Biochars derived from carp residues: characteristics and copper immobilization performance in water environments

● P-rich carp residues-derived biochars presented excellent Cu sorption capacity. ● Sorption mechanisms of Cu on CRBs were mainly precipitation and surface complexation. ● CRBs could immobilize Cu and reduce its bioavailability in aquatic environment. Heavy metal pollution has attracted worldwide attention because of its adverse impact on the aquatic environment and human health. The production of biochar from biowaste has become a promising strategy for managing animal carcasses and remediating heavy metal pollution in the aquatic environment. However, the sorption and remediation performance of carp residue-derived biochar (CRB) in Cu-polluted water is poorly understood. Herein, batches of CRB were prepared from carp residues at 450–650 °C (CRB450–650) to investigate their physicochemical characteristics and performance in the sorption and remediation of Cu-polluted water. Compared with a relatively low-temperature CRB (e.g., CRB450), the high-temperature biochar (CRB650) possessed a large surface area and thermodynamic stability. CRB650 contained higher oxygen-containing functional groups and P-associated minerals, such as hydroxyapatite. As the pyrolytic temperature increased from 450 to 650°C, the maximum sorption capacity of the CRBs increased from 26.5 to 62.5 mg/g. The adsorption process was a type of monolayer adsorption onto homogenous materials, and the sorption of Cu²⁺ on the CRB was mainly based on chemical adsorption. The most effective potential adsorption mechanisms were in order of electrostatic attraction and cation-π interaction > surface complexation and precipitation > pore-filling and cation exchange. Accordingly, the CRBs efficiently immobilized Cu²⁺ and reduced its bioavailability in water. These results provide a promising strategy to remediate heavy metal-polluted water using designer biochars derived from biowastes, particularly animal carcasses.     

Simulation and evaluation on the eco-industrial system of Changchun economic and technological development zone, China

Reasonable structure, adaptive patterns and effective regulation of society, economy and environment subsystems should be taken into account in order to obtain harmonious development of urban eco-industrial system. We simulated and evaluated a redesigned eco-industrial system in Changchun Economic and Technological Development Zone (CCETDZ) in the present work using system dynamics and grey cluster methods. Four typical development strategies were simulated during 2005–2020 via standard system dynamic models. Furthermore, analytic hierarchy process and grey cluster allowed for the eco-industrial system evaluation and scenarios optimizing. Our dynamic simulation and statistical analysis revealed that: (1) CCETDZ would have different development scenarios under different strategies. The total population in scenario 2 grew most rapidly and reached 3.28 × 10⁵ in 2020, exceeding its long-term planning expected population. And the GDP differences among these four scenarios would amount to 6.41 × 10¹⁰ RMB. On the other hand, environmental pollution would become serious along with economy increasing. As a restriction factor, positive or negative increment of water resource will occur according to the selected strategy. (2) The fourth strategy would have the best efficiency, which means that the most efficiently development of CCETDZ required to take science, technology, environment progress and economy increase into account at the same time. (3) Positive environment protection measures, such as cleaner production, green manufacture, production life cycle management and environment friendly industries, should be attached great importance the same as economy development during 2005–2020 in CCETDZ.     

Optimization of digestion parameters for analysing the total sulphur of mine tailings by inductively coupled plasma optical emission spectrometry

The oxidation of sulphidic mine tailings and consequent acid generation poses challenges for the environment. Accurate and precise analysis of sulphur content is necessary for impact assessment and management of mine tailings. Here, the authors aim at developing a rapid and easy digestion procedure, which may analyse and measure the total amount of sulphur in mine tailings by using inductively coupled plasma. For evaluating effects of several variables, the researchers used a univariate (analysis of variance (ANOVA)) strategy and considered factors such as composition of the acid mixture, heating time, and refluxing device to optimize the performance. To do the experiment, the researchers have used two certified reference materials (KZK-1 and RTS-2) and samples of tailings from Musselwhite mine. ANOVA result shows that heating time is the most influencing factor on acid digestion of the reference materials whereas in case of a digestion of tailings sample, hydrochloric acid proved to be the most significant parameter. Satisfactory results between the measured and referenced values are found for all experiments. It is found that the aqua regia (1 ml HNO₃ + 3 ml HCl) digestion of 0.1 g of samples after only 40 min of heating at 95°C produced fast, safe, and accurate analytical results with a recovery of 97% for the selected reference materials.     

