Bamboo charcoal addition enhanced the nitrogen removal of anammox granular sludge with COD: Performance, physicochemical characteristics and microbial community

The effects of different chemical oxygen demand(COD) concentrations on the anammox granular sludge with Bamboo Charcoal(BC) addition were evaluated in UASB reactor. The results showed that the average total nitrogen(TN) removal efficiency was reduced from85.9% to 81.4% when COD concentration was increased from 50 to 150 mg/L. However, the TN removal efficiency of BC addition reactors was dramatically 3.1%–6.4% higher than that without BC under different COD concentrations. The average diameter o...     

ESTROM—a Romanian–Swiss research programme

Background, aim, and scope  Composting is an effective treatment process to realize sludge land application. However, nitrogen loss could result in the reduction of nutrient value of the compost products and the stabilization effect of composting on heavy metal concentration and mobility in sludge has been shown to be very limited. Materials and methods  Laboratory-scale experiments were carried out to investigate the effects of bamboo charcoal (BC) on nitrogen conservation and mobility of Cu and Zn during sludge composting. Results  The result indicated that the incorporation of BC into the sludge composting material could significantly reduce nitrogen loss. With 9% BC amendment, total nitrogen loss at the end of composting decreased 64.1% compared with no BC amendment (control treatment). Mobility of Cu and Zn in the sludge may also have been lessened, based on the decline in diethylenetriaminepentaacetic acid-extractable Cu and Zn contents of composted sludge by 44.4% and 19.3%, respectively, compared to metal extractability in the original material. Discussion  Ammonia adsorption capability of BC might be the main reason for the retention of nitrogen in sludge composting materials. Decrease of extractable Cu²⁺ and Zn²⁺ in the composting material mainly resulted from the adsorption of both metals by BC. Conclusions  Incorporation of BC into composting material could significantly lessen the total nitrogen loss during sludge composting. Mobility of heavy metals in the sludge composting material could also be reduced by the addition of BC. Recommendations and perspectives  Bamboo charcoal could be an effective amendment for nitrogen conservation and heavy metal stabilization in sludge composts. Further research into the effect of BC-amended sludge compost material on soil properties, bioavailability of heavy metals, and nutrient turnover in soil needs to be carried out prior to the application of BC-sludge compost in agriculture.     

Removal of microcystin-LR from drinking water using a bamboo-based charcoal adsorbent modified with chitosan

The bamboo charcoal adsorbent modified with chitosan can effectively remove microcystin-LR from drinking water.     

多孔炭/硅胶复合吸附剂吸附除铬(Ⅵ)研究

用静态吸附法研究了吸附条件对多孔炭/硅胶复合吸附剂的吸附除铬(Ⅵ)性能的影响,这些条件包括接触时间、溶液pH值、吸附剂用量、初始溶液浓度和吸附温度等。结果表明多孔炭/硅胶是有效的吸附除铬(Ⅵ)材料,除铬(Ⅵ)过程强烈依赖于溶液pH值,优化的pH值为2.3,在此pH下有部分铬(Ⅵ)被还原。吸附剂用量、吸附温度、初始溶液浓度等也影响吸附过程。20h可以达到吸附平衡。吸附等温线可以用Langmuir方程描述。     

电动力学-新型竹炭联合作用下土壤镉的迁移吸附及其机理

研究了土壤中镉在均匀电动力学作用下的迁移特征及其影响因素,以及电场双向切换并加有新型竹炭材料条件下电动力学对镉的去除特性,揭示了利用均匀电动力学-新型竹炭材料联合修复镉污染土壤的特征及其可行性.结果表明,竹炭是一种良好的吸附材料,对镉具有较强的吸附作用,可以用 Freundlich和Langmuir模型很好的模拟吸附过程（R²>0.96）;在电压梯度为1.0 V/cm的条件下,受试土壤中Cd²⁺在均匀电动力学下的迁移速率为0.678 6～0.687 5　cm/h,并且迁移速率大小与Cd²⁺浓度和场强分布有关,电动力场可以有效地迁移土壤中的重金属离子;使用竹炭作为吸附剂的新型工艺中,在与速率实验相同的电压梯度,电场48　h的切换周期下,土壤中镉能够在电场作用下高效迁移至处理区并被吸附去除（12　d去除79.6%）,过程中可以很好地维持土壤的pH和水分条件,过程的电流随切换呈周期性的变化.电动迁移-竹炭吸附作为一种新型工艺具有广泛的应用前景.     

