蓝藻资源化技术研究及应用进展

针对蓝藻资源化问题,概述国内外利用蓝藻制备有机肥、提取高纯度藻蓝蛋白、制备活性炭和藻粉这4种利用方式的特点、现状及应用进展。提出,应从高温好氧堆肥技术、藻蓝蛋白提取技术和藻水分离技术这3个方面,解决其关键技术问题并进行进一步研究开发。     

水中藻类对连续流动法测定总氮结果的影响

以天津市河道、水库为研究对象,在藻类增殖期采用连续流动法与碱性过硫酸钾消解法对水体中总氮进行比对监测,同时分析水中藻类分类和藻细胞密度。试验表明:虽然两种方法测定总氮的结果精密度基本相同,但二者之间的系统误差存在显著差异,连续流动法较碱性过硫酸钾消解法的测定结果低5.4%。两种方法测定总氮结果的相对偏差与水体中藻细胞密度呈正相关性,当水体中藻细胞密度﹥2.41×108L-1时,对连续流动法测定总氮的结果产生显著影响,相对偏差超过标准规范要求。     

深水型水库藻类功能组时空演替及生境变化的影响

藻类功能分组是近年来生态学藻类研究的重要理论和方法.为了探明西安某深水型水源水库藻类功能组时空演替及生境变化的影响,于2011年8月起开展实验研究.研究采用现场在线监测和实验室分析相结合的方法.结果表明,水库藻类可分为10个功能组类别:B、D、P、X1、X3、F、G、J、LM、MP.其中,功能组B、P、F、X1、MP、D、J在水库中较为常见,X3、G、LM出现几率较低,功能组B、D、P、X1、X3的藻类数量占优.通过分析环境因子的变化对功能组时空演替的影响,发现水温为最主要的影响因子.水库藻类生长策略为:春季R/CR策略藻种→春末夏初CR/C策略藻种→夏末秋初C/CR/R/CS/S策略藻种→秋末及冬季CR/R策略藻种.此研究可为深水型水库安全取水提供理论支持.     

饮用水源地的水华对人体健康风险评价

饮用水源地的水华现象近年来在世界各地不断爆发,给人类饮水安全造成极大的威胁。本文通过检测微囊藻毒素和三卤甲烷类物质,利用急性暴露安全阈值（浓度）计算模型,计算出了各自的急性暴露安全阅值,并对健康风险进行了评价。     

贵州喀斯特地区土壤细菌群落结构特征及变化

为探明贵州喀斯特不同植被演替群落下的土壤细菌群落结构及变化特征,本文利用高通量测序技术对5个主要植被演替群落(稀灌草丛、藤刺灌丛、灌木林、乔灌过渡林、乔木林)的根际(竹叶椒)、非根际土壤细菌群落结构及环境因子进行了分析研究。结果表明:贵州喀斯特高原土壤细菌类群主要为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、疣微菌门(Verrucomicrobia)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和浮霉菌门(Planctomycetes),其相对丰富度分别为43.35%、12.97%、7.53%、7.12%、6.19%、5.35%、5.05%,未分类类群占7.36%。样品中检测到了较低丰度的广古菌门和泉古菌门。随植被群落演替,根际土壤中变形菌门、厚壁菌门和浮霉菌门丰度逐渐增加;非根际土壤中酸杆菌门和疣微菌门丰度随植被演替逐渐减小。贵州喀斯特高原土壤细菌的影响因子大小为土壤有机碳、土壤总氮、含水量、电导率等,其中土壤有机碳和土壤总氮有显著性影响。     

三峡水库浮游植物群落特征及水体富营养化评价

基于2003—2017年三峡水库浮游植物群落结构、优势种群的变化和2017年水库干支流水质数据,全面分析浮游植物群落结构和演替特征,并运用综合营养状态指数法对水体富营养化程度进行评价。结果表明,三峡水库浮游植物种类丰富,监测期间共鉴定出浮游植物7门62属,细胞密度在7.5×10~4~2.8×10~7cell/L之间变化,Shannon-Wiener多样性指数为1.0~3.0,在α-中污带和β-中污带之间,说明三峡水库水生态环境健康状况相对较好;三峡水库浮游植物季节性演替特征呈硅藻和甲藻向蓝藻和绿藻演替的趋势,年际变化特征分析发现浮游植物密度在2008年175 m实验蓄水后大量增长,且优势藻类由河道型藻类向湖泊型藻类转化。通过监测数据分析,得出三峡水库干流处于中营养状态,支流在春季主要处于轻度富营养状态,秋季支流比春季支流的富营养化程度低,主要处于中营养状态,总氮(total nitrogen,TN)、总磷(total phosphorus,TP)和透明度(transparency,SD)为水质主要影响因子。     

