Particle size distribution and property of bacteria attached to carbon fines in drinking water treatment

The quantitative change and size distribution of particles in the effluents from a sand filter and a granular activated carbon （GAC） filter in a drinking water treatment plant were investigated. The average total concentration of particles in the sand filter effluent during a filter cycle was 148 particles/mL, 27 of which were larger than 2 μm in size. The concentration in the GAC effluent （561 particles/mL） was significantly greater than that in the sand filter effluent. The concentration of particles larger than 2 μm in the GAC filter effluent reached 201 particles/mL, with the amount of particles with sizes between 2 μm and 15 μm increasing. The most probable number （MPN） of carbon fines reached 43 unit/L after six hours and fines between 0.45 μm and 8.0 μm accounted for more than 50%. The total concentration of outflowing bacteria in the GAC filter effluent, 350 CFU （colony-forming units） /mL, was greater than that in the sand filter effluent, 210 CFU/mL. The desorbed bacteria concentration reached an average of 310 CFU/mg fines. The disinfection efficiency of desorbed bacteria was lower than 40% with 1.5 mg/L of chlorine. The disinfection effect showed that the inactivation rate with 2.0 mg/L of chloramine （90%） was higher than that with chlorine （70%）. Experimental results indicated that the high particle concentration in raw water and sedimentation effluent led to high levels of outflowing particles in the sand filter effluent. The activated carbon fines in the effluent accounted for a small proportion of the total particle amount, but the existing bacteria attached to carbon fines may influence the drinking water safety. The disinfection efficiency of desorbed bacteria was lower than that of free bacteria with chlorine, and the disinfection effect on bacteria attached to carbon fines with chloramine was better than that with only chlorine.

Applicability of Fractal Models in Estimating Soil Water Retention Characteristics from Particle-Size Distribution Data

Soil water retention characteristics are the key information required in hydrological modeling. Frac-tal models provide a practical alternative for indirectly estimating soil water retention characteristics fromparticle-size distribution data. Predictive capabilities of three fractal models, i.e, Tyler-Wheatcraft model,Rieu-Sposito model, and Brooks-Corey model, were fully evaluated in this work using experimental datafrom an international database and literature. Particle-size distribution data were firstly interpolated into20 classes using a van Genuchten-type equation. Fractal dimensions of the tortuous pore wall and the poresurface were then calculated from the detailed particle-size distribution and incorporated as a parameter infractal water retention models. Comparisons between measured and model-estimated water retention cha-racteristics indicated that these three models were applicable to relatively different soil textures and pressurehead ranges. Tyler-Wheatcraft and Brooks-Corey models led to reasonable agreements for both coarse- andmedium-textured soils, while the latter showed applicability to a broader texture range. In contrast, Rieu-Sposito model was more suitable for fine-textured soils. Fractal models produced a better estimation of watercontents at low pressure heads than at high pressure heads.

Effect of Time Step Size and Turbulence Model on the Open Water Hydrodynamic Performance Prediction of Contra-Rotating Propellers

A growing interest has been devoted to the contra-rotating propellers （CRPs） due to their high propulsive efficiency, torque balance, low fuel consumption, low cavitations, low noise performance and low hull vibration. Compared with the single-screw system, it is more difficult for the open water performance prediction because forward and aft propellers interact with each other and generate a more complicated flow field around the CRPs system. The current work focuses on the open water performance prediction of contra-rotating propellers by RANS and sliding mesh method considering the effect of computational time step size and turbulence model. The validation study has been performed on two sets of contra-rotating propellers developed by David W Taylor Naval Ship R ＆ D center. Compared with the experimental data, it shows that RANS with sliding mesh method and SST k-ω turbulence model has a good precision in the open water performance prediction of contra-rotating propellers, and small time step size can improve the level of accuracy for CRPs with the same blade number of forward and aft propellers, while a relatively large time step size is a better choice for CRPs with different blade numbers.

