“高壓帶機+好氧發(fā)酵”聯(lián)用工藝在糞便污泥處理中的實踐和研究

阮燕霞，楊文文，唐秀華，劉立文，黃健，魏宏斌

（上海中耀環(huán)保實業(yè)有限公司，上海    200092）

摘  要  河北省某糞便處理站收集并處理附近學校產(chǎn)生的糞便污水，原采用“絮凝脫水+好氧發(fā)酵堆肥”工藝，將糞便污泥處理至含水率84%左右進行好氧發(fā)酵堆肥。但含水率84%的糞便直接進行好氧發(fā)酵須添加大量的輔料，堆肥物料存在易板結(jié)、氧氣傳質(zhì)效率低、運行成本高等問題，影響了堆肥成品質(zhì)量。為提高糞便污泥好氧發(fā)酵效率及降低運行成本，在充分利用原有設(shè)備和場地的前提下，在原脫水工藝后端和好氧發(fā)酵工藝前端增加高壓帶式深度脫水工藝。該項目連續(xù)運行結(jié)果表明，經(jīng)高壓帶式深度脫水工藝處理后，糞便平均含水率從84%降至59%以下，糞便減量率達61%以上，節(jié)省輔料量90 %以上，改造之后糞便減量效果和經(jīng)濟效益顯著。

關(guān)鍵詞  高壓帶機    深度脫水    糞便污泥    好氧發(fā)酵    減量

Practice and Research on the Combined Process of "High-pressure Belt Conveyor+Aerobic Fermentation" in the Treatment of Fecal Sludge

RUAN Yanxia

(Shanghai Zhongyao Environment Protection Industry Co. Ltd, Shanghai    200092, China)

Abstract   A fecal treatment station in Hebei Province collects and treats fecal wastewater generated by nearby schools. The original process use "flocculation dehydration+aerobic fermentation composting" to treat fecal sludge, and it’s treated to about 84% moisture content for aerobic fermentation composting. However, direct aerobic fermentation of feces with a moisture content of 84% requires the addition of a large amount of auxiliary materials. There are problems with composting materials such as easy solidification, low oxygen mass transfer efficiency, and high operating costs, which affect the quality of compost products. To improve the efficiency of aerobic fermentation of fecal sludge and reduce operating costs, a high-pressure belt deep dehydration process is added at the back end of the original dehydration process and the front end of the aerobic fermentation process, while fully utilizing the existing equipment and site. The continuous operation results of this project indicate that after being treated with high-pressure belt deep dehydration process, the average moisture content of feces decreases from 84% to below 59%, and the reduction rate of fecal sludge reaches over 61%, saving more than 90% of the amount of auxiliary materials. After the reconstruction, the fecal reduction effect and economic benefits is significant.

Keywords   high-pressure filter belt press    deep dewatering    fecal sludge     aerobic fermentation     reducing quantity

糞便污泥（Fecal sludge，FS）是一種由人類初始糞便、沙土、灰水混合部分消化后形成漿料等構(gòu)成的粘稠狀物質(zhì)^{[1, 2]}，FS中含有大量的有害的細菌、病毒等，若處理不當，很容易造成細菌或病毒感染的傳播^{[3, 4]}，同時化糞池FS中的COD、TN、TP和NH3-N含量分別可達1600mg/L、3724mg/L、988mg/L和2432 mg/L，若直接應用于土地利用，很容易對自然環(huán)境和人類健康造成威脅^[5]。另一方面，隨著城市人口的快速增加，集中式的糞便處理中心需求不斷增加，使集中處理的FS產(chǎn)量不斷增加，因此FS的高效穩(wěn)定無害化處理處置十分必要。

韓圩娟通過分析技術(shù)、經(jīng)濟、社會等10個評價因子構(gòu)件的綜合評價體系得出“絮凝脫水+好氧發(fā)酵+除臭”是目前國內(nèi)FS處理處置的最佳工藝路線^[6]，但是經(jīng)過固液分離后絮凝脫水FS含水率普遍在70-80%左右^[7]，FS減量不明顯，同時好氧堆肥階段添加的輔料較多，好氧堆肥運行費用較高。

針對上述問題，本文提出將高壓帶機應用于FS“絮凝脫水+好氧發(fā)酵+除臭”的整體工藝中，通過高壓帶機連續(xù)脫水，將FS含水率降低至60%以下，從而降低好氧堆肥的處理規(guī)模和降低運行費用。

1 案例簡述

河北省某糞便處理站消納附近學校產(chǎn)生的糞便污水，該糞便處理站設(shè)計糞便污水處理規(guī)模200噸/天，污泥濃度20g/L。糞便污水先經(jīng)過化糞池處理后，上清液排入市政管網(wǎng)，輸送至附近污水處理廠進一步無害化處理，吸糞車將剩余的固液混合物運送到該糞便處理站進行“絮凝脫水+好氧堆肥”。