共查询到19条相似文献，搜索用时 218 毫秒
1.
首先将熊本牡蛎(Crassostrea sikamea)暴露于不同质量浓度(0、50、100、500、1000和5000 mg/L)悬沙中15d后,再将受试牡蛎转移到干净海水中恢复培养15 d,观察牡蛎的存活率,检测鳃丝中Na+-K+-ATP酶、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性变化、鳃细胞DNA损伤情况和肌肉中RNA/DNA比率变化,探讨悬沙对牡蛎的影响。结果表明,悬沙暴露试验后,本研究所设悬沙浓度对牡蛎存活率几乎无影响,但当悬沙质量浓度≥500mg/L时,鳃丝中Na+-K+-ATP酶、SOD和CAT活性开始显著降低,鳃细胞中开始检测到明显的DNA损伤,反映牡蛎生长状况的RNA/DNA比率也较对照组明显减小(P<0.05)。这些受损牡蛎经干净海水培养15 d后,检测的生理生化指标虽有一定程度的恢复,但仍未恢复到对照组和低浓度悬沙组的水平。可见,较高水平的悬沙胁迫对牡蛎并没有产生致命的影响,依据常规的生态毒理学指标如存活率并不能得出有效的评价结果,但分子细胞水平上的各指标就能比较灵敏地反映悬沙胁迫的影响。 相似文献
2.
为检测氰戊菊酯对菲律宾蛤仔染毒培育25 d后消化腺细胞DNA的损伤情况,将菲律宾蛤仔分为6组进行不同剂量染毒,采用彗星实验技术进行DNA损伤分析,并通过Comet Score 1.5分析软件对拖尾率、尾长、彗尾DNA相对含量、尾矩、Olive矩等DNA损伤指标进行统计。在对各指标分别建立一元回归方程的基础上,又通过SPSS软件进行判定分析,筛选影响作用更大的检测指标,建立了多参数的多元回归方程。结果显示,与空白对照组相比,菲律宾蛤仔各染毒组消化腺细胞DNA均有不同程度的损伤且各检测指标均有显著性差异,对照组受损细胞极少,拖尾率仅为8.06%±1.94%,彗尾DNA相对含量、尾矩和Olive矩都接近0,0.067 5~1.080 0 mg/L染毒实验组各指标值显著增加。研究表明,各检测指标与染毒浓度表现出良好的剂量效应关系,随着染毒浓度递增,各检测指标都呈规律性地增长趋势,具有高度的相关性,多项式回归方程和多元回归方程均有显著性的统计学意义,通过多元回归方程可以有效地推断氰戊菊酯染毒浓度和染毒时间。 相似文献
3.
《福建水产》2020,(3)
为了评价联苯菊酯的遗传毒性,研究了不同浓度联苯菊酯对菲律宾蛤仔肝胰腺细胞DNA的损伤作用。研究分别在0.05、0.10、0.15、0.20 mg/L联苯菊酯暴露25 d后,取菲律宾蛤仔肝胰腺细胞并用单细胞凝胶电泳(彗星实验)进行分析,以彗尾DNA相对含量(TDNA%)、彗星尾长(TL)、Olive尾矩(OTM)和拖尾率(TR)作为DNA损伤的指标,实验结果表明:与空白对照组相比,各处理组菲律宾蛤仔肝胰腺细胞DNA均有不同程度的损伤且各检测指标值均显著增加(P0.05);随着联苯菊酯浓度的增加,各检测指标均呈规律性的增长趋势,具有高度的相关性(r0.99),表现出良好的剂量效应关系。评价彗星实验较好的检测指标为彗尾DNA相对含量和Olive矩,实验获得的多元回归方程具有显著的统计学意义(P0.01),可以有效地推断联苯菊酯对菲律宾蛤仔的染毒毒性浓度。 相似文献
4.
