Cattle manure biochar and earthworm interactively affected CO2 and N2O emissions in agricultural and forest soils: Observation of a distinct difference

• Earthworms increase CO₂ and N₂O emissions in agricultural and forest soil. • 10% biochar suppresses CO₂ and N₂O emissions in forest soil. • Biochar interacted with earthworm to significant affect CO₂ and N₂O emissions. The application of manure-derived biochar offers an alternative to avoid the direct application of manure to soil causing greenhouse gas emission. Soil fauna, especially earthworms, can markedly stimulate carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions from soil. This study therefore investigated the effect of cattle manure biochar (added at rates of 0, 2%, or 10%, coded as BC0, BC2 and BC10, respectively) application, with or without earthworm Aporrectodea turgida, on emissions of CO₂ and N₂O and changes of physic-chemical properties of agricultural and forest soils in a laboratory incubation experiment. The BC10 treatment significantly enhanced cumulative CO₂ emissions by 27.9% relative to the untreated control in the agricultural soil. On the contrary, the BC2 and BC10 treatments significantly reduced cumulative CO₂ emissions by 16.3%–61.1% and N₂O emissions by 92.9%–95.1% compared to the untreated control in the forest soil. The addition of earthworm alone significantly enhanced the cumulative CO₂ and N₂O fluxes in agricultural and forest soils. Cumulative CO₂ and N₂O fluxes were significantly increased when BC2 and BC10 were applied with earthworm in the agricultural soil, but were significantly reduced when BC10 was applied with earthworm in the forest soil. Our study demonstrated that biochar application interacted with earthworm to affect CO₂ and N₂O emissions, which were also dependent on the soil type involved. Our study suggests that manure biochar application rate and use of earthworm need to be carefully studied for specific soil types to maximize the climate change mitigation potential of such management practices.     

Occurrence and distribution of micro- and mesoplastics in the high-latitude nature reserve,northern China

• The first study on micro(meso)plastics (MMPs) in the Liaohe River Reserve is reported. • Diverse MMP were detected in surface water and sediment at all 32 sites. • The abundance of MMPs decreased in the course of the river. • The MMPs abundance in water is significant association with the county population. Microplastics pollution has received growing attention worldwide in recent years. However, data on microplastics in the freshwater environment are still limited, especially in high-latitude nature reserves in Northern China. The first study on microplastic pollution in the Liaohe River Reserve in Northern China is reported here, and mesoplastics were also incorporated. Surface water and sediment samples were collected from 32 sites along the nature reserve. The abundance, type, shape, color, and size of micro- and mesoplastics were measured using density extraction, optical microscopy, and FTIR spectroscopy. The data showed that diverse micro- and mesoplastics were found widespread in the 32 sites, and the average abundance of these plastics was 0.11±0.04 10⁻² items/L in surface water and 62.29±54.30 items/kg in sediment. Moreover, 70% and 66% were smaller than 2000 μm in surface water and sediment, respectively. Fiber accounted for 91.86% in surface water and 43.48% in sediment, indicating that the major source of micro- and mesoplastics in the Liaohe River Reserve may be domestic sewage and aquaculture. A total of 16 and 27 polymers were identified in surface water and sediment, respectively, and mostly consisted of rayon, polyester, polystyrene, and poly(ethylene terephthalate). Moreover, both the risk index and the pollution load index demonstrated a low risk of micro- and mesoplastics in surface water and sediment in the Liaohe River Reserve.     

Environmental effects on perishable product quality and trading under OBOR supply chain different route scenarios

Environmental Science and Pollution Research - The world becomes advance rapidly, and the demand of perishable food increases in the global market. Food firms perceive the cheapest supply chain...     

