Complexity of the relationship between 2D/3D urban morphology and the land surface temperature: a multiscale perspective

Environmental Science and Pollution Research - Urban morphology is a crucial contributor to urban heat island (UHI) effects. However, few studies have explored the complex effect of 2D/3D urban...     

Status of water use and potential of rainwater harvesting for replacing centralized supply system in remote mountainous areas: a case study

Environmental Science and Pollution Research - The failure of the centralized water supply system forced XY community to become more dependent on uncertain and unstable water sources. The results...     

碱渣对锌(Ⅱ)离子吸附特性的研究

研究了锌在碱渣表面的吸附特征.结果表明,碱渣总吸附量随体系温度的升高而降低;随体系 pH 值的升高而增加;随吸附质初始浓度的增加而增大.在 pH<5.51 时其等温吸附能较好地符合 Freudlich 等温吸附规律,而在 pH5.51 时,能较好地符合 Langmuir 等温吸附规律,吸附热随 pH 的增大而升高.当pH≤5.51时,碱渣的吸附力以范德华力平和疏水键力的作用为主,而当 pH6.17 时,以化学键力为主.在 pH 为 5.05、6.07和7.03时,碱渣对 Zn26 的吸附动力学方程都以 Langmuir 方程的拟合效果最优.     

大型蚤标志酶用于城市二级出水毒性的评价

大型蚤是一种国际公认的标准实验生物,广泛应用于污水、地表水等水质毒性检测。毒性水平较低的城市二级出水,对大型蚤往往无急性毒性效应,而具有慢性毒性效应,但慢性毒性检测周期过长,因此探索一种更灵敏的指标,实现快速检测,对于控制二级出水的水质风险具有重要意义。本研究考察了大型蚤在短期暴露于城市二级出水条件下,其体内乙酰胆碱酯酶、超氧化物歧化酶、过氧化氢酶、ATP酶、羧酸酯酶和碱性磷酸酯酶的酶活变化特征,从中筛选出对二级出水毒性响应灵敏的标志酶指标。实验结果表明,碱性磷酸酯酶、过氧化氢酶对二级出水毒性响应相对较灵敏,具有成为标志酶的潜力,研究结果为城市二级出水生物毒性评价方法优化提供新的思路。     

The use of ultrasound-assisted anaerobic compost tea washing to remove poly-chlorinated dibenzo-p-dioxins (PCDDs), dibenzo-furans (PCDFs) from highly contaminated field soils

The remediation of dioxin-contaminated soil of a specific coastal area previously employed for the manufacture of pentachlorophenol (PCP) in southern Taiwan’s Tainan City has attracted much attention of researchers there. This work addresses the possibility of providing an effective and environmentally friendly option for removing PCDD/Fs from soil in that field. Soil screening/sieving was first conducted to assess particle distribution. Fine sand was observed to be the major component of the soil, accounting for more than 60% of the total mass. A combination of ultrasonification and mechanical double-blade agitation was used to facilitate the washing of the soil using the biosurfactant anaerobic compost tea. More than 85 and 95% of total removal efficiencies were achieved for moderately and highly contaminated soils after 6 and 10 washing cycles, respectively, under ambient temperature, a soil/liquid ratio 1:2.5, 700 rpm, and over a relatively short duration. These results were achieved through the collision and penetration effects of this combined treatment as well as PCDD/F partitioning between the particles and anaerobic compost tea. This study represents the first to report the use of anaerobic compost tea solvent to wash soil highly contaminated by dioxin. It was concluded that anaerobic compost tea, rich in non-toxic bio-surfactants (e.g., alcohols, humic acids), can be used to improve bioavailability and bioactivity of the soil making bio-attenuation and full remediation more efficient.     

Sorbent-based devices for the removal of spilled oil from water: a review

Environmental Science and Pollution Research - Always, oil spills do cause serious and dire consequences for the environment, nature, and society that it consumes much time and socio-economic...     

Hydrolysis and photolysis of oxytetracycline in aqueous solution

Oxytetracycline ((2Z,4S,4aR,5S,5aR,6S,12aS)-2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene-1,3,12-trione) is a member of tetracycline antibiotics family and is widely administered to farm animals for the purpose of therapeutical treatment and health protection. Increasing attention has been paid to the environmental fate of oxytetracycline and other veterinary antibiotics with the occurrence of these antibiotics in the environment. The hydrolysis and photolysis degradation of oxytetracycline was investigated in this study. Oxytetracycline hydrolysis was found to obey the first-order model and similar rate constant values ranging from 0.094 ± 0.001 to 0.106 ± 0.003 day^{? 1} were obtained at different initial concentration ranging from 10 to 230 μ M. Solution pH and temperature were shown to have remarked effects on oxytetracycline hydrolysis. The hydrolysis in pH neutral solution appeared to be much faster than in both acidic and alkaline solutions. Oxytetracycline half-life decreased from 1.2 × 10² to 0.15 day with the increasing temperature from 4 ± 0.8 to 60 ± 1°C. The presence of Ca^{2 +} made oxytetracycline hydrolytic degradation kinetics deviate from the simple first-order model to the availability-adjusted first-order model and greatly slowed down the hydrolysis. Oxytetracycline photolysis was found to be very fast with a degradation rate constant at 3.61 ± 0.06 day^{? 1}, which is comparable to that of hydrolysis at 60°C. The presence of Ca^{2 +} accelerated oxytetracycline photolysis, implying that oxytetracycline become more vulnerable to sunlight irradiation after chelating with Ca^{2 +}. The photolysis may be the dominant degradation pathway of oxytetracycline in shallow transparent water environment.     