采用0、100、200、400、800μmol/L的硫酸铜和0、200、400、800、1600μmol/L的氯化锌分别处理泥鳅鳍细胞系,培养24 h后,用单细胞凝胶电泳检测其DNA损伤情况,同时对金属硫蛋白基因的表达进行研究。试验结果表明,随着两种重金属浓度的增加,泥鳅鳍细胞的DNA损伤程度呈现明显的剂量依赖性。当硫酸铜浓度≥200μmol/L、氯化锌浓度≥400μmol/L时,细胞的拖尾率、彗尾DNA比例、彗星尾长、彗星尾距和Olive尾矩均显著增大(P<0.05)。泥鳅细胞金属硫蛋白基因的表达量随着硫酸铜浓度的升高呈现出短暂稳定后显著下降的趋势,而随着氯化锌浓度的增大呈现出显著上升再显著下降的趋势,表明氯化锌浓度≤400μmol/L时可显著诱导泥鳅鳍细胞系金属硫蛋白的转录表达。综合来看,与锌相比,泥鳅鳍细胞对铜的解毒能力和耐受力更差。因此,铜污染对泥鳅细胞的遗传毒性更加明显。本研究将为探讨重金属对生物的毒性效应及生物学监测提供理论依据。 相似文献
5.
为研究溴氰菊酯对中华绒螯蟹的遗传毒性作用,将中华绒螯蟹分为5组进行半静水毒性试验,分别为0μg/L的空白对照组,只添加丙酮的溶剂对照组,以及0.10、0.20、0.40μg/L的溴氰菊酯质量浓度试验组。通过彗星检测的方法,分别测定溴氰菊酯暴露1、2、4、8、12d后中华绒螯蟹血细胞拖尾率及Olive尾距(OTM值)。结果显示,溶剂组在各时间点拖尾率及Olive尾距均同对照组无显著差异(P0.05),表明溶剂丙酮并非造成中华绒螯蟹血细胞DNA损伤的原因。溴氰菊酯对中华绒螯蟹血细胞有较强的DNA损伤作用,1d后0.20μg/L和0.40μg/L组拖尾率和Olive尾距均显著高于对照组(P0.05),此后3个质量浓度组在各时间点均极显著高于对照组(P0.01),至12d后仍未恢复。拖尾率和Olive尾距随着暴露时间增加而上升,呈现明显的时间效应和剂量效应,表明其可以作为评估溴氰菊酯对中华绒螯蟹遗传毒性的敏感指标。 相似文献
6.
为了探讨低盐度(0.6～0.8 g/L)条件下初始体质量为(0.38±0.004)g的凡纳滨对虾(Litopenaeus vannamei)幼虾的亮氨酸需求量,以鱼粉、花生麸和L-晶体氨基酸为蛋白源配制含粗蛋白400 g/kg的6种等氮饲料,标记为L7～L12组,各组亮氨酸水平分别为15.95、17.95、19.95、21.95、23.95和25.95 g/kg(饲料干物质).每组3个重复,每个重复30尾虾,进行56 d生长实验.结果表明,凡纳滨对虾幼虾的增重率随饲料亮氨酸水平的升高而升高,当亮氨酸水平达到23.95 g/kg(L11组)时,增重率达到最高值(1143.11±36.40)％,显著高于L7组(P＜0.05);亮氨酸水平继续提高,增重率变化不显著(P＞0.05).幼虾的蛋白质效率、全虾体蛋白沉积率和血淋巴总蛋白随着饲料亮氨酸水平的升高呈现升高趋势,最高值出现在L11组,并显著高于L7组(P＜0.05).各实验组饵料系数、血淋巴谷丙转氨酶、谷草转氨酶活性和尿素氮含量则呈现降低的趋势,最低值出现在L11组,且显著低于L7组(P＜0.05).以增重率为指标,根据折线模型可知,低盐度条件下凡纳滨对虾幼虾的亮氨酸最适需要量为24.80 g/kg饲料,即61.99 g/kg饲料蛋白. 相似文献
7.
为了解在池塘养殖条件下,养殖密度对图们雅罗鱼(Leuciscuswaleckiitumensis)生长指标和饲料利用率的影响。在水温11.8～27.3℃,将初始体重没有显著差异的图们雅罗鱼幼鱼以3尾/m~2(D1)、6尾/m~2(D2)、9尾/m~2(D3)和12尾/m~2(D4)的密度放养。经过90d的养殖,结果表明:养殖密度对养殖水质、体重、变异系数、肥满度、增重率、日增重、特定生长率、存活率和饲料系数均有显著差异。高密度组NH4+-N大于0.025 mg/L,TP大于0.01 mg/L,TN大于0.05 mg/L;体重、增重率、日增重、特定生长率,9尾/m~2密度组差异最大,与其余3个密度组有显著差异;生长离散低密度组(D1、D3)与高密度组(D3、D4)有显著差异,低密度组之间、高密度组之间无显著差异;12尾/m~2存活率最低,与其他密度组有显著差异;肥满度和饲料系数低密度组之间、高密度组之间均无显著差异,低密度组与高密度组之间有显著差异。综合试验结果,建议图们雅罗鱼幼鱼放养密度在9尾/m~2。 相似文献
8.