Treatment of Acetonitrile by Catalytic Supercritical Water Oxidation in Compact-Sized Reactor

The objective of this research was to study the treatment of acetonitrile by catalytic supercritical water oxi-dation in a compact-sized tubular reactor, with an internal volume of 4.71 mL. Manganese dioxide was used as the catalyst and H2O2 was used as the oxidant. The oxidation of acetonitrile in supercritical water was studied at 400-500 oC, 25-35 MPa, the flow rate of 2-4 mL/min, the initial concentration of acetonitrile 0.077-0.121 M and the %excess O2 of 50-200%. As a result, the products were mainly N2, CO2 and CO and acetonitrile can be decomposed > 93 % within a very short contact time (1.45-6.19 s). The oxidation process was carried out with respect to the conversion of acetonitrile by 25 factorial design. Regression models were obtained for correlating the conversion of acetonitrile with temperature and flow rate. The complete oxida-tion can be achieved at a condition as moderate as 400 oC, 25 MPa with the flow rate of 2 mL/min.

Rapid manufacturing of SiC molds with micro-sized holes using abrasive water jet

Silicon carbide (SiC) is highly wear resistant with good mechanical properties, including high temperature strength, excellent chemical resistance, and high thermal conductivity and thermal shock resistance. SiC molds, which can be produced with diverse microstructural features, are now widely used in glass molding owing to their excellent characteristics, and also have potential applicability in IT industries. SiC molds are traditionally fabricated by silicon micromachining or dicing. The fabrication cost of silicon micromachining is very high, however, because several expensive masks are needed. Furthermore, the fabrication time is very long. Meanwhile, it is difficult to make micro-patterned molds with arbitrary shapes using dicing saws. Abrasive water jet (AWJ) is widely applied to cut and drill very brittle, soft and fibrous materials. It offers high energy density, the absence of a heat affected zone(HAZ), high performance, and an environment friendly process. In spite of these advantages, micro-hole drilling via conventional AWJ processing suffers from notable shortcomings. We proposed a new abrasive supplying method of AWJ. The proposed method reduces frosting phenomena, and provides micro-machining of AWJ. The characteristics of a hole machined was investigated by the proposed AWJ process according to the ratio of water and abrasives. With the optimal experimental conditions, 3×3 array SiC molds with the diameter of 700 μm and depth of 900 μm were successfully manufactured.

Comparison of Ground Water Bacterial Cell Sizes from the Agricultural, Domestic and Industrial Areas of Mysore District, Karnataka State, India

A two-year study on temporal variations in the ground water heterotrophic bacterial cell sizes of free living bacteria (FLB) and particle bound bacteria (PBB) from the agricultural, domestic and industrial areas was carried out from February 2005 to January 2007. The overall mean cell length of FLB and PBB was similar in all the ground water studied. However, the season wise grouped data revealed significant seasonal changes in cell length of FLB and PBB, as smaller bacteria were noticed during rainy season in the ground water in agricultural area in both the years, and only in the second year of study in domestic and industrial areas. Generally, it was noticed that there were summer maximum and rainy minimum values of the cell length of PBB in the ground water in agricultural, domestic and industrial areas in the second year of study. The Pearson's correlations showed the presence of 8 (in agricultural area), 5 (in domestic) and 3 (in industrial) significant correlations with environmental (Physico-chemical) parameters, respectively. The regression analysis revealed that as much as 12% of variation in the mean length of FLB was due to NO3 (+) in agricultural area and 9% due to total solids (+) in domestic area. However, the 8 % variation in bacterial cell size of FLB was due to Mg (+) in industrial area. Whereas, 13 % variation in mean length of PBB was due to SO4 (+) in agricultural area and 10% due to total anions of strong acid (TASA) (+) in domestic area. Furthermore, 10 % of variation was due to PO4 (+) in industrial area. Thus, the statistical analysis revealed that several environmental variables were potentially responsible for some of the temporal variations in aquatic heterotrophic bacterial cell size, suggesting probably the stressed environment in these ecosystems.

