Experimental Study On Sludge And Food Waste Mixed Aerobic Composting

Sludge is a byproduct of the sewage treatment plant, the higher the moisturecontent, carbon and nitrogen is relatively low, unstable organic matter, such asmanure directly into the soil nutrient cycle disorders can cause harmful microbialproliferation, environmental pollution and plant poisoning; kitchen waste highercrude protein and crude fiber, organic matter content, perishable and produceodor, oil content and Salts higher than other living garbage, both of which arerequired for proper handling. Although domestic sludge and food waste compostmixed aerobic conducted a number of studies, due to the low ambienttemperature in Northeast China, and how the characteristics of the northernregion for the cold environment, in-depth study of mixed aerobic sludge and foodwaste composting efficacy and mechanism to further explore aerobic compostingto improve the efficiency of mixing technical approach for the treatment anddisposal of sewage sludge and food waste is significant.Based on physical and chemical properties of the sludge and compostedmaterials, microstructure and elemental composition study, mixed aerobic sludgeand food waste composting process stockpiles of each component (sludge, foodwaste, conditioning agent) mixing ratio, ventilation, air supply method, theambient temperature of the four conditions for mixed aerobic composting andprocessing performance; for added eco-conditioner mixed aerobic sludge andfood waste composting conducted studies to determine its composting anddiscuss changes in catalase activity during composting cadmium, mercury,arsenic, iron and other heavy metal content of several changes, and thecomposting process over; choose a different mix of aerobic compost conditions,according to the fuzzy mathematical evaluation methods compost maturityevaluation of aerobic composting products fuzzy evaluation, research on theeffects of temperature and aerobic conditioning of compost maturity.Through the analysis of residual sludge and mixed stockpile SEM and EDX,the results showed that after adding food waste and sludge plant conditioners andstir to improve the content of elements C and lower initial moisture content of thesludge, it can help composting smoothly. After testing of different ventilation and ventilation showed the best ventilation is0.6m3/h, the best way is to supply iscontinuous ventilation; compare the compost temperature, decomposition oforganic matter degradation and the impact of the process according to thedifferent material ratio proposed sludge, food waste and conditioners bestmaterial ratio is2:1:1; based on the effects of different environmentaltemperature on the composting process to determine the ambient temperature of35℃is more suitable for composting.Adding humus for plants conditioner conditioners aerobic compostingcontrast and shows that variation of temperature and water stockpiles extractCOD with composting time are first increased and then decreased growth;moisture, volatile matter, flooding variation extract ammonia are compostingtime with growth gradually declined. Adding different conditioners extractammonia to pH changes and flooding large, adding pH variation of plantconditioner for the first and then gradually reduce the rapid growth, pH valuesranging between6.5to7.5; adding humus conditioner pH variation wasdecreased after the first rapid rise to neutral, pH values ranging between6.3to7.6. Add a pile of plant conditioner Extracts ammonia showed a gradualdownward trend, adding compost humus conditioners time increases withaqueous extract ammonia content gradually increased. Through the temperature,moisture content, organic matter degradation index contrast showed that humusconditioner conditioners than plant organic matter degradation rate, heating upfast and have a better compost effect, the higher the proportion of humuscompost better. Humus soil conditioner can promote heavy metals in sludge fromthe excited state to a stable transition, the composting process catalase activityshowed a downward trend.By mixing aerobic compost heap material after maturity fuzzy evaluationcarried out, the results show the outside temperature and conditioners have agreater impact on the compost maturity, under natural temperature mixed withsludge and compost food waste, its degree of maturity can not meet therequirements, composting effect is not very satisfactory, but the outsidetemperature by regulating appropriate, stockpile maturity can be furtherimproved, especially suitable for the outside temperature regulation and addedmaturity level of ecological conditioning agents can achieve higher stockpiles, compost surface appear mold, white, has obvious characteristics of apparentdecomposition products in line with national standards.