胭脂鱼仔鱼的生长和消化酶活力变化 总被引：2，自引：1，他引：1
对胭脂鱼(Myxocyprinus asiaticus)孵化后1～37 d仔鱼的体长、体重、RNA/DNA比率、胰蛋白酶、脂肪酶和淀粉酶的酶活力变化进行了测定。结果显示:胭脂鱼仔鱼1～37 d体长稳定增长。体重增加呈阶段性,在1～21 d体重增长缓慢,21～29 d体重增加较快,29～37 d体重快速增加。仔鱼从7 d开始摄食,1～6 d,RNA/DNA比率变化很小,蛋白含量逐渐降低;7～21 d,RNA/DNA比率波动较大,蛋白含量增长缓慢;21～37 d,RNA/DNA比率和蛋白质均增长迅速。生长率(GR)与RNA/DNA比率的回归方程为:GR=1.01RNA/DNA+1.6077(R2=0.8516)。从2、5和7 d开始分别检测到明显的胰蛋白酶、脂肪酶和淀粉酶活力,之后,消化酶活力随着发育先快速地上升然后波动性地下降到一个稳定水平。结果表明:胭脂鱼仔鱼从内源性到外源性营养转化过程中,不同的消化酶能够检测到明显酶活力的时间不同,到仔鱼开始摄食时已经具备消化蛋白质、脂肪和淀粉的能力;RNA/DNA比率可以作为判定仔鱼生长率的可靠指标。 相似文献
9.
为研究低氧胁迫对虾夷扇贝(Patinopecten yessoensis)行为、生理生化(免疫防疫功能及关键呼吸酶)的影响, 设置了 1 mg/L、2 mg/L、4 mg/L、7 mg/L (对照组) 4 个溶解氧梯度, 测定分析了虾夷扇贝行为特征(外壳的开闭合程度大小)、耗氧率、排氨率、抗氧化酶[超氧化物歧化酶(SOD), 过氧化氢酶(CAT)]和呼吸相关酶[乳酸脱氢酶(LDH) 和丙酮酸激酶(PK)]活性的响应情况。结果发现: (1)虾夷扇贝的存活率随着 DO 浓度的降低而降低, DO=1 mg/L 时的存活率仅为 55%; 在 DO=1 mg/L, 2 mg/L 和 4 mg/L 时, 虾夷扇贝的半致死时间分别为 95.97 h、147.37 h 和 209.58 h。 (2)将扇贝行为特征划分为 5 个等级, 按照 0~4 赋分, 评分越高, 代表扇贝状态越好。从扇贝行为特性的量化指标来看, DO 浓度越低, 评分分数越低, 虾夷扇贝状态越差。(3)低氧胁迫对虾夷扇贝耗氧率、排氨率有显著影响(P＜0.05), 在 DO≤2 mg/L 下, 氧氮摩尔比＜7, 虾夷扇贝主要由蛋白质供能; DO≥4 mg/L, 虾夷扇贝由蛋白质和脂肪氧化供能为主。(4)低氧胁迫对虾夷扇贝 SOD、CAT 和呼吸酶有显著性影响(P＜0.05)。24 h 的低氧胁迫使得肝胰腺及闭壳肌的自由基 ROS浓度升高; 48~96 h的低氧胁迫下, SOD、CAT酶活开始降低。不同的溶解氧浓度下代谢途径不同, DO= 2 mg/L 时, 有氧呼吸代谢转变为葡萄糖-丙酮酸-乳酸的呼吸途径; DO=1 mg/L 时, 呼吸代谢途径可能优先选择葡萄糖-琥珀酸途径。从生理生化层次上来看, 免疫功能下降和呼吸代谢途径改变可能会引起虾夷扇贝行为特征改变。 相似文献
10.