Ultrasound pretreatment of filamentous algal biomass for enhanced biogas production

The filamentous alga Hydrodictyon reticulatum harvested from a bench-scale wastewater treatment pond was used to evaluate biogas production after ultrasound pretreatment. The effects of ultrasound pretreatment at a range of 10–5000 J/mL were tested with harvested H. reticulatum. Cell disruption by ultrasound was successful and showed a higher degree of disintegration at a higher applied energy. The range of 10–5000 J/mL ultrasound was able to disintegrated H. reticulatum and the soluble COD was increased from 250 mg/L to 1000 mg/L at 2500 J/mL. The disintegrated algal biomass was digested for biogas production in batch experiments. Both cumulative gas generation and volatile solids reduction data were obtained during the digestion. Cell disintegration due to ultrasound pretreatment increased the specific biogas production and degradation rates. Using the ultrasound approach, the specific methane production at a dose of 40 J/mL increased up to 384 mL/g-VS fed that was 2.3 times higher than the untreated sample. For disintegrated samples, the volatile solids reduction was greater with increased energy input, and the degradation increased slightly to 67% at a dose of 50 J/mL. The results also indicate that disintegration of the algal cells is the essential step for efficient anaerobic digestion of algal biomass.     

周期性的温度扰动对藻类群落结构演替的影响

为了研究水库生境扰动对藻类水华的作用机制,以中度扰动理论为基础,结合藻类群落生境选择学说和藻类生态功能组,开展了不同温度扰动周期、相同扰动幅度下藻类多样性变化特性和群落结构演替特征的室内控制实验.结果表明:1适度的扰动会促进藻类的生长且增加其多样性.中度扰动组Δ22℃/48 h藻类生物量最大,但多样性最高,不存在绝对占优藻种,而高频次扰动组Δ22℃/24 h生物多样性较小,但可降低藻类生物量.2温度的周期性变化对浮游藻类群落的演替有明显的影响,优势种也呈现一定的差异性.藻类优势功能组演替基本规律为:X_1(小球藻)→J(栅藻)→S_1(席藻)或X_2(衣藻),群落结构呈现出C/CR型藻类先行占优向R型演替的趋势.高温扰动频繁时,R型藻类(S_1)明显占优;无扰动或低扰动时,群落结构组成特点以C/R策略为主.适度的扰动组Δ22℃/48 h形成了多种生长策略的藻类共存的格局,且耐受高温胁迫的S策略藻类(L_0)开始出现.     

Numerical simulation for impacts of hydrodynamic conditions on algae growth in Chongqing Section of Jialing River, China

Hydrodynamic conditions are important factors for planktonic algae growth, through introducing two parameters which express the optimal velocity and the velocity range for planktonic algae growth, a new velocity factor was put forward for the formula of growth rate. Therefore, the two-dimensional unsteady ecological dynamic model for algae growth was established to analyze the effects of hydrodynamic conditions on algae growth in Chongqing Reach of Jialing River in China. The temporal and spatial distribution of Chlorophyll-a (Chl-a) concentration was simulated numerically for various water levels, under climate conditions in period of high frequency for algae blooms of Three Gorges Reservoir and nutrition status at present in the research reach. The corresponding locations and areas of likely algae blooms were analyzed and forecasted. The results showed that about 0.04 m s⁻¹ was the optimal velocity for algae growth, and the occurrence of algae blooms in large scale is almost impossible because of relatively high water flow velocity for Jialing River.     

Bioavailability of wastewater derived dissolved organic nitrogen to green microalgae Selenastrum capricornutum, Chlamydomonas reinhardtii, and Chlorella vulgaris with/without presence of bacteria

Effluent dissolved organic nitrogen (DON) is problematic in nutrient sensitive surface waters and needs to be reduced to meet demanding total dissolved nitrogen discharge limits. Bioavailable DON (ABDON) is a portion of DON utilized by algae or algae + bacteria,while biodegradable DON (BDON) is a portion of DON decomposable by bacteria. ABDON and BDON in a two-stage trickling filter (TF) wastewater treatment plant was evaluated using three different microalgal species, Selenastrum capricornutum, Chlamydomonas reinhardtii and Chlorella vulgaris and mixed cultured bacteria. Results showed that up to 80% of DON was bioavailable to algae or algae + bacteria inoculum while up to 60% of DON was biodegradable in all the samples. Results showed that C. reinhardtii and C. vulgaris can be used as a test species the same as S. capricornutum since there were no significant differences among these three algae species based on their ability to remove nitrogen species.