1°,填料亲水性明显增强;填料表面出现褶皱,粗糙度增加;上述材料成功负载在填料表面并引入了亲水基团且未改变填料基本结构;填料挂膜时间由25 d提前至16 d,挂膜时间提前了9 d,COD、NH₃-N、TN、TP去除率分别达到94.9%、95.4%、83.5%、71.6%,与改性前比分别提高了9.3%、6.7%、13.7%、11.5%;填料的生物膜量是改性前的1.57倍,从27.35 mg·g⁻¹提高到42.87 mg·g⁻¹,其中蛋白质和多糖的含量分别从改性前的6.48 mg·g⁻¹和3.38 mg·g⁻¹提高到8.83 mg·g⁻¹和5.82 mg·g⁻¹,分别为改性前的1.36倍和1.72倍。由此可以看出,表面涂覆可以提高HDPE填料的亲水性,改性后的HDPE填料可以缩短在MBBR中的挂膜时间及强化对COD、NH₃-N、TN、TP的去除效果。本研究结果可为HDPE填料亲水改性的深入研究及在MBBR中的实际应用提供参考。     

潜流湿地填料比选及对氨氮的去除效应研究

为了提高西北地区潜流湿地净化污水中氮的效率,采用吸附动力学和热力学实验,对比研究了6种填料对水中氨氮的吸附特性。结果表明:砾石、生物炭、红砖、瓷砖、无烟煤和混凝土渣对氨氮的吸附平衡时间分别为12、24、17、12、8、12h,吸附量体现为生物炭砾石无烟煤瓷砖混凝土渣红砖。6种填料对氨氮的动力学吸附过程符合准二级动力学模型,吸附过程受到固体颗粒表面液膜影响,并非速率控制单独起作用。溶液浓度和温度升高有利于填料对氨氮的吸附,6种填料对氨氮的吸附过程符合Freundlich模型,表明吸附过程为多分子层吸附且吸附表面不均匀。6种填料对氨氮的吸附以物理吸附为主,吸附为吸热过程、焓推动作用,均不属于自发过程。6种填料都适合作潜流湿地填料,但生物炭对氨氮吸附效果最佳。     

Effects of development on runoff and pollutant export.

Runoff from two similar drainage areas in the Piedmont physiographic region of North Carolina was monitored simultaneously for 5.6 years. One of the drainage areas was developed as part of a large residential subdivision, while the other remained in woods and agricultural fields. Runoff volume was 68% greater for the developed compared with the undeveloped area, and baseflow as a percentage of overall discharge was approximately 0% compared with 25% for the undeveloped area. Overall annual export of sediment was 95% greater for the developed area, while export of nitrogen and phosphorus forms was 66 to 88% greater for the developed area. These results document the significant increases in runoff, sediment, and nutrient export associated with residential development.     

过硫酸盐在岩溶管道地下水中的稳定性及其对苯系物的去除效果

原位化学氧化(in situ chemical oxidation,ISCO)是一种高效便捷的去除地下水有机污染物的技术,相比于多孔介质,岩溶地下河中ISCO技术应用还未见报道.为了更好地认识ISCO技术在岩溶地下河石油污染修复中应用的可行性,使用过硫酸盐(persulfate,PS)作为化学氧化剂,在实验室利用碳酸盐...     

The effect of limited aeration on swine manure phosphorus removal.

Two low level aeration schemes (intermittent vs. continuous) were investigated on a laboratory scale, in conjunction with swine manure pH adjustment using sodium hydroxide (1.0 M), for manure phosphorus (P) removal. According to the data, an 80% reduction in soluble P was observed when the manure pH was increased to 8. Both intermittent and continuous aeration treatments could raise manure pH above 8 with an airflow rate of 1 L/minute in a period of 15 days. A drastic increase in pH (about 1 unit) was observed for both aeration schemes within the first day of test, resulting in a 76% reduction in soluble P concentration in the liquid. It appeared that there is no difference in terms of P removal between the two aeration programs, suggesting that the intermittent aeration be preferred to save energy while still achieving the same level of P removal.