缺氧—好氧—催化臭氧氧化工艺处理石化厂含盐废水

采用缺氧—好氧—催化臭氧氧化工艺处理某石化厂的含盐废水。实验结果表明：在进水COD为200~350 mg/L的条件下,经生化处理后的出水COD稳定在50~60 mg/L,COD去除率稳定在75%左右;在臭氧投加量为4.5 g/L、V（催化剂Ⅱ）∶V（废水）=1.5∶1的条件下,进行连续催化臭氧氧化后出水COD稳定在20 mg/L以下,COD去除率大于70%,满足DB 61/224—2011《黄河流域（陕西段）污水综合排放标准》。表征结果显示,催化剂表面含有铜元素,比表面积为250.815 m²/g,吸水率为60.9%,经过滤可去除废水中残留的催化剂。     

丙烯酸废水超临界水氧化动力学研究

用H2O2作为氧化剂,对丙烯酸生产废水进行超临界水氧化研究.得到了反应速率方程表达式.COD、H2O2和水的反应级数分别为1、0和0,指前因子A为4.97 s-1,反应活化能Ea为20.64 kJ/mol,诱导时间为8 s左右.     

化工厂硫酸生产中尾气达标排放与低浓度SO2资源化回收利用措施

针对金川集团公司化工厂硫酸生产中,冶炼烟气SO2浓度波动大、频繁及其系统故障引发的制酸系统的非正常、正常SO2烟气条件下尾气超标排放及其低浓度SO2无法回收利用问题,结合化工厂产业特点及其优势;采用尾气吸收等技术措施,不但使硫酸系统尾气达标排放,而且使尾气中低浓度SO2作为资源生产亚硫酸钠得到开发利用。     

哈药污泥的化学组成及农田应用安全性研究

通过对哈药总厂污水处理车间排放的污泥进行化学成分及施入土壤后重金属元素在土壤及水稻子粒中残留的分析,探讨该污泥能否应用于农田及适宜的用量.试验结果表明,污泥中有机质含量高,达800mg/kg,全氮含量达7%左右.重金属元素含量均明显低于农用污泥中污染控制标准值.大剂量施入土壤后,子粒中重金属元素的残留量与常规施肥无明显差异.随污泥用量的增加,土壤中有机质的含量明显提高,重金属元素除汞和锌有较大幅度提高外,其他元素差异不大.     

柳江国家地质公园的科学价值与地质环境保护

秦皇岛柳江国家地质公园以地质遗迹资源丰富、地貌景观多样而闻名,具有重要的科学研究价值和旅游价值。然而地方政府为满足短期经济发展的需要,过度开发园区内的煤炭、水泥灰岩等矿产资源,致使一些珍贵的地质遗迹被破坏。为此,从政策、法规以及宣传教育层面对地质遗迹的保护提出一些建议。     

Membrane fouling controlled by coagulation/adsorption during direct sewage membrane filtration (DSMF) for organic matter concentration

Unlike the role of the membrane in a membrane bioreactor, which is designed to replace a sediment tank, direct sewage membrane filtration(DSMF), with the goal of concentrating organic matters, is proposed as a pretreatment process in a novel sewage treatment concept. The concept of membrane-based pretreatment is proposed to divide raw sewage into a concentrated part retaining most organics and a filtered part with less pollutant remaining, so that energy recovery and water reuse, respectively, could be realized by post-treatment. A pilot-scale experiment was carried out to verify the feasibility of coagulant/adsorbent addition for membrane fouling control, which has been the main issue during this DSMF process. The results showed that continuous coagulant addition successfully slowed down the increase in filtration resistance, with the resistance maintained below 1.0 × 1013m~(-1) in the first 70 hr before a jump occurred. Furthermore,the adsorbent addition contributed to retarding the occurrence of the filtration resistance jump, achieving simultaneous fouling control and chemical oxygen demand(COD)concentration improvement. The final concentrated COD amounted to 7500 mg/L after 6 days of operation.     

三甲基氯化锡对斑马鱼(Danio rerio)生理生化特性的影响

为初步探讨三甲基氯化锡(trimethyltin chloride,TMT)对鱼类的毒性效应以及评价环境中TMT的安全性,采用静态鱼类急性毒性试验法测定了TMT对斑马鱼(Danio rerio)生理生化指标的影响;参考TMT的96 h-LC50值,设定3个浓度(0.39、0.78和1.17 mg·L-1)处理斑马鱼,测...