Partial anammox achieved in full scale biofilm process for typical domestic wastewater treatment

• A full scale biofilm process was developed for typical domestic wastewater treatment. • The HRT was 8 h and secondary sedimentation tank was omitted. • Candidatus Brocadia were enriched in the HBR with an abundance of 2.89%. • Anammox enabled a stable ammonium removal of ~15% in the anoxic zone. The slow initiation of anammox for treating typical domestic wastewater and the relatively high footprint of wastewater treatment infrastructures are major concerns for practical wastewater treatment systems. Herein, a 300 m³/d hybrid biofilm reactor (HBR) process was developed and operated with a short hydraulic retention time (HRT) of 8 h. The analysis of the bacterial community demonstrated that anammox were enriched in the anoxic zone of the HBR process. The percentage abundance of Candidatus Brocadia in the total bacterial community of the anoxic zone increased from 0 at Day 1 to 0.33% at Day 130 and then to 2.89% at Day 213. Based upon the activity of anammox bacteria, the removal of ammonia nitrogen (NH₄⁺-N) in the anoxic zone was approximately 15%. This showed that the nitrogen transformation pathway was enhanced in the HBR system through partial anammox process in the anoxic zone. The final effluent contained 12 mg/L chemical oxygen demand (COD), 0.662 mg/L NH₄⁺-N, 7.2 mg/L total nitrogen (TN), and 6 mg/L SS, indicating the effectiveness of the HBR process for treating real domestic wastewater.     

CuCo2S4/sulfite reaction for efficient removal of tetracycline in water

Water pollution by antibiotics is an increasing concern, which may be addressed by advanced oxidation processes using sulfites as precursors of sulfate radicals (SO₄^·–), yet the efficiency of sulfite activation is limited. Here, we tested copper cobalt sulfide (CuCo₂S₄) to activate sulfite, based on the synergy among transition metals and the facilitation of transition metal redox circulation by reductive sulfur species. We analyzed CuCo₂S₄ structure by X-Ray photoelectron spectroscopy, and we studied the effect of pH and radical scavengers. Results show 90–100% abatement of tetracycline concentration at pH 8.0–10.0, with SO₄^·– and HO^· as the main reactive radicals. This finding is explained by the accelerated redox recycling of copper and cobalt by sulfur, and by the synergetic effect between active cobalt and copper sites.

     

北京市大气OH自由基测量结果及其特征

利用2种基于高效液相色谱技术的大气OH测量方法测定了北京城市大气中OH自由基,得到了其浓度水平和日变化情况.测得夏季日间最大OH浓度为～8×10⁷ cm^-3,秋季日间最大浓度为2×10⁷～4×10⁷cm^-3,并根据同步测量光强和其它污染物的浓度,分析了OH浓度与这些条件的相关性.结果表明,OH浓度与UV-B相对强度、O₃和HNO₂的浓度具有一定的正相关性     

77％氢氧化铜水分散粒剂对6种陆生生物的毒性及环境风险评估

氢氧化铜是一种利用铜离子杀死孢子细胞的杀菌剂,对柑橘树溃疡病具有良好的防治效果.本研究依据《化学农药环境安全评价试验准则》和《农药登记环境风险评估指南》,对6种模式陆生生物:日本鹌鹑(Cotumix japonica)、蜜蜂(Apis mellif-era L.)、家蚕(Bombyx mori)、赤眼蜂(Trichogramma dendrolimi)、七星瓢虫(Coccinella septempunctata)和蚯蚓(Eisenia foetida)进行急性毒性试验并对其进行环境风险评估.结果 表明,对鹌鹑急性经口半致死剂量(7 d-LD50)为225.9 mg a.i.-(kg bw)-1,对蜜蜂急性经口48 h-LD50为6.19 μg a.i.-蜂-1.在飘移场景下评估该农药对家蚕的风险,得到最外围一行桑树上的风险商(RQ):RQfr=3.083＞1,风险不可接受;该农药在农田内对寄生性天敌赤眼蜂的危害商(HQ):HQin =9.702＞5,风险不可接受.对土壤生物蚯蚓急性和慢性的RQ值分别为799.8和2666,RQ＞1,因此对土壤生物蚯蚓的风险不可接受.77％氢氧化铜水分散粒剂对蜜蜂急性经口和鸟类毒性为中毒.环境风险评估结果显示,上述3项环境风险不可接受,说明农药环境风险评估方法不能只停留在对某一类型模式生物的毒性分级上.基于目前发展趋势,更新评估手段,建立风险评估模型是大势所趋.所以,更需要对农药进行全面研究,以提高农药使用的安全性和合理性.     