pH变化对日本囊对虾仔虾离子转运酶活力和存活、生长的影响 总被引：7，自引：1，他引：6
研究了pH变化对日本囊对虾(Marsupenaeus japonicus)仔虾离子转运酶(ATPase、Na -K -ATPase、V-ATPase和HCO3--ATPase)活力和存活、生长的影响.结果表明:pH(7.1、7.6←8.1→8.6、9.1)变化对日本囊对虾仔虾离子转运酶活力和存活率、体质量增重率的影响显著(F>F0.05),而对照组无明显变化.各处理组仔虾ATPase、Na -K -ATPase活力在72 h内呈峰值变化,于24 h时达到最大值,至72 h后趋于稳定,稳定后ATPase活力和对照组差异显著,与pH值呈负相关,而Na -K -ATPase活力则恢复至对照组水平;仔虾V-ATPase和HCO3--ATPase活力随着pH变化的增加而变化增大,24 h后保持稳定,且与pH值呈负相关.在实验梯度范围内,pH 7.6、8.6处理组与对照组仔虾存活率差异不显著,且pH 8.6处理组仔虾体质量增重率与对照组也无明显差异.建议日本囊对虾仔虾pH变化范围不应大于0.5. 相似文献
11.
随着沿海经济的迅速发展和海洋资源的大规模开发,海洋工程建设产生的悬浮物会对海洋生物生长发育产生影响。为研究悬浮物对中国对虾(Fenneropenaeus chinensis)幼体的毒性效应,采用室内模拟半静态方法,研究了不同浓度悬浮物对中国对虾幼体的急性毒性效应。结果显示,随着时间的延长,高浓度的悬浮物可抑制中国对虾幼体的游泳能力,中国对虾幼体死亡率呈现出明显的剂量效应关系,悬浮物对中国对虾幼体48 h和96 h的半数致死浓度(48 h-LC_(50)和96 h-LC_(50))分别为452.21 mg/L和183.74 mg/L,对应的安全浓度为18.37 mg/L。镜检观察结果显示,中国对虾幼体体表有底泥附着,鳃内有大量的悬浮物颗粒物。该研究为深入研究悬浮物对海洋生物的毒性效应提供了理论依据。 相似文献
12.
为评价疏浚、吹填过程中产生的底泥悬浮物对南海区凡纳滨对虾仔虾的毒性影响,根据《水质-物质对淡水鱼(斑马鱼)急性致死毒性的测定》方法,对南海区凡纳滨对虾仔虾的生物毒性影响进行了分析。结果表明:疏浚区海水中底泥悬浮物浓度超过10mg/L,持续12h,对凡纳滨对虾仔虾产生一定的致死效应。底泥悬浮物浓度超高80mg/L,且持续48h以上,将对仔虾产生严重的影响,甚至导致全部仔虾的死亡。根据仔虾的死亡概率和底泥悬浮物浓度对数,分别计算出12h、24h、36h、48h的半致死量(LC50)为54.56、40.29、25.89、19.18mg/L。 相似文献
13.
Guillermina Alcaraz Verónica Espinoza Ceclilia Vanegas Xavier Chiappa Carrara 《Journal of the World Aquaculture Society》1999,30(1):98-106
The white shrimp Penaeus setiferus is a potential species for culture in the Gulf of Mexico. It has been demonstrated that postlarval P. setiferus is a species sensitive to ammonia and nitrite. In this study, the effect of ammonia and nitrite on the oxygen consumption of Penaeus setiferus postlarvae subjected to different dissolved oxygen concentrations was investigated. Un-ionized ammonia tended to reduce the oxygen consumption of P. setiferus postlarvae. The addition of 0.4 mg/L un-ionized ammonia-N modified the response of the postlarvae to lower dissolved oxygen levels. Exposure to 0.7 mg/L un-ionized ammonia-N caused severe effects on the respiratory rate and it was lethal at low dissolved oxygen concentrations. Nitrite exposure decreased the respiratory rate of post-larvae in high dissolved oxygen concentrations, whereas postlarvae exposed to nitrite under hypoxic conditions showed higher oxygen consumption than unexposed animals. The decreases of the oxygen consumption induced by the interactive effect of ammonia or nitrite and low dissolved oxygen concentration indicate a harmful condition. The results indicate that P. setiferus postlarvae is a sensitive organism to the combined effect of un-ionized ammonia or nitrite and low dissolved oxygen concentrations. 相似文献
14.