深松与秸秆覆盖还田对半干旱区土壤碳组分和玉米产量的影响

为促进黑龙江省西部半干旱区土壤固碳和玉米增产,以黑龙江省农业科学院耕作与秸秆长期定位试验田为研究对象,以CK(常规种植)、NFG(秸秆覆盖还田)、SFG(深松+秸秆覆盖还田)3种处理对土壤有机碳、不同粒径有机碳、水溶性有机碳含量及玉米产量的影响进行分析,研究深松与秸秆覆盖还田对半干旱区土壤碳组分和玉米产量的影响。结果表明,(1)本试验中,在0~10 cm和10~20 cm土层的土壤有机碳和水溶性有机碳含量顺序均为SFG>NFG>CK。(2)<0.053 mm粒级团聚体有机碳含量明显高于>0.250 mm和0.053~0.250 mm粒级,在0~10 cm土层,SFG、NFG处理土层>0.250 mm、<0.053 mm和0.053~0.250 mm粒级团聚体有机碳含量均比对照CK提高10%以上。(3)在10~20 cm土层,SFG处理>0.250 mm粒级和NFG处理0.053~0.250 mm粒级团聚体有机碳含量增加较为明显。(4)不同处理之间玉米穗长、穗粗和穗行数差异不显著,穗粒数和产量差异达到显著水平,其中SFG和NFG处理分别较CK产量提高了28.57%和15.10%。产量与土壤有机碳含量之间呈极显著正相关关系,与团聚体有机碳和水溶性有机碳含量呈显著正相关关系。

涤纶长丝织物上浆浆料类型判别

涤纶长丝织物上浆浆料主要有水分散性聚酯浆料和聚丙烯酸酯浆料两大类,为了准确鉴别涤纶长丝织物上浆浆料的类型,通过分析水分散性聚酯浆料和聚丙烯酸酯浆料的分子结构差异,采用阳离子染料染色法、紫外光谱分析法、傅里叶红外光谱分析法、EDS能谱分析法等方法,对涤纶长丝织物上两种浆料进行鉴别。结果表明:可以通过0.2 g/L NaOH溶液退浆后的退浆液在波长240 nm处是否有紫外吸收峰来区别两种浆料,有吸收峰的是水分散性聚酯浆料上浆涤纶长丝织物,无吸收峰的是聚丙烯酸酯浆料上浆涤纶长丝织物,而阳离子染料染色法、傅里叶红外光谱分析法、EDS能谱分析法无法准确鉴别这两种浆料。

基于结构表征和热力学分析的2种菊花粉水分吸附特性研究

为探讨干制菊花吸湿特性与其结构、水分活度(A_(w))、贮藏温度的关系,本文以2种菊花粉末(小黄菊和贡菊王)为对象,采用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)、X射线电子能谱(XPS)对其结构特征进行分析,结果显示菊花粉末表面粗糙,含有大量凹陷和孔洞;与小黄菊相比,贡菊王粉末粒径较小且表面含有更多的亲水基团,如-OH,O-C-O等。采用静态称量法在20、30和40℃和A_(w)=0.112~0.976下研究了2种菊花粉末的水分吸附行为,并通过模型拟合和热力学分析阐明了物料的水分吸附机制。菊花粉末的平衡干基含水率(X_(e))随水分活度(A_(w))增加而升高,但在同一A_(w)下,温度越高X_(e)值越低。Peleg模型是描述水分吸附等温线的最佳模型。热力学分析表明,净等量吸附热(qst)随平衡干基含水率升高而降低,其中小黄菊和贡菊王粉末的qst值分别于X_(e)>0.14 g/g和X_(e)>0.24 g/g时趋于恒定。小黄菊在20、30和40℃下的单分子层干基含水率(X_(m))分别为0.0690、0.0525、0.0505 g/g(干基),而贡菊王为0.0645、0.0591和0.0584 g/g(干基)。有效孔径(rp)随温度和水分含量增加而增大,其中当X_(e)>0.09 g/g(干基)时小黄菊粉末呈现介孔特性,而贡菊王粉末则当X_(e)>0.11 g/g(干基)时内部孔隙才由微孔转变成介孔。研究结果可为菊花的干燥工艺优化与贮藏条件选择提供参考。

