摘要
针对干湿分离集约化养猪废水污染物浓度高,生化处理难以达标排放的现状,使用生态型无生物毒性的蛭石无机矿物絮凝剂以及常规的阳离子助凝剂聚丙烯酰胺(C-PAM),以资源化为目的,进行一级强化絮凝预处理,降低后续生化处理的负荷,分别调查了蛭石絮凝剂以及蛭石絮凝剂与助凝剂C-PAM的协同效应,分析了一级强化絮凝预处理对浊度、化学需氧量(COD)、悬浮物(SS)、总磷和氨氮的去除率,以及对絮体的沉降速度和体积的影响。研究发现:蛭石絮凝剂对养猪废水具有很好的絮凝效果,在蛭石絮凝剂投加量为8 g·L^(-1)的情况下,废水的浊度和COD、SS、总磷、氨氮的浓度分别由原水的405 NTU和1340、260、38.2、296.4 mg·L^(-1),减少到73.4 NTU和611.7、60、2.5、284.4 mg·L^(-1),去除率分别为81.9%和54.4%、76.9%、93.3%、4.1%,大幅降低后续生化处理的负荷;蛭石絮凝剂4 g·L^(-1)和C-PAM 24 mg·L^(-1)组合下,浊度和COD、SS、总磷、氨氮的浓度分别减少到19.2 NTU和454.5、34、5.5、267.1 mg·L^(-1),二者协同作用下的总去除率分别高达95.3%和66.1%、86.9%、85.5%、9.9%,优于蛭石絮凝剂单独使用的效果,相对于单一使用4 g·L^(-1)蛭石絮凝剂而言,去除率提高了24.6%和19.2%、26.9%、8.0%、6.2%,说明阳离子助凝剂C-PAM的投加有助于污染物的去除,两者具有很好的协同效应,不仅降低了蛭石絮凝剂用量,而且有效地降低了后续生化处理的负荷。上清液与絮凝沉积物的重金属分析结果表明,其均符合排放标准和农业用肥标准,沉积物可以作为堆肥的原料,实现资源化。与传统无机絮凝剂PAC絮凝效果相比,蛭石絮凝剂以及与C-PAM协同处理后的絮体的沉降速度更快,体积更小。因此,生态型一级强化絮凝预处理将会成为未来养猪废水无害化和资源化处理的重要途经之一。
Owing to the high concentration of pollutions in swine wastewater produced via dry-wet separation,the current volume of discharge is difficult to process with biochemical treatments.Therefore,primary enhanced flocculation pretreatments were conducted using both vermiculite as an ecological,non-toxic inorganic mineral flocculant and the conventional cationic coagulant C-PAM.This procedure aimed to reduce the load of subsequent biochemical treatments.The isolated effect of vermiculite flocculant alone and the synergistic effect of vermiculite flocculant combined with the coagulant C-PAM were investigated;changes in turbidity,COD,SS,ammonia nitrogen,total phosphorus,sedimentation velocity,and floc volume were analyzed after the flocculation pretreatment.Results showed that vermiculite had a good flocculation effect on swine wastewater.When the dosage of vermiculite flocculant alone was 8 g·L^(-1),the turbidity,COD,SS,total phosphorus and ammonia nitrogen of the swine wastewater were reduced from 405 NTU,1340 mg·L^(-1),260 mg·L^(-1),38.2 mg·L^(-1),and 296.4 mg·L^(-1) to 73.4 NTU,611.7 mg·L^(-1),60 mg·L^(-1),2.5 mg·L^(-1) and 284.4 mg·L^(-1),respectively.Their removal efficiencies in wastewater reached 81.9%,54.4%,76.9%,93.3%,and 4.1%,respectively,which greatly reduced the load for subsequent biochemical treatment.After primary pretreatment with 4 g·L^(-1) of a vermiculite flocculant and 24 mg·L^(-1) of C-PAM.Then the synergistic effect was studied,and turbidity,COD,SS,total phosphorus and ammonia nitrogen in the swine wastewater were 19.2 NTU,454.5 mg·L^(-1),34 mg·L^(-1),5.5 mg·L^(-1),and 267.1 mg·L^(-1),respectively,with removal efficiencies of 95.3%,66.1%,86.9%,85.5%,and 9.9%,respectively.These values were better than those of the vermiculite flocculant alone;compared with the latter,the removal rate via the synergetic treatment increased by 24.6%,19.2%,26.9%,8.0%,and 6.2%.This indicated that the addition of C-PAM could help to remove pollutants and result in a good synergistic effect as it not only reduced the amount of vermiculite flocculant needed but also could be used as a raw material for composting with pig manure.Compared with the flocculation effect of traditional inorganic compounds,the load of the subsequent biochemical treatment was reduced effectively.The heavy metal concentration of the supernatant and flocculated sediment meet emissions and agricultural fertilizer standards.Additionally,the synergistic effect of vermiculite flocculant and C-PAM meant that the floc settling speed in the sediment flocculant PAC was faster and the volume was smaller.Therefore,ecological primary enhanced flocculation pretreatment will become an important method for the harmless and resourceful treatment of swine wastewater in the future.
作者
王力
陈冠仪
郝林林
邵维敏
曾明
王昶
WANG Li;CHEN Guanyi;HAO Linlin;SHAO Weimin;ZENG Ming;WANG Chang(College of Marine and Environmental Sciences,Tianjin University of Science&Technology,Tianjin 300457,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2022年第7期1575-1581,共7页
Journal of Agro-Environment Science
基金
宁夏回族自治区科技厅资助项目(2019BBE02024)。
关键词
养猪废水
生态型絮凝剂
蛭石絮凝剂
一级强化预处理
swine wastewater
ecological flocculant
vermiculite flocculant
primary enhanced pretreatment
作者简介
王力(1997—),男,山西朔州人,硕士研究生,从事水污染控制技术研究。E-mail:1065216199@qq.com;通信作者:王昶,E-mail:wangc88@163.com。