Ammonia emissions from different pig production scales and their temporal variations in the North China Plain

ABSTRACT

Pig production systems in China are shifting from small to industrial scale. Significant variation in housing ammonia (NH₃) emissions can exist due to differences in diet, housing design, and management practices. However, there is a knowledge gap regarding the impacts of farm-scale in China, which may be critical in identifying hotspots and mitigation targets. Here, continuous in-situ NH₃ concentration measurements were made at pig farms of different scales for sows and fattening pigs over periods of 3–6 days during two different seasons (summer vs. winter). For the sow farms, NH₃ emission rates were greater at the small farm (summer: 0.52 g pig^?1 hr^?1; winter: 0.21 g pig^?1 hr^?1) than at the large farm (summer: 0.34 g pig^?1 hr^?1; winter: 0.12 g pig^?1 hr^?1). For the fattening pig farms, NH₃ emission rates were greater at the large farm (summer: 0.22 g pig^?1 hr^?1; winter: 0.16 g pig^?1 hr^?1) than at the small farm (summer: 0.19 g pig^?1 hr^?1; winter: 0.07 g pig^?1 hr^?1). Regardless of farm scale, the NH₃ emission rates measured in summer were greater than those in winter; the NH₃ emission rates were greater in the daytime than at the nighttime; a positive relationship (R² = 0.06–0.68) was established between temperature and NH₃ emission rate, whereas a negative relationship (R² = 0.10–0.47) was found between relative humidity and NH₃ emission rate. The effect of farm-scale on indoor NH₃ concentration could mostly be explained by the differences in ventilation rates between farms. The diurnal variation in NH₃ concentration could be partly explained by ventilation rate (R² = 0.48–0.78) in the small traditional farms and by emission rate (R² = 0.26–0.85) in the large industrial farms, except for the large fattening pig farm in summer. Overall, mitigation of NH₃ emissions from sow farms should be a top priority in the North China Plain.

Implications: The present study firstly examined the farm-scale effect of ammonia emissions in the North China Plain. Of all farms, the sow farm was identified as the greatest source of ammonia emission. Regardless of farm scale, ammonia emission rates were observed to be higher in summer. Ammonia concentrations were mostly higher in the large industrial farms partly due to lower ventilation rates than in the small traditional farms.     

Utilization of a biosurfactant foam/nanoparticle mixture for treatment of oil pollutants in soil

Oil contamination has become a primary environmental concern due to increased exploration, production, and use. When oil enters the soil, it may attach or adsorb to soil particles and stay in the soil for an extended period, contaminating the soil and surrounding areas. Nanoparticles have been widely used for the treatment of organic pollutants in the soil. Surfactant foam has effectively been employed to remediate various soil contaminants or recover oil compounds. In this research, a mixture of biosurfactant foam/nanoparticle was utilized for remediation of oil-contaminated soil. The results demonstrated that the biosurfactant/nanoparticle mixture and nitrogen gas formed high-quality and stable foams. The foam stability depended on the foam quality, biosurfactant concentration, and nanoparticle dosage. The pressure gradient change in the soil column relied on the flowrate (N₂ gas + surfactant/nanoparticle mixture), foam quality, and biosurfactant concentration. The optimal conditions to obtain good quality and stable foams and high oil removal efficiency involved 1 vol% rhamnolipid, 1 wt% nanoparticle, and 1 mL/min flowrate. Biosurfactant foam/nanoparticle mixture was effectively used to remediate oil-contaminated soil, whereas the highest treatment efficiency was 67%, 59%, and 52% for rhamnolipid biosurfactant foam/nanoparticle, rhamnolipid biosurfactant/nanoparticle, and only rhamnolipid biosurfactant, respectively. The oil removal productivity decreased with the increase of flowrate due to the shorter contact time between the foam mixture and oil droplets. The breakthrough curves of oil pollutants in the soil column also suggested that the foam mixture’s maximum oil treatment efficiency was higher than biosurfactant/nanoparticle suspension and only biosurfactant.

     

微波诱导Fe2O3/沸石负载型催化剂催化氧化焦化废水的研究

以天然沸石为载体,采用尿素均匀沉淀法制备了Fe2O3/沸石负载型催化剂(简称负载催化剂),研究其在微波辐射下对焦化废水的处理效果,探讨了负载催化剂投加量、微波辐射功率、微波辐射时间等因素对处理效果的影响,并考察了负载催化刑的重复使用性能.结果表明,天然沸石、于350℃焙烧得到的负载催化刑和于550℃焙烧得到的负载催化剂...