峰丛洼地岩溶裂隙水土漏失过程室内模拟试验

[目的]水土漏失控制是喀斯特地区石漠化防治的关键,因此对水土漏失机理及其影响因素进行探究。[方法]通过室内模拟试验,研究水压力(0.3,1.3,2.3,5.5 m水头)、岩溶裂隙宽度(0.25,0.50,0.75,1.00 cm)和土壤团聚体粒径(0~1.0,1.0~2.0,2.0~5.0,0~5.0 mm)对峰丛洼地水土漏失过程的影响。[结果]水压力和裂隙宽度越大、团聚体粒径越小或粒组缺失的土壤,上覆土层越易被击穿。土层被击穿时间约需2~20 min。在土层被击穿后,水漏失速率迅速增大并逐渐趋于稳定,土壤漏失速率则急剧增大至峰值后减小并趋于其稳定值,且水土漏失速率及其累积漏失量显著大于未击穿土层。水土漏失量随着水压力或裂隙宽度的增大而增大。当裂隙宽度为0.25,0.50,0.75,1.00 cm时,1.3~5.5 m水压力时的累积水漏失量分别比0.3 m水压力时增大1.2~13.2,2.4~131.0,2.1~167.3,75.8~141.9倍。累积土壤漏失量随团聚体粒径的增大而显著减小。在大团聚体缺失时土壤漏失量随着裂隙宽度的增大而减小,而在小团聚体缺失时则随之增大。当裂隙宽度为0.25,0.5,0.75,1.0 cm时,1.0~2.0,2.0~5.0 mm团聚体粒组的土壤漏失量分别比0~1.0 mm粒组减小98.4%和99.1%,46.3%和83.7%,43.2%和74.0%及41.1%和27.1%。[结论]上覆土层的稳定状况决定峰丛洼地水土漏失过程,水力条件、土壤性质及岩溶裂隙发育程度是影响其稳定的关键因素。

碱激发矿渣-赤泥新型低碳透水混凝土性能研究

以粒化高炉矿渣与拜耳法赤泥两种工业固废作为胶凝材料,硅酸钠溶液作为碱激发剂,石灰岩碎石作为粗骨料,制备透水混凝土,研究了设计孔隙率、水胶比与骨料粒径对透水混凝土强度与透水性能的影响。结果表明:随设计孔隙率增大,试样的强度逐渐减小,但透水性能逐渐增强。最优水胶比受设计孔隙率和骨料粒径的影响,当透水混凝土设计孔隙率为15%、骨料粒径为4.75~9.50 mm时,最优水胶比为0.36,其强度较高且具有良好的透水性能。碱矿渣-赤泥透水混凝土的力学与透水性能均优于水泥透水混凝土,符合低碳绿色的发展理念。

膜阻垢剂及其阻垢机理研究新进展

由于水资源紧缺的问题,反渗透膜处理技术发展迅速。膜阻垢剂因能减缓膜组件的结垢、提高水净化效率,因而被广泛应用于反渗透膜处理技术。常见的膜阻垢剂有磷酸盐类、阴离子聚合物类、阳离子聚合物类以及绿色阻垢剂等,一般认为它们可以通过螯合、分散、晶格畸变等作用或阈值效应阻碍或缓解垢的形成。树枝状聚合物膜阻垢剂具有优异的阻垢性能,与其结构相似的球形聚电解质刷作为一种刷状聚合物膜阻垢剂也在膜处理领域中崭露头角。深入研究新型膜阻垢剂的阻垢机理可为设计开发针对性强、经济环保的高效阻垢产品奠定理论基础。

水淬硅锰渣的机械粉磨特性

这是一篇矿物加工工程领域的论文。根据机械力化学原理,采用振动磨的方式对水淬硅锰渣进行粉磨,通过研究粉磨时间对水淬硅锰渣粉比表面积、粒度分布、活性评价等影响,并使用比表面积和激光粒度分析仪、XRD和SEM等表征方法对水淬硅锰渣粉的比表面积、粒径分布、难磨物相和颗粒形貌进行了探讨,同时也研究了不同粉磨时间的水淬硅锰渣粉作掺合料对地聚物抗压强度的影响。结果表明,随着粉磨时间延长,硅锰渣粒度分布逐渐左移,颗粒粒径逐步细化,石英相逐渐向无定形结构转变。从成本角度考虑,当粉磨时间为25 min、比表面积为1.8281 m^(2)/g时作粉煤灰地聚物掺合料时,28 d抗压强度可达26.79 MPa。并确定出难磨物相为直锰辉石晶体结构,以及不同的含锰物相。