Janaina Mitsue Kimpara Julio F. Queiroz Michael Bernard New 《Journal of the World Aquaculture Society》2013,44(2):210-219
Studies to determine suitable levels of intensification are essential for developing sustainable aquaculture. The objective of this study was to evaluate the quality of effluents discharged from ponds stocked with 10 (D10), 20 (D20), 40 (D40), and 80 (D80) postlarvae of Macrobrachium amazonicum/m2. Intake and effluent water samples were taken throughout a 5.5‐mo grow‐out cycle. In that study, twelve 0.01‐ha earthen ponds were stocked postlarvae with 0.01 g. Average water exchange rate was 15%/d; water was discharged from the bottom of the ponds. Prawns were fed a commercial feed with 38% crude protein according to their biomass (3–10%) and the concentration of dissolved oxygen (DO). In our research, temperature, turbidity, total suspended solids, conductivity, DO, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), N‐ammonia, N‐nitrite, N‐nitrate, N‐Kjeldahl nitrogen, total phosphorus, and soluble orthophosphate were measured every 15 d throughout the experiment in the early morning (0630 to 0730 h). Turbidity was lower in D10 than in D20 and D40 and total phosphorus was higher in D80 than in D10 and D20. An analysis of principal components comparing treatments and intake water showed three groups: intake, D10 and a cluster of D20, D40, and D80. On the basis of the water characteristics found in our study it appears that the farming of M. amazonicum is likely to have a low environmental impact, at least up to a stocking density of 80 prawns/m2. 相似文献
15.
Feasibility of using foam fractionation for the removal of dissolved and suspended solids from fish culture water 总被引：4，自引：0，他引：4
The results of an experimental study on the feasibility of foam fractionation to remove suspended and dissolved solids from fish culture water are presented. Foam fractionation was found to concentrate volatile solids (VS), total Kjeldahl nitrogen (TKN), and total suspended solids (TSS) in the foam condensate. Foam fractionation did not concentrate fixed solids (FS). Air flow rate and overflow height were found to be important operational factors in determining condensate concentration, condensate production and removal rates of VS. Predictive regression equations are presented to predict the performance of a typically configured foam fractionation device. Measurements of TKN and TSS in the foam condensate and fish culture water were well correlated with VS, indicating that VS measurements can be used to predict concentrations and removal rates of both TKN and TSS from fish culture waters that are similar to those analyzed. 相似文献
16.
2013年,河北、天津等地区养殖的凡纳滨对虾(Litopenaeus vannamei)育苗期出现死苗、出苗率低的情况,生产上,仔虾个体大小差异较大,造成了严重损失.本研究采用荧光定量PCR方法(Real-time PCR)对天津大港地区采集的108尾凡纳滨对虾仔虾样品进行单尾病原检测.结果显示,传染性皮下及造血组织坏死病毒(Infectious hypodermal and hematopoietic necrosis virus,IHHNV)和虾肝肠胞虫(Enterocytozoon hepatopenaei,EHP)均有检出.IHHNV阳性检出率100％,每微克对虾组织DNA的病毒拷贝数为103-107,且个体较大的样品(1.2-2.0 cm)携带病毒拷贝数偏高;EHP阳性检出率为49.1％,每微克对虾组织DNA的拷贝数为103-105,且集中于个体较小样品(0.7-1.1 cm).对IHHNV和EHP阳性凡纳滨对虾样品进行生物学体长与病毒载量指数相关性分析,显示IHHNV载量指数与对虾生长速率呈正相关,虾组织IHHNV平均载量达8.51×104 copies/μg DNA,为较高的感染水平;EHP的载量与对虾生长速率呈负相关关系,与较大个体阳性检出率较低相对应,虾组织EHP平均载量达到2.19× 104 copies/μg DNA,为较高的感染水平.由此,该批凡纳滨对虾仔虾患病为IHHNV和EHP的混合感染所致,本研究数据为IHHNV和EHP病原混合感染流行情况及其对养殖育苗期仔虾生长的影响提供科学依据. 相似文献
17.
