Co-pyrolysis of sewage sludge and biomass for stabilizing heavy metals and reducing biochar toxicity: A review

The huge amounts of sewage sludge produced by municipal wastewater treatment plants induce major environmental and economical issues, calling for advanced disposal methods. Traditional methods for sewage sludge disposal increase greenhouse gas emissions and pollution. Moreover, biochar created from sewage sludge often cannot be used directly in soil applications due to elevated levels of heavy metals and other toxic compounds, which alter soil biota and earthworms. This has limited the application of sewage sludge-derived biochar as a fertilizer. Here, we review biomass and sewage sludge co-pyrolysis with a focus on the stabilization of heavy metals and toxicity reduction of the sludge-derived biochar. We observed that co-pyrolyzing sewage sludge with biomass materials reduced heavy metal concentrations and decreased the environmental risk of sludge-derived biochar by up to 93%. Biochar produced from sewage sludge and biomass co-pyrolysis could enhance the reproduction stimulation of soil biota by 20‒98%. Heavy metals immobilization and transformation are controlled by the co-feed material mixing ratio, pyrolysis temperature, and pyrolysis atmosphere.

     

原噬菌体诱导法在环境诱变剂研究中的应用

应用原噬菌体诱导法检测35种不同化学物质的潜在遗传毒性,S_9作代谢激活系统。试验结果有13个样品具有诱变性(占37.1％),其中有10个样品在S_9激活下和3个样品无论有与无S_9活化均能诱导溶源性大肠杆菌释放λ噬菌体。检出的阳性样品中有些为已知的诱变剂和致癌剂(黄曲霉毒素B_1)或抗癌药(丝裂霉素C)。提示诱导检测法作为环境遗传毒物的预警系统初筛潜在致癌危险物质是一种极为有用的手段。     

蚕豆根尖微核技术监测环境污染物的诱变活性

应用蚕豆根尖微核技术对10份矿尘样品、黄曲霉毒素B_1(AFB_1)和15份真菌提取物进行诱变性研究,结果有10份矿尘、AFB_1和5种真菌提取物能明显诱发蚕豆根尖细胞微核率的增高;对其中5~#矿尘、AFB_1和杂色曲霉提取物进行剂量效应测定,显示了良好的剂量效应关系,提示具有诱变活性,这对当地的肿瘤发病率可能起重要作用。说明蚕豆根尖微核技术对研究环境诱变剂不失为一种有效的手段。     

Horizon scanning for South African biodiversity: A need for social engagement as well as science

Ambio - A horizon scan was conducted to identify emerging and intensifying issues for biodiversity conservation in South Africa over the next 5–10 years. South African biodiversity...     

Efficient removal and mechanisms of water soluble aromatic contaminants by a reduced-charge bentonite modified with benzyltrimethylammonium cation

A novel strategy utilizing the phenyls interaction and the hydrophobic affinity of available siloxane surface in the interlayer of bentonite was proposed to improve the sorption capabilities of organobentonites for water soluble aromatic contaminants. A unique organobentonite (65BTMA) was synthesized by intercalating benzyltrimethylammonium cation (BTMA⁺) into the interlayer of a reduced-charge bentonite with cation exchange capacity (CEC) of 65 cmol kg⁻¹. Phenol, aniline and toluene were used as model compounds of water soluble aromatic contaminants. Their respective removal efficiencies by 65BTMA were achieved at 83.3%, 89.2% and 97.3% at the initial concentration of 20 mg l⁻¹. To reveal the sorption mechanism, sorption characteristics of aromatic contaminants to 65BTMA were compared with that of aliphatic contaminants in similar molecular size. And various organobentonites were prepared by combining TMA⁺ (tetramethylammonium), BTMA⁺, HTMA⁺ (heptyltrimethylammonium) and CTMA⁺ (cetyltrimethylammonium) with two bentonites (CEC = 108 and 65 cmol kg⁻¹). To 65BTMA, sorption magnitudes of aromatic contaminants were much greater than that of aliphatic compounds with similar size; and dramatically higher than those to other organobentonites at low pollutant concentrations. These observations revealed that the strong phenyls interactions contributed significantly to sorb the aqueous soluble aromatic contaminants to 65BTMA (>90%), and which favored to design uniquely powerful sorbents.     

生物法生成单质硫过程中氧化还原电位的研究

采用升流式好氧反应器,接种实验室自行培养的排硫硫杆菌,进水硫化物质量浓度为343～356 mg/L,在不同容积负荷下,研究不同氧化还原电位(ORP)对硫化物生物转化的影响.结果表明,ORP为(-260±10)mV时,硫化物去除率均达95%以上;随着ORP的降低,硫化物去除率和硫酸根生成率均呈下降趋势;不同容积负荷下,控制合适的ORP均可得到单质硫的最大生成率.     

粉煤灰固定化絮凝剂填充床-鼓气工艺漂染污水处理研究

以粉煤灰固定化絮凝剂填充成絮凝过滤床 ,并组合成连续 -鼓气式五级絮凝过滤床污水处理系统。在吸附、絮凝、沉降、过滤和降解等协同作用下 ,污水流量为 2 5 L/h、鼓气量为 5 0 L/( L· h)、级数为 5时 ,处理水的悬浮物、色度、COD、氨氮、硫化物和苯胺的去除率分别为 99.0 %、91.8%、96.9%、95 %、96.9%、90 .6% ,p H=6.2～ 6.9,基本达到纺织染整工业污水 级排放标准     

地下金属矿山安全评价体系的探讨

对矿山实行安全评价是确保安全生产的重要措施。根据地下金属矿山生产工艺的特点，分析发生事故的原因及影响因素，以定量分析的方法，从企业管理、工程设计、人员配备、环境条件等方面进行安全评价，提出评价体系，系统而直观地反映企业生产安全程度。     

南京外秦淮河河岸带原生植被初步调查

对南京外秦淮河河岸带原生植被进行了初步调查.外秦淮河河岸带原生植被共有28科、50属、53种,其中漂浮植物4种,占7.55%,沉水植物1种,占1.89%,挺水和湿生植物13种,占24.53%,陆生草本和藤本植物24种,占45.28%,乔木和灌木11种,占20.75%.在概括外秦淮河自然环境和分析原生植被主要特征的基础上,提出在进行河岸带植被群落重建时应注重闸下段河岸带植被群落的重建,增加沉水植物、浮叶植物和观赏性植物的种植.另外,植被群落可按河道垂向的常水位以下区域、变化水位区域和洪水位以上区域来构建.