Reduction in uptake by rice and soybean of aromatic arsenicals from diphenylarsinic acid contaminated soil amended with activated charcoal

Activated charcoal (AC) amendment has been suggested as a promising method to immobilize organic contaminants in soil. We performed pot experiments with rice and soybean grown in agricultural soil polluted by aromatic arsenicals (AAs). The most abundant AA in rice grains and soybean seeds was methylphenylarsinic acid (MPAA). MPAA concentration in rice grains was significantly reduced to 2% and 3% in 0.2% AC treated soil compared to untreated soil in the first year of rice cultivation. In the second year, MPAA concentration in rice grains was significantly reduced to 15% in 0.2% AC treated soil compared to untreated soil. MPAA concentration in soybean seeds was significantly reduced to 44% in 0.2% AC treated soil compared to untreated soil. AC amendment was effective in reducing AAs in rice and soybean.     

新型填料曝气生物滤池处理抗生素类废水

针对抗生素类制药工业废水难处理的特点,将某高效复合微生物菌群负载在以中孔和大孔为主的污泥炭颗粒的表面和孔隙内部,制备得到生物改性污泥炭。采用装填生物改性污泥炭的新型填料曝气生物滤池及向下流、中下部曝气的运行方式对以抗生素类制药废水为主的混合工业废水絮凝沉淀池出水中的主要污染物进行深度处理。结果表明,污泥炭载体在水中发挥2种作用,即吸附功能和载体功能,污泥炭表面及内部孔隙结构非常发达,为不同种类和功能的高效微生物菌群的构建和负载提供了良好的载体;采用粒径为8~10 mm的生物改性污泥炭、HRT 100 min及气水比3∶1,进水COD浓度96~123 mg/L、NH3-N浓度8.8~17.4 mg/L、TP浓度0.390~0.623 mg/L、pH 6~9,新型填料曝气生物滤池对混合工业废水中的COD、NH3-N和TP的平均去除率分别为47.2%、49.2%和35.6%,相比污水厂常规陶料填料生物滤池分别提高了27.9、21.6和12.8个百分点,该工艺处理效果稳定,运营管理简单,为极难生物降解的抗生素类废水为主的混合工业废水的深度处理提供了新思路。     

微波辅助（NH4）2S2O8改性竹炭对Cu2+的吸附性能

以竹炭为原料,采用(NH4)2S2O8作为改性药剂,通过微波辅助加热的方法对竹炭进行改性;运用Boehm滴定、扫描电镜(SEM)、电子能谱(EDAX)和傅里叶红外光谱(FTIR)对改性竹炭进行表征;考察了pH、时间、温度和离子强度等对改性竹炭吸附Cu2+的影响。结果表明,微波辅助(NH4)2S2O8改性使得竹炭表面的酚羟基、内酯基、羧基等酸性含氧官能团的数量有所增加;改性竹炭对Cu2+吸附更符合Langmuir等温方程,吸附为自发的吸热过程;吸附动力学符合准二级动力学方程;溶液离子强度增大不利于其对Cu2+的吸附。     

In vitro study of oxytetracycline adsorption on activated charcoal

Abstract

In vitro adsorption experiments simulating pH in gastric environment and using Langmuir isotherm, showed that 408 mg of oxytetracycline was adsorbed per gram of activated charcoal. Langmuir isotherm fitted adsorption data better than a Freundlich isotherm. Freundlich isotherm showed a specific adsorption capacity of 518 mg/g for activated charcoal. Both isotherm parameters indicated a strong oxytetracycline adsorption on activated charcoal in terms of quantity and binding strength. The results demonstrate that the concomitant use of oxytetracyline and activated charcoal should be avoided.     

Sorption and desorption of lindane by wood charcoal in fixed‐bed reactor

Abstract

Sorption and desorption of lindane (y‐HCH) by wood charcoal (WC) and wood charcoal treated by 1N HNO₃ (WCT) in fixed‐bed reactor (FBR) were investigated in this study. WCT revealed a better performance than WC, in removing lindane in FBR. The breakthrough of lindane was significantly affected by the size of WCT, flow rate to the FBR, and depth of WCT bed. The removal of lindane in the presence of mixture of other pesticides was considerably reduced. The design parameters for FBR were calculated based on the bed‐depth service time (BDST) approach. Many parameters Viz. depth of sorption zone, velocity of sorption, sorbent use rate, critical bed‐depth, bed efficiency, and service time, were determined for design of the fixed‐bed. Using the material balance principle, the characteristics of the wave‐front were evaluated and found that the wave‐front velocity is approximately equal to the sorption velocity determined from the BDST approach. Desorption studies were performed in dilute organic solvent media and they gave an excellent performance in regeneration process.