本研究测定了盐化幅度(3/d、6/d、9/d、12/d和15/d)、盐化速度(1、3、6、12和18 h/次)和盐化方式(前期盐化、中期盐化、后期盐化和间隔盐化)与凡纳滨对虾(Litopenaeus vannamei)仔虾生长发育、活力和存活率的关系。研究结果显示,不同盐化幅度、盐化速度和盐化方式均显著影响盐化标粗过程中仔虾的生长发育、活力和存活率(P<0.05)。综合考虑生长性能、苗种活力和存活率等因素,最适盐化幅度为3~6/d,在该盐化幅度范围内,仔虾存活率可达74.07%~78.83%;盐化幅度超过9/d时,仔虾存活率显著下降(P<0.05),其中,盐化幅度达到15/d时,存活率仅为43.37%。过快的盐化速度导致存活率和活力显著下降,盐化速度>1 h/次时,仔虾死亡率接近50%;随着盐化速度的放缓,仔虾生长速度加快,盐化速度为6~18 h/次时,生长速度维持稳定,日增重量为1.48~1.51 mg。在盐化方式方面,后期盐化和间隔盐化时,苗种的质量和存活率优于前期盐化和中期盐化,仔虾活力表现为间隔盐化>后期盐化>中期盐化>前期盐化。综合考虑,仔虾的最适盐化幅度为3~6/d,最佳盐化速度为6~12 h/次,后期盐化和间隔盐化更有助于仔虾保持较好活力和较高存活率。本研究通过探讨凡纳滨对虾苗种盐化标粗的最适盐化幅度、盐化速度和盐化方式,丰富了凡纳滨对虾高盐环境抗逆性研究,为凡纳滨对虾苗种的盐化标粗生产实践提供了理论支持。 相似文献
18.
Jason M. Cohen Tzachi M. Samocha Joe M. Fox Ryan L. Gandy Addison L. Lawrence 《Aquacultural Engineering》2005,32(3-4):425-442
Disease epizootics have negatively affected production and expansion of the shrimp culture industry. This, along with environmental concerns regarding limited water resources and contamination of receiving streams, has caused the industry to investigate more sustainable and biosecure management practices. A study was conducted to evaluate the effect of limited water exchange on water quality, growth and survival of the Pacific white shrimp Litopenaeus vannamei postlarvae (PL) in greenhouse-enclosed raceways. Concentrations of NH4-N did not exceed 2.0 mg l−1 during this period; whereas, NO2-N exceeded 26.4 mg l−1, indicating assimilation of primary amines by primary productivity. Periodic removal of suspended solids by a common pressurized sand filter and injection of oxygen into culture water resulted in high-survival rates for both raceways (97.5 and 106.0%) with an average biomass yield of 4.29 ± 0.06 kg m−3. Shrimp samples collected during the nursery trial and at harvest showed no signs of bacterial or viral pathogen infections. 相似文献
19.
Screening and evaluation of polymers as flocculation aids for the treatment of aquacultural effluents 总被引：3，自引：0，他引：3
As environmental regulations become more stringent, environmentally sound waste management and disposal are becoming increasingly more important in all aquaculture operations. One of the primary water quality parameters of concern is the suspended solids concentration in the discharged effluent. For example, EPA initially considered the establishment of numerical limitations for only one single pollutant: total suspended solids (TSS). For recirculation systems, the proposed TSS limitations would have applied to solids polishing or secondary solids removal technology. The new rules and regulations from EPA (August 23, 2004) require only qualitative TSS limits, in the form of solids control best management practices (BMP), allowing individual regional and site specific conditions to be addressed by existing state or regional programs through NPDES permits. In recirculation systems, microscreen filters are commonly used to remove the suspended solids from the process water. Further concentration of suspended solids from the backwash water of the microscreen filter could significantly reduce quantity of discharge water. And in some cases, the backwash water from microscreen filters needs to be further concentrated to minimize storage volume during over wintering for land disposal or other final disposal options. In addition, this may be required to meet local, state, and regional discharge water quality. The objective of this research was an initial screening of several commercially available polymers routinely used as coagulation–flocculation aids in the drinking and wastewater treatment industry and determination of their effectiveness for the treatment of aquaculture wastewater. Based on the results of the initial screening, a further evaluation of six polymers was conducted to estimate the optimum polymer dosage for flocculation of aquaculture microscreen effluent and overall solids removal efficiency. Results of these evaluations show TSS removal was close to 99% via settling, with final TSS values ranging from as low as 10–17 mg/L. Although not intended to be used for reactive phosphorus (RP) removal, RP was reduced by 92–95% by removing most of the TSS in the wastewater to approximately 1 mg/L–P. Dosage requirements were fairly uniform, requiring between 15 and 20 mg/L of polymer. Using these dosages, estimated costs range from $4.38 to $13.08 per metric tonne of feed. 相似文献