鄱阳湖南昌湖区典型断面总磷超标成因

以南矶山国家控制断面及其汇入区域为研究对象,通过水环境因子和沉积物现场调查,分析水体TP超标现象,探究其影响因素.结果表明,研究区域表层水TP超标现象主要发生在枯水期和退水期,超标倍数分别为3.06倍和2.78倍;且TP与溶解性有机物(DOM)、浊度显著相关.三维荧光光谱(3D-EEM)区域积分法和平行因子分析(PARAFAC)结果发现,该区域水体DOM为3个组分,其中以富里酸等类腐殖质物质(组分C1和C2、分区Ⅲ)为主,主要来源为湿地植物枯落物降解,在枯水期占比最高(55.47%).涨水期受汇入支流及周边碟形湖等外源输入影响,类蛋白质物质(组分C3和分区I)占比升高至35%以上;TP与腐殖质类有机物呈显著正相关(P<0.05),与蛋白质类有机物呈显著负相关(P<0.05),表明TP与腐殖质类有机物具有共源性.TP与浊度呈显著正相关(P<0.05),枯水期水体浊度最高(均值为320.83NTU),该时期南矶山断面汇入支流及碟形湖来水均断流;调研发现表层沉积物底质为粉砂质,以细组分为主,中值粒径DX(50)属于细粉砂质(2~16μm);分选系数范围为2.11~2.75,分选性差;沉积物样品多位于底边悬浮和均匀悬浮搬运区,搬运能力弱;沉积水动力弱,再悬浮后颗粒物不易沉积,造成浊度较高.0~5cm表层沉积物TP平均含量较高(527.89mg/Kg),泥-水界面P向上覆水释放,其中断面的P释放通量最大(0.21mg/(m2·d));表层沉积物是断面水体TP浓度的重要影响因素之一.

含小水电区域配电网制氢系统优化配置

送出功率有限和局部电压偏高已成为限制富集地区的径流式小水电消纳率的主要因素。本文利用储能有功调节就地消纳的能力,提出一种含小水电区域配电网制氢系统优化配置方法。首先,建立了制氢系统的电转气模型及考虑启停特性的运行模型,并对比了目前主流的两种电解水制氢技术的特点;其次,考虑小水电运营主体的上网收益、氢气售卖收益以及配电网安全性约束,基于混合整数规划建立了制氢系统优化配置模型,其中运行模型中充分从能量角度体现了两种制氢技术在响应时间与爬坡率方面的差异;最后,利用浙江某富集地区配电网算例验证了所提配置方案能够充分缓解丰水期电压问题,提升区域小水电消纳率,并有一定的经济可行性。

2种水土保持林土壤微团聚体组成及其在不同坡位和不同土层间的分布特征

2022年8月份,在黑龙江省齐齐哈尔市克山县境内的克山农场,选择位置相邻,坡度、坡向、坡长、林龄基本一致的樟子松水土保持林、杨树水土保持林、坡耕地(对照)为研究对象;在选定的坡面上沿着和坡面等高线垂直的方向分别布设3条样线作为3个重复,每2条样线之间间隔3 m,每条样线从坡顶至坡底分别设置10个取样点,每个取样点之间间隔30m;使用环刀法,按照土层深度(h)采集土壤表层(0<h≤15 cm)、下层(15 cm<h≤30 cm)土样,放在通风处自然风干后过2.00、0.15 mm土壤筛,测定土壤微团聚体的粒径分布、比表面积、土壤理化性质;运用体积分布模型计算不同粒径土壤颗粒体积分形维数(D值),比较不同树种水土保持林的土壤微团聚体粒径组成、微团聚体分形维数的坡面分布特征,分析土壤理化性质与土壤微团聚体粒径组成、微团聚体分形维数之间的相关性。结果表明:坡面主要土壤养分质量分数,全磷质量分数(土壤表层、下层),由大到小依次为耕地、杨树林地、樟子松林地;有效磷质量分数(土壤表层、下层),由大到小依次为耕地、樟子松林地、杨树林地;有机质质量分数,土壤表层由大到小依次为杨树林地、樟子松林地、耕地,土壤下层由大到小依次为杨树林地、耕地、樟子松林地。分形维数,与有效磷质量分数、全磷质量分数、微团聚体颗粒比表面积显著相关;分形维数在一定程度上可用于表征土壤的养分状况;土壤下层整个坡面,坡耕地的分形维数明显小于樟子松林地、杨树林地的分形维数,说明水土保持林的林下土壤的土质优于耕地;根据坡面土壤微团聚体分布特征及其趋势、坡面养分分布特征综合对比,杨树林地土质优于樟子松林地。