Bioaerosolization behavior along sewage sludge biostabilization

• Aerosolization behavior during a lab-scale sludge biostabilization was determined. • Many pathogenic species were identified to be preferentially aerosolized. • Bioaerosol concentration along the biostabilization ranged from 160 to 1440 cell/m³. • Sludge aerosolization behavior was different with that of other biowaste. Biostabilization is a cost-effective method for the beneficial utilization of sewage sludge. However, during the operation of sludge biostabilization, some microbial species could be released into the atmospheric environment from the solid-phase of sludge easily and present a high risk to human health. This study aimed to evaluate the risk of bioaerosol during sludge biostabilization. We found a total of nine bacterial phyla, one archaeal phylum, and two fungal phyla in the bioaerosol samples. Among them, Proteobacteria, Actinobacteria, Bacteroidetes, and Ascomycota were the dominant phyla. In addition, the bioaerosolization indexes (BI) of prokaryotic phyla and fungal phyla ranged 0–45 and 0–487, respectively. Massilia, Pseudarthrobacter, Pseudomonas, Tremellales spp., and Fusarium were the preferentially aerosolized microbial genera with maximum bioaerosolization indexes of 19962, 10360, 1802, 3055, and 7398. The bioaerosol concentration during the biostabilization ranged from 160 to 1440 cell/m³, and we identified species such as Stenotrophomonas rhizophila and Fusarium graminerum with high bioaerosolization indexes that could be threats to human health. Euryachaeota, which belongs to archaeal phyla, had the highest biostabilization index in our study. We also found that Pseudarthrobacter was the easiest to aerosolize during the sludge biostabilization process.     

Coexistence of antibiotic resistance genes,fecal bacteria,and potential pathogens in anthropogenically impacted water

Environmental Science and Pollution Research - Microbial indicators are often used to monitor microbial safety of aquatic environments. However, information regarding the correlation between...     

Macromolecule simulation studies on mechanical properties and CH4/CO2 adsorption characteristics in bituminous coal matrix based on uniaxial tension–compression effect

With the increasing complication of production and geology conditions, and the increase of mining intensity and depth in coal mine, the coal structure presents varying degrees of deformation. In order to study the influence of uniaxial tension–compression effect on mechanical properties of coal matrix and CH₄/CO₂ adsorption characteristics, a macromolecular model reflecting the realistic bituminous coal structure was established. Results demonstrate that the influence of tension strain on the microporous structural parameters is greater than that of compression strain, and the tension strain weakens the mechanical properties but enhances the adsorbates adsorption amount. For the pure gases adsorption, there is a negative linear correlation between the total energy and adsorption amount. Additionally, the strain ranging from??0.20 to 0.20, the distribution of punctated adsorbates density develops to that of banded adsorbates density, and the mean adsorption density and saturated adsorption amount increase linearly. For the binary components adsorption (1:1), the CH₄ adsorption strength increases while the CO₂ adsorption strength slightly decreases. The minimum of total energy decreases in a quadratic polynomial relationship with the strain, and the proportion of van der Waals energy is 75.8–85.5%. Nevertheless, the competitive adsorption and strain have little effect on the potential energy range of the adsorbates. Furthermore, the diffusibility of CO₂ molecular layers is relatively good, and the strain enhances the stability of CH₄ molecular layers for the saturated binary adsorption. The findings provide essential guidance for the improvement of carbon capture and storage and CO₂-enhanced coalbed methane technologies in the deformation area of coal seam.

     

Effects of Ginkgo biloba extract on growth,photosynthesis, and photosynthesis-related gene expression in Microcystis flos-aquae

Environmental Science and Pollution Research - The inhibitory effect of plants on algae offers a new and promising alternative method for controlling harmful algal blooms. Previous studies showed...     

Versatile superhydrophobic bismuth molybdate cotton fabric for oil/water separation and decompose dyestuff

Water pollution caused by the discharged insolubility petroleum contaminants and organic compound dyes seriously threatens the natural self-purity capacity of the water body and the survival of aquatic species, so it is imperative to restraint the deterioration of the aquatic environment. In this paper, pathways are propounded for the simultaneous removal of insoluble spilling oil and organic dye contaminants. Particularly, hydrophobic ZnSnO₃ after stearic acid modification and Bi₂MoO₆ photocatalysts are introduced into the cotton fabric substrate through solution dip-coating. The durability of the prepared fabric suffers from the acid–base corrosion, thermal treatment and mechanical wear, while still exhibiting remarkable water-repellent (WCA?>?150°) property. Furthermore, the remarkable photocatalytic activity makes it possible for reusable degradation and the primary active species, namely the holes, to be verified by the radicals-capturing experiment. It is worth observing that as-prepared superhydrophobic fabric possesses admirable water-proof property and cycling durability of decomposing toxic water-soluble organic dye, thereby contributing to further realizing the ecological concept of clear waters.

     

Knowledge graph analysis and visualization of AI technology applied in COVID-19

Environmental Science and Pollution Research - With the global outbreak of coronavirus disease (COVID-19) all over the world, artificial intelligence (AI) technology is widely used in COVID-19 and...