Assessing the health of an urban stream: a case study of Suzhou Creek in Shanghai, China

Restoration of urban streams and rivers has increased rapidly in developing countries in recent years. Estimating river health provides a new perspective on evaluating the ecological conditions of streams and rivers. The Suzhou Creek restoration project in Shanghai, China is a milestone for environmental protection. Based on the environmental and ecological data, including 17 indicators in five categories, collected from March 11 to April 20, 2007, the river health index (RHI) for Suzhou Creek was constructed and analysed to quantify the ecosystem of this urban river after a restoration project. The RHI scores of 34 sites ranged from 19.24 to 33.36, i.e. from poor to good. There were no significant RHI differences among stream orders, while differences in land use resulted in significant differences in channel flow status (B12), channel alteration (B21), channel sinuosity (B22), bank stability (B23), bank profile type (B25) and riparian vegetative zone width (B31). River restoration led to improved hydrological condition and channel physical form, while ammonia nitrogen (B44) and indicator scores of the presence of macro-invertebrate families (B51) were the lowest of any indicator. This case study supports the use of river health assessment as a supplement to water quality analysis in China.     

Bubble size distribution in a laboratory-scale electroflotation study

The performance of electroflotation (EF) is strongly influenced by the size of O₂ and H₂ bubbles. Therefore, in this study, the bubble sizes are measured in a lab-scale EF cell using a high-speed camera. The mean bubble size is found to vary in the range of 32.7–68.6 μm under different operating conditions. This study shows that the electrode material, current density, water pH, ionic strength, and frother (Tennafroth 250) concentration are important factors in controlling the bubble size. Furthermore, four mathematical distributions (normal, log-normal, Weibull, and gamma distributions) are fitted to the experimental data, among which the log-normal distribution is found to be the best fit based on the lower Anderson-Darling (AD) value.     

基于荧光素酶发光检测体系的几种工业污染物综合毒性评价

利用化工污染物能抑制荧光素酶催化发光反应这一特性,对水质中6种化工化合物分别进行毒性测试,建立一种快速检测水质中化工污染物毒性的生物学方法。实验结果表明,对苯二酚、4-氨基酚、苯胺、氯仿、盐酸邻联甲苯胺和硫柳汞的EC50值分别为:5.563、10.225、20.236、38.432、8.827和0.6 mg/L,6种污染物毒性大小依次为:硫柳汞>对苯二酚>盐酸邻联甲苯胺>4-氨基酚>苯胺>氯仿,相关系数>0.95。该方法为进一步研究基于荧光素酶反应体系检测水质中化工污染物综合毒性的生物传感器方法奠定基础。     

含油污水处理用旋流气浮一体化设备的CFD数值模拟

借助商业计算流体动力学(CFD)软件Fluent,对国内自主研发的含油污水处理用BIPTCFU-1型旋流气浮一体化设备进行内部流场的数值模拟研究,讨论了射流器挡板和缓流板等主要结构参数对设备分离性能的影响,并对污水处理量和回流比等运行参数对设备除油率的影响进行了评估。为下一步通过CFD数值模拟手段进行优化设计,进而成功研发含油污水旋流气浮一体化处理设备奠定了较为坚实的基础。     

分置式膜-生物反应器凝胶层膜污染模型研究

通过紊流条件下阻力模型和凝胶极化模型对膜生物反应器的阻力进行分析,结果表明,膜面流速在3～10 m/s,运行时间在5h之内时,阻力模型可以很好地符合凝胶模型.通过分置式膜-生物反应器对染料废水超滤膜阻力进行了分析,膜的总阻力随着运行时间增加而增加,在所有阻力中,凝胶阻力占比重最大.     

Toxicity measurements in aqueous solution during ozonation of mono-chlorophenols

The Microtox toxicity and Oxygen Uptake Rate (OUR) inhibition tests were conducted to monitor the variation of toxicity during ozonation of 2-chlorophenol (2-CP), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP) under neutral conditions. The results revealed that the oxidized 2-CP solution exhibited new toxicity to pure bacteria and mixed microorganisms in the early stage of ozonation. The largest inhibition of OUR appeared at one mol of applied ozone dosage per mol of initial 2-CP, and the percentage of inhibition was 63.8%. In addition, ozonated 3-CP and 4-CP also significantly induced new aqueous toxicity, if these toxic intermediates were not further ozonated. Comparing the variation of toxicity and the hydroxylated/chlorinated intermediates formed, 3-chloro-catechol, 2-chloro-2, 4-hexadienedioic acid and the dimmer compounds may be related to the sources of toxicity during the ozonation of 2-CP.     

钷－147在模拟水域生态系中的行为

研究了在模似池塘小生境中,147Pm在水体、土壤及水生生物之间的转移和积累情况,建立了动力学模型。结果表明：其行为符合一级反应动力学模式;水生植物对¹⁴⁷Pm的浓缩能力最强;鱼对¹⁴⁷Pm的吸收极少;¹⁴⁷Pm在土壤中的渗透力较弱,80％浓缩于泥土表层1cm内。因此,水生植物可作为¹⁴⁷Pm污染水体的环境监测指示生物,并可用于净化被¹⁴⁷Pm污染的水体;土壤可以沉淀水体中的147Pm,对去污有一定效果。