纳米SiO_(2)微球的制备及其结构与性能研究

以十二烷基三甲基溴化铵(CTAB)为表面活性剂,氨水为催化剂,正硅酸乙酯(TEOS)为前驱体,采用工艺简单的氨催化水解法在乙醇/水混合溶剂中制备纳米SiO_(2)微球。利用扫描电镜(SEM)对样品的形貌和粒度进行了表征。结果表明,在其它条件不变的情况下,随着CTAB用量的增加,SiO_(2)微球粒径逐渐增大、粒度分布逐渐变宽;随着醇水比例的降低、TEOS用量及氨水浓度的增加,SiO_(2)微球粒径均先增大后减小;而随着醇水比例的降低,粒度分布先变宽后变窄;TEOS用量的增加,粒度分布先变窄后变宽;氨水浓度的增加,SiO_(2)微球的粒度分布逐渐变宽。制备SiO_(2)微球的最佳醇水比例为0.6∶1,所得微球分散性较好,粒度分布较窄,平均粒径为533 nm。并研究得出CTAB和乙醇在纯水体系中是通过“水包油”体系发生作用。所得微球成膜后的光学性能(透过率为76.06%;雾度为48.35%)满足实际应用,表明其在防眩增透显示屏领域具有潜在的应用价值。

凡纳滨对虾养殖尾水悬浮物粒径分布研究

为探明凡纳滨对虾养殖尾水中悬浮物的物质组成和粒径分布特性,2021年11月对上海市3口典型对虾养殖池塘(SP1、SP2、SP3)尾水排放过程进行动态监测,采集不同排水深度的尾水样品,分析尾水中悬浮物物质组成和变化规律,研究尾水中悬浮颗粒粒径数量和体积分布特征。试验结果显示,尾水中悬浮物、颗粒态氮、颗粒态磷含量随排水深度的增加呈递增趋势,在排水深度达2/3以后增幅明显升高,悬浮物中氮、磷含量平均占比则随之下降,分别由排水前的6.11%和1.20%降至排水末期的0.38%和0.11%;悬浮颗粒粒径分布受排水过程驱动,排水末期SP1、SP2和SP3尾水悬浮颗粒体积组成的中值粒径分别为11.69、20.89μm和38.23μm,主要以<100μm的胶体和细颗粒为主,平均体积占比达92.68%;虾塘尾水悬浮颗粒粒径数量分布符合可变β模型(r^(2)=0.849±0.128),粒径体积分布符合对数正态分布模型(r^(2)=0.879±0.141)。

山东半岛南部海域鱼类群落生物量粒径谱季节变化

为了解山东半岛南部海域鱼类群落粒径结构特征,本文根据2016—2017年渔业资源底拖网季度调查数据,构建了山东半岛南部海域鱼类生物量粒径谱,分析了该海域鱼类群落的粒径结构特征及其季节变化。研究表明,山东半岛南部海域Sheldon型鱼类生物量粒径谱呈双峰模式,鱼类粒径范围为2~12粒径级,粒径分布相对均匀,出现波峰的粒径区间存在季节差异,春、夏季第一个波峰出现在3~4粒径级,主要由细纹狮子鱼(Liparis tanakae)、方氏云鳚(Pholis fangi)和大泷六线鱼(Hexagrammos otakii)等种类组成。秋、冬季第一个波峰出现在5~6粒径级,主要由小眼绿鳍鱼(Chelidonichthys spinosus)、长蛇鲻(Saurida elongata)和斑鰶(Konosirus punctatus)等种类组成。四个季节的第二个波峰均由细纹狮子鱼、黄鮟鱇(Lophius litulon)和大头鳕(Gadus macrocephalus)等鱼类个体组成。全部鱼类群落标准化生物量粒径谱的斜率和截距存在季节差异,其中夏季粒径谱陡峭,截距值显著高于其他季节,而冬季粒径谱最平缓,截距值最小,粒径谱斜率和截距的变化主要受当年生幼鱼群体的影响。在山东半岛南部海域,底层鱼类群落与全部鱼类群落的标准化生物量粒径谱的变化趋势相似。在同一季节,底层鱼类群落与全部鱼类群落的标准化生物量粒径谱斜率和截距之间无显著性差异(P>0.05),而暖温性鱼类群落与全部鱼类群落之间存在显著性差异(P<0.05)。山东半岛南部海域的全部鱼类群落粒径结构以小粒径鱼类为主,大型鱼种和大个体较少。鱼类的种类组成有明显的季节变化,当年生幼鱼及洄游性鱼类的个体数量变化是影响该海域鱼类群落粒径